AN EXPERIMENTAL STUDY ON PERVIOUS CONCRETE AS AN ASPHALT LAYER

286 | P a g e

AN EXPERIMENTAL STUDY ON PERVIOUS

CONCRETE AS AN ASPHALT LAYER

Nagireddigari

. Madhava Reddy

, Kasireddy. prathap reddy

1_{Pursuing M.Tech ,} 2 _{Working as HOD(Assistant Professor)}

Samskruti College of Engineering & Technology,

Kondapur Village, Ghatkesar, RangaReddy District, TG, (India)

ABSTRACT

This project deals with the pervious concrete as a pavement layer and its chiefly accustomed cut back the

environmental attack on the pavement. Here the existed grades of concrete are going to be modified to cut back

the mixture content. Currently days concreting leads in to the environmental problems reminiscent of reduction

within the discharge, that makes the life at major cities miserable. The answer to avoid this downside is

victimization permeable (pervious) concrete pavements rather than asphalt pavements or impervious concrete

for low traffic areas.

This project deals clearly regarding the employment of pervious concrete as pavement material. During this

study, we tend to thought of combine proportion of permeable concrete from reference mixture of M40 there

in by dynamical the fine mixture or fine aggregate volume is replaced by coarse mixture volume to 0-20% by

replacement methodology. i.e. the fine mixture volume in combine proportion, there’ll be no amendment in

volume of mixture, thus we tend to had downside find the amount of cement paste are going to be constant in

proportions, thus during this project we tend to area unit finding the link of varied fines with compressive

strength, failure load and consistency (without cement paste). Because it satisfies the standards of victimization

it of sub base for concrete pavement as leaky.

Keywords: Pervious Concrete, Fine Mixture And Consistency.

I.

INTRODUCTION

Pervious concrete could be a special high consistence concrete used for flatwork applications that permits water

from precipitation and alternative sources to have, thereby reducing the runoff from a site and recharging water

levels. Its void content ranges from eighteen to 35 with compressive strengths of 3 to 28 MPa (28 to 281

kg/cm2). The infiltration rate of permeable concrete can be varying of 720 liters per minute per square measure.

In previous concrete, rigorously controlled amounts of water and cementations materials are accustomed

produce a paste that forms a thick coating around combination particles. A pervious concrete mixture

contains very little or no sand, making a considerable void content. Victimization ample paste to coat and bind

287 | P a g e

quickly. both the low mortar content and high consistency conjointly cut back strength compared to standard

concrete mixtures, however ample strength for several applications.

Renewed interest in pervious concrete is associate degree increasing stress on property construction. Due to its

edges in dominant storm water runoff and pollution interference. The light color of concrete pavements absorbs

less heat from solar radiation than darker pavements, and also the comparatively open pore structure of pervious

concrete stores less heat serving to lower heat island effects in urban areas. Trees planted in parking areas and

town sidewalks supply shade and manufacture a cooling result within the space, more reducing heat island

effects.

II.

LITERATURE REVIEW

In Europe, receptive concrete, most ordinarily mentioned as Gap hierarchal concrete, has been utilized in the

development business for about a hundred and fifty years. The initial usage of this sort of concrete in Europe

was in applications similar to prefab panels, steam cured blocks or cast-in-place load bearing walls for single

and multi-story homes and, in some instances, in high-rise buildings. In 1852, Richard Langley used a precursor

of receptive concrete for the development of two concrete homes on the islet of weight within the United

Kingdom. This concrete consisted of solely coarse gravel and cement. It’s not mentioned within the printed

literature once more till1923, once a bunch of 50 two-story homes were engineered with

clinker combination in capital, Scotland. Within the late thirties, the Scottish special housing association

restricted adopted the employment of receptive concrete for residential construction.

III.

METHODOLOGY

3.1 Material Properties Of Pervious Concrete

3.1.1 Cementitious Materials

As in ancient concreting, normal hydraulic cement, fifty three grades (I.S-12269, 1989) and PPC (IS1489: half I

1991) is also utilized in pervious concrete. Additionally, supplementary cementations materials like flyash and

natural pozzolans ground-granulated furnace scoria, and silicon oxide fume is also used. Testing materials

through trial batching is strongly suggested in order that correct proportions for the specified concrete

performance (which includes setting time, rate of strength development, porosity, and permeableness,

among alternative traits) are often established.

