Research ArticleHydration Heat of Nonshrinkage Concrete in Large-DiameterCFST Arch Ribs Cured at Low Temperatures

Tuo Shi 1 Nianchun Deng 1 Dong Pan2 and Shi Wang3

1College of Civil Engineering and Architecture Guangxi University Nanning Guangxi China2Guangxi Traffic Engineering Testing Co Ltd Nanning Guangxi China3Tibet Railway Construction Co Ltd Nanning Guangxi China

Correspondence should be addressed to Nianchun Deng dengnchgxueducn

Received 19 May 2020 Revised 7 November 2020 Accepted 13 November 2020 Published 23 November 2020

Academic Editor Leonidas Alexandros Kouris

Copyright copy 2020 Tuo Shi et al+is is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

To study the construction of concrete-filled steel tubular (CFST) arch bridges in Tibet China the hydration-temperature field ofnonshrinkage concrete in large-diameter CFSTarch ribs was evaluated in a temperature-testing box to simulate a low-temperatureenvironment A finite element simulation was then conducted to replicate the experimental results Finally an improved formulawith the parameters related to the diameter the position and the retarding time of concrete for predicting the hydration heatgenerated by non-shrinkage concrete in large-diameter CFST arch ribs cured at low temperatures was proposed +e formularesults were shown to be consistent with the experimental results for low-temperature conditions and large diameters +isresearch method can be extended to predict the hydration heat at all locations in different-diameter CFSTs with different concretemixes cured at various temperatures

1 Introduction

Concrete-filled steel tubular (CFST) arch bridges can undersuitable conditions be constructed for half the cost of asuspension bridge with the same span [1] As a result manyCFST arch bridges have been built to carry highway andrailway traffic in the past 20 years in China At present morethan 400 CFST arch bridges have been built in country andthe longest spans are 530 and 575m [2] +e pouring ofconcrete into steel tubes is key to constructing CFST archbridges and various high-performance concretes (egnonshrinkage and self-compacting) have been applied [3]

Hydration heat occurs during the curing of concrete andhas been studied experimentally by many scholars Zhou et al[4] conducted experimental research and numerical simu-lations on the early hydration heat and stress in a concretewall showing that insulation measures were necessary duringcold weather A microsimulation of hydration heat undercreep was carried out by Briffaut et al [5] who determinedthat the rate of increase in the elastic stiffness and the tensilestrength of ordinary concrete were reduced under higherhydration heat Byard et al [6] studied the hydration

performance of concrete that included prewetted lightweightaggregate and found an increased degree of hydration Zhouet al [7] conducted hydration heat tests and finite elementsimulation analyses on a new impermeable concrete deter-mining that high or low ambient temperatures were notconducive to a reduction in the temperature difference causedby concrete hydration +rough experiments Sedaghat et al[8] established an empirical formula for the hydration heat ofPortland cement cured at 23degC Li et al [9] studied the in-fluence of nanoalumina and graphene oxide on the earlyhydration of cement +eir experimental research showedthat both materials could increase the hydration heat of ce-ment and accelerate the hydration process Hu et al [10]studied the effect of different functional agglomerations ofcarboxylic acid superplasticizer on the hydration heat ofcement paste showing that different functional units haddifferent effects on the retarding time and peak hydration ofthe cement paste Tan et al [11] studied the effect of fly ash onthe hydration of magnesium sulfate slurry using electro-chemical impedance spectroscopy and confirmed the validityof this new research method through testing Chorzepa et al[12] established amultifactor hydrationmodel simulation and

HindawiAdvances in Civil EngineeringVolume 2020 Article ID 8858702 11 pageshttpsdoiorg10115520208858702

carried out test verification showing that the effect of thehydration model was significant Chen and Xu [13] investi-gated the hydration-temperature field of three CFST mem-bers observing that after filling the steel tube with concretethe cross section temperature of each member was higherthan the ambient temperature +ese results demonstratedthat the temperature field was characterized by high insideand low outside temperatures +e maximum temperaturedifference between the inside and outside reached 85degC Feng[14] conducted hydration-temperature field tests on circularand square CFST members showing that their cross sectiontemperatures first increased and then decreased before finallyapproaching the atmospheric temperature +e temperaturedifference between the atmosphere and the square CFSTmembers was greater than that between the atmosphere andthe circular CFSTmembers Lin et al [15 16] tested a CFSTarch having an outer diameter of 325mm and a span of 10m+e hydration temperature of the concrete in the test arch ribwas similar to that of mass concrete the temperature firstincreased and then decreased and a temperature gradient wasobserved in the section Xuan [17] observed that the tem-perature gradients and stresses observed in a CFST archbridge having a 60m span were likely caused by a higherhydration heat occurring when the arch-rib concrete waspoured at low temperatures Sun et al [18] suggested that thethickness of the steel tube used in a CFST arch had less in-fluence on the hydration-temperature field than did the di-ameter of the tube Gao [19] conducted experiments and finiteelement analyses on CFST members and concluded that theouter surfaces of the CFST section were more affected by theambient temperature than was the core over the first 7 days ofhydration

Experts and scholars have thus explored the temperaturefield of hydration heat in CFSTarch bridges but the sizes andquantities of the test specimens in previous studies were toosmall to be applied to full-span bridges the test conditionswere not sufficiently controlled and there was little research atlow temperatures +erefore further research is urgentlyneeded With more CFST arch bridges currently being builtfor the Sichuan-Tibet Railway it is important to study thehydration heat in large-diameter CFST arch ribs cured at lowtemperatures +is study addresses these gaps +e diametersof the CFST members tested in this study were sufficientlylarge to explore the temperature field of the hydration heatand a temperature test box was employed to ensure specimencuring at consistently low temperatures +e results of thisresearch were then used to reveal the law of hydration-heattemperature change of nonshrinkage concrete in large-di-ameter CFSTs cured at low temperatures and to predict thetemperatures of different-diameter CFSTs at an early age atdifferent locations using an empirical equation +is ad-vancement could provide a helpful reference for the con-struction of CFST arch bridges in winter in Tibet

2 Experimental Means and Methods

+e experiments conducted in this study were designed toevaluate the development of the hydration-heat temperaturefield in 14m and 16m diameter CFST members in a

temperature test box +e specific dimensions of themembers are shown in Figures 1 and 2 shows photos of themembers +e mixing proportion of C55 nonshrinkageconcrete used in the CFSTmembers is shown in Table 1 +eC55 concrete mix applied in this study was selected based onthe results of a previous study showing good volume stabilityand mechanical properties of this mix in CFSTs cured at lowtemperature [20]

Because the influence of the CFST arch rib angle on thetemperature field of the hydration heat could be ignored thetest pieces were oriented vertically in the temperature box tofacilitate the placement of concrete Four locating rings werewelded within each steel tube and high-strength insulatedwire ropes were fixed to them across the test section toprovide a lattice for attaching the temperature sensors (iethermal resistors) as shown in Figure 3 Note that a No0measuring point was also placed in the temperature test boxto measure the ambient temperature A wireless data ac-quisition system was used to acquire the temperature andstress data +e range of temperature sensors was fromminus30degC to +120degC whose accuracy was 02degC

After the sensors were installed the CFSTmembers wereplaced in the temperature test box (Figure 4) and the dataacquisition system was connected +e temperature in thetemperature test box was set to 0degC +e nonshrinkageconcrete was then poured into the 14-m and 16-m diameterCFST members (Figure 5) at initial casting temperatures of28 and 30degC respectively After casting was complete theends of the members were sealed with steel plates andinsulation material to ensure that heat radiated from onlythe walls of the tubes Finally the temperature test box wasclosed Data were then collected every 10min starting fromthe beginning of pouring to obtain the temperature variationof the concrete during the process of hydration heat release+e testing was terminated after 7 days

3 Results and Analysis

+e hydration heats in the 14- and 16-m diameter CFSTmembers exhibited consistent changes over time +e hy-dration temperatures of the concrete in the CFSTmemberswere centrosymmetric +us only one quarter of themeasured points (Nos 1 2 3 and 4) and the ambienttemperature (No 0) were selected for data plotting andanalysis +e temperatures of the concrete in the membersrapidly reached their maximum after 20 h in the low-tem-perature test box (Figure 5) and then decreased graduallyuntil equalizing near the ambient temperature As can beobserved in Figure 5 the concrete near the edge of the steeltube was more affected by the low ambient temperature

+e initial casting temperature of the 14-m diameterCFST member was 28degC and its maximum temperatureduring hydration was 621degC indicating a temperature in-crease of 341degC caused by hydration heat +e initial castingtemperature of the 16-m diameter CFSTmember was 30degCand its maximum temperature during hydration was 728degCindicating a temperature increase of 428degC caused by hy-dration heat +erefore the larger-diameter CFST corre-sponded to a higher maximum hydration heat +e

2 Advances in Civil Engineering

15

14

15So adiabatic foam

Steel plate

Test section

Hardadiabaticfoam

002

002

002

01

(a)

15

16

17So adiabatic foam

Steel plate

Test section

Hardadiabaticfoam

002

002

002

01

(b)

Figure 1 Dimensions of the CFST members evaluated in this study (m) (a) 14m diameter (b) 16m diameter

(a) (b)

(c)

Figure 2 Photos of the CFST members evaluated in this study (a) 14m diameter (b) 16m diameter (c) Hard adiabatic foam

Table 1 Mixing proportion of C55 nonshrinkage concrete (kgm3)

Cement Fly ash Water-reducing agent Expansive agent Sand Gravel Water Total400 45 129 50 711 1052 157 24279

Advances in Civil Engineering 3

maximum difference in hydration heat measured within the14- and 16-m diameter CFSTmembers was 349 and 372degCrespectively +us a larger-diameter CFST will exhibit agreater difference in temperature owing to hydration heat+e hydration-heat characteristics of the CFST specimenswere similar to those of mass concrete suggesting that therewas a greater temperature difference caused by the hydrationheat of the CFSTcured at low curing temperatures Owing tothe low curing temperature and the large difference intemperature caused by hydration heat the cooling rate of theconcrete was also large

A finite element analysis was conducted usingANSYS v170to further investigate the distribution of the hydration tem-perature of the nonshrinkage concrete in large-diameter CFSTarch ribs +e PLANE77 element was selected to represent theconcrete +e material parameters used in the finite elementmodel are listed in Table 2 +e model was divided into 4161nodes and 1360 elements+e hydration-heat model was based

on the composite exponential formula and its parameters wereselected from the literature [21]+e formula is given as follows

Q(t) Q0 1 minus exp mtn( 11138571113858 1113859 (1)

where Q(t) is the cumulative hydration heat at time t at age t(d) Q0 is the final hydration heat and m and n are coef-ficients of the rate of hydration heat

+e axial length of the specimen was 15m and thediameters were 14m and 16m respectively In the test twolayers of heat preservation material were placed to coverboth ends of the specimen to prevent heat escape +ereforethe influence of the environment on the temperature field inthe axial direction of the specimen could be ignored Fur-thermore because the temperature field of the CFSTmembers was assumed to be uniform the model wassimplified as a 2D model +e boundary temperature of the2D model was set to 0degC and the heat-transfer coefficient

8

76

9

10

1 2 3 4 5

11

12

13

Locating ring

Locating ring

Locating ring

Locating ring

R3

Figure 3 Layout of the measuring points

Temperaturetest box

Figure 4 Temperature test box

4 Advances in Civil Engineering

was 499Wm2 degC +e model mesh and selected mea-surement points are shown in Figure 6

As indicated by the comparisons in Figure 7 the finiteelement analysis results agreed well with the experimentalresults the heating and cooling sections of the hydration-heat curves were generally consistent except during theinitial concrete retarding phase +is result demonstrates

that the finite element model established in the study wasaccurate but that the composite exponential formula usedto model the hydration heat could be improved for theearly phase

At the retarding stage too low ambient temperaturewould affect the hydration rate and prolong the retardingtime of concrete so the retarding time of edge concrete was

20 40 60 80 100 120 1400 t (h)

0

10

20

30

40

50

60

70

80T

(degC)

123

40

(a)

123

40

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400 t (h)

(b)

0

5

10

15

20

25

30

35

40

T (deg

C)

20 40 60 80 100 120 1400 t (h)

14 m16 m

(c)

Figure 5 Change in hydration temperature in the CFSTmembers over time when curing at 0degC (a) 14-m diameter (b) 16-m diameter(c) Maximum temperature difference

Table 2 +ermal parameters of the materials used in the finite element model

Material Density (kgm3) Specific-heat capacity (kJm2 degC) +ermal conductivity (kJm2middothdegC)Concrete 2450 098 1009Steel 7850 045 199124

Advances in Civil Engineering 5

longer than that of core concrete At the retarding stage ofedge concrete the temperature of concrete would decreasedue to the influence of low ambient temperature +e finiteelement simulation could not simulate the retarding stage sothere were differences at the retarding stage

4 Discussion

41 Improved Hydration Heat Formula An improved for-mula was developed in this study based on the experimentaland finite element simulation results +e formula was builtupon the work of Lee et al [22] and Koo et al [23] who

previously improved the formula for predicting hydrationtemperature +e applicable condition for their formula is aconstant temperature or the quasi-adiabatic condition givenas follows

ΔT(t) ΔTmax 1 minus exp atb1113872 11138731113960 1113961 (2)

where ΔT(t) is the difference between the temperature of theconcrete at age t (d) and its initial casting temperatureΔTmax is the maximum increase in temperature and a and b

are coefficients of the rate of temperature changeAs demonstrated by the early discrepancy in Figure 8

the initial retarding time of the nonshrinkage concrete

1 2 3 4

X

Figure 6 Finite element model and measuring-point locations

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

Experimental results1234

ANSYS results1234

(a)

0

10

20

30

40

50

60

70

80T

(degC)

Experimental results1234

ANSYS results1234

20 40 60 80 100 120 1400t (h)

(b)

Figure 7 Comparison of experimental and finite element simulation results for (a) 14m and (b) 16-m diameter members

6 Advances in Civil Engineering

was not considered in this formula Furthermore for-mula (4) was only able to calculate the maximum tem-perature difference at the center of the section Notablythe law describing the hydration temperature of concretein a CFST is related to the CFST diameter and there aresome regularities in the temperature-field distribution ofthe concrete hydration heat at any location within+erefore an improved formula was developed asfollows

ΔT(t) αDβrΔTmax 1 minus exp a t minus t0( 1113857b

1113960 11139611113966 1113967 (3)

where αD is the diameter coefficient defined as the ratio ofthe center temperature of the current-diameter CFST to thecenter temperature of a 15-m diameter CFST βr is thelocation coefficient defined as the ratio of the temperature atthe current location to that at the core and t0 is the retardingtime of the concrete

+e heating and cooling phases at the core of a 15-mdiameter CFST were simulated to serve as benchmark datafor formula (3) +e maximum increase in temperatureduring the heating phase (ΔTmax 1) was defined as the dif-ference between the maximum temperature (Tmax) and theinitial casting temperature (T1) +us ΔTmax 1 Tmax minus T1+emaximum decrease in temperature in the cooling phase(ΔTmax 2) was defined as the difference between the max-imum temperature (Tmax) and the ambient temperature(T0) +us ΔTmax 2 Tmax minus T0 +e ambient temperature(T0) was 0degC the initial casting temperature of the concreteT0 was 30degC and the maximum temperature (Tmax) was69degC +erefore the maximum temperature increaseduring the heating phase was ΔTmax1 TmaxminusT1 394degC+is value was fit according to formula (3) to obtain thecoefficients a1 minus010 and b1 135 +e maximumtemperature decrease in the cooling phase wasΔTmax2 695degC +is value was fit according to formula (3)to obtain the coefficients a2 minus78754 and b2 minus235 +ecalculated value obtained using the fitted formula (3) andthe simulated values obtained from the finite elementanalysis were then compared and found to be similar asshown in Figure 8

42 Determination of Parameter αD +e parameter αD (theratio of the current-diameter CFST center temperature to the15-m diameter CFSTcenter temperature) in formula (3) wasdetermined by the following method First CFST membershaving different diameters of 10 12 14 16 18 and 20mwere simulated using finite element software to obtain thecenter temperature curves of the shrinkage-free concreteshown in Figure 9+en the different diameters were listed asabscissa coordinates and the corresponding values of αD weretaken as ordinate coordinates +e resulting points for theseven evaluated diameters are plotted in Figure 10 as is thefitted curve plotted using the Origin software +e followingfitting formula was obtained by taking the maximum increasein temperature using the 15-m diameter CFSTmember as thebenchmark setting the diameter as the independent variableand αD as the dependent variable

αD minus2531 times eminusx1155

+ 1693 (4)

43 Determination of Parameter βr +e parameter βr (theratio of the temperature at the current location to that atthe core) in formula (3) was determined by the followingmethod First the 15-m diameter CFST member wassimulated via finite element analysis and the temperaturecurves of the nonshrinkage concrete were obtained atseven locations (0 R6 R3 R2 2 R3 5 R6R and Rwhere R is the radius of the tube) as shown in Figure 11

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

ANSYS resultFormula result

Figure 8 Comparisons of the core temperature calculated by finiteelement analysis and formula (5) for a 15-m diameter CFST

0

10

20

30

40

50

60

70

90

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

10m12m14m15m

16m18m20m

Figure 9 Center temperature curves of various finite elementmodeled CFST specimens

Advances in Civil Engineering 7

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

15

14

15So adiabatic foam

Steel plate

Test section

Hardadiabaticfoam

002

002

002

01

(a)

15

16

17So adiabatic foam

Steel plate

Test section

Hardadiabaticfoam

002

002

002

01

(b)

Figure 1 Dimensions of the CFST members evaluated in this study (m) (a) 14m diameter (b) 16m diameter

(a) (b)

(c)

Figure 2 Photos of the CFST members evaluated in this study (a) 14m diameter (b) 16m diameter (c) Hard adiabatic foam

Table 1 Mixing proportion of C55 nonshrinkage concrete (kgm3)

Cement Fly ash Water-reducing agent Expansive agent Sand Gravel Water Total400 45 129 50 711 1052 157 24279

Advances in Civil Engineering 3

maximum difference in hydration heat measured within the14- and 16-m diameter CFSTmembers was 349 and 372degCrespectively +us a larger-diameter CFST will exhibit agreater difference in temperature owing to hydration heat+e hydration-heat characteristics of the CFST specimenswere similar to those of mass concrete suggesting that therewas a greater temperature difference caused by the hydrationheat of the CFSTcured at low curing temperatures Owing tothe low curing temperature and the large difference intemperature caused by hydration heat the cooling rate of theconcrete was also large

A finite element analysis was conducted usingANSYS v170to further investigate the distribution of the hydration tem-perature of the nonshrinkage concrete in large-diameter CFSTarch ribs +e PLANE77 element was selected to represent theconcrete +e material parameters used in the finite elementmodel are listed in Table 2 +e model was divided into 4161nodes and 1360 elements+e hydration-heat model was based

on the composite exponential formula and its parameters wereselected from the literature [21]+e formula is given as follows

Q(t) Q0 1 minus exp mtn( 11138571113858 1113859 (1)

where Q(t) is the cumulative hydration heat at time t at age t(d) Q0 is the final hydration heat and m and n are coef-ficients of the rate of hydration heat

+e axial length of the specimen was 15m and thediameters were 14m and 16m respectively In the test twolayers of heat preservation material were placed to coverboth ends of the specimen to prevent heat escape +ereforethe influence of the environment on the temperature field inthe axial direction of the specimen could be ignored Fur-thermore because the temperature field of the CFSTmembers was assumed to be uniform the model wassimplified as a 2D model +e boundary temperature of the2D model was set to 0degC and the heat-transfer coefficient

8

76

9

10

1 2 3 4 5

11

12

13

Locating ring

Locating ring

Locating ring

Locating ring

R3

Figure 3 Layout of the measuring points

Temperaturetest box

Figure 4 Temperature test box

4 Advances in Civil Engineering

was 499Wm2 degC +e model mesh and selected mea-surement points are shown in Figure 6

As indicated by the comparisons in Figure 7 the finiteelement analysis results agreed well with the experimentalresults the heating and cooling sections of the hydration-heat curves were generally consistent except during theinitial concrete retarding phase +is result demonstrates

that the finite element model established in the study wasaccurate but that the composite exponential formula usedto model the hydration heat could be improved for theearly phase

At the retarding stage too low ambient temperaturewould affect the hydration rate and prolong the retardingtime of concrete so the retarding time of edge concrete was

20 40 60 80 100 120 1400 t (h)

0

10

20

30

40

50

60

70

80T

(degC)

123

40

(a)

123

40

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400 t (h)

(b)

0

5

10

15

20

25

30

35

40

T (deg

C)

20 40 60 80 100 120 1400 t (h)

14 m16 m

(c)

Figure 5 Change in hydration temperature in the CFSTmembers over time when curing at 0degC (a) 14-m diameter (b) 16-m diameter(c) Maximum temperature difference

Table 2 +ermal parameters of the materials used in the finite element model

Material Density (kgm3) Specific-heat capacity (kJm2 degC) +ermal conductivity (kJm2middothdegC)Concrete 2450 098 1009Steel 7850 045 199124

Advances in Civil Engineering 5

longer than that of core concrete At the retarding stage ofedge concrete the temperature of concrete would decreasedue to the influence of low ambient temperature +e finiteelement simulation could not simulate the retarding stage sothere were differences at the retarding stage

4 Discussion

41 Improved Hydration Heat Formula An improved for-mula was developed in this study based on the experimentaland finite element simulation results +e formula was builtupon the work of Lee et al [22] and Koo et al [23] who

previously improved the formula for predicting hydrationtemperature +e applicable condition for their formula is aconstant temperature or the quasi-adiabatic condition givenas follows

ΔT(t) ΔTmax 1 minus exp atb1113872 11138731113960 1113961 (2)

where ΔT(t) is the difference between the temperature of theconcrete at age t (d) and its initial casting temperatureΔTmax is the maximum increase in temperature and a and b

are coefficients of the rate of temperature changeAs demonstrated by the early discrepancy in Figure 8

the initial retarding time of the nonshrinkage concrete

1 2 3 4

X

Figure 6 Finite element model and measuring-point locations

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

Experimental results1234

ANSYS results1234

(a)

0

10

20

30

40

50

60

70

80T

(degC)

Experimental results1234

ANSYS results1234

20 40 60 80 100 120 1400t (h)

(b)

Figure 7 Comparison of experimental and finite element simulation results for (a) 14m and (b) 16-m diameter members

6 Advances in Civil Engineering

was not considered in this formula Furthermore for-mula (4) was only able to calculate the maximum tem-perature difference at the center of the section Notablythe law describing the hydration temperature of concretein a CFST is related to the CFST diameter and there aresome regularities in the temperature-field distribution ofthe concrete hydration heat at any location within+erefore an improved formula was developed asfollows

ΔT(t) αDβrΔTmax 1 minus exp a t minus t0( 1113857b

1113960 11139611113966 1113967 (3)

where αD is the diameter coefficient defined as the ratio ofthe center temperature of the current-diameter CFST to thecenter temperature of a 15-m diameter CFST βr is thelocation coefficient defined as the ratio of the temperature atthe current location to that at the core and t0 is the retardingtime of the concrete

+e heating and cooling phases at the core of a 15-mdiameter CFST were simulated to serve as benchmark datafor formula (3) +e maximum increase in temperatureduring the heating phase (ΔTmax 1) was defined as the dif-ference between the maximum temperature (Tmax) and theinitial casting temperature (T1) +us ΔTmax 1 Tmax minus T1+emaximum decrease in temperature in the cooling phase(ΔTmax 2) was defined as the difference between the max-imum temperature (Tmax) and the ambient temperature(T0) +us ΔTmax 2 Tmax minus T0 +e ambient temperature(T0) was 0degC the initial casting temperature of the concreteT0 was 30degC and the maximum temperature (Tmax) was69degC +erefore the maximum temperature increaseduring the heating phase was ΔTmax1 TmaxminusT1 394degC+is value was fit according to formula (3) to obtain thecoefficients a1 minus010 and b1 135 +e maximumtemperature decrease in the cooling phase wasΔTmax2 695degC +is value was fit according to formula (3)to obtain the coefficients a2 minus78754 and b2 minus235 +ecalculated value obtained using the fitted formula (3) andthe simulated values obtained from the finite elementanalysis were then compared and found to be similar asshown in Figure 8

42 Determination of Parameter αD +e parameter αD (theratio of the current-diameter CFST center temperature to the15-m diameter CFSTcenter temperature) in formula (3) wasdetermined by the following method First CFST membershaving different diameters of 10 12 14 16 18 and 20mwere simulated using finite element software to obtain thecenter temperature curves of the shrinkage-free concreteshown in Figure 9+en the different diameters were listed asabscissa coordinates and the corresponding values of αD weretaken as ordinate coordinates +e resulting points for theseven evaluated diameters are plotted in Figure 10 as is thefitted curve plotted using the Origin software +e followingfitting formula was obtained by taking the maximum increasein temperature using the 15-m diameter CFSTmember as thebenchmark setting the diameter as the independent variableand αD as the dependent variable

αD minus2531 times eminusx1155

+ 1693 (4)

43 Determination of Parameter βr +e parameter βr (theratio of the temperature at the current location to that atthe core) in formula (3) was determined by the followingmethod First the 15-m diameter CFST member wassimulated via finite element analysis and the temperaturecurves of the nonshrinkage concrete were obtained atseven locations (0 R6 R3 R2 2 R3 5 R6R and Rwhere R is the radius of the tube) as shown in Figure 11

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

ANSYS resultFormula result

Figure 8 Comparisons of the core temperature calculated by finiteelement analysis and formula (5) for a 15-m diameter CFST

0

10

20

30

40

50

60

70

90

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

10m12m14m15m

16m18m20m

Figure 9 Center temperature curves of various finite elementmodeled CFST specimens

Advances in Civil Engineering 7

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

maximum difference in hydration heat measured within the14- and 16-m diameter CFSTmembers was 349 and 372degCrespectively +us a larger-diameter CFST will exhibit agreater difference in temperature owing to hydration heat+e hydration-heat characteristics of the CFST specimenswere similar to those of mass concrete suggesting that therewas a greater temperature difference caused by the hydrationheat of the CFSTcured at low curing temperatures Owing tothe low curing temperature and the large difference intemperature caused by hydration heat the cooling rate of theconcrete was also large

A finite element analysis was conducted usingANSYS v170to further investigate the distribution of the hydration tem-perature of the nonshrinkage concrete in large-diameter CFSTarch ribs +e PLANE77 element was selected to represent theconcrete +e material parameters used in the finite elementmodel are listed in Table 2 +e model was divided into 4161nodes and 1360 elements+e hydration-heat model was based

on the composite exponential formula and its parameters wereselected from the literature [21]+e formula is given as follows

Q(t) Q0 1 minus exp mtn( 11138571113858 1113859 (1)

where Q(t) is the cumulative hydration heat at time t at age t(d) Q0 is the final hydration heat and m and n are coef-ficients of the rate of hydration heat

+e axial length of the specimen was 15m and thediameters were 14m and 16m respectively In the test twolayers of heat preservation material were placed to coverboth ends of the specimen to prevent heat escape +ereforethe influence of the environment on the temperature field inthe axial direction of the specimen could be ignored Fur-thermore because the temperature field of the CFSTmembers was assumed to be uniform the model wassimplified as a 2D model +e boundary temperature of the2D model was set to 0degC and the heat-transfer coefficient

8

76

9

10

1 2 3 4 5

11

12

13

Locating ring

Locating ring

Locating ring

Locating ring

R3

Figure 3 Layout of the measuring points

Temperaturetest box

Figure 4 Temperature test box

4 Advances in Civil Engineering

was 499Wm2 degC +e model mesh and selected mea-surement points are shown in Figure 6

As indicated by the comparisons in Figure 7 the finiteelement analysis results agreed well with the experimentalresults the heating and cooling sections of the hydration-heat curves were generally consistent except during theinitial concrete retarding phase +is result demonstrates

that the finite element model established in the study wasaccurate but that the composite exponential formula usedto model the hydration heat could be improved for theearly phase

At the retarding stage too low ambient temperaturewould affect the hydration rate and prolong the retardingtime of concrete so the retarding time of edge concrete was

20 40 60 80 100 120 1400 t (h)

0

10

20

30

40

50

60

70

80T

(degC)

123

40

(a)

123

40

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400 t (h)

(b)

0

5

10

15

20

25

30

35

40

T (deg

C)

20 40 60 80 100 120 1400 t (h)

14 m16 m

(c)

Figure 5 Change in hydration temperature in the CFSTmembers over time when curing at 0degC (a) 14-m diameter (b) 16-m diameter(c) Maximum temperature difference

Table 2 +ermal parameters of the materials used in the finite element model

Material Density (kgm3) Specific-heat capacity (kJm2 degC) +ermal conductivity (kJm2middothdegC)Concrete 2450 098 1009Steel 7850 045 199124

Advances in Civil Engineering 5

longer than that of core concrete At the retarding stage ofedge concrete the temperature of concrete would decreasedue to the influence of low ambient temperature +e finiteelement simulation could not simulate the retarding stage sothere were differences at the retarding stage

4 Discussion

41 Improved Hydration Heat Formula An improved for-mula was developed in this study based on the experimentaland finite element simulation results +e formula was builtupon the work of Lee et al [22] and Koo et al [23] who

previously improved the formula for predicting hydrationtemperature +e applicable condition for their formula is aconstant temperature or the quasi-adiabatic condition givenas follows

ΔT(t) ΔTmax 1 minus exp atb1113872 11138731113960 1113961 (2)

where ΔT(t) is the difference between the temperature of theconcrete at age t (d) and its initial casting temperatureΔTmax is the maximum increase in temperature and a and b

are coefficients of the rate of temperature changeAs demonstrated by the early discrepancy in Figure 8

the initial retarding time of the nonshrinkage concrete

1 2 3 4

X

Figure 6 Finite element model and measuring-point locations

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

Experimental results1234

ANSYS results1234

(a)

0

10

20

30

40

50

60

70

80T

(degC)

Experimental results1234

ANSYS results1234

20 40 60 80 100 120 1400t (h)

(b)

Figure 7 Comparison of experimental and finite element simulation results for (a) 14m and (b) 16-m diameter members

6 Advances in Civil Engineering

was not considered in this formula Furthermore for-mula (4) was only able to calculate the maximum tem-perature difference at the center of the section Notablythe law describing the hydration temperature of concretein a CFST is related to the CFST diameter and there aresome regularities in the temperature-field distribution ofthe concrete hydration heat at any location within+erefore an improved formula was developed asfollows

ΔT(t) αDβrΔTmax 1 minus exp a t minus t0( 1113857b

1113960 11139611113966 1113967 (3)

where αD is the diameter coefficient defined as the ratio ofthe center temperature of the current-diameter CFST to thecenter temperature of a 15-m diameter CFST βr is thelocation coefficient defined as the ratio of the temperature atthe current location to that at the core and t0 is the retardingtime of the concrete

+e heating and cooling phases at the core of a 15-mdiameter CFST were simulated to serve as benchmark datafor formula (3) +e maximum increase in temperatureduring the heating phase (ΔTmax 1) was defined as the dif-ference between the maximum temperature (Tmax) and theinitial casting temperature (T1) +us ΔTmax 1 Tmax minus T1+emaximum decrease in temperature in the cooling phase(ΔTmax 2) was defined as the difference between the max-imum temperature (Tmax) and the ambient temperature(T0) +us ΔTmax 2 Tmax minus T0 +e ambient temperature(T0) was 0degC the initial casting temperature of the concreteT0 was 30degC and the maximum temperature (Tmax) was69degC +erefore the maximum temperature increaseduring the heating phase was ΔTmax1 TmaxminusT1 394degC+is value was fit according to formula (3) to obtain thecoefficients a1 minus010 and b1 135 +e maximumtemperature decrease in the cooling phase wasΔTmax2 695degC +is value was fit according to formula (3)to obtain the coefficients a2 minus78754 and b2 minus235 +ecalculated value obtained using the fitted formula (3) andthe simulated values obtained from the finite elementanalysis were then compared and found to be similar asshown in Figure 8

42 Determination of Parameter αD +e parameter αD (theratio of the current-diameter CFST center temperature to the15-m diameter CFSTcenter temperature) in formula (3) wasdetermined by the following method First CFST membershaving different diameters of 10 12 14 16 18 and 20mwere simulated using finite element software to obtain thecenter temperature curves of the shrinkage-free concreteshown in Figure 9+en the different diameters were listed asabscissa coordinates and the corresponding values of αD weretaken as ordinate coordinates +e resulting points for theseven evaluated diameters are plotted in Figure 10 as is thefitted curve plotted using the Origin software +e followingfitting formula was obtained by taking the maximum increasein temperature using the 15-m diameter CFSTmember as thebenchmark setting the diameter as the independent variableand αD as the dependent variable

αD minus2531 times eminusx1155

+ 1693 (4)

43 Determination of Parameter βr +e parameter βr (theratio of the temperature at the current location to that atthe core) in formula (3) was determined by the followingmethod First the 15-m diameter CFST member wassimulated via finite element analysis and the temperaturecurves of the nonshrinkage concrete were obtained atseven locations (0 R6 R3 R2 2 R3 5 R6R and Rwhere R is the radius of the tube) as shown in Figure 11

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

ANSYS resultFormula result

Figure 8 Comparisons of the core temperature calculated by finiteelement analysis and formula (5) for a 15-m diameter CFST

0

10

20

30

40

50

60

70

90

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

10m12m14m15m

16m18m20m

Figure 9 Center temperature curves of various finite elementmodeled CFST specimens

Advances in Civil Engineering 7

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

was 499Wm2 degC +e model mesh and selected mea-surement points are shown in Figure 6

As indicated by the comparisons in Figure 7 the finiteelement analysis results agreed well with the experimentalresults the heating and cooling sections of the hydration-heat curves were generally consistent except during theinitial concrete retarding phase +is result demonstrates

that the finite element model established in the study wasaccurate but that the composite exponential formula usedto model the hydration heat could be improved for theearly phase

At the retarding stage too low ambient temperaturewould affect the hydration rate and prolong the retardingtime of concrete so the retarding time of edge concrete was

20 40 60 80 100 120 1400 t (h)

0

10

20

30

40

50

60

70

80T

(degC)

123

40

(a)

123

40

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400 t (h)

(b)

0

5

10

15

20

25

30

35

40

T (deg

C)

20 40 60 80 100 120 1400 t (h)

14 m16 m

(c)

Figure 5 Change in hydration temperature in the CFSTmembers over time when curing at 0degC (a) 14-m diameter (b) 16-m diameter(c) Maximum temperature difference

Table 2 +ermal parameters of the materials used in the finite element model

Material Density (kgm3) Specific-heat capacity (kJm2 degC) +ermal conductivity (kJm2middothdegC)Concrete 2450 098 1009Steel 7850 045 199124

Advances in Civil Engineering 5

longer than that of core concrete At the retarding stage ofedge concrete the temperature of concrete would decreasedue to the influence of low ambient temperature +e finiteelement simulation could not simulate the retarding stage sothere were differences at the retarding stage

4 Discussion

41 Improved Hydration Heat Formula An improved for-mula was developed in this study based on the experimentaland finite element simulation results +e formula was builtupon the work of Lee et al [22] and Koo et al [23] who

previously improved the formula for predicting hydrationtemperature +e applicable condition for their formula is aconstant temperature or the quasi-adiabatic condition givenas follows

ΔT(t) ΔTmax 1 minus exp atb1113872 11138731113960 1113961 (2)

where ΔT(t) is the difference between the temperature of theconcrete at age t (d) and its initial casting temperatureΔTmax is the maximum increase in temperature and a and b

are coefficients of the rate of temperature changeAs demonstrated by the early discrepancy in Figure 8

the initial retarding time of the nonshrinkage concrete

1 2 3 4

X

Figure 6 Finite element model and measuring-point locations

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

Experimental results1234

ANSYS results1234

(a)

0

10

20

30

40

50

60

70

80T

(degC)

Experimental results1234

ANSYS results1234

20 40 60 80 100 120 1400t (h)

(b)

Figure 7 Comparison of experimental and finite element simulation results for (a) 14m and (b) 16-m diameter members

6 Advances in Civil Engineering

was not considered in this formula Furthermore for-mula (4) was only able to calculate the maximum tem-perature difference at the center of the section Notablythe law describing the hydration temperature of concretein a CFST is related to the CFST diameter and there aresome regularities in the temperature-field distribution ofthe concrete hydration heat at any location within+erefore an improved formula was developed asfollows

ΔT(t) αDβrΔTmax 1 minus exp a t minus t0( 1113857b

1113960 11139611113966 1113967 (3)

where αD is the diameter coefficient defined as the ratio ofthe center temperature of the current-diameter CFST to thecenter temperature of a 15-m diameter CFST βr is thelocation coefficient defined as the ratio of the temperature atthe current location to that at the core and t0 is the retardingtime of the concrete

+e heating and cooling phases at the core of a 15-mdiameter CFST were simulated to serve as benchmark datafor formula (3) +e maximum increase in temperatureduring the heating phase (ΔTmax 1) was defined as the dif-ference between the maximum temperature (Tmax) and theinitial casting temperature (T1) +us ΔTmax 1 Tmax minus T1+emaximum decrease in temperature in the cooling phase(ΔTmax 2) was defined as the difference between the max-imum temperature (Tmax) and the ambient temperature(T0) +us ΔTmax 2 Tmax minus T0 +e ambient temperature(T0) was 0degC the initial casting temperature of the concreteT0 was 30degC and the maximum temperature (Tmax) was69degC +erefore the maximum temperature increaseduring the heating phase was ΔTmax1 TmaxminusT1 394degC+is value was fit according to formula (3) to obtain thecoefficients a1 minus010 and b1 135 +e maximumtemperature decrease in the cooling phase wasΔTmax2 695degC +is value was fit according to formula (3)to obtain the coefficients a2 minus78754 and b2 minus235 +ecalculated value obtained using the fitted formula (3) andthe simulated values obtained from the finite elementanalysis were then compared and found to be similar asshown in Figure 8

42 Determination of Parameter αD +e parameter αD (theratio of the current-diameter CFST center temperature to the15-m diameter CFSTcenter temperature) in formula (3) wasdetermined by the following method First CFST membershaving different diameters of 10 12 14 16 18 and 20mwere simulated using finite element software to obtain thecenter temperature curves of the shrinkage-free concreteshown in Figure 9+en the different diameters were listed asabscissa coordinates and the corresponding values of αD weretaken as ordinate coordinates +e resulting points for theseven evaluated diameters are plotted in Figure 10 as is thefitted curve plotted using the Origin software +e followingfitting formula was obtained by taking the maximum increasein temperature using the 15-m diameter CFSTmember as thebenchmark setting the diameter as the independent variableand αD as the dependent variable

αD minus2531 times eminusx1155

+ 1693 (4)

43 Determination of Parameter βr +e parameter βr (theratio of the temperature at the current location to that atthe core) in formula (3) was determined by the followingmethod First the 15-m diameter CFST member wassimulated via finite element analysis and the temperaturecurves of the nonshrinkage concrete were obtained atseven locations (0 R6 R3 R2 2 R3 5 R6R and Rwhere R is the radius of the tube) as shown in Figure 11

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

ANSYS resultFormula result

Figure 8 Comparisons of the core temperature calculated by finiteelement analysis and formula (5) for a 15-m diameter CFST

0

10

20

30

40

50

60

70

90

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

10m12m14m15m

16m18m20m

Figure 9 Center temperature curves of various finite elementmodeled CFST specimens

Advances in Civil Engineering 7

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

longer than that of core concrete At the retarding stage ofedge concrete the temperature of concrete would decreasedue to the influence of low ambient temperature +e finiteelement simulation could not simulate the retarding stage sothere were differences at the retarding stage

4 Discussion

41 Improved Hydration Heat Formula An improved for-mula was developed in this study based on the experimentaland finite element simulation results +e formula was builtupon the work of Lee et al [22] and Koo et al [23] who

previously improved the formula for predicting hydrationtemperature +e applicable condition for their formula is aconstant temperature or the quasi-adiabatic condition givenas follows

ΔT(t) ΔTmax 1 minus exp atb1113872 11138731113960 1113961 (2)

where ΔT(t) is the difference between the temperature of theconcrete at age t (d) and its initial casting temperatureΔTmax is the maximum increase in temperature and a and b

are coefficients of the rate of temperature changeAs demonstrated by the early discrepancy in Figure 8

the initial retarding time of the nonshrinkage concrete

1 2 3 4

X

Figure 6 Finite element model and measuring-point locations

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

Experimental results1234

ANSYS results1234

(a)

0

10

20

30

40

50

60

70

80T

(degC)

Experimental results1234

ANSYS results1234

20 40 60 80 100 120 1400t (h)

(b)

Figure 7 Comparison of experimental and finite element simulation results for (a) 14m and (b) 16-m diameter members

6 Advances in Civil Engineering

was not considered in this formula Furthermore for-mula (4) was only able to calculate the maximum tem-perature difference at the center of the section Notablythe law describing the hydration temperature of concretein a CFST is related to the CFST diameter and there aresome regularities in the temperature-field distribution ofthe concrete hydration heat at any location within+erefore an improved formula was developed asfollows

ΔT(t) αDβrΔTmax 1 minus exp a t minus t0( 1113857b

1113960 11139611113966 1113967 (3)

where αD is the diameter coefficient defined as the ratio ofthe center temperature of the current-diameter CFST to thecenter temperature of a 15-m diameter CFST βr is thelocation coefficient defined as the ratio of the temperature atthe current location to that at the core and t0 is the retardingtime of the concrete

+e heating and cooling phases at the core of a 15-mdiameter CFST were simulated to serve as benchmark datafor formula (3) +e maximum increase in temperatureduring the heating phase (ΔTmax 1) was defined as the dif-ference between the maximum temperature (Tmax) and theinitial casting temperature (T1) +us ΔTmax 1 Tmax minus T1+emaximum decrease in temperature in the cooling phase(ΔTmax 2) was defined as the difference between the max-imum temperature (Tmax) and the ambient temperature(T0) +us ΔTmax 2 Tmax minus T0 +e ambient temperature(T0) was 0degC the initial casting temperature of the concreteT0 was 30degC and the maximum temperature (Tmax) was69degC +erefore the maximum temperature increaseduring the heating phase was ΔTmax1 TmaxminusT1 394degC+is value was fit according to formula (3) to obtain thecoefficients a1 minus010 and b1 135 +e maximumtemperature decrease in the cooling phase wasΔTmax2 695degC +is value was fit according to formula (3)to obtain the coefficients a2 minus78754 and b2 minus235 +ecalculated value obtained using the fitted formula (3) andthe simulated values obtained from the finite elementanalysis were then compared and found to be similar asshown in Figure 8

42 Determination of Parameter αD +e parameter αD (theratio of the current-diameter CFST center temperature to the15-m diameter CFSTcenter temperature) in formula (3) wasdetermined by the following method First CFST membershaving different diameters of 10 12 14 16 18 and 20mwere simulated using finite element software to obtain thecenter temperature curves of the shrinkage-free concreteshown in Figure 9+en the different diameters were listed asabscissa coordinates and the corresponding values of αD weretaken as ordinate coordinates +e resulting points for theseven evaluated diameters are plotted in Figure 10 as is thefitted curve plotted using the Origin software +e followingfitting formula was obtained by taking the maximum increasein temperature using the 15-m diameter CFSTmember as thebenchmark setting the diameter as the independent variableand αD as the dependent variable

αD minus2531 times eminusx1155

+ 1693 (4)

43 Determination of Parameter βr +e parameter βr (theratio of the temperature at the current location to that atthe core) in formula (3) was determined by the followingmethod First the 15-m diameter CFST member wassimulated via finite element analysis and the temperaturecurves of the nonshrinkage concrete were obtained atseven locations (0 R6 R3 R2 2 R3 5 R6R and Rwhere R is the radius of the tube) as shown in Figure 11

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

ANSYS resultFormula result

Figure 8 Comparisons of the core temperature calculated by finiteelement analysis and formula (5) for a 15-m diameter CFST

0

10

20

30

40

50

60

70

90

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

10m12m14m15m

16m18m20m

Figure 9 Center temperature curves of various finite elementmodeled CFST specimens

Advances in Civil Engineering 7

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

was not considered in this formula Furthermore for-mula (4) was only able to calculate the maximum tem-perature difference at the center of the section Notablythe law describing the hydration temperature of concretein a CFST is related to the CFST diameter and there aresome regularities in the temperature-field distribution ofthe concrete hydration heat at any location within+erefore an improved formula was developed asfollows

ΔT(t) αDβrΔTmax 1 minus exp a t minus t0( 1113857b

1113960 11139611113966 1113967 (3)

where αD is the diameter coefficient defined as the ratio ofthe center temperature of the current-diameter CFST to thecenter temperature of a 15-m diameter CFST βr is thelocation coefficient defined as the ratio of the temperature atthe current location to that at the core and t0 is the retardingtime of the concrete

+e heating and cooling phases at the core of a 15-mdiameter CFST were simulated to serve as benchmark datafor formula (3) +e maximum increase in temperatureduring the heating phase (ΔTmax 1) was defined as the dif-ference between the maximum temperature (Tmax) and theinitial casting temperature (T1) +us ΔTmax 1 Tmax minus T1+emaximum decrease in temperature in the cooling phase(ΔTmax 2) was defined as the difference between the max-imum temperature (Tmax) and the ambient temperature(T0) +us ΔTmax 2 Tmax minus T0 +e ambient temperature(T0) was 0degC the initial casting temperature of the concreteT0 was 30degC and the maximum temperature (Tmax) was69degC +erefore the maximum temperature increaseduring the heating phase was ΔTmax1 TmaxminusT1 394degC+is value was fit according to formula (3) to obtain thecoefficients a1 minus010 and b1 135 +e maximumtemperature decrease in the cooling phase wasΔTmax2 695degC +is value was fit according to formula (3)to obtain the coefficients a2 minus78754 and b2 minus235 +ecalculated value obtained using the fitted formula (3) andthe simulated values obtained from the finite elementanalysis were then compared and found to be similar asshown in Figure 8

42 Determination of Parameter αD +e parameter αD (theratio of the current-diameter CFST center temperature to the15-m diameter CFSTcenter temperature) in formula (3) wasdetermined by the following method First CFST membershaving different diameters of 10 12 14 16 18 and 20mwere simulated using finite element software to obtain thecenter temperature curves of the shrinkage-free concreteshown in Figure 9+en the different diameters were listed asabscissa coordinates and the corresponding values of αD weretaken as ordinate coordinates +e resulting points for theseven evaluated diameters are plotted in Figure 10 as is thefitted curve plotted using the Origin software +e followingfitting formula was obtained by taking the maximum increasein temperature using the 15-m diameter CFSTmember as thebenchmark setting the diameter as the independent variableand αD as the dependent variable

αD minus2531 times eminusx1155

+ 1693 (4)

43 Determination of Parameter βr +e parameter βr (theratio of the temperature at the current location to that atthe core) in formula (3) was determined by the followingmethod First the 15-m diameter CFST member wassimulated via finite element analysis and the temperaturecurves of the nonshrinkage concrete were obtained atseven locations (0 R6 R3 R2 2 R3 5 R6R and Rwhere R is the radius of the tube) as shown in Figure 11

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

ANSYS resultFormula result

Figure 8 Comparisons of the core temperature calculated by finiteelement analysis and formula (5) for a 15-m diameter CFST

0

10

20

30

40

50

60

70

90

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

10m12m14m15m

16m18m20m

Figure 9 Center temperature curves of various finite elementmodeled CFST specimens

Advances in Civil Engineering 7

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

+e resulting temperature curves are shown in Figure 12+en the ratios of the present locations to the radius ofthe CFST were taken as abscissa coordinates and theratios of the temperatures at each location to the centertemperature were taken as ordinate coordinates resultingin the seven points shown in Figure 13 +e Originsoftware was then used to obtain the fitted curve throughthese points Based on the center temperature of a 15-mdiameter CFST the distance from the center of the CFSTwas set as the independent variable and βr was set as thedependent variable resulting in the following fittingformula

βr minus0205 times ex0580

+ 1233 (5)

44 Discussion of the Application of the Proposed Formulas+e temperature curves of the 14- and 16-m diameter CFSTmembers were calculated using formulas (3)ndash(5) +e cal-culated curves shown in Figures 14 and 15 can be observedto be consistent with the experimental results

Based on the results of finite element calculation theformula proposed in this paper only prolonged the

05 10 15 20 25 3000D (m)

00

02

04

06

08

10

12

14

αD

Maximum temperaturedifferenceFitted curve

Figure 10 Fitted curve of parameter αD for different CFSTdiameters

1 2 3 4 5 6 7Y X

Figure 11 Measuring-point locations of the finite element model

0

10

20

30

40

50

60

70

80

T (deg

C)

20 40 60 80 100 120 1400t (h)

1234

567

Figure 12 Temperature curves of concrete at different locations

ANSYS resultFitted curve

02 04 06 08 1000rR

00

02

04

06

08

10

12

14

16

βr

Figure 13 Fitted curve of parameter βr Note A comparison offormulas (4) and (5) indicates that the expressions for the CFSTdiameter parameter αD and the CFST location parameter βr aregiven in similar forms

8 Advances in Civil Engineering

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

retarding time of concrete and the temperature change ofedge concrete (No1 measuring point) at the retardingsection was not considered+erefore the formula resultsat No1 measuring point were different from the exper-imental results at the retarding stage of concrete

Furthermore formulas (3)ndash(5) were applied using thedata from three published studies [18 19] to assess their

consistency with the experimental results reportedtherein +e calculated curves shown in Figures 16 and17 can be observed to be consistent with the experi-mental results in the literature [18 19]

+e improved formulas proposed in this study aretherefore able to adequately predict the hydration heat inlarge-diameter CFST at low temperatures

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 14 Comparison of experimental and formula-calculated results for the 14-m diameter CFST member

0

10

20

30

40

50

60

70

80

T (deg

C)

Experimental results1234

Formula results1234

20 40 60 80 100 120 1400t (h)

Figure 15 Comparison of experimental and formula-calculated results for the 16-m diameter CFST member

Advances in Civil Engineering 9

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

5 Conclusion

A series of CFST specimens were subjected to curing in a0degC temperature-controlled room to observe the rela-tionship between hydration heat and curing timeaccording to the diameter of and location within the CFSTspecimens +e hydration-heat characteristics of CFSTwere observed to be similar to mass concrete suggestingthat there was a greater temperature difference caused byCFST hydration heat when cured at low temperaturesOwing to the low curing temperature and large

temperature difference caused by hydration heat thecooling rate of concrete was large

A finite element model of hydration heat was thenestablished and its behavior was compared with the ex-perimental results +e observed differences were then usedto derive an improved formula for predicting the change inhydration heat according to CSFT parameters +e im-proved formulas proposed in this study were demonstratedto effectively predict the law of hydration heat in large-diameter nonshrinkage CFSTarch ribs at low temperaturesof about 0degC

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterEdge

CenterEdge

Experimental results Formula results

Figure 16 Comparison of formula-calculated results with the experimental results from Sun et al [18]

7020 30 40 50 6010 800t (h)

0

10

20

30

40

50

60

70

80

T (deg

C)

CenterR2Edge Edge

CenterR2

Experimental results Formula results

Figure 17 Comparison of formula-calculated results with the experimental results from Gao [19]

10 Advances in Civil Engineering

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11

Although limited to a single type of concrete in a smallvariety of CFST specimens cured at 0degC in this study theresearch method applied can be extended to predict thehydration heat at many different locations in many different-diameter CFSTs cured at different temperatures with variousconcrete-mix proportions

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Disclosure

+e funders had no role in the design of the study in thecollection analyses or interpretation of data in the writingof the manuscript or in the decision to publish the results

Conflicts of Interest

+e authors declare no conflicts of interest

Acknowledgments

+e authors would like to thank China Railway GuangzhouEngineering Group Co Ltd for materials used for exper-iments and Editage (wwweditagecn) for English-languageediting +is research was funded by the National NaturalScience Foundation of China (Grant nos 5173800451868006 and 51878186) the Major Science and TechnologyFoundation of Guangxi (Grant no AA18118029) andProject of Science and Technology Research and Develop-ment Plan of China Railway Corporation (2017G006-B)

References

[1] J Zheng ldquoDevelopment and prospect of long span archbridgesrdquo China Highway vol 22 no 24 pp 41-42 2017

[2] J Zheng and J Wang ldquoConcrete-filled steel tube arch bridgesin Chinardquo Engineering vol 4 no 1 pp 143ndash155 2018

[3] J Zheng J Wang Z Feng et al ldquoVacuum-assisted processtest for concrete filled steel tube arch sectionrdquo China Journalof Highway and Transport vol 27 no 6 pp 44ndash50 2014

[4] J Zhou X Chen and J Zhang ldquoEarly-age temperature andstrain in basement concrete walls field monitoring and nu-merical modelingrdquo Journal of Performance of ConstructedFacilities vol 26 no 6 pp 754ndash765 2012

[5] M Briffaut F Benboudjema F Benboudjema C Laborderieand J-M Torrenti Creep consideration effect on meso-scalemodeling of concrete hydration process and consequences onthe mechanical behaviorrdquo Journal of Engineering Mechanicsvol 139 no 12 pp 1808ndash1817 2013

[6] B E Byard A K Schindler and R W Barnes ldquoEarly-agecracking tendency and ultimate degree of hydration of in-ternally cured concreterdquo Journal of Materials in Civil Engi-neering vol 24 no 8 pp 1025ndash1033 2012

[7] Y Zhou D Meng and Y Wang ldquoFinite-element simulationof hydration and creep of early-age concrete materialsrdquoJournal of Materials in Civil Engineering vol 26 no 11Article ID 05014006 2014

[8] A Sedaghat N Shanahan and A Zayed ldquoPredicting one-daythree-day and seven-day heat of hydration of Portland

cementrdquo Journal of Materials in Civil Engineering vol 27no 9 Article ID 04014257 2015

[9] W Li X Li S Chen et al ldquoEffects of nanoalumina andgraphene oxide on early-agerdquo Journal of Materials in CivilEngineering vol 29 no 9 Article ID 04017087 2017

[10] K Hu Z Sun and H Yang ldquoEffects of polycarboxylatesuperplasticizers with different functional units on earlyhydration behavior of cement pasterdquo Journal of Materials inCivil Engineering vol 31 no 5 Article ID 04019041 2019

[11] Y Tan H YuW Bi et al ldquoHydration behavior of magnesiumoxysulfate cement with fly ash via electrochemical impedancespectroscopyrdquo Journal of Materials in Civil Engineeringvol 31 no 10 Article ID 04019237 2019

[12] M G Chorzepa H Hamid S A Durham et al Analysis ofCracking Caused by Hydration Heat in Bridge Seals UtilizingInnovative Massive Concrete Mixtures Structures Congress2018 Bridges pp 167ndash175 Transportation Structures andNonbuilding Structures Fort Wirth TX USA 2018

[13] B Chen and A Xu ldquoTemperature field analysis of concretefilled steel tube arch rib sectionrdquo Journal of Harbin Universityof Architecture vol 32 no 3 pp 86ndash91 1999

[14] B Feng Study on Calculation Model of Hydration HeatShrinkage and Creep of Core Concrete in Concrete Filled SteelTube Fuzhou University Learn Fuzhou China 2004

[15] C Lin J Zheng and R Qin ldquoAnalysis of the influence ofhydration heat on the forming process of concrete filled steeltube arch ribsrdquo Journal of Guangxi University vol 32 no 2pp 186ndash188 2007

[16] C Lin J Zheng and R Qin ldquoFinite element analysis oftemperature distribution of hydration heat in concrete filledsteel tubular sectionrdquo China-foreign Highway vol 27 no 4pp 125ndash127 2007

[17] J Xuan ldquoTemperature field and thermal stress analysis ofhydration heat of arch rib of concrete filled steel tube archbridgerdquo Bridge Construction vol 3 pp 29ndash32 2010

[18] G Sun S Li W Lu et al ldquoTemperature field test and nu-merical simulation analysis of hydration heat process crosssection of concrete filled steel tube arch ribs with compositecementitious materialsrdquo Journal of Shandong University(Engineering Edition) vol 41 no 3 pp 106ndash111 2011

[19] W Gao ldquoTest and numerical analysis of hydration heat oflong-span concrete filled steel tube arch bridgerdquo RailwayConstruction vol 8 pp 35ndash38 2016

[20] T Shi N Deng X Guo et al ldquoExperimental study on de-formation behavior and compressive strength of concrete castin steel tube arches under low-temperature conditionsrdquoAdvances in Materials Science and Engineering vol 2020Article ID 8016282 10 pages 2020

[21] B Zhu Temperature Stress and Temperature Control of MassConcrete China Electric Power Press Beijing China 2003

[22] M H Lee B S Khil andH D Yun ldquoInfluence of cement typeon heat of hydration and temperature rise of the mass con-creterdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 536ndash542 2014

[23] K M Koo G-Y Kim J-K Yoo et al ldquoProperties of adiabatictemperature rise on concrete considering content and settingtimerdquo Indian Journal of Engineering and Materials Sciencevol 21 no 5 pp 527ndash535 2014

Advances in Civil Engineering 11