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1 EFFECT OF MATERIAL PROPORTIONS ON THE ENGINEERING PROPERTIES OF PERVIOUS CONCRETE A Project work submitted to the Faculty of Civil Engineering, Kakatiya University. In partial fulfilment of the requirements for the award of the degree of BACHELOR OF TECHNOLOGY IN CIVIL ENGINEERING BY V SHIVA PRAKASH (10016T0033) N MANOHAR (10016T0031) K RAJESH (10016T0052) B RAHUL (10016T0054) Under the guidance of Sri N.SRIKANTH Assistant Professor, Dept. of Civil Engineering Department of Civil Engineering KAKATIYA INSTITUTE OF TECHNOLOGY & SCIENCE WARANGAL-506015 2013-2014

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EFFECT OF MATERIAL PROPORTIONS ON THE ENGINEERING

PROPERTIES OF PERVIOUS CONCRETE

A Project work submitted to the

Faculty of Civil Engineering, Kakatiya University.

In partial fulfilment of the requirements for the award of the degree of

BACHELOR OF TECHNOLOGY

IN

CIVIL ENGINEERING

BY

V SHIVA PRAKASH (10016T0033)

N MANOHAR (10016T0031)

K RAJESH (10016T0052)

B RAHUL (10016T0054)

Under the guidance of

Sri N.SRIKANTH

Assistant Professor, Dept. of Civil Engineering

Department of Civil Engineering

KAKATIYA INSTITUTE OF TECHNOLOGY & SCIENCE

WARANGAL-506015

2013-2014

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KAKATIYA INSTITUTE OF TECHNOLOGY & SCIENCE

WARANGAL-506015

Department of Civil Engineering

CERTIFICATE

This is to certify that the project work entitled “DEVELOPMENT OF

PERVIOUS CONCRETE” is the bonafied work carried out by V.Shiva Prakash,

N.Manohar, K.Rajesh, B.Rahul bearing roll numbers 10016T0033, 10016T0031,

10016T0052, 10016T0054 respectively, in partial fulfilment of the requirements for the

award of the Degree of Bachelor of Technology from Kakatiya University during the

academic year 2013-2014, under our guidance and supervision

sri N Srikanth prof. S.G.Narayana Reddy

Assistant Professor Head of the department

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ACKNOWLEDGEMENT

We would like to express our deep sense of gratitude to our project guide

Sri.N.SRIKANTH, Assistant Professor, Dept. of CE, KITS, Warangal, who has guided

our work with scholarly advice and meticulous care. He had shown keen interest and

personal care at every stage of our project. We consider it as our privilege to have worked

under his guidance.

We are profoundly thankful to Project Coordinator Sri E. Maheshwar

Reddy, Associate professor, Dept. of CE for his moral support and to Sri S.G. Narayana

Reddy, Professor & Head, Dept. of CE for his cooperation and encouragement.

We wish to express our sincere thanks to Dr. K. Ashoka Reddy, Principal

KITS Warangal for his kind gesture and support. We are indebted to the Management of

Kakatiya Institute of Technology and Science, Warangal, for providing the necessary

infrastructure and good academic environment in an endeavour to complete the project.

We would like to acknowledge the faculty of Civil Engineering Department

and non-teaching staff.

V.SHIVA PRAKASH

N.MANOHAR

K RAJESH

B RAHUL

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ABSTRACT

Pervious concrete is a special type of concrete with high porosity

used for concrete flat work applications that allow water from precipitation

and other sources to pass directly through, thereby reducing the runoff

from a site and allowing ground water recharge. This porosity is attained

by a highly interconnected void content. Typically pervious concrete has

little or no fine aggregate and has just enough cementing paste to coat the

coarse aggregate particles while preserving the interconnectivity of the

voids.

Pervious concrete is traditionally used in Parking areas, areas with

high traffic, walk ways in parks and gardens, Residential streets,

Pedestrian walkways and Green houses, Basket ball and volley ball courts

etc.

Pervious concrete is an important application for the sustainable

construction and is one of many low impact development techniques used

by builders to protect water quality.

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CONTENTS

1. INTRODUCTION 06

2. MATERIALS USED 10

3. LITERATURE REVIEW 19

4. PROPERTIES 24

5. DESIGN CRITERIA 26

6. SPECIFIC DESIGN CONSIDERATIONS AND LIMITATIONS 29

7. CONSTRUCTION 31

8. MAINTENANCE 35

9. COST 37

10. EXPERIMENTAL VALUES 38

11. CONCLUSIONS AND RESULTS 41

12. PERVIOUS CONCRETE IN INDIA 42

13. REFERENCES 43

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CHAPTER 1

INTRODUCTION

Pervious concrete which is also known as the no-fines, porous, gap-

graded, and permeable concrete and enhance porosity concrete has been

found to be a reliable storm water management tool . By definition,

pervious concrete is a mixture of gravel or granite stone, cement, water,

little to no sand (fine aggregate) with or without admixtures. When

pervious concrete is used for paving (Figure 1), the open cell structures

allow storm water to filter through the pavement and into the underlying

soils. In other words, pervious concrete helps in protecting the surface of

the pavement and its environment.

As stated above, pervious concrete has the same basic constituents as

conventional concrete that is, 15% -30% of its volume consists of

interconnected void network, which allows water to pass through the

concrete. Pervious concrete can allow the passage of 3-5 gallons (0.014 -

0.023m3) of water per minute through its open cells for each square foot

(0.0929m2) of surface area which is far greater than most rain

occurrences. Apart from being used to eliminate or reduce the need for

expensive retention ponds, developers and other private companies are

also using it to free up valuable real estate for development, while still

providing a paved park.

Figure 1: Polish surface of a pervious concrete pavement (Source: Mary

et al, 2010) International Journal of Engineering and Technology (IJET) –

IJET Publications UK.

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Pervious concrete is also a unique and effective means to address

important environmental issues and sustainable growth. When it rains,

pervious concrete automatically acts as a drainage system, thereby putting

water back where it belongs. Pervious concrete is rough textured, and has

a honeycombed surface, with moderate amount of surface raveling which

occurs on heavily travelled roadways (Concrete network, 2009). Carefully

controlled amount of water and cementitious materials are used to create

a paste (Dan, 2003). The paste then forms a thick coating around

aggregate particles, to prevent the flowing off of the paste during mixing

and placing. Using enough paste to coat the particles maintain a system

of interconnected voids which allow water and air to pass through. The

lack of sand in pervious concrete results in a very harsh mix that

negatively affects mixing, delivery and placement. Also, due to the high

void content, pervious concrete is light in weight (about 1600 to

1900kg/m3). Pervious concrete void structure provides pollutant captures

which also add significant structural strength as well. It also results in a

very high permeable concrete that drains quickly.

Pervious concrete can be used in a wide range of applications, although

its primary use is in pavements which are in: residential roads, alleys and

driveways, low volume pavements, low water crossings, sidewalks and

pathways, parking areas, tennis courts, slope stabilisation, sub-base for

conventional concrete pavements etc.

Pervious concrete system has advantages over impervious concrete in that

it is effective in managing run-off from paved surfaces, prevent

contamination in run-off water, and recharge aquifer, repelling salt water

intrusion, control pollution in water seepage to ground water recharge

thus, preventing subterranean storm water sewer drains, absorbs less

heat than regular concrete and asphalt, reduces the need for air

conditioning. Pervious concrete allows for increased site optimization

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because in most cases, its use should totally limit the need for detention

and retention ponds, swales and other more traditional storm water

management devices that are otherwise required for compliances with the

Federal storm water regulations on commercial sites of one acre or more.

By using pervious concrete, the ambient air temperature will be reduced,

requiring less power to cool the building. In addition, costly storm water

structures such as piping, inlets and ponds will be eliminated.

Construction scheduling will also be improved as the stone recharge bed

will be installed at the beginning of construction, enhancing erosion

control measures and preventing rain delays due to harsh site conditions.

Apparently, when compared to conventional concrete, pervious concrete

has a lower compressive strength, greater permeability, and a lower unit

weight (approximately 70% of conventional concrete). However, pervious

concrete has a greater advantage in many regards. Nevertheless, it has its

own limitations which must be put in effective consideration when

planning its use. Structurally when higher permeability and low strength

are required the effect of variation in aggregate size on strength and

permeability for the same aggregate cement ratio need to be investigated.

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Figure:1

Figure:2

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CHAPTER 2

MATERIALS USED

2.1 Constituents of concrete

If a concrete is to be suitable for a particular purpose, it is necessary to

select the constituent materials and combine them in such a manner as

to develop the special qualities required as economical as possible. The

selection of materials and choice of method of construction is not easy,

since many variables affect the quality of the concrete produced, and both

quality and economy must be considered.

The characteristics of concrete should be evaluated in relation to the

required quality for any given construction purpose. The closest

practicable approach to perfection in every property of the concrete would

result in poor economy under many conditions, and the most desirable

structure is that in which the concrete has been designed with the correct

emphasis on each of the various properties of the concrete, and not solely

with a view to obtaining of maximum possible strength.

2.1.1 Cement

Cement is a key to infrastructure industry and is used for various

purposes and also made in many compositions for a wide variety of uses.

Cements may be named after the principal constituents, after the intended

purpose, after the object to which they are applied or after their

characteristic property.

Cement used in construction are sometimes named after their commonly

reported place of origin, such as Roman cement, or for their resemblance

to other materials, such as Portland cement, which produces a concrete

resembling the Portland stone used for building in Britain. The term

cement is derived from the Latin word Caementum, which is meant stone

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chippings such as used in Roman mortar not-the binding material itself.

Cement, in the general sense of the word, described as a material with

adhesive and cohesive properties, which make it capable of bonding

mineral fragments in to a compact whole. The first step of reintroduction

of cement after decline of the Roman Empire was in about 1790, when an

Englishman, J. Smeaton, found that when lime containing a certain

amount of clay was burnt, it would set under water. This cement

resembled that which had been made by the Romans. Further

investigations by J. Parker in the same decade led to the commercial

production of natural hydraulic cement

Chemical compounds of Portland cement

The raw material used in the manufactures of Portland cement comprises

four principal compounds. These compounds are usually regarded as the

major constituents of cement and tabulated with their abbreviated

symbols

Table 2.1 Typical composition of ordinary Portland cement

Name of compound Oxide Abbreviation

Composition

Tricalcium Silicate 3CaO.SiO2 C3S

Dicalcium Silicate 2CaO.SiO2 C2S

Tricalcium aluminate 3CaO.Al2 O3 C3A

Tetracalcium

aluminoferrite

4CaO.Al2O3.Fe2O

3 C4AF

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These compounds interact with one another in the kiln to form a series of

more complex products. Portland cement is varied in type by changing the

relative proportions of its four predominant chemical compounds and by

the degree of fineness of the clinker grinding. A small variation in the

composition or proportion of its raw materials leads to a large variation in

compound composition Calculation of the potential composition of

Portland cement is generally based on the Bogue composition (R.H Bogue).

In addition to the main compounds, there exist minor compounds such as

MgO, TiO2, K2O and Na2O; they usually amount to not more than a few

percent of the mass of the cement. Two of the minor compounds are of

particular interest: the oxides of sodium and potassium, K2O and Na2O,

known as the alkalis. They have been found to react with some aggregates,

the products of the reaction causing disintegration of the concrete and

have also observed to affect the rate of gain of strength of cement.Present

knowledge of cement chemistry indicates that the major cement

compounds have the following properties.

Tricalcium Silicate, C3S hardens rapidly and is largely responsible

for initial set and early strength development. The early strength of

Portland cement concrete is higher with increased percentages of

C3S.

Dicalcium Silicate, C2S hardens slowly and contributes largely to

strength increase at ages beyond one week.

Tricalcium aluminate, C3A liberates a large amount of heat during

the first days of hardening. It also contributes slightly for early

strength development. Cements with low percentages of this

compound are especially resistant to soils and waters containing

sulphates. Concrete made of Portland cement with C3A contents as

high as 10.0%, and sometimes greater, has shown satisfactory

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durability, provided the permeability of the concrete is low.

Tetracalcium aluminoferrite, C4AF reduces the clinkering

temperature. It will act as a flux in burning the clinker. It hydrates

rather rapidly but contributes very little to strength development.

Most colour effects are due to C4AF series and its hydrates.The

compounds tricalcium aluminate and tricalcium silicate develop the

greatest heat, then follows tetracalcium aluminoferrite, with

dicalcium silicate developing the least heat of all.

2.1.2 Aggregates

2.1.2.1 General

Aggregates were first considered to simply be filler for concrete to reduce

the amount of cement required. However, it is now known that the type of

aggregate used for concrete can have considerable effects on the plastic

and hardened state properties of concrete. They can form 80% of the

concrete mix so their properties are crucial to the properties of concrete.

Aggregates can be broadly classified into four different categories: these

are heavyweight, normal weight, lightweight and ultra-lightweight

aggregates. However in most concrete practices only normal weight and

lightweit aggregates are used. The other types of aggregates are for

specialist uses, such as nuclear radiation shielding provided by

heavyweight concrete and thermal insulation using lightweight concrete.

2.1.2.2 Classification of aggregates

The alternative used in the manufacture of good quality concrete, is to

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obtain the aggregate in at least two size groups, i.e.:

1) fine aggregate often called sand not larger than 5mm in size.

2) course aggregate, which comprises material at least 5mm in size.

On the other hand, there are some properties possessed by the aggregate

but absent in the parent rock: particle shape and size, surface texture,

and absorption. All these properties have a considerable influence on the

quality of the concrete, either in fresh or in the hardened state.

It has been found that aggregate may appear to be unsatisfactory on some

count but no trouble need be experienced when it is used in concrete

2.1.2.3 Aggregate properties

By selecting different sizes and types of aggregates and different ratios of

aggregate to cement ratios, a wide range of concrete can be produced

economically to suit different requirements. Important properties of an

aggregate which affect the performance of a concrete are discussed as

follows:

2.1.2.3.1 Sampling

Samples shall be representative and certain precautions in sampling have

to be made. No detailed procedures can be laid down as the conditions

and situations involved in taking samples in the field can vary widely from

case to case. Nevertheless, a practitioner can obtain reliable results

bearing in mind that the sample taken is to be representative of the bulk

of the material. The main sample shall be made up of portions drawn from

different parts of the whole. The minimum number of these portions. In

the case of stockpiles, the sample obtained is variable or segregated, a

large number of increments should be taken and a larger sample should

be dispatched for testing.

2.1.2.3.2 Particle shape and texture

Roundness measures the relative sharpness or angularity of the edges and

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corners of a particle. Roundness is controlled largely by the strength and

abrasion resistance of the parent rock and by the amount of wear to which

the particle has been subjected. In the case of crushed aggregate, the

particle shape depends not only on the nature of the parent rock but also

on the type of crusher and its reduction ratio, i.e. the ratio of the size of

material fed into the crusher to the size of the finished product. Particles

with a high ratio of surface area to volume are also of particular interest

for a given workability of the control mix.

Elongated and flaky particles are departed from equi-dimensional shape

of particles and have a larger surface area and pack in an isotropic

manner. Flaky particles affect the durability of concrete, as the particles

tend to be oriented in one plane, with bleeding water and air voids forming

underneath. The flakiness and elongation tests are useful for general

assessment of aggregate but they do not adequately describe the particle

shape. The presence of elongated particles in excess of 10 to 15% of the

mass of coarse aggregate is generally undesirable, but no recognized limits

are laid down .Surface texture of the aggregate affects its bond to the

cement paste and also influences the water demand of the mix, especially

in the case of fine aggregate. The shape and surface texture of aggregate

influence considerably the strength of concrete. The effects of shape and

texture are particularly significant in the case of high strength concrete.

The full role of shape and texture of aggregate in the development of

concrete strength is not known, but possibly a rougher texture results in

a larger adhesive force between the particles and the cement matrix.

Likewise, the larger surface area of angular aggregate means that a larger

adhesive force can be developed.

The shape and texture of fine aggregate have a significant effect on the

water requirement of the mix made with the given aggregate. If these

properties of fine aggregate are expressed indirectly by it’s packing, i.e. by

the percentage voids in a loose condition, then the influence on the water

requirement is quite definite. The influence of the voids in coarse aggregate

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is less definite. Flakiness and shape of coarse aggregates have an

appreciable effect on the workability of concrete.

2.1.2.3.3 Bond of aggregate

Bond between aggregate and cement paste is an important factor in the

strength of concrete, but the nature of bond is not fully understood. Bond

is to the interlocking of the aggregate and the hydrated cement paste due

to the roughness of the surface of the former. A rougher surface, such as

that of crushed particles, results in a better bond due to mechanical

interlocking; better bond is not usually obtained with softer, porous, and

minor logically heterogeneous particles. Bond is affected by the physical

and chemical properties of aggregate. For good development of bond, it is

necessary that the aggregate surface be clean and free from adhering clay

particles .The determination of the quality of bond of aggregate is difficult

and no accepted tests exist. Generally, when bond is good, a crushed

specimen of normal strength concrete should contain some aggregate

particles broken right through, in addition to the more numerous ones

pulled out from their sockets. An excess of fractured particles, might

suggest that the aggregate is too weak .

2.1.2.3.4 Strength of aggregate

The compressive strength of concrete cannot significantly exceed that of

the major part of the aggregate contained. If the aggregate under test leads

to a lower compressive strength of concrete, and in particular if numerous

individual aggregate particles appear fractured after the concrete specimen

has been crushed, then the strength of the aggregate is lower than the

nominal compressive strength of the concrete mix. Such aggregate can be

used only in a concrete of lower strength.

The influence of aggregate on the strength of concrete is not only due to

the mechanical strength of the aggregate but also, to a considerable

degree, to its absorption and bond characteristics. In general, the strength

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of aggregate depends on its composition, texture and structure. Thus a

low strength may be due to the weakness of constituent grains or the

grains may be strong but not well knit or cemented together.

A test to measure the compressive strength of prepared rock cylinders

used to be prescribed. However, the results of such a test are affected by

the presence of planes of weakness in the rock that may not be significant

once the rock has been comminuted to the size used in concrete.In essence

the crushing strength test measures the quality of the parent rock rather

than the quality of the aggregate as used in concrete. For this reason the

test is rarely used. Crushing value test BS 812: part 105:1990, measures

the resistance to pulverization. The crushing value is a useful guide when

dealing with aggregates of unknown performance, when lower strength

may be suspected. There is no obvious physical relation between this

crushing value and the compressive strength, but the results of the two

tests are usually in agreement.

2.1.2.3.5 Deleterious substances of aggregate

For satisfactory performance, concrete aggregates should be free of

deleterious materials. There are three categories of deleterious substances

that may be found in aggregates: impurities, coatings and weak or

unsound particles.

2.1.2.3.6 Grading of fine and coarse aggregate

The actual grading requirements depend on the shape and surface

characteristics of the particles. For instance, sharp angular particles with

rough surfaces should have a slightly finer grading in order to reduce the

possibility of interlocking and to compensate for the high friction between

the particles

2.1.2.3.6.1 Maximum aggregate size

Extending the grading of aggregate to a larger maximum size lowers the

water requirement of the mix, so that, for a specified workability and

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cement content, the water /cement ratio can be lowered with a consequent

increase in strength. Experimental results indicated that above the

38.1mm maximum size the gain in strength due to the reduced water

requirement is offset by the detrimental effects of lower bond area (so that

volume changes in the paste cause larger stresses at interfaces) and of

discontinuities introduced by the very large particles. In structural

concrete of usual proportions, there is no advantage in using aggregate

with a maximum size greater than about 25 or 40mm when compressive

strength is a criterion.

. 2.1.4 Water

Water is a key ingredient in the manufacture of concrete. Water used in

concrete mixes has two functions: the first is to react chemically with the

cement, which will finally set and harden, and the second function is to

lubricate all other materials and make the concrete workable . Although it

is an important ingredient of concrete, it has little to do with the quality of

concrete . One of the most common causes of poor-quality concrete is the

use of too much mixing water. Fundamentally “the strength of concrete is

governed by the nature of the weight of water to the weight of cement in a

mix, provided that it is plastic and workable, fully compacted, and

adequately cured”.

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CHAPTER 3

LITERATURE REVIEW

Portland cement pervious concrete (PCPC) has great potential to reduce

roadway noise, improve splash and spray, and improve friction as a

surface wearing course. A pervious concrete mix design for a surface

wearing course must meet the criteria of adequate strength and durability

under site-specific loading and environmental conditions. To date, two key

issues that have impeded the use of pervious concrete in the United States

are that strengths of pervious concrete have been lower than necessary for

required applications and the freeze-thaw durability of pervious concrete

has been suspect.

A research project on the freeze-thaw durability of pervious concrete mix

designs at Iowa State University (ISU) has recently been completed

(Schaefer et al. 2006). The results of this study have shown that a strong,

durable pervious concrete mix design that will withstand wet, hard- freeze

environments is possible. The strength is achieved through the use of a

small amount of fine aggregate (i.e., concrete sand) and/or latex admixture

to enhance the particle-to-particle bond in the mix. The preliminary results

were reported in Kevern et al. (2005). The recent work has been limited to

laboratory testing and to only a few mixes using two sources of aggregates.

Preliminary laboratory testing has shown the importance of compaction

energy on the properties and performance of the mixes, an issue that has

direct bearing on the construction technique used to place the materials

in the field. Additional laboratory and field testing is necessary to establish

minimum mix design properties and determine optimum construction

techniques.

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A recent study at Purdue University (Olek et al. 2003) has shown that

pervious concrete (termed enhanced porosity concrete in the Purdue

University study) can reduce tire-pavement interaction noise. Tests

conducted in Purdue University’s Tire-Pavement Test Apparatus showed

reduced noise levels above 1,000 hertz (Hz) and some increase in noise

levels below 1,000 Hz. The increased porosity of pervious concrete

increased mechanical excitation and interaction between the tire and

pavement at frequencies below about 1,000 Hz and at frequencies above

about 1,000 Hz; the air pumping mechanics that dominate at such

frequencies are relieved by the increased porosity leading to decreased

high-frequency noise levels. Several pervious concrete pavements have

been constructed in Europe, and pervious concrete has been shown to be

promising in reducing tire-pavement noise and wet weather spray.

A recent European Scan (sponsored by the Federal Highway

Administration/FHWA) indicated that the use of pervious pavements as

friction courses is declining, due to the European preference toward an

exposed aggregate concrete. Also, clogging, raveling, and winter

maintenance were indicated as problem areas. Participants in the Scan

felt that the use of pervious concrete was not given enough time to develop

into a viable paving alternative.

The American experience with pervious concrete is limited. It is important

to ascertain what material elements can be included in the pervious mix

design to address the raveling and clogging issues. If winter maintenance

elements and concerns cannot be overcome, pervious concrete may be able

to be used in warm weather regions. An extensive research program of

laboratory work and field installations is needed to determine the

possibilities for the use of pervious concrete in highway applications.

The National Concrete Pavement Technology Center (National CP Tech

Center) at ISU developed a research project titled “An Integrated Study of

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Portland Cement Pervious Concrete for Wearing Course Applications.” The

objective of the research was to conduct a comprehensive study focused

on the development of pervious concrete mix designs having adequate

strength and durability for wearing course pavements and having surface

characteristics that reduce noise and enhance skid resistance while

providing adequate removal of water from the pavement surface and

structure. A range of mix designs was used necessary to meet

requirements for wearing course applications. Further, constructability

issues for wearing course sections were addressed to ensure that

competitive and economical placement of the pervious concrete can be

done in the field. Hence, during the evaluation phases, both laboratory

and field testing of the materials and construction were conducted. The

focus of the National CP Tech Center’s work on pervious concrete was the

development of a durable wearing course that can be used in highway

applications for critical noise, splash/spray, skid resistance, and

environmental concerns. The comprehensive study is anticipated to be

conducted over a five-year period and is further described below.

Background

A recent National CP Tech Center report titled Mix Design Development for

Pervious Concrete in Cold Weather Climates (Schaefer et al. 2006) provides

a summary of the available literature concerning the construction

materials, material properties, surface characteristics, pervious pavement

design, construction, maintenance, and environmental issues for PCPC.