3.1.2 Aggregates

Commonly used gradations of coarse mixture embrace (20 millimeter to 4.75 mm) and (12.5 to 2.36 mm)

square measure to be used as per IS 383:1970. Single sized aggregates up to one in. (25 mm) even have been

used. Specific property of the coarse aggregate is concerning 2.70 and crushing worth is concerning 20.50 %.

Larger aggregates give a rougher concrete surface, whereas smaller aggregates give a drum sander surface that

will be higher suited to some applications, like pedestrian walkways. As in typical concrete, permeable concrete

needs aggregates to be near a saturated, surface-dry (SSD) condition. It ought to be noted that management of

water is vital in permeable concrete mixtures. Water absorbed from the mixture by aggregates that area unit too

288 | P a g e

3.1.3 Water

Water to cementations materials ratios from 0.27 to 0.30 are used habitually with correct inclusion of chemical

admixtures, and w/c ratios as high as 0.40 are used with success. The relation between strength and water to

cementations materials quantitative relation isn't clear for receptive concrete. Not like typical concrete, the full

in paste content is a smaller amount than the voids content between the aggregates. Therefore, creating the paste

stronger might not continuously result in accrued strength. Water content should be tightly controlled. The

proper water content has been represented as giving the mixture shininess, while not flowing off of the mixture.

Some of receptive concrete shaped into a ball won’t crumble or lose its void structure because the paste flows

into the areas between the aggregates.

3.1.4 Admixtures

Chemical admixtures are utilized in permeable concrete to get special properties, as in standard concrete. Owing

to the fast setting time related to permeable concrete, retarding or hydration-stabilizing admixtures area unit

used normally. Air-entraining admixtures will scale back freeze-thaw harm in permeable concrete.

MATERIALS

PROPERTIES

Cementations materials 270 to 415 kg/m3

Aggregate

1200 to 1600 kg/m3

Water-cement ratio (by mass) 0.27 to 0.30

Aggregate-cement ratio (by mass)

4 to 4.5:1

Fine-coarse aggregate ratio (by mass)

_{0 to 1:1}

3.1.5 Typical Composition Of Pervious Concrete Pavement

Pervious concrete describes a zero in slump concrete product of gap stratified hydraulic cement, coarse mixture,

very little or no fine mixture, water and admixtures. Receptive concrete isn’t specific male erectile function by

water-cement magnitude relation or workability like alternative styles of concrete. The standard of receptive

concrete is measured by air void content, unit weight and water porousness rate. These properties are vital for

the practicality of this material. Higher compressive strength may be a however not a decisive issue for quality.

As compared to standard or self-consolidating concrete, pervious concrete works as a system composed

of many elements. Each component is crucial to the general practicality of the final product. There are four

basic components in permeable composition:

1.

2.

3.

4.

3.2 Properties Of Hardened Concrete

3.2.1 Density And Porosity

The density of permeable concrete depends on the properties and proportions of the materials used, and on the

289 | P a g e

unit common, that is within the higher vary of light-weight concretes. A pavement 125 millimeter thick with two

hundredth voids are ready to store twenty five millimeter of a sustained storm in its voids, that covers the over

whelming majority of downfall events. Once placed on a 150-mm thick layer of open-graded gravel or rock sub

base, the storage capability will increase to the maximum amount as seventy five millimeter of precipitation.

3.2.2 Permeability

The flow through pervious concrete depends on the materials and inserting operations. Typical flow rates for

water through pervious concrete area unit 0.2 cm/s to 0.54 cm/s with rates up to 1.2 cm/s and better having been

measured within the laboratory.

3.2.3 Compressive Strength

Pervious concrete mixtures will develop compressive strengths within the vary of 3.5 MPa to twenty-eight

MPa, that is appropriate for a large vary of applications. Typical values are seventeen MPa. Like any concrete,

the properties and mixtures of specific materials, in addition as placement techniques and environmental

conditions, can dictate the particular in-place strength. Trained cores are the simplest measure of in-place

strengths, as compaction variations build solid cylinders less representative of field concrete.

3.2.4 Flexural Strength

Flexural strength in pervious concretes\ typically ranges between concerning 1MPa and 3.8MPa.several factors

influence the flexural strength, significantly degree of compaction, porosity, and therefore the aggregate: cement

(A/C) quantitative relation. However, the standard application made with pervious concrete doesn’t need the

measure of flexural strength for style.

3.2.5Durability

Because of the rougher surface texture and open structure of permeable concrete, abrasion and fibre of

combination particles will be a tangle, significantly wherever snowplows are accustomed clear pavements. this

is often one reason why applications like highways usually aren't appropriate for permeable concretes.

