analytical approach to study …€¦ · in plaxis 2d with various loading from irc 58:2002, irc...

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International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 5, May 2018, pp. 1260–1271, Article ID: IJCIET_09_05_141

Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=5

ISSN Print: 0976-6308 and ISSN Online: 0976-6316

© IAEME Publication Scopus Indexed

ANALYTICAL APPROACH TO STUDY

PERFORMANCE OF DEMOLISHED WASTE IN

RIGID PAVEMENT USING PLAXIS 2D

Shweta A. Dandekar

Student, M.Tech. (Geotech. Engg.), Shri Ramdeobaba College of Engineering and

Management (RCOEM), Katol Road, Gittikhadan, Nagpur- 440013, India

Pravin B. Kulkarni

Associate Professor, Dept. of Civil Engineering, Shri Ramdeobaba College of Engineering

and Management (RCOEM), Katol Road, Gittikhadan, Nagpur- 440013, India

ABSTRACT

In present scenario, the Indian Ministry Road Transport and Highways has been

relentlessly promoting sustainable development to achieve both economic growth and

a good living environment for future generations. Given that the provision of

infrastructure and buildings is indispensable to support local economic development,

the construction industry will increasingly play a vital role in shaping a sustainable

environment for the residents of India, especially Nagpur. However, the construction

industry has long been confronted with its adverse impacts on the environment by

generating many waste materials and consuming substantial quantities of natural

resources.

Moreover, the lack of natural resources has resulted in a strong dependency on

importing natural aggregates from overseas. Thus, there is an urgency regarding the

divergence of waste materials away from the Landfill area and to source alternative

materials to replace natural aggregates. As an important component of the

sustainable development trend, the use of recycled waste materials in construction an

application is a method to enhance resource efficiency.

To realize the beneficial use of C & D material, an in-depth study was conducted

to evaluate its use in road construction using PLAXIS 2D. This software accomplishes

to analyze the effect of cyclic loading on construction and demolished waste

underneath the rigid pavement in static, dynamic and applying geo -synthetics as well.

This dissertation report paraphrases the inclusion of subbase material as C and D

waste beneath the rigid pavement to dwindle the settlement of it. The static and

dynamic analysis of rigid pavement incorporating geo -synthetics has been studied to

find the effect over it with the help of PLAXIS 2D. Several models have been analyzed

in Plaxis 2D with various loading from IRC 58:2002, IRC 58:2011 and IRC Class AA

Loading. The temperature check is also studied for the existing ongoing Roads in

Analytical Approach to Study Performance of Demolished Waste in Rigid Pavement Using Plaxis

2d


Nagpur Region, The results from study shows that the stresses developed at higher

temperature.

Keywords: Rigid pavement, Demolished waste, Concrete Roads, Geogrid, Plaxis 2D.

Cite this Article: Shweta A. Dandekar and Pravin B. Kulkarni, Analytical Approach

to Study Performance of Demolished Waste in Rigid Pavement Using Plaxis 2d,

International Journal of Civil Engineering and Technology, 9(5), 2018,

pp. 1260–1271.

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=9&IType=5

1. INTRODUCTION

Latterly, the great magnitude for the economic development of the Country are road

pavements, valuing the environmental perspective and seeking to terminate all long term

impacts (economic, social, environmental, or other) of this type of investments. The concept

of sustainable development has been subjected to various construe. ‘‘Brundtland Report’’, the

development that ‘‘meets the needs of the present without compromising the ability of future

generations to meet their own needs’’. At the present time, the term ‘‘sustainability’’ is

commonly applied to almost every facet of life, although it is being increasingly used in the

reference of human sustainability on Earth, with special focus on the causes of global

warming and climate change. Preservation of the environment and conservation of the rapidly

diminishing natural resources should be the essence of sustainable development. There is

consequent effect on environment of any construction activity, viz., constructing road

pavements.

A road pavement is a structure consisting of superimposed layers of processed materials

above the natural soil sub-grade, whose primary function is to distribute the applied vehicle

loads to the sub-grade. The pavement structure should be able to provide a surface of

acceptable riding quality, adequate skid resistance, favorable light reflecting characteristics,

and low noise pollution. The ultimate aim is to ensure that the transmitted stresses due to

wheel load are sufficiently reduced, so that they will not exceed bearing capacity of the

subgrade.

Concrete pavements, often called rigid pavements, are made up of Portland cement

concrete. The concrete pavement, because of its rigidity and high modulus of elasticity, tends

to distribute the applied load over a relatively wide area of soil.

Figure 1 Underlying layers of rigid pavement

The natural materials and costly material cement is becoming waste and just used for land

filling is a major problem. Recycling of waste material is not being implemented for waste

material management of Nagpur city.

Shweta A. Dandekar and Pravin B. Kulkarni


Figure 1.1 Site Picture of C & D waste 1 (Demolition of Chhatrapati Square Flyover)

Figure 1.2 C & D waste site 2 (Demolition of Chhatrapati Square Flyover)

Figure 1.3 C & D waste site 3 (Demolition of Unauthorized Flat Scheme)

The above pictures are of the various sites, where structures are to be demolished with

many reasons as such the structures which are hurdle in Smart city and also which are

unauthorized running in Nagpur and also redevelopment.

Until last two decades, landfill was considered as the low cost and efficient method of

C&D waste management in Nagpur. But land filling is considered to be undesirable due to

environmental and ecosystem hazards. Now most of the landfills are at the end of arriving at

its full capacity due to construction of basement oriented buildings.

1.1. Processing of Construction and Demolition Waste in road construction

The processing consists of very well-known processing steps in the C & D W recycling

industry such as primary crushing and sieving, wind shifting and the sorting out of ferric and

non-ferric parts. Next to those the Stone Recycling processing concept is built around the

purification of the material in terms of sorting out unwanted components such as gypsum by

using Near-Infrared (NIR) technology and the separation of the non-concrete fraction from

the concrete fraction using colour-sorting equipment.

Finally, the pure concrete aggregates resulting from the processing concept are brought to

the right size fraction by crushing and sieving. These resultant high-grade recycled aggregates

are applicable in both the bound and unbound application for road construction.

In the case of sub-base applications of C & D W, different tests have been performed in

order to determine if C&DW can be used as a substitute of contribution soil for sub-base

applications.


2d


1.2. Properties of aggregate made from C&D waste

Recycled concrete aggregate could be produced from (a) recycled precast elements and cubes

after testing, and (b) demolished concrete buildings. Whereas in the former case, the

aggregate could be relatively clean, with only the cement paste adhering to it, in the latter case

the aggregate could be contaminated with salts, bricks and tiles, sand and dust, timber,

plastics, cardboard and paper, and metals. It has been shown that contaminated aggregate after

separation from other waste, and sieving, can be used as a substitute for natural coarse

aggregates in concrete. As with natural aggregate, the quality of recycled aggregates, in terms

of size distribution, absorption, abrasion, etc. also needs to be assessed before using the

aggregate. Some of the important properties of such recycled aggregate are discussed in the

following paragraphs.

1.3. Size distribution

It has been now generally accepted that, recycled aggregates, either fine or coarse, can be

obtained by primary and secondary crushing and subsequent removal of impurities. Generally,

a series of successive crushers are used, with oversize particles being returned to the

respective crusher to achieve desirable grading. The best particle distribution shape is usually

achieved by primary crushing and then secondary crushing, but from an economic point of

view, a single crushing process is usually most effective. Primary crushing usually reduces

the C&D concrete rubble to about 50mm pieces and on the way to the second crusher,

electromagnets are used to remove any metal impurities in the material. The second crusher is

then used to reduce the material further to a particle size of about 14–20mm. Care should be

taken when crushing brick material because more fines are produced during the crushing

process than during the crushing of concrete or primary aggregates.

1.4. Absorption

The water absorption in RA ranges from 3 to 12% for the coarse and the fine fractions (Jose,

2002; Katz, 2003; Rao, 2005) with the actual value depending upon the type of concrete used

for producing the aggregate. It may be noted that this value is much higher than that of the

natural aggregates whose absorption is about 0.5–1%. The high porosity of the recycled

aggregates can mainly be attributed to the residue of mortar adhering to the original

aggregate.

This, in fact, also affects the workability and other properties of the new concrete mix as

discussed separately.

1.5. Abrasion resistance

Very limited literature is available on the abrasion resistance of RA. However, studies on the

use of such aggregates as sub-base in flexible pavements show promising results. These

recycled aggregates have also been used in generating concrete that is further used in rigid

pavements. As discussed earlier in the paper, they are extensively used in USA, UK and other

countries as new material for rigid pavements (Gilpin et al., 2004; Khalaf et al., 2004).

2. INTRODUCTION OF COMPUTER PROGRAM: PLAXIS 2D

Plaxis is finite element software developed at the Technical University of Delft for Dutch

Government. Initially, it was intended to analyze the soft soil river embankments of the

lowlands of Holland. Soon after, the company Plaxis BV was invented, and the program was

extended to cover a broader range of geotechnical issues. The Plaxis program started at Delft

University of Technology in early 1970’s when Peter Vermeer started to do a program of



research on finite element analysis on the design and construction of Eastern Scheldt Storm-

Barrier in Netherland. Initial finite element code was developed to calculate the elastic-plastic

plane using six-nodded triangular elements. In the year 1982 Rene De Borst under the

supervision of Pieter Vermeer, performed his master’s program related topic on the analysis

of cone penetration test in clay. The study of axisymmetric led to the existence of Plaxis. The

study was on six-nodded triangles in the element. This 15 – noded triangle was developed

thus increasing the number of nodes in the element. The usage of 15-noded triangle is the

simplest element for any analysis in axisymmetric. Then the experts De Borst and Vermeer

implement the 15-noded triangle in Plaxis thus solving the problem of cone penetrometer. The

development of Plaxis proceeds with the problem to solve the soil structure interaction

effects. This led to the study on beam element by Klaas Bakker under the supervision of

Pieter Vermeer. The outcome of the experiment using beam element was applicable to

flexible retaining wall and later application to the analysis of flexible footings and rafts.

Baker’s work formulated the implementation of 5-noded beam element in Plaxis (Bakker et al

(1990), Bakker et al (1991)). The 5- noded beam element is compatible to the 15-noded

triangular elements (has 5 nodes). Baker’s work was novel for the invention of hybrid method

introducing the displacement of degree-of –freedom to the element behaviour. The lack of

degree of freedom has made solution to reduce the number of variables thus simplified the

element.

2.1. Steps in Computational Modelling and calculation in PLAXIS 2D

In general, the analysis in Plaxis includes:

1. Defining the geometry and finite element model layout

2. Specifying material parameters: appropriate material strength and stiffness from

library or in-situ tests.

3. Generating stresses.

4. Construction stage i.e. defining various stage of excavation or filling using stage

construction

5. Engineering judgment.

2.2. Sets of Properties of Material

In PLAXIS 2D, soil properties and material properties of structure are stored in material data

sets. There are four different types of material sets grouped soil interfaces, Plate, Geo -

synthetics, and Anchor. Global database can be used to store the material properties.

Sr. No. Name of Author with year of publication Modulus of rigidity Poisson’s Ratio

Obrzud & Truty 2012 complied from Kezdi

1974 & Prat et.al. (1995) 80,000 kN/m2 -

Wojciech Sas, Katarzyna Gabrys, Alojzy

Szymanski (2013) 9,13,000 kN/m2 0.2

Arul Arulrajah, Mahdi M. Disfani, Suksun Horpibulsuk, Cherdsak Suksiripattanapong,

Nutthachai Prongmanee (2014) 310 kN/m2 -

Javier Tavira, José Ramón Jiménez, Jesús

Ayuso, María José Sierrac, Enrique Fernández Ledesma(2018)

22,000 kN/m2 0.35

Present study 58,076.67 kN/m2 0.3

Figure 2 Material properties of Demolished Waste


2d


Table 1 Properties of plate as rigid pavement

Sr. no. Properties Unit Value

1 Axial stiffness kN/m 7 x 105

2 Flexural rigidity kNm2/m 7146

3 Poisson’s ratio (�) --- 0.15

4 Density kN/m3 24

3. GEOMETRIC MODELLING OF RIGID PAVEMENT WITH ITS

UNDERLYING LAYERS

The Rigid Pavement with its underlying layers is shown in figure 1, the thickness of rigid

pavement and its subsequent underlying layers is shown in figure 3.

Figure 3 Assigning of material Properties to the geometries

3.1. Material sets and mesh generation

The properties of the different soil types are given in Table 1. Three material sets are to be

created, containing the data according to the table. The clay and the peat layer are undrained.

This type of behavior leads to an increase of pore pressures during the construction of the

embankment. Assign the data to the corresponding clusters in the geometry model. After the

input of material parameters, a simple finite element mesh may be generated using the

Medium coarseness setting. Generate the mesh by clicking on the Generate mesh button.

Figure 3.1.1 Assigning of material Properties to the geometries of underlying Layers

Figure 3.1.2 Assigning of material Properties to the Plate for pavement



Figure 3.1.3 Generation of Mesh

Figure 3.1.4 Deformed mesh Due to self-weight of Pavement

Figure 3.1.5 Vertical displacement of subbase Due to self-weight of Pavement (Max Deformation =

2.1 mm)

Figure 3.1.6 Application of Wheeledwheeledloading (40 kN


2d


Figure 3.1.7 Deformed mesh Due to wheeled wheel loading of 40 kN

Figure 3.1.8 Vertical displacement of subbase due to Self-weight with loading (40 kN)

Max deformation = 4.00 mm

Figure 3.1.9 Geometric model of demolished waste based rigid pavement incorporating geogrid at the

interfaces.

Figure 3.1.10 Contours of vertical Deformation



4. THE TRAFFIC LOADING ON PAVEMENTS

Traffic load in pavement evaluation is considered to be a load from heavily loaded vehicles

(trucks, lorries). Load can affect the pavement either as a static or dynamic load. Load in

calculations is considered to be simple or repeated. Heavy vehicles, which have recently been

used on roads, are considered. The effect of these vehicles is transferred into the pavement

through the contact area with consideration of the tyres inflation and the constructional

solution of the undercarriage. According to the calculation methodology, substitute or real

contact areas are used, which respond to tyre inflation and undercarriage dimensions.

4.1. PARAMETRIC CALCULATIONS

Parametric calculations of the stresses on a concrete slab were made by a traffic load on

models of the pavement structures by selected methods. C & D Waste as the sub-base and

different load locations are considered in the calculations.

4.1.1. Pavement loading

Simple static loading of the pavements was simulated by axles with the following

characteristics:

• a design axle with a weight of 10.0 tons, loading of 2P = 100 kN, average contact

pressure p= 0.60 MPa,

• an axle with maximum allowed weight of 11.5 tons, loading of 2P = 115 kN,

average contact pressure p = 0.65 MPa,

• a non-standard axle with a weight of 24,0 tons, loading of 3P = 240 kN, average

contact pressure p = 0,70 MPa,

5. WESTERGAARD'S THEORY FOR RIGID PAVEMENTS

“It is a common observation that the theory of elasticity is useful beyond the range of

elasticity.” - M. M. Westergaard

Westergaard's theory is considered good to design the rigid pavements.

Rigid pavement slab is considered as a thin elastic plate resting on soil sub-grade, which is

assumed to be a dense liquid. So, here the upward reaction is assumed to be proportional to

the deflection, i.e. p = K.d, where K is a constant defined as modulus of subgrade reaction.

Units of K are kg/cm3.

Figure 4.1 Concrete pavement

5.1. Westergaard's modulus of sub-grade reaction

Modulus of sub-grade reaction is proportional to amount of deflection (d). Displacement level

is taken as 0.125 cm in calculating K i.e. d = 0.125 cm, so modulus of sub-grade reaction,


2d


5.2. Radius of relative stiffness of slab to sub-grade

Amount of deflection which will occur on the pavement surface depends on the stiffness of

the slab and also on the stiffness of the sub-grade. Same amount of deflection will occur on

the top surface of the sub-grade.

This means that the amount of deflection which is going to occur in the rigid pavement

layer depends both on relative stiffness of the pavement slab with respect to that of sub-grade.

Westergaard defined this by a term "Radius of relative stiffness" which, can be written

numerically as below:

where,

l = radius of relative stiffness, cm

E = Modulus of elasticity of cement concrete kg/cm2

µ = Poisson's ratio for concrete = 0.15

K = Modulus of Sub-grade reaction in kg/cm2

5.3. Traffic Parameters

1. Design Wheel Load

2. Traffic Intensity

5.4. Critical Load Positions

Figure 4.2 3D view of Rigid Pavement

When the wheel load is applied on the pavement surface, flexural stresses are induced in

the pavement. There are three critical positions which are to be checked for maximum

stresses.

1. Interior loading

2. Edge Loading

3. Corner loading

Whenever loading is applied at the interior of the slab, remote than the edges and corner,

this is called interior loading.

When loading is applied on the edges, remote than the corners is called edge loading.

When the loading is applied on the corner angle bisector and loading is touching the

corner the edges.

5.5. Equivalent Radius of Resisting section

When the loading is at the interiors there is a particular area which will resist the bending

moment. Westergaard assumed that the area will be circular in plan and its radius is called

as Equivalent radius of Resisting section.



Numerically,

b= (1.6 x a2 + h2)(1/2) - 0.675h

Here,

b = equivalent radius of resisting section, cm when 'a' is less than 1.724h

a = radius of wheel load distribution, cm

h = slab thickness, cm

When 'a' is greater than 1.724h, b =a.

In case of corner loading,maximum stresses are not produced at corner but they are

produced at a certain distance ‘X’ along the corner bisector. This is given by the relation:

X = 2.58(al)1/2

Here, X = distance from apex of the slab corner to section of maximum stress along the

corner bisector, cm.

a= Radius of wheel load distribution, cm

l = Radius of relative stiffness, cm.

The following formulas used to calculate the amount of stresses developed at the three

critical positions due to the given wheel load P.

1. Interior Loading,

Si = �.��

�� + �. ��

2. Edge Loading,

Se= �.��

�� + �. ��

3. Corner Loading,

Si = � � �� − ��√

� �� Here,

Si, Se and Sc = maximum stress at interior, edge and corner loading kg/cm2

h = Slab thickness, cm

6. RESULS AND DISCUSSIONS:

Vertical displacement of rigid Slab = 2.1 mm ----(self-weight)

Vertical displacement of rigid Slab with Load of 40 kN = 4.00mm

Impact of Load (40kN) at frequency of 2Hz gives Maximum = 26mm

Effective Vertical stress in Soil = 180 kPa

With Geogrid, the Maximum deformation for Impact loading in slab is 2.40 mm

Demolished waste could be better option for Rigid pavement.

After using geogridsettlement/deformation gets reduced.

7. CONCLUSION

Recycled concrete aggregate or demolished waste can be used as base and sub-base materials,

in place of crushed stone aggregate for supporting a concrete pavement system. The

compaction of recycled concrete aggregate is the same as that of crushed stone aggregate and


2d


gravel. The stability and the shear resistance of recycled concrete aggregate in dry conditions

are higher than those of gravel and equal to or better than those of crushed stone aggregate.

Breakage of aggregate particles increases in severity from gravel to recycled concrete

aggregate.

Numerical modeling of the demolished waste under rigid pavement is done by using

PLAXIS 2D. After intensive modeling it is clear that the settlement in RCC slab. For axle

load it is found 2.1 mm and after impact load the settlement is 4.1 mm.

The uses of geogridin RCC road to wrap the demolished waste at the interfaces,

deformation get reduced and which is found 2.4 mm.

REFERENCES

[1] IRC 58:2002, “Guidelines for the Design of Plain Jointed Rigid Pavement s for

Highways”. Highway Engineering by Rangwala.

[2] Milind V. Mohod 1*, Dr. K.N.Kadam 2, “A Comparative Study on Rigid and Flexible

Pavement: A Review”, IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)

e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 13, Issue 3 Ver. VII (May- Jun. 2016),

PP 84-88.

[3] Rafaela Cardoso, Rui Vasco Silva, Jorge de Brito, RavindraDhir, “Use of recycled

aggregates from construction and demolition waste in geotechnical applications: A

literature review”, Waste Management xxx (2015) xxx – xxx, journal homepage:

www.elsevier.com/locate/wasma.

[4] Taesoon Park1, “Application of Construction and Building Debris as Base and Subbase

Materials in Rigid Pavement”, 10.1061/~ASCE! 0733-947X~2003!129:5 ~558!

[5] Javier Tavira , José Ramón Jiménez , JesúsAyuso, María José Sierrac, Enrique Fernández

Ledesma, “Functional and structural parameters of a paved road section constructed with

mixed recycled aggregates from non-selected construction and demolition waste with

excavation soil”, Construction and Building Materials 164 (2018) 57 – 69, journal

homepage: www.elsevier.com/locate/conbuildma.

[6] Arul Arulrajah, Mahdi M. Disfani, SuksunHorpibulsuk, CherdsakSuksiripattanapong,

NutthachaiProngmanee, “Physical properties and shear strength responses of recycled

construction and demolition materials in unbound pavement base/sub-base applications”,

Construction and Building Materials 58 (2014) 245 – 257, journal homepage:

www.elsevier.com/locate/conbuildma.

[7] TabassomAfshar, Mahdi M Disfani, Arul Arulrajah, Guillermo A Narsilio, Sacha Emam,

“Impact of particle shape on breakage of recycled construction and demolition

aggregates”, Powder Technology 308 (2017) 1-12, journal homepage:

www.elsevier.com/locate/powte

[8] SeyedhamedSadati, Kamal H. Khayat, “Field performance of concrete pavement

incorporating recycled concrete aggregate”, Construction and Building Materials 126

(2016) 691–700, journal homepage: www.elsevier.com/locate/ conbuildma

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