The primary goal of the research conducted was to develop a pervious

concrete that would provide freeze- thaw resistance while maintaining

adequate strength and permeability for pavement applications. The

complete report is available on the Institute for Transportation (InTrans)

and National CP Tech Center website at

http://www.intrans.iastate.edu/reports/mix_design_pervious.pdf.

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The key findings from the literature review can be summarized as follows:

The engineering properties reported in the literature from the United

States indicate a high void ratio, low strength, and limited freeze-thaw test

results. It is believed that these reasons have hindered the use of pervious

concrete in the hard wet freeze regions (i.e., Midwest and Northeast United

States). The typical mix design of pervious concrete used in the United

States consists of cement, single-sized coarse aggregate (i.e., between one

inch and No. 4), and water to cement ratio ranging from 0.27 to 0.43. The

28-day compressive strength of pervious concrete ranges from 800 psi

(pound per square inch) to 3,000 psi, with a void ratio ranging from 14%

to 31% and a permeability ranging from 36 inch/hour (in./hr) to 864

in./hr. The advantages of pervious concrete include improving skid

resistance by removing water that creates splash and spray during

precipitation events, reducing noise, minimizing heat islands in large

cities, preserving native ecosystems, and minimizing cost in some cases.

Surface coarse pervious concrete pavement systems have been reported to

be used in Europe and Japan. Studies have shown that pervious concrete

generally produces a quieter than normal concrete with noise levels

ranging from 3% to 10% lower than those of normal concrete. The research

conducted at ISU included studies of the materials used in the pervious

concrete, the mix proportions and specimen preparation, the resulting

strength and permeability, and the effects of freeze-thaw cycling. A variety

of aggregate sizes was tested and both limestone aggregates and river run

gravels were used. The effects of the addition of sand, latex, and/or silica

fume on the resulting behavior were investigated. The key parameters

investigated were strength, permeability, and freeze-thaw resistance. The

overall results can be summarized in Figure 1, where it can be seen that

an interdependent relationship exists between the void ratio, seven-day

compressive strength, and permeability of the pervious concrete. In Figure

1 it can be seen that as the void ratio increases, the strength decreases

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but the permeability increases. Shown in the figure is a target range of

void ratio between 15% and 19% in which the strength and permeability

are sufficient for the intended purpose. Subsequent freeze-thaw tests

showed that a durable mix can be developed, as shown in Figure 2. Key to

the development of a mix that would provide sufficient strength, adequate

permeability, and freeze-thaw resistance was the addition of a small

amount of sand, about 5% to 7%, that increased the bonding of the paste

to the aggregates. The laboratory studies also raised the issue of

compaction energy on the results. The difference between the compaction

energies related to the amplitude of the vibrating pan, while the frequency

was constant. Figure 3 shows the results of comparisons of two

compaction energies used in the laboratory, and it can be seen that higher

compaction energy results in stronger mixes at given void ratios. These

results point to the importance of proper compaction in the field.A number

of field sites have also been investigated and the results are reported in

the master’s thesis by Kevern (2006). Samples from a Sioux City, Iowa site

showed more uniform compaction in the top six inches, with low

compaction causing high voids and low strength in the bottom layer. A mix

proposed for a site in North Liberty, Iowa showed that limestone mixes

with unit weight less than 125 pcf (pounds per cubic foot) can be freeze-

thaw resistant.

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CHAPTER 4

PROPERTIES

The plastic pervious concrete mixture is stiff compared to traditional

concrete. Slumps, when measured, are generally less than 3/4 inches

(20mm), although slumps as high as 2 inches (50mm) have been used.

However, slump of pervious concrete has no correlation with its

workability and hence should not be specified as an acceptance criterion.

Typical densities and void contents are on the order of 1600 kg/m3 to 2000

kg/m3 and 20 to 25% respectively.

The infiltration rate (permeability) of pervious concrete will vary with

aggregate size and density of the mixture, but will fall into the range of 2

to 18 gallons per minute per square foot (80 to 720 liters per minute per

square meter). A moderate porosity pervious concrete pavement system

will typically have a permeability of 3.5 gallons per minute per square foot

(143 liters per minute per square meter). Converting the units to in./hr

(mm/hr) yields 336 in./hr (8534 mm/hr). Perhaps nowhere in the world

would one see such a heavy rainfall. In contrast the steady state

infiltration rate of soil ranges from 1 in./hr (25 mm/hr) and 0.01 in./hr

(.25 mm/hr). This clearly suggests that unless the pervious concrete is

severely clogged up due to possibly poor maintenance it is unlikely that

the permeability of pervious concrete is the controlling factor in estimating

runoff (if any) from a pervious concrete pavement. For a given rainfall

intensity the amount of runoff from a pervious concrete pavement system

is controlled by the soil infiltration rate and the amount of water storage

available in the pervious concrete and aggregate base (if any) under the

pervious concrete. Generally for a given mixture proportion strength and

permeability of pervious concrete are a function of the concrete density.

Greater the amount of consolidation higher the strength, and lower the

permeability. Since it is not possible to duplicate the in-place consolidation

levels in a pervious concrete pavement one has to be cautious in

interpreting the properties of pervious concrete specimens prepared in the

laboratory. Such specimens may be adequate for quality assurance

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namely to ensure that the supplied concrete meets specifications. Core

testing is recommended for knowing the in-place properties of the pervious

concrete pavement. The relationship between the w/cm and compressive

strength of conventional concrete is not significant. A high w/cm can

result in the paste flowing from the aggregate and filling the void structure.

A low w/cm can result in reduced adhesion between aggregate particles

and placement problems. Flexural strength in pervious concretes generally

ranges between about 150 psi (1 MPa) and 550 psi (3.8 MPa). Limited

testing in freezing-and-thawing conditions indicates poor durability if the

entire void structure is filled with water. Numerous successful projects

have been successfully executed and have lasted several winters in harsh

Northern climates such as IN, IL, PA etc. This is possibly because pervious

concrete is unlikely to remain saturated in the field. The freeze thaw

resistance of pervious concrete can be enhanced by the following measures

1. Use of fine aggregates to increase strength and slightly reduce voids

content to about 20%.

2. Use of air-entrainment of the paste.

3. Use of a 6 to 18 in. aggregate base particularly in areas of deep frost

depths.

4. Use of a perforated PVC pipe in the aggregate base to capture all the

water and let it drain away below the pavement. Abrasion and raveling

could be a problem. Good curing practices and appropriate w/cm (not too

low) is important to reduce raveling. Where as severe raveling is

unacceptable some loose stones on a finished pavement is always

expected. Use of snow ploughs could increase raveling. A plastic or rubber

shield at the base of the plow blade may help to prevent damage to the

pavement.

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CHAPTER 5

DESIGN CRITERIA

Pervious concrete should be designed and sited to intercept, contain, filter,

and infiltrate storm water on site. Several design possibilities can achieve

these objectives. For example, pervious concrete can be installed across

an entire street width or an entire parking area. The pavement can also be

installed in combination with impermeable pavements or roofs to infiltrate

runoff. Several applications use pervious concrete in parking lot lanes or

parking stalls to treat runoff from adjacent impermeable pavements and

roofs. This design economizes pervious concrete installation costs while

providing sufficient treatment area for the runoff generated from

impervious surfaces. Inlets can be placed in the pervious concrete to

accommodate overflows from extreme storms. The storm water volume to

be captured, stored, infiltrated, or harvested determines the scale of

permeable pavement .

Pervious concrete comprises the surface layer of the permeable pavement

structure and consists of Portland cement, open-graded coarse aggregate

(typically 5/8 to 3/8 inch), and water. Admixtures can be added to the

concrete mixture to enhance strength, increase setting time, or add other

properties. The thickness of pervious concrete ranges from 4 to 8 inches

depending on the expected traffic loads.

Choke course - This permeable layer is typically 1 - 2 inches thick and

provides a level bed for the pervious concrete. It consists of small-sized,

open-graded aggregate.

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Open-graded base reservoir - This aggregate layer is immediately beneath

the choke layer. The base is typically 3 - 4 inches thick and consists of

crushed stones typically 3/4 to 3/16 inch. Besides storing water, this high

infiltration rate layer provides a transition between the bedding and sub

base layers.

Open-graded sub base reservoir - The stone sizes are larger than the base,

typically 2½ to ¾ inch stone. Like the base layer, water is stored in the

spaces among the stones. The sub base layer thickness depends on water

storage requirements and traffic loads. A sub base layer may not be

required in pedestrian or residential driveway applications. In such

instances, the base layer is increased to provide water storage and

support.

Under drain (optional) - In instances where pervious concrete is installed

over low-infiltration rate soils, an under drain facilitates water removal

from the base and sub base. The under drain is perforated pipe that ties

into an outlet structure. Supplemental storage can be achieved by using a

system of pipes in the aggregate layers. The pipes are typically perforated

and provide additional storage volume beyond the stone base.

Geotextile (optional) - This can be used to separate the sub base from the

sub grade and prevent the migration of soil into the aggregate sub base or

base.

Sub grade - The layer of soil immediately beneath the aggregate base or

sub base. The infiltration capacity of the sub grade determines how much

water can exhilarate from the aggregate into the surrounding soils. The

sub grade soil is generally not compacted.

Properly installed pervious concrete requires trained and experienced

producers and construction contractors. The installation of pervious

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concrete differs from conventional concrete in several ways. The pervious

concrete mix has low water content and will therefore harden rapidly.

Pervious concrete needs to be poured within one hour of mixing. The pour

time can be extended with the use of admixtures. A manual or mechanical

screed set ½ inch above the finished height can be used to level the

concrete. Floating and troweling are not used, as those may close the

surface pores. Consolidation of the concrete, typically with a steel roller,

is recommended within 15 minutes of placement (Figure 6). Pervious

concrete also requires a longer time to cure. The concrete should be

covered with plastic within 20 minutes of setting and allowed to cure for a

minimum of 7 days

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CHAPTER 6

SPECIFIC DESIGN CONSIDERATIONS AND LIMITATIONS

The load-bearing and infiltration capacities of the sub grade soil, the

infiltration capacity of the pervious concrete, and the storage capacity of

the stone base/sub base are the key storm water design parameters. To

compensate for the lower structural support capacity of clay soils,

additional sub base depth is often required. The increased depth also

provides additional storage volume to compensate for the lower infiltration

rate of the clay sub grade. Under drains are often used when permeable

pavements are installed over clay. In addition, an impermeable liner may

be installed between the sub base and the sub grade to limit water

infiltration when clay soils have a high shrink-swell potential, or if there is

a high depth to bedrock or water table (Hunt and Collins, 2008).

Measures should be taken to protect permeable pavement from high

sediment loads, particularly fine sediment. Appropriate pretreatment

BMPs for run-on to permeable pavement include filter strips and swales.

Preventing sediment from entering the base of permeable pavement during

construction is critical. Runoff from disturbed areas should be diverted

away from the permeable pavement until they are stabilized.

Several factors may limit permeable pavement use. Pervious concrete has

reduced strength compared to conventional concrete and will not be

appropriate for applications with high volumes and extreme loads. It is not

appropriate for storm water hotspots where hazardous materials are

loaded, unloaded, stored, or where there is a potential for spills and fuel

leakage. For slopes greater than 2 percent, terracing of the soil sub grade

base may likely be needed to slow runoff from flowing through the

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pavement structure. In another approach for using pervious concrete

slopes, lined trenches with under drains can be dug across slope to

intercept flow through the sub base

Consistent porosity through the concrete structure is critical to prevent

freeze-thaw damage. Cement paste and smaller aggregate can settle to the

bottom of the structure during consolidation and seal off the concrete

pores. If surface water becomes trapped in pavement voids, then it can

freeze, expand, and break apart the pavement. An evaluation of four (4)

pervious concrete sites (3 with deterioration and 1 without) in Denver, CO

by the Urban Drainage and Flood Control District, found that the larger

aggregate size mix exhibited better permeability and less surface

deterioration . The National Ready Mixed Concrete Association also

recommends the following precautions to prevent pervious concrete from

becoming saturated in regions where hard wet freezes occur.

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CHAPTER 7

CONSTRUCTION

An experienced installer is vital to the success of pervious concrete

pavements. As with any concrete pavement, proper subgrade preparation

is important. The subgrade should be properly compacted to provide a

uniform and stable surface. When pervious pavement is placed directly on

sandy or gravelly soils it is recommended to compact the subgrade to 92

to 95% of the maximum density (ASTM D 1557). With silty or clayey soils,

the level of compaction will depend on the specifics of the pavement design

and a layer of open graded stone may have to be placed over the soil.

Engineering fabrics are often used to separate fine grained soils from the

stone layer. Care must be taken not to over compact soil with swelling

potential. The subgrade should be moistened prior to concrete placement

to prevent the pervious concrete from setting and drying too quickly. Also

wheel ruts from construction traffic should be raked and re-compacted.

This material is sensitive to changes in water content, so field adjustment

of the fresh mixture is usually necessary. The correct quantity of water in

the concrete is critical. Too much water will cause segregation, and too

little water will lead to balling in the mixer and very slow mixer unloading.

Too low a water content can also hinder adequate curing of the concrete

and lead to a premature raveling surface failure. A properly proportioned

mixture gives the mixture a wet-metallic appearance or sheen. Pervious

concrete has little excess water in the mixture. Any time the fresh material

is allowed to sit exposed to the elements is time that it is losing water

needed for curing. Drying of the cement paste can lead to a raveling failure

of the pavement surface. All placement operations and equipment should

be designed and selected with this in mind and scheduled for rapid

placement and immediate curing of the pavement. A pervious concrete

pavement may be placed with either fixed forms or slip-form paver. The

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most common approach to placing pervious concrete is in forms on grade

that have a riser strip on the top of each form such that the strike off device

is actually 3/8-1/2 in. (9 to 12 mm) above final pavement elevation. Strike

off may be by vibratory or manual screeds. After striking off the concrete,

the riser strips are removed and the concrete compacted by a manually

operated roller that bridges the forms. Rolling consolidates the fresh

concrete to provide strong bond between the paste and aggregate, and

creates a smoother riding surface. Excessive pressure when rolling should

be avoided as it may cause the voids to collapse. Rolling should be

performed immediately after strike off. Since floating and trowelling tend

to close up the top surface of the voids they are not carried out. Jointing

pervious concrete pavement follows the same rules as for concrete slabs

on grade, with a few exceptions. With significantly less water in the fresh

concrete, shrinkage of the hardened material is reduced significantly,

thus, joint spacings may be wider. The rules of jointing geometry, however,

remain the same. Joints in pervious concrete are tooled with a rolling

jointing tool. This allows joints to be cut in a short time, and allows curing

to continue uninterrupted. Saw cutting joints also is possible, but is not

preferred because slurry from sawing operations may block some of the

voids, and excessive raveling of the joints often results. Removing covers

to allow sawing also slows curing, and it is recommended that the surfaces

be re-wet before the covering is replaced. Some pervious concrete

pavements are not jointed, as random cracking is not viewed as a

significant deficit in the aesthetic of the pavement (considering its texture),

and has no significant affect on the structural integrity of the pavement.

Proper curing is essential to the structural integrity of a pervious concrete

pavement. The open structure and relatively rough surface of pervious

concrete exposes more surface area of the cement paste to evaporation,

making curing even more essential than in conventional concreting.

Curing ensures sufficient hydration of the cement paste to provide the

necessary strength in the pavement section to prevent raveling. Curing

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should begin within 20 minutes after final consolidation and continue

through 7 days. Plastic sheeting is typically used to cure pervious concrete

pavements

Figure: showing laying of pervious concrete pavement and rolling

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Figure: showing rolling and finishing of pervious concrete surface.

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CHAPTER 8

MAINTENANCE

The most prevalent maintenance concern is the potential clogging of the

pervious concrete pores. Fine particles that can clog the pores are

deposited on the surface from vehicles, the atmosphere, and runoff from

adjacent land surfaces. Clogging will increase with age and use. While

more particles become entrained in the pavement surface, it does not

become impermeable. Studies of the long-term surface permeability of

pervious concrete and other permeable pavements have found high

infiltration rates initially, followed by a decrease, and then leveling off with

time (Bean, et al., 2007a). With initial infiltration rates of hundreds of

inches per hour, the long-term infiltration capacity remains high even with

clogging. When clogged, surface infiltration rates usually well exceed 1

inch per hour, which is sufficient in most circumstances for the surface to

effectively manage intense storm water events (ICPI, 2000). A study of

eleven (11) pervious concrete sites found infiltration rates ranging from 5

in/hr to 1,574 in/hr. The sites taking runoff from poorly maintained or

disturbed soil areas had the lowest infiltration rates, but they were still

high relative to rainfall intensities (Bean, et al., 2007a). Permeability can

be increased with vacuum sweeping. In areas where extreme clogging has

occurred, half inch holes can be drilled through the pavement surface

every few feet or so to allow storm water to drain to the aggregate base.

Many large cuts and patches in the pavement will weaken the concrete

structure. Freeze/thaw cycling is a major cause of pavement breakdown,

especially for parking lots in northern climates. Properly constructed

permeable concrete can last 20 to 40 years because of its ability to handle

temperature impacts.

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In cold climates, sand should not be applied for snow or ice conditions.

However, snow plowing can proceed as with other pavements and salt can

be used in moderation. Pervious concrete has been found to work well in

cold climates as the rapid drainage of the surface reduces the occurrence

of freezing puddles and black ice. Melting snow and ice infiltrates directly

into the pavement facilitating faster melting (Gunderson, 2008).

Cold weather and frost penetration do not negatively impact surface

infiltration rates. Permeable concrete freezes as a porous medium rather

than a solid block because permeable pavement systems are designed to

be well-drained; infiltration capacity is preserved because of the open void

spaces (Gunderson, 2008). However, plowed snow piles should not be left

to melt over the pervious concrete as they can receive high sediment

concentrations that can clog them more quickly.

Permeable pavements do not treat chlorides from road salts but also

require less applied deicers. Deicing treatments are a significant expense

and chlorides in storm water runoff have substantial environmental

impacts. Reducing chloride concentrations in runoff is only achieved

through reduced application of road salts because removal of chloride with

storm water BMPs is not effective. Road salt application can be reduced

up to 75% with the use of permeable pavements.

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CHAPTER 9

COST

Several factors influence the overall cost of pervious concrete:

1. Material availability and transport - The ease of obtaining

construction materials and the time and distance for delivery.

2. Site conditions - Accessibility by construction equipment, slope, and

existing buildings and uses.

3. Subgrade - Subgrade soils such as clay may result in additional base

material needed for structural support or added storm water storage

volume.

4. Storm water management requirements - The level of control

required for the volume, rate, or quality of storm water discharges will

impact the volume of treatment needed.

5. Project size - Larger pervious concrete areas tend to have lower per

square foot costs due to construction efficiencies.

Costs vary with site activities and access, pervious concrete depth,

drainage, curbing and under drains (if used), labor rates, contractor

expertise, and competition. The cost of the pervious concrete material

ranges from 100 rupees to 350 rupees per square foot. The material cost

of pervious concrete can drop significantly once a market has opened and

producers have made initial capacity investments. Eliminating or reducing

the use of admixtures, which are a significant cost in construction, can

also lower installation costs.

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CHAPTER 10

EXPERIMENTAL VALUES

RESULTS OF EXPERIMENTS CONDUCTED ON MATERIALS

1.CEMENT (53 GRADE ULTRATECH CEMENT)

Specific gravity :3.02

Fineness of cement :3.15

Consistency :35%

Initial setting time :120min.

2.COARSE AGGREGATE

Specific gravity :3.00

Bulk density :1.50

3.FINE AGGREGATE

Specific gravity :2.63

Fineness modulus :2.5

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COMPRESSIVE STRENGTH

Compressive strength at 7 days for 6:1,8:1 and

10:1agg/cement ratio and agg.size of 20mm

Compressive strength at 7 days for 6:1,8:1 and

10:1agg/cement ratio and agg.size of 10mm

AGE W/C

RATIO

AGG/CEMENT

RATIO

LOAD

(TONNES)

COMPRESSIVE

STRENGTH(kg/sq.cm)

7 0.4 6:1 8 35.56

7 0.4 8:1 5 22.22

7 0.4 10:1 4 17.78

AGE W/C

RATIO

AGG/CEMENT

RATIO

LOAD

(TONNES)

COMPRESSIVE

STRENGTH(kg/sq.cm)

7 0.4 6:1 11 48.89

7 0.4 8:1 5 22.22

7 0.4 10:1 4 17.78

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PERMEABILITY

Permeability for 20mm aggregates for different w/c ratio

Permeability for 10mm aggregates for different w/c ratio

Agg/cement

ratio

W/C RATIO coefficient of

permeability(cm/sec*103)

6:1 0.4 3.2

8:1 0.4 3.5

10:1 0.4 3.65

Agg/cement

ratio

W/C RATIO coefficient of

permeability(cm/sec*103)

6:1 0.4 1.6

8:1 0.4 2.5

10:1 0.4 3.14

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CHAPTER 11

CONCLUSIONS AND RESULTS

RESULTS

Pervious concrete made from coarse aggregate size 10mm has

compressive strength of 48.89kg*cm-2 and 20mm aggregate has

35.56kg*cm-2

Pervious concrete made from coarse aggregate size 20mm had

compressive strength value of 74% compared to that of 10mm.

The aggregate/cement ratio of 10:1 produced pervious concrete of

higher co-efficient of permeability of 3.14x10-3cm/sec and 3.65x10-

3cm/sec for aggregate size 10mm and 20mm respectively.

CONCLUSIONS

The smaller the size of coarse aggregate should be able to produce a

higher compressive strength and at the same time produce a higher

permeability rate.

The mixtures with higher aggregate/cement ratio 8:1 and 10:1 are

considered to be useful for a pavement that requires low

compressive strength and high permeability rate.

Finally, further study should be conducted on the pervious concrete

pavement produced with these material proportions to meet the

condition of increased abrasion and compressive stresses due to

high vehicular loading and traffic volumes.

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CHAPTER 12

PERVIOUS CONCRETE IN INDIA

Pervious concrete can be used and it is being implemented in some

metropolitan cities in parking lots, drive ways, gullies, sidewalks, road

platforms etc. The roads around the apartments and the surfacing inside

the compound can be made with pervious concrete. Another significant

advantage in India is low cost of labour compared to western countries,

much of the pervious concrete is laid manually without using heavy

machinery, so this can be placed in lower costs even in rural areas.

In future with increased urbanization, diminishing ground water

levels and focus on sustainability technologies such as pervious concrete

are likely to become even more popular in India compared to other

countries.

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CHAPTER 13

REFERENCES

1. Pervious Pavement Manual, Florida Concrete and Products Association

Inc., Orlando, FL.

2. Obla, K., Recent Advances in Concrete Technology, Sep. 2007,

Washington DC3.

3. Pervious concrete, The Indian Concrete Journal, August 2010.

4. Ghafoori, N., and Dutta, S., “Building and Nonpavement Applications of

No-Fines Concrete,”

Journal of Materials in Civil Engineering, Volume 7, Number 4, November

1995.

5. National Ready Mixed Concrete Association (NRMCA), Freeze Thaw

Resistance of Pervious

Concrete, Silver Spring, MD, May 2004, 17 pp.

6. NRMCA, “What, Why, and How? Pervious Concrete,” Concrete in

Practice series, CIP 38,

Silver Spring, Maryland, May 2004b, 2 pages.

7. Tennis, P.Leming. M.L., and Akers, D.J., “Pervious Concrete

Pavements,” EB 302, Portland

Cement Association (PCA), Skokie, Illinois, 2004, 25 pp.

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8. Leming, M.L., Rooney, M.H., and Tennis, P.D., “Hydrologic Design of

Pervious Concrete,” PCA R&D.

9. Pervious Concrete: Hydrological Design and Resources, CD063, CD-

ROM, PCA, Skokie.

10. Storm water Phase II Final Rule Fact Sheet Series, United States

Environmental Protection

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