However, anecdotal proof indicates that a permeable concrete pavement enables now to soften quicker,

requiring less tilting. Most permeable concrete pavements can have a number of loose aggregates on the

surface within the early weeks once gap to traffic. These rocks were loosely guaranteed to the surface at the

start, and popped out owing to traffic loading. Once the primary few weeks, the speed of surface fiber is

reduced significantly and therefore the pavement surface becomes far more stable. Correct compaction

and solidifying techniques can scale back the prevalence of surface fiber.

3.3Tests

3.3.1 Determination Of Porosity

Porosity of pervious concrete specimens can even be determined victimization the distinction in weight between

the dry sample and therefore the weight of the immersed sample, like the tactic delineate in ASTM C 140 as

shown in equation

290 | P a g e

Where,

Vr = total void ratio, %,

W1= weight immersed (lbs or kg),

W2= dry weight (lbs or kg),

Vol = nominal sample volume based on dimensions of the sample (ft3 or m3), and

ρw= density of water (lbs/ft3 or kg/m3).

3.3.2 Determination Of Permeability

Permeability of receptive concrete is measured within the laboratory by many means that. A falling head

permeameter is often used for convenience. The cylindrical sample is prepared specified no water flow

son the facet of the specimens and water flows from high to bottom of the specimen. Water is supplementary to

the graduate to fill the specimen and therefore the drain pipe, up to the initial head level, with the valve closed.

The valve is then opened and therefore the time needed for water to fall from an initial head to a final head is

measured (Figure.1) [Neithalath, Weiss and Olek, 2003; Kevern, Schaefer, Wang and Suleiman, 2008]. The

common constant of porosity (k) is set victimization equation 2.2, supported Darcy’s law principle of flow

in homogenized porous material. K= (a L /A t) log (h2/h1)

Where,

k = coefficient of permeability, in./s or cm/s,

a = cross-sectional area of the pipe, in2 or cm2,

L = Length of sample, in. or cm,

A = cross-sectional area of the sample, in2 or cm2,

t = time for water to drop from h1 to h2, s,

h1 = initial water level, in or cm, and

h2 = final water level, in or cm.

Falling head permeability

3.4 Durability

Several studies were conducted by varied agencies to verify the durability of permeable concrete. A number of

the studies have indicated that thaw/ freeze sturdiness isn’t sufficient and huge scale deterioration was

291 | P a g e

investigation and may alright be an indication that typical testing strategies adore ASTM 666 might not be the

correct testing technique for permeable concrete. Critical conditions needed for freeze/thaw injury are:

1. Temperatures below 32°F (0°C)

2. Concrete saturation should be beyond 91oF

3.5 Compressive and flexural strength

Compressive strength can vary with combine style. Typical values are between 2000 psi to 3000 psi. If a

little quantity of sand is employed then compressive strengths over 4000 psi may be achieved. In cases such as

this, special attention should incline to air void and percolation rate as these could also be reduced with the

introduction of fine mixture.

The majority of permeable concrete, as indicated antecedently, is used in pavement applications.

Compressive strength testing machine

3.6 Compaction methods

The only compacting technique is compaction with steel rollers. Immediately when initial strike off concrete is

rolled with significant steel rollers to confirm for proper compaction. Rolling is performed in two perpendicular

directions to ensure plainness and smoothness of concrete. There are completely different sizes and weights of

the rollers offered for different placement sizes.

3.7 Curing

Special attention should be paid to correct action. Permeable concrete must always be placed on a pre-wet

sub-base, which will give further wet for action. Because the permeable concrete itself contains loads of air voids,

the exposed surface area that has for the evaporation of blending water is beyond that of typical concrete. It’s

necessary to stop excessive wet loss, which can lead to the reduced performance of the concrete. It’s suggested

to slightly mist the concrete surface before applying the protecting plastic sheet.

IV

. RESULTS AND DICUSSIONS

4.1 Evaluation Of Volume Of Voids

As percentage of fines increases, the volume of voids gets decreases as a result of fines fill the space the

materials (aggregates) as we have tendency to increasing the fines.

292 | P a g e

Above equation shows volume of voids is the function of fine content. Therefore with the legendary fines

content we will notice the several volume of voids value.

4.2 Compressive Strength

Pervious concrete mixtures will develop compressive strengths within the vary of 500 psi to 4000 psi (3.5 MPa

to 28 MPa), that is appropriate for a good range of applications. Typical values area unit 2500 psi (17 MPa).

Belo tabular column shows the compressive strength of the permeable concrete combine at the ages of 7 and 28

days. Every result showed the three identical cube tested at constant age of each concrete mixture. Compressive

strength will increase once share of fines will increase in permeable concrete.

7 days, y = 0.021x2 + 0.011x +10.26

28 days, y = 0.024x2 + 0.026x +12.43

Above equation shows compressive strength is that the function of fines content. So with the familiar fines

content. We are able to notice the various compressive worth.

% FINES 0 4 8 12 14 16 18 20

COMPRESSIVE STRENGTH

(7DAYS)

10.26 12 13 15.2 17.5 18.6 20 28.5

COMPRESSIVE STRENGTH

(28DAYS)

12.43 13.4 14.6 17.3 19.7 20.5 26.5 42.6

COMPRESSIVE STRENGTH (vs) % FINES

4.3 Permeability

Permeability decreases once proportion of fines increases.

%FINES 0 4 8 12 14 16 18 20

TIME (SEC) 3.8 5.2 6.9 8 8.5 9.2 9.63 10

PERMEABILITY (K) (CM/S) 0.78 0.7 0.63 0.54 0.45 0.40 0.37 0.25

0 5 10 15 20 25 30 35 40 45

0 4 8 12 14 16 18 20

293 | P a g e

TIME (SEC) VS %FINES

PERMEABILITY VS % FINES

As proportion of fines will increase it fills the void between the aggregates although the degree is same, hence

the permeableness can decreases.

Y= -0.000x2 – 0.01x + 0.75

Above equation shows permeability is that operate of fines content, therefore with the proverbial fines content

we will find the several permeableness value.

FAILURE LOAD:

As proportion of fines will increase, the maximum allowable load to the pervious sample conjointly increases.

Y = 5.603x2 + 143.0 x + 1860

Above equation shows failure load is that the performance of fine content, thus with the noted fines content, we

will find the several most allowable load value.

% FINES 0 4 8 12 14 16 18 20

FAILURE LOAD (Kg) 2035 1950 1800 1975 1700 1825 1600 1996

0 2 4 6 8 10 12

0 4 8 12 14 16 18 20

TIME (SEC)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

0 4 8 12 14 16 18 20

294 | P a g e

% FINES VS FAILURE LOAD

V.

CONCLUSION

Based on the experiments carried out the following are terminated,

1. As performance of fines will increase the volume of voids gets slashed given by,

Y = -0.000x3 + 0.006 x2 – 0.058x + 0.357

2. Compressive strength will increase once percentage fines increases in receptive concrete that is given

by the subsequent expressions.

7 days, y = 0.021 x2 + 0.11 x + 10.26

28 days, y = 0.024 x2 + 0.026x +12.43

3. Permeability decreases once percentage of fines increases. The subsequent expression is obtained,

Y = -0.000x2 – 0.01x + 0.75

4. As percentage of fines will increase, the most allowable load to the receptive sample additionally will

increase given by,

Y = 5.603x2 + 143.0 x +1860

The pervious concrete pavement is ecofriendly to the environment. Pervious concrete will conjointly be used as

permeable sub-base. In recent years, several road agencies intimate with or such drainable pavement systems for

significant duty pavements wherever past expertise has indicated the potential of pavement faulting and

pumping. These semi-pervious sub-base courses are designed to hold the water away rapidly. Dry lean concrete

should have a minimum compressive strength, The receptive concrete will be used as a pavement material as

dry lean concrete (DLC) is primarily a sub base that acts to stop mud pumping and offer a support for

construction instrumentality and conjointly enhance the pavement performance underneath frost condition. The

pervious concrete pavement is designed for low volume traffic areas. In this project the fine aggregate is

replaced with the coarse aggregate. The water absorption capacity of pervious concrete pavement is more

compare to conventional concrete pavement. The moisture loss in pervious concrete is more. If we place a

protective layer on the pervious concrete the moisture loss is reduced.

VI.

REFERENCES

1. Karthik Obla.H, Pervious concrete - An overview, the Indian concrete journal, August 2010

2. Tennis.P, Leming.M.L and Akers.D.J, Pervious concrete pavements, EB 302, Portland cement

association(PCA), Skokia, US 0 500 1000 1500 2000 2500

0 4 8 1214161820

295 | P a g e

3. Yogesh D.Barot, Pervious concrete - A concrete step towards greener earth, Proceeding of ICI.

ACECON 2010, IIT Madras, Chennