Complete Project Reportd

8/16/2019 Complete Project Reportd

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ABSTRACT

Pervious concrete is a special type of concrete with high

porosity used for concrete at work applications that allow

water from precipitation and other sources to pass directl

through, thereby reducing the ru noff from a site and allowing

ground water r echarge. This porosity is attained by a highlyinterconnected void content. Typically pervious concrete has

little or n o ne aggregate and has j ust enough cementing paste

to coat t he coarse aggregate particles while preserving the

interconnectivity o f 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 et c.

Pervious concrete is an important application for thesustainable construction and is one of many low impact

development techniques used by builders to protect water

quality.


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CONTENTS

1. INTRODUCTION 03

2. MATERIALS USED 07

3. LITERATURE REVIEW 23

4. OBJECTIVE OF THE PROJECT 30

5. PROPERTIES 31

6. DESIGN CRITERIA 34

7. SPECIFIC DESIGN CONSIDERATIONS AND LIMITATIONS 37

. CONSTRUCTION 3!

!. MAINTENANCE 47

10. COST 50

11. E"PERIMENTAL VALUES 51

12. CONCLUSIONS AND RESULTS 54


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13. PERVIOUS CONCRETE IN INDIA 56

14. REFERENCES 57

1. INTRODUCTION

Pervious concrete which is also known as the no-nes,

porous, gap-graded, and permeable concrete and enhance

porosity concrete has been found to be a reliable storm water

management tool . B y denition, pervious concrete is a

mixture of gravel or granite stone, cement, water, little to no

sand (ne aggregate) with or without admixtures. When

pervious concrete is used for p aving (Figure 1), the open cell

structures allow storm water to lter through the pavement

and into the underlying soils. In other words, pervious

concrete helps in protecting the surface of the pavement and

its en vironment.

As stated above, pervious concrete has the same basicconstituents a s co nventional concrete t hat 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 o f 3-5 gallons (0.014 - 0.023m3) of water per

minute through its op en cells for each square foot (0.0929m2)


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of surface area which is far greater than most rain

occurrences. Apart from being used to eliminate or r educe the

need for expensive retention ponds, developers and otherprivate companies are a lso using it to free up valuable real

estate for d evelopment, while st ill providing a paved park.

Pervious concrete is also a unique and effective means to

address important environmental issues and sustainable

growth. When it rains, pervious co ncrete a utomatically acts a s

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 o n heavily travelled roadways . Carefully

controlled amount of water an d cementitious materials are

used to create a paste . The paste then forms a thick coating

around aggregate particles, to prevent the owing off of the

paste during mixing and placing. Using enough paste to coat

the particles m aintain 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

to1900kg/m3). Pervious concrete void structure provides


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pollutant captures which also add signicant structural

strength as well. It also results in a very high permeable

concrete t hat drains q uickly.

Pervious con crete ca n be u sed in a wide range of applications,

although its primary use is in pavements which are in:

residential roads, alleys a nd driveways, low volume p avements,

low water crossings, sidewalks and pathways, parking areas,

tennis courts, sl ope stabilisation, su b-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, rep elling salt water intrusion, co ntrol p ollution in

water seepage to ground water recharge thus, preventing

subterranean storm water sewer drains, absorbs less heat

than regular concrete and asphalt, reduces t he need for air

conditioning. Pervious concrete allows for increased site

optimization because i n most cases, its use s hould totally limit

the need for detention and retention ponds, swales a nd othermore traditional storm water management devices that are

otherwise required for compliances with the Federal storm

water regulations on commercial sites of one acre or

using pervious concrete, the ambient air temperature will be

reduced, requiring less p ower t o cool the building. In addition,


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costly storm water structures su ch as p iping, inlets a nd ponds

will be eliminated. Construction scheduling will also be

improved as the stone recharge bed will be installed at t he 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 com pressive strength,

greater p ermeability, and a lower u nit weight (approximately

70% of conventional con crete). Nevertheless, it h as 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 n eed to be investigated.


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Figure 1:

Polish surface of a pervious con crete pavement


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Figure 2:


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2.MATERIALS USED

2.1 Constituents of concrete

If a concrete is to be suitable for a particular p urpose, it is

necessary to select the constituent m aterials and combine

them in such a manner as to develop the special qualitiesrequired as ec onomical as p ossible. The sel ection of materials

and choice of method of construction is n ot easy, since many

variables affect the quality of the concre

quality and economy must be considered.

The characteristics of concrete should be eval

to the required quality for an y given construction purpose. The

closest p racticable 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.


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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 theprincipal constituents, after t he intended purpose, after t he

object t o 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 u sed for b uilding in Britain. The term cement is d erived

from the Latin word Caementum, which is meant

stonechippings such as u sed in Roman mortar not-the bindingmaterial itself. Cement, in the general sense of the word,

described as a material with adhesive an d cohesive properties,

which make it capable of bonding mineral fragments in to a

compact whole. The rst step of reintroduction of cement after

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


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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 theRomans. Further investigations by J. Parker in the same

decade led to the com mercial production of natural hydraulic

cement


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Chemical compounds of Portland cement

The raw material used in the manufactures of Portland cementcomprises 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 aluminate3CaO.Al2 O3 C3A

Tetracalcium

4CaO.Al2O3.F

e2O

Aluminoferrite 3 C4AF


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These compounds interact with one another in the kiln

a series of more complex products. Portland cement is vari ed

in type by changing the relative proportions of its four

predominant chemical compounds and by the degree of

neness of the clinker grinding. A small variation in the

composition or p roportion of its raw materials leads t o a large

variation in compound composition Calculation of the

potential composition of Portland cement is gen erally based onthe 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 morethan a few percent of the m ass of the cem ent.

Two of the minor compounds are of particular interestoxides of sodium and potassium, K2O and Na2O,known as the

alkalis.

They have been found to react with some aggregates, the

products o f the r eaction causing disintegration of the co ncrete

and have a lso o bserved to affect the r ate of gain of strength of

cement .Present knowledge of cement chemistry indicates t hat

the major cement compounds h ave the following properties.

• Tricalcium Silicate, C3S hardens rapidly and is largely

responsible for initial set and early strength development. The


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early st rength of

Portland cement concrete is higher with increased

percentages of C3S.

• Dicalcium Silicate, C2S hardens slowly and contributes

largely to st rength increase a t ages b eyond one week.

• Tricalcium aluminate, C3A liberates a large amount of

heat d uring the rst 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 h igh as 10.0%, and sometimes

greater, has shown satisfactory durability, provided the

permeability of the c oncrete i s l ow.

• Tetracalcium aluminoferrite, C4AF reduces the

clinkering temperature. It will act as a ux in burning the

clinker. It hydrates rather ra pidly 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 h eat, then follows


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tetracalcium aluminoferrite, with dicalcium silicate

developing the l east heat of all.


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2.1.2.2 Classication of aggregates

The alternative used in the manufacture of good qualconcrete, is t o obtain the a ggregate in at least two s ize g roups,i.e.:

1)ne aggregate often called sa nd not larger than 5mm in size.

2)course aggregate, which comprises m aterial at least 5mm insize.

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 inuence on the quality of the concrete,either in fresh or i n the h ardened state.

It has been found that aggregate may appear to be

unsatisfactory on some count but no trouble need be

experienced when it is u sed in concrete

2.1.2.3 Aggregate p roperties

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


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requirements. Important properties of an aggregate which

affect the performance of a concrete a re d iscussed 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 eld can vary widely from case to case.

Nevertheless, a practitioner ca n obtain reliable resu lts b earing

in mind that t he 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 sa mple obtained is va riable or se gregated, a large n umber

of increments sh ould be taken and a larger sample should be

dispatched for t esting.

2.1.2.3.2 Particle shape and texture

Roundness m easures t he relative sharpness or angularity of

the ed ges a ndcorners of a p article. Roundness i s con trolled

largely by the st rength and abrasion resistance o f the p arent


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rock and by the am ount of wear to which the particle has b een

subjected. In the ca se o f crushed aggregate, the p article sh ape

depends n ot only on the nature of the parent rock but also onthe t ype o f crusher a nd its red uction ratio, i.e. the ra tio of the

size of material fed into the cru sher t o the si ze o f the nished

product. Particles w ith a high ratio of surface a rea to volume

are a lso of particular i nterest for a given workability of the

control mix.

Elongated and aky particles are departed from equi-

dimensional shape of particles a nd have a larger surface a rea

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 akiness a nd elongation tests a re 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 gen erally u ndesirable, but no recognized limits a re

laid down .Surface texture of the aggregate affects its b ond to

the cement paste and also inuences the water demand of the

mix, especially in the case of ne aggregate. The shape and

surface texture of aggregate inuence considerably the


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strength of concrete. The effects of shape and texture are

particularly s ignicant in the ca se o f high strength concrete.

The full role of shape and texture of aggregate in the

development of concrete st rength is n ot known, but possibly a

rougher t exture resu lts in a larger ad hesive force b etween the

particles and the cement matrix. Likewise, the larger su rface

area of angular a ggregate means that a larger ad hesive force

can be developed.

The shape and texture of ne aggregate have a signicant

effect on the water requirement of the mix made with the givenaggregate. If these properties of ne aggregate are expressed

indirectly by it’s p acking, i.e. by the p ercentage voids i n a loose

condition, then the inuence on the water requirement is qu ite

denite. The inuence of the voids in coarse aggregateis less

denite. Flakiness and shape of coarse aggregates have an

appreciable eff ect on the w orkability of concrete.

2.1.2.3.3 Bond of aggregate

Bond between aggregate and cement paste is an important

factor i n the st rength of concrete, but the n ature o f bond is n ot


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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 ofcrushed particles, results in a better bo nd due to mechanical

interlocking; better b ond is not u sually obtained with softer,

porous, and minor logically heterogeneous particles. Bond is

affected by the physical and chemical properties of aggregate.

For good development of b ond, it is necessary that the

aggregate surface be clean and free from adhering clay

particles . The d etermination of the quality of bond of aggregate

is d ifficult and no accepted tests exi st. Generally, when bond is

good, a cru shed specimen of normal strength concrete should

contain some aggregate particles broken right through, in

addition to the more numerous ones pulled out from theirsockets. An excess of fractured particles, might su ggest t hat

the a ggregate is t oo weak .

2.1.2.3.4 Strength of aggregate

The compressive strength of concrete cannot signicantly

exceed that of the m ajor p art of the a ggregate c ontained. If the

aggregate under t est leads to a lower com pressive st rength 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


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the nominal compressive strength of the concrete mix. Such

aggregate ca n be u sed only in a concrete of lower strength.

The inuence of aggregate on the strength of concrete is

only due to the m echanical strength of the aggregate but also,

to a considerable degree, to its absorption and bond

characteristics. In general, the strength of agg regate depends

on its co mposition, texture a nd structure. Thus a low strength

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

may be st rong but not well knit or cemented together.

A test to measure the compressive strength of prepared rock

cylinders u sed to be p rescribed. However, the results of such a

test are affected by the presence of planes of weakness in the

rock that may not be signicant once the rock has been

comminuted to the size used in concrete .In essence the

crushing st rength test measures t he quality of the p arent rock

rather t han the quality of the aggregate as used in concrete.

For t his reaso n the test is rar ely u sed. Crushing value test BS812: part 105:1990, measures t he 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


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this crushing value and the compressive strength, but the

results o f the t wo tests a re u sually 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 a nd weak or u nsound particles.

2.1.2.3.6 Grading of ne and coarse aggregate

The actual grading requirements depend on the shape and

surface characteristics of the particles. For instance, sh arp

angular p articles with rough surfaces sh ould have a slightly

ner grad ing in order t o reduce the possibility of interlocking

and to compensate for t he h igh friction between the particles

2.1.2.3.6.1 Maximum aggregate sizeExtending the grading of aggregate to a larger maximum size


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lowers the water requirement of t he mix, so that, for a

specied workability and 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 t hat volume ch anges i n the p aste ca use l arger stresses

at interfaces) an d of discontinuities introduced by the very

large particles. I n structural concrete of u sual proportions,

there is n o advantage in using aggregate with a maximum size

greater than about 25 or 40mm when compressive strength is

a criterion.

2 . 2.1.4 Water Water is a key ingredient in the manufacture of concrete.

Water used in concrete mixes has two functions: the rs

react chemically with the cement, which will nally set and

harden, an d the second function is to lubricate all other

materials a nd make the concrete workable . Although it is a n

important ingredient of con crete, it h as 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,


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

adequately cured”.

FIGURES OFMATERIAL USED

1.CEMENT BAG2.CEMENT POWDER


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3. 10MM COARSE AGGREGATE

4. 20MM COARSE AGGREGATE


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5. TROWEL

6. TAMPING ROD


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7. IRON MOULD

8. WEIGHING MACHINE

9. SEIVES O DI ERENT SI!ES

3. LITERATURE

REVIEWPortland cement pervious con crete (PCPC) has great potential

to reduce roadway noise, improve splash and spray, and

improve friction as a surface wearing course. A pervious


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concrete mix design for a surface wearing course must meet

the criteria of ad equate strength and durability under si te-

specic loading and environmental conditions. To date, twokey issues t hat h ave impeded the use of pervious concrete in

the United States a re that strengths o f pervious co ncrete h ave

been lower than necessary for required applications and the

freeze-thaw durability of pervious co ncrete h as b een suspect.

A research project on the freeze-thaw durability of

concrete mix designs at Iowa State University (ISU) has

recently been completed . The results of this st udy have sh own

that a strong, durable pervious concrete mix design that w ill

withstand wet, hard- freeze environments is possible. The

strength is ach ieved through the use of a small amount of neaggregate (i.e., concrete sand) and/or latex admixture to

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

preliminary resu lts were rep orted in Kevern et al. (2005). The

recent work has b een 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 h as direct bearing on the construction technique

used to place t he materials in the eld. Additional laboratory

and eld testing is n ecessary t o est ablish minimum mix design


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properties a nd determine optimum construction techniques.A

recent study at Purdue University (Olek et al. 2003) has sh own

that p ervious concrete (termed enhanced porosity concrete inthe Purdue University study) can reduce tire-pavement

interaction noise. Tests co nducted 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 ab ove 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 beenconstructed in Europe, and pervious concrete has b een 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 p avements a s friction courses i s d eclining, 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


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the use of pervious concrete was not given enough time to

develop into a viable p aving a lternative.

The American experience with pervious concrete is limited.

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 eld installations is n eeded to

determine the possibilities for t he use of pervious concrete in

highway a pplications.

The National Concrete Pavement Technology Center (National

CP Tech Center) at ISU developed a research project titled “An

Integrated Study of 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 con crete mix designs having adequate

strength and durability for wearing course pavements andhaving surface characteristics t hat r educe n oise a nd enhance

skid resistance w hile p roviding adequate removal of water from

the pavement surface and structure. A range of mix designs

was used necessary to meet requirements for wearing course


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applications. Further, constructability issues for wearing

course sect ions were a ddressed to ensure t hat competitive an d

economical placement of the pervious con crete can be done in

the eld. Hence, during the eva luation phases, both laboratory

and eld 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 cri ticalnoise, splash/spray, skid resistance, and environmental

concerns. The comprehensive study is anticipated to be

conducted over a ve-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 d esign,construction, maintenance, and environmental issues for

PCPC.

The primary goal of the research conducted was to develop


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pervious con crete that would provide freeze- thaw resistance

while maintaining adequate strength and permeability fo

pavement applications. The com plete report is ava ilable on theInstitute for Transportation (InTrans) and National CP Tech

Center website a t

http://www.intrans.iastate.edu/reports/mix_design_pervi

ous.pdf .

The key ndings from the literature reviw summarized as follows:

The engineering properties reported in the l

United States i ndicate a high void ratio, low strength, and

limited freeze -thaw test results. It is b elieved that thesereasons h ave h indered the u se of pervious con crete in the

hard wet freeze r egions (i.e., Midwest and Northeast United

States). The t ypical mix design of pervious co ncrete u sed in

the United States co nsists o f 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.

The28-day compressive strength of pervious concrete ranges

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


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from 800 psi(pound per square i nch) 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 ad vantages ofpervious con crete include improving sk id resistance by

removing water that creates splash and spray during

precipitation events, reducing n oise, minimizing h eat islands

in large ci ties, preserving n ative eco systems, and minimizing

cost in some cases .

Surface coar se 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 u sed 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 w as tested and both

limestone aggregates and river run gravels were used. The


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effects o f the a ddition of sand, latex, and/or si lica fume on the

resulting behavior were investigated. The key parameters

investigated were strength, permeability, and freeze-thaw

resistance. The overall results ca n be su mmarized in Figure 1,

where it can be seen that an interdependent relationship

exists b etween the void ratio, seven-day compressive st rength,

and permeability of the pervious concrete. In Figure 1 it can

be seen that as the void ratio ic but the permeability increases. Shown in the gure i

range of void ratio between 15% and 19% in which the

strength and permeability are sufficient for the intended

purpose. Subsequent freeze-thaw tests sh owed 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 com paction energiesrelated 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 m ixes at given void ratios. These results


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point to the importance of proper compaction in the eld.A

number of el d 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 cu bic foot) can be freeze-thaw resistant.

4.OBJECTIVE OF


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THE PROJECT

• To know about size of coarse aggregate should be able to

produce a higher compressive strength and at the same time

produce a higher permeability rat e.

• To know about mixtures with aggregate/cement ratio

are con sidered to be useful for a pavement that r equires low

compressive st rength and high permeability rat e.

•

To study should material proportions to meet thecondition of increased abrasion and compressive stresses d ue

to h igh vehicular loading and traffic volumes.


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5. PROPERTIES

The plastic pervious concrete mixture is stiff compared to

traditional con crete. Slumps, when measured, ar e 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 sp ecied as an acceptance cr iterion.

Typical densities and void contents are on the order kg/m 3 to 2000 kg/m 3 an d 20 to 25% respectively.

The inltration rate (permeability) of pervious concr

vary with aggregate size and density of the mixture,

fall into the r ange of 2 to 18 gallons p er minute p er square foot

(80 to 720 liters per minute per square meter). A moderate

porosity pervious co ncrete pavement system will typically have

a p ermeability of 3.5 gallons p er minute per square foot

(143 liters p er minute per square m eter). Converting the u nits

to in./hr(mm/hr) yields 33 6 in./hr (8534 mm/hr). Perhaps

nowhere in the world would one see su ch a heavy rainfall. In

contrast the st eady st ate inltration rate o f soil ranges from 1


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in./hr (25 mm/hr) and 0.01 in./hr(.25 mm/hr). This clearly

suggests t hat unless t he p ervious co ncrete i s severel y clogged

up due to possibly poor maintenance it is u nlikely that thepermeability of pervious c oncrete i s t he c ontrolling factor i n

estimating ru noff (if any) from a pervious con crete pavement.

For a gi ven rainfall intensity the a mount of runoff from a

pervious con crete pavement system is con trolled by the soi l

inltration rate a nd the a mount of water s torage available in

the p ervious co ncrete a nd aggregate b ase (if any) under the

pervious co ncrete. Generally for a given mixture p roportion

strength and permeability of pervious con crete are a f unction

of the concrete density.

Greater t he amount of consolidation higher the st rength, and

lower t he p ermeability. Since it is n ot possible to duplicate t he

in-place consolidation levels in a pervious concrete pavement

one has to be cautious in interpreting the properties of

pervious co ncrete sp ecimens p repared in the laboratory. Such

specimens may be adequate for quality assurancenamely to

ensure that t he supplied concrete meets specications. Core

testing is re commended for k nowing the in-place properties of

the pervious con crete pavement. The relationship between the

w/cm and compressive strength of conventional concrete is o

signicant. A high w/cm can result in the paste owing from


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the aggregate and lling the void structure. A low w/cm can

result in reduced adhesion between aggregate particles and

placement problems. Flexural strength in pervious concretesgenerally ranges between about 150 psi (1 MPa) and 550 psi

(3.8 MPa). Limited testing in freezing-and-thawing conditions

indicates poor d urability if the entire void structure is lled

with water. Numerous successful projects have been

successfully exec uted 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 saturat

the eld. The freeze t haw resistance of pervious concrete can

be enhanced by the following measures

1.Use of ne aggregates t o increase st rength and slightly reduce voids content to about 20%.

2.Use of air-entrainment of the paste.

3.Use o f a 6 to 18 in. aggregate base p articularly 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 a nd appropriate w/cm (not too low) is important to


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reduce r aveling. Where as sever e raveling is u nacceptable som e

loose stones on a nished pavement is always expect ed. Use of

snow ploughs could increase raveling. A plastic or rubbershield at the base of the plow blade may help to prevent

damage to the pavement.


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6. DESIGN CRITERIAPervious concrete should be designed and sited to intercept,

contain, lter, and inltrate st orm 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 inltrate runoff. Several applications use pervious concrete

in parking lot lanes or parking stalls to treat ru noff from

adjacent impermeable pavements and roofs. This design

economizes pervious concrete installation costs while

providing sufficient treatment area for the runoff generated

from impervious su rfaces. Inlets ca n be placed in the pervious

concrete to accommodate overows from extreme storms. The

storm water volume to be captured, stored, inltrated, or

harvested determines t he scal e of permeable pavement .

Pervious con crete com prises t he su rface layer of the permeable

pavement structure and consists of Portland cement, open-

graded coarse a ggregate (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 p roperties. The


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thickness of pervious concrete ranges from 4 to 8 inches

depending on the expected traffic loads.

Choke course - T his 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.

Open-graded base reservoir - This aggregate layer is

immediately beneath the ch oke layer. The base is t ypically 3 -

4 inches t hick and consists of crushed stones t ypically 3/4 to

3/16 inch. Besides storing water, this high inltration rate

layer pr ovides a transition between the bedding and sub base

layers.

Open-graded sub base reservoir - Th e stone sizes are larger

than the base, typically 2½ to ¾ inch stone. Like the base

layer, water is st ored in the sp aces a mong the st ones. The su b

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 suchinstances, the base layer i s increased to provide water st orage

and support.

Under d rain (optional) - In instances w here pervious concrete

is installed over low-inltration rate soils, a n under drain


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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 asystem of pipes in the a ggregate layers. The p ipes a re t ypically

perforated and provide additional storage volume beyond the

stone b ase.

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

base from the sub grade and prevent the migration of sothe aggregate su b base or base.

Sub grade - The layer of soil immediately beneath the

aggregate base or su b base. The inltration capacity of the su b

grade determines how much water can exhilarate from the

aggregate into the surrounding soils. The sub grade soil isgenerally not compacted.

Properly installed pervious concrete requires trained and

experienced producers and construction contractors. The

installation of perviousconcrete 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 nished

height can be u sed to level the co ncrete. Floating a nd troweling


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are not used, as those may close the surface pores.

Consolidation of the concrete, t ypically 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 an d allowed to cure for a m inimum of 7 days


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7. SPECIFIC DESIGNCONSIDERATIONS

AND LIMITATIONS The load-bearing and inltration capacities of t

soil, the inltration capacity of the pervious concrete, and thestorage ca pacity of the stone base/sub base are t he key storm

water design parameters. To compensate for the lower

structural support cap acity of clay soils, additional sub base

depth is often required. The increased depth also provides

additional storage volume to compensate for the lower

inltration rate of the clay sub grade. Under d rains are often

used when permeable pavements are installed over clay. In

addition, an impermeable liner m ay be installed between the

sub base and the sub grade to limit water inltration when

clay soils have a high shrink-swell potential, or i f 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 ne sediment. Appropriate

pretreatment

BMPs for run-on to permeable pavement include lter strips


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and swales. Preventing sediment from entering the base of

permeable pavement during construction is critical. Runoff

from disturbed areas should be diverted away from thepermeable p avement until they a re st abilized.

Several factors may limit permeable pavement use. Pervious

concrete has reduced strength compared to conventional

concrete and will not be appropriate for a pplications with high

volumes and extreme loads. It is not appropriate for storm water hotspots where hazardous materials are loaded,

unloaded, stored, or w here there is a potential for spills and

fuel leakage. For sl opes g reater t han 2 percent, terracing of the

soil sub grade base m ay likely be needed to slow runoff from

owing through the pavement structure. In another approach

for u sing pervious concrete slopes, lined trenches w ith underdrains can be dug across slope to intercept ow through the

sub base

Consistent p orosity through the concrete structure is critical

to prevent freeze-thaw damage. Cement paste and smaller

aggregate can settle to the bottom of the structure duringconsolidation 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 co ncrete si tes (3 with deterioration and 1 without)

in Denver, CO by the Urban Drainage and Flood Control


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District, found that the larger aggregate size mix exhibited

better permeability and less surface deterioration . The

National Ready Mixed Concrete Association also recommendsthe following precautions to prevent pervious concrete from

becoming saturated in regions where hard wet freezes occur


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8. CONSTRUCTION

An experienced installer is vital to the succes

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 i t is r ecommended to compact the su bgrade to 92

to 95% of the m aximum density . With silty or clayey soi ls, the

level of compaction will depend on the specics of the

pavement design and a layer of open graded stone may have to

be placed over the soil. Engineering fabrics

separate ne grained soils from the stone layer. Care m ust be

taken not to over com pact soi l 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 ia

adjustment of t he fresh mixture is usually necessary. The

correct qu antity of water i n the concrete is critical. Too much

water will cause segregation, and too litt


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balling in the mixer and very slow mixer unloading

Too low a water content can also hinder adequate curig

concrete and lead to a premature raveling surface failure. A

properly proportioned mixture gives t he m ixture a wet-metallic

appearance o r sh een. Pervious concrete has l ittle excess water

in the mixture. Any time the fresh material is allowed to sit

exposed to the elements is t ime that i t is losing water n eeded

for cu ring. 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 ofthe pavement. A pervious concrete pavement may be placed

with either xed forms or slip-form paver. The most common

approach to placing pervious concrete is in forms on grade

that h ave a riser strip on the top of each form such that t he

strike off device is actually 3/8-1/2 in. (9 to 12 mm) above

nal pavement elevation. Strike off may be by vibratory or

manual screed s. After st riking off the co ncrete, the ri ser st rips

are removed and the concrete compacted by a manually

operated roller t hat bridges the forms. Rolling consolidates the

fresh concrete to provide strong bond between the paste and


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aggregate, and creates a smoother ri ding surface. Excessive

pressure when rolling should be avoided as it may cause the

voids to collapse. Rolling should be performed immediately

after st rike off. Since oating 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

signicantly less water i n the fresh concrete, shrinkage of thehardened material is red uced signicantly, thus, joint spacings

may be wider. The ru les of jointing geometry, however, remain

the sa me. Joints in pervious c oncrete a re tooled with a rolling

jointing tool. This allows joints

allows curing to continue uninterrupted. Saw cutting joints

also is possible, b ut is not p referred because slurry from

sawing operations m ay 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 n ot viewed as a s ignicant decit in the a esthetic of

the pavement (considering its texture), and has n o signicant

affect on the structural integrity of the pavement. Proper

curing is essential to the structural integrity of a pervious


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concrete pavement. The open structure and relatively rough

surface of pervious concrete exposes m ore su rface 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 should begin within 20 minutes after nal

consolidation and continue through 14 days. Plastic sheeting

is t ypically used to cu re pervious con crete pavements

PREPARATION O PERVIOUSCONCRETE AND MOULDING

1. T"#$ %$&$'( )' "**+,*+)"($ *+,*,+(),' (, "--+$-"($


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2. T"#$ %,"+ $ "--+$-"($ ,/ "**+,*+)"($ ) $ "'*+,*,+(),'

3 . M) %$&$'( "' "--+$-"($

4.A "($+ (, &) ,/ %$&$'( "--+$-"($


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5. M) ,/ %$&$'( "--+$-"($ "' "($+

6 .T"#$ " % $"' )+,' &, ,/ ) $15%& 15%& 15%&


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7. A** ,) ,' ( $ )' ) $ " ,/ &, , ( "( &, ", ',( ()%# )( &)

8. ) ( $ &, )( %,'%+$($ &)U )'- ("&*)'- +, , ( "( &, ) / : $

9. P ")' (,* +/"%$


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10. %,;$+ (,* /"%$ (, ";,) &,) ( +$ ,

11. O*$' &, "/($+ 24 +


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12. C +)'- ,/ %,'%+$($ /,+ 14 "

13.P$+;), %,'%+$($ < ,%# "/($+ 14 " ,/ % +)'-


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14. T$ ()'- ,/ %,&*+$ );$ (+$'-( ,/ *$+;),%,'%+$($

9. MAINTENANCE The most prevalent maintenance concern is the potential

clogging of the p ervious c oncrete p ores. Fine p articles t hat can

clog the pores a re deposited on the su rface from vehicles, the

atmosphere, and runoff from adjacent land surfaces. Clogging

will increase with age and use. While more particles become


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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 inltration rates initially, followed by a decrease, and then

leveling off with time . With initial inltration rates of

hundreds of inches per hour, the long-term inltration

capacity remains high even with clogging. When clogged,

surface inltration rates usually well exceed 1 inch per h our, 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 inltration

rates ranging from 5 in/hr to 1,574 in/hr. The sites taking

runoff from poorly maintained or disturbed soil areas h ad the

lowest inltration rates, b ut t hey were still h igh relative to

rainfall intensities . 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 t o 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 br eakdown, especially for parking lots in northern

climates. Properly constructed permeable concrete ca n last 20


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to 40 years because of its ability to handle temperature

impacts.

In cold climates, sand should not be applied for sn ow 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 a s the

rapid drainage of the surface reduces the occurrence of

freezing puddles a nd black ice. Melting sn ow and ice inltrates

directly into the pavement facilitating faster melting

(Gunderson, 2008).

Cold weather an d frost penetration do not negatively impact

surface inltration rates. P ermeable concrete freezes as a

porous medium rather than a solid block because permeable

pavement systems are d esigned to be well-drained; inltration

capacity is preserved because of the open void spaces(Gunderson, 2008). However, plowed snow piles sh ould not be

left to melt over the p ervious co ncrete a s t hey c an receive h igh

sediment concentrations that can clog them more quickly.

Permeable pavements do not treat chlorides from road salts


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but also require less applied deicers

signicant expense an d chlorides in storm water runoff have

substantial environmental impacts. Reducing chlorideconcentrations in runoff is only achieved through reduced

application of road salts because removal of chloride with

storm water BMPs is n ot effective. Road salt application can be

reduced up to 75% with the use of permeable pavements.


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10. COSTSeveral factors i nuence t he overall cost of pervious co ncrete:

1. Material availability and transport - The ease of obtaining

construction materials a nd the t ime a nd distance for d elivery.

2. Site conditions - Accessibility by con struction equipment,

slope, and existing b uildings a nd uses.

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

additional base material needed for structural su pport or

added storm water storage volume.

4. Storm water management requirements - The level of

control required for t he volume, rate, or qu ality 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 d ue to construction efficiencies.

Costs vary with site activities and access, pervious concrete

depth, drainage, curbing and under drains (if used), labor

rates, contractor ex pertise, and competition. The cost of the

pervious concrete material ranges from 100 rupees to 350

rupees p er squ are foot. The m aterial cost of pervious co ncrete

can drop signicantly once a market has opened and

producers have m ade initial capacity investments. Eliminating


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or r educing the u se of admixtures, which are a si gnicant cost

in construction, can also lower i nstallation costs.


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11.EXPERIMENTAL VALUES

RESULTS OF EXPERIMENTSCONDUCTED ON MATERIALS

1.CEMENT (53 GRADE ULTRATECH CEMENT)

• Specic gravity :3.02

• Fineness of cement :3.15

• Consistency :35%

• Initial setting time :120min .

2.COARSE AGGREGATE

• Specic gravity :3.00

• Bulk density :1.50

3.FINE AGGREGATE

• Specic gravity :2.63• Fineness modulus :2.5


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COMPRESSIVE STRENGTH

AGE W/C AGG/CEMENT LOAD COMPRESSIVE

RATIO RATIO (KN) STRENGTH(N/sq.mm)

7 0.4 6:1 76 3.377

7 0.4 8:1 40 1.777

7 0.4 10:1 35 1.555

Compressive strength at 14days for 6:1,8:1 and

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

AGE W/C AGG/CEMENT LOAD COMPRESSIVE

RATIO RATIO (TONNES) STRENGTH(N/sq.mm)

7 0.4 6:1 100 4.444

7 0.4 8:1 55 2.444

7 0.4 10:1 45 2.0

Compressive strength at 14 days for 6:1,8:1 and

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


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PERMEABILITY

Agg/cement W/C RATIO coefficient of

Ratio permeability(cm/sec*103)

6:1 0.4 3.2

8:1 0.4 3.5

10:1 0.4 3.65

Permeability for 20mm aggregates for different w/c ratio

Agg/cement W/C RATIO coefficient of

Ratio permeability(cm/sec*103)

6:1 0.4 1.6

8:1 0.4 2.5

10:1 0.4 3.14

Permeability for 10mm aggregates for different w/c ratio


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12.RESULTS &CONCLUSION

RESULTS

•

Pervious concrete made from coarse aggregate size 10mmhas compressive strength of 4.444 N/sq. mm and 20mm

aggregate has 3.377 N/sq. mm

• Pervious concrete made from coarse aggregate size 20mm

had compressive strength value of 76% compared to that of10mm.

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

concrete of higher co-efficient of p ermeability of 3.14x10-

3cm/sec and 3.65x10-3cm/sec for aggregate size 10mm and

20mm respectively.


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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 rat e.

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

10:1 are considered to be u seful for a pavement that r equires

low compressive st rength and high permeability rat e.

• Finally, further study should be conducted on the

pervious concrete pavement produced with these material

proportions to meet the condition of increased abrasion andcompressive stresses du e to high vehicular loading and traffic

volumes.


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13. PERVIOUSCONCRETE IN INDIA

Pervious concrete can be used and it is being

implemented in some m etropolitan cities in parking lots, drive

ways, gullies, sidewalks, road platforms et

the apartments and the surfacing inside the compound can be

made with pervious con crete. Another signicant advantage in

India is low cost of labour compared to western countries,

much of the pervious con crete is laid manually without using

heavy m achinery, so this ca n 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 i n India compared to other countries.


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14. REFERENCES1. Pervious Pavement Manual, Florida Concrete and Products

AssociationInc., Orlando, FL.

2 . Obla, K., Recent Advances i n Concrete Tech nology, Sep.

2007,Washington DC 3.

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, November1995.

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

Thaw Resistance of PerviousConcrete, Silver Spring, MD, May

2004, 17 pp.

6. NRMCA, “What, Why, and How? Pervious Concrete,”Concrete inPractice seri es, CIP 38,Silver Spring, Maryland,May 2004b, 2 pages.

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

Pavements,” EB 302, PortlandCement Association (PCA),

Skokie, Illinois, 2004, 25 pp.

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

Design of Pervious Concrete,” PCA R&D.


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9.Pervious Concrete: Hydrological Design and Resources,

CD063, CD-ROM, PCA, Skokie


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