pietro lura dariusz gawin - navier.enpc.frh)ydoc12/pdf/whydoc12_wyrzykowski.pdf · modelling...

MODELLING INTERNAL CURING IN CONCRETE

Mateusz WyrzykowskiPietro Lura

Dariusz Gawin

W(H)YDOC 12, ParisTech, 22.11.2012

Concrete & Construction Chemistry

Materials Sci ence & Technolog y2

PhD Thesis 2005-2010

Dariusz Gawin- Department of Building Physics and Building

MaterialsLodz University of Technology, Poland

Pietro Lura- Empa, Swiss Federal Laboratories for

Materials Science and TechnologyConcrete/Construction Chemistry Lab

- Intitute for Building Materials, ETH Zurich, Switzerland


Outline

Motivation Autogenous shrinkage

Modeling of phenomena at early age

Internal curing Modelling internal curing at meso-level Modelling internal curing at macro-level

Further applications and developments of the model Summary


Motivation

Shrinkage and cracking problem

Measuring techniqueMechanism

Solution

capp

r

RH<100%

cappcapp

r

RH<100%

•ASTM C1698-09•Loser, Münch, Lura, CCR (2010)•Lura, Jensen, van Breugel CCR (2003)•Jensen & Hansen CCR (2001, 2002)

SAP


MotivationInternal curing with superabsorbent polymers (SAP)

•Jensen & Hansen CCR (2001, 2002)dry

swollen

-400

-300

-200

-100

0

0 2 4 6 8 10 12 14 16Time [days]

Auto

geno

us s

train

[ m

/m]

plain-exp.

w ith SAP-exp.


Availability of water

KineticJensen & Lura MS 2006

Thermodynamic

Motivation


Water transport from the SAP

Optimization of the chemistry and particle size distribution of the SAP:

When is the water released from the SAP?

How far does water reach in the hardening cement paste?

How small should the SAP be? Lura et al. 2004

Motivation


Outline






Lura, Jensen, van Breugel, CCR (2003) Lura & Jensen, (2005, 2007)

Autogenous shrinkage

Self-desiccation

Autogenous shrinkage

Chemical shrinkage

capp

r

RH<100%

cappcapp

r

RH<100%


Autogenous phenomena-experimetnal methods

Balance

Paraffin oilWater

Sample

Linear measurementVolumetric measurement

Internal RHAutogenous deformation

Water activity (Rotronic)


Outline






Description of phenomena in fresh cement-based materialsMathematical model – fundamental assumptions

Multi-phase porous medium solid (skeleton), water (capillary water + bound water), gaseous phase (dry air + water vapour).

Various mechanisms of mass and energy transport

Full coupling: hygral, thermal, chemical, mechanical phenomena

• Gawin, Pesavento, Schrefler, IJNME (2006)


Description of phenomena… Mathematical model

Macroscopic governing equations

The dry air + skeleton mass conservation

The water species + skeleton mass conservation

The multiphase medium enthalpy balance

The multiphase medium momentum balance (mechanical equilibrium)

Evolution equation for hydration

• Gawin, Pesavento, Schrefler, IJNME (2006)



State variables gas pressure, pg

capillary pressure, pc

temperature, T displacement vector, u

Evolution variable hydration degree, hydr



Hydration evolution(Ulm & Coussy, 1996)

Water species conservation equation

Scheme of the early-age processes description (hygral and mechanical phenomena)

nhydrhydr wtt

m

Drop of saturation,Increase of capillary pressure

Mechanical equilibrium equation

Effective stress principle

Increase of effective stress


Description of phenomena… Numerical model

Description of the material behavior at different scale levels

Meso-level (~mm) Macro level (~cm-m)


Outline






Modelling internal curing at the meso-level

Meso level simulations

Cement paste w/c 0.25, 6% of entrained water (vol.)

Trtik, Münch, Weiss, Herth, Kaestner, Lehmann, Lura, Neutron tomography investigation of water release … 2010

0

20

40

60

80

100

120

0 4 8 12 16 20 24Time (hours)

Cum

ulat

ive

sign

al (%

)

Portland cement paste w/c 0.25, curing 28C

When is the water released from the SAP?

How far does water reach in the hardening cement paste?


Water and solid skeleton mass conservation

Modelling internal curing at the meso-level Mathematical model

hydrhydrws

w

hydrws

gwcg

w

rww

gg

rggw

g

gwgwd

g

wagw

ww

gw

gw

www

wswgw

s

c

cwgww

mmSmSpgradpgradkkdiv

pgradkkdivppgrad

MMMdiv

tdivSS

tT

TnS

tTSnnSn

tp

pSn

1

1

1111

2

I

IDu

Accumulation terms

Flux terms Source terms



Simulations at the meso-level characteristics of the components of REV

Permeability evolution in the paste

1.0E-24

1.0E-22

1.0E-20

1.0E-18

1.0E-16

1.0E-14

0.0 0.2 0.4 0.6 0.8 1.0Hydration degree [-]

Intri

nsic

per

mea

bilit

y [m

2 ]

w /c 0.25-sim.

w /c 0.25-GEM model

cgw

rwws

w gradp+gradpμkkvnS



Results from the meso-level

Cement paste w/c 0.25, 6% of entrained water (vol.)

Wyrzykowski, Lura, Pesavento, Gawin, Modeling of water migration ... MTENG (2012)


70

80

90

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14Time [days]

Satu

ratio

n [%

]


Saturation evolution in time-cement paste

at the reservoir2.5 mm distance

SAP size 2.4 mm, w/ce 0.035, max dist. 2.5 mm





Saturation evolution in time-cement paste


0.E+00

5.E-05

1.E-04

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14Time [h]

Rate

of a

dditi

onal

wat

er re

ceiv

ed

[% o

f sat

/s]



Conclusion

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Time [days]

Satu

ratio

n [%

]

SAP size 800 m, w/ce 0.050, max dist. 740 m


For the commonly applied sizes of SAP the whole volume of cured material is practically uniformly and instantaneously provided with curing water during the initial days of hydration



Outline






Modelling internal curing at the macro-level

Additional water source term

IChydrhydrws

w

hydrws

gwc

cwgww mmmSmS

tp

pS

n

1

tp

pS

pmc

c

ICwwc

IC

1

Capillary suction

Demand-supply w

hydrhydrhydrs

w

m

-11 0

0

20

40

60

80

100

0 2 4 6 8 10 12 14 16

Time [days]

Satu

ratio

n [%

] capillary suction'demand-supply'

Wyrzykowski, Lura, Pesavento, Gawin, Modeling of internal curing in maturing mortar, CCR (2011)



Simulation results – w/c 0.3 mortar with SAP

Mortarsw/c 0.3 + 0.04

00.10.2

0.30.40.50.60.7

0.80.9

1

0 1 2 3 4 5 6

Time [days]

Nor

m. h

ydra

tion

degr

ee [-

]

plain-exp.plain-sim.with SAP-exp.with SAP-sim.

80

82

84

86

88

90

92

94

96

98

100

0 2 4 6 8 10 12 14 16Time [days]

RH [%

]

plain-exp.plain-sim.w ith SAP-exp.w ith SAP-sim. cap. suctionw ith SAP-sim. 'demand-supply'




Simulation results – w/c 0.3 mortar with SAP

Mortarsw/c 0.3 + 0.04

-400

-300

-200

-100

0

0 2 4 6 8 10 12 14 16Time [days]

Auto

geno

us s

train

[ m

/m]

plain-exp.plain-sim.w ith SAP-exp.w ith SAP-sim. cap. suctionw ith SAP-sim. 'demand-supply'



Conclusions

At the meso-level the transport of water is explicitly analyzed the whole volume of material is practically uniformly and

instantaneously provided with curing water during the first day of hydration

At the macro-level the additional source term is introduced internal curing may be also analyzed directly at the macro-level two source terms describing internal curing are proposed , i.e.

capillary suction mechanism and demand-supply mechanism


Outline






Further applications

Autogenous conditions vs. realistic conditions

Drying

Self-heating + cooling

External load

Autogenous phenomena


Further applicationsDrying shrinkage

Gawin, Pesavento, Schrefler, IJNME (2006)Gawin, Wyrzykowski, Pesavento, J. Build Phys. (2008)

Photo: PCA

Development of capillary pressure

Increase of effective stress

Shrinkage (+creep) strains

hydrhydrws

w

hydrws

gwcg

w

rww

gg

rggw

g

gwgwd

g

wagw

ww

gw

gw

www

wswgw

s

c

cwgww

mmSmSpgradpgradkkdiv

pgradkkdivppgrad

MMMdiv

tdivSS

tT

TnS

tTSnnSn

tp

pSn

1

1

1111

2

I

IDu


Further applicationsSelf-heating / cooling

Gawin, Pesavento, Schrefler, IJNME (2006)

Heat of hydration

Thermal strains

Heat transfer temperature gradients 05101520253035404550

0 5 10 15 20 25 30 35

Tempe

rature [°C]

Time [days]

E3 193cm mid‐height

simulation



diffusion

water

0

2

4

6

8

10

12

14

16

0 2 4 6 8 10 12 14 16 18 20 22

Ca ions concentr. [mol/m3]

Solid

Ca

conc

entr

. [km

ol/m

3 ]

0.00E+00

5.00E-07

1.00E-06

1.50E-06

2.00E-06

2.50E-06

3.00E-06

Sour

ce [m

ol/m

3 s]

SCa-Ca,T=25°CSCa-Ca,T=60°Csource,T= 25°Csource,T= 60 C

Calcium leaching

Gawin, Pesavento, Schrefler, Int. J. Solids Struct. (2008)Koniorczyk & Gawin, J. Build. Phys., (2006)

Salts in concrete



Alkali-Silica Reaction (ASR)

Gawin, Pesavento, Schrefler, Comput. Methods Appl. Mech. Engrg.(2003)Pesavento, Gawin, Wyrzykowski, Schrefler, Simoni, Comput. Methods Appl. Mech. Engrg.(accepted)

Concrete at high temperatures


Outline

Motivation Autogenous shrinkage Description of phenomena in fresh concrete Application of the model for internal curing:

Modelling internal curing at meso-level Modelling internal curing at macro-level

Further applications and developments Summary


Summary

Porous media mechanics allows for macroscopic analysis of phenomena in maturing concrete as the direct effect of their physical origins (mechanistic approach)

The model can be considered as a general framework for description of concrete at the macro level incorporation of sub-models possible

Further applications of the model: maturing in realistic conditions (self-heating, shrinkage + creep) calcium leaching salts in concrete concrete at high temperature ASR


Thank you !

Concrete & Construction Chemistry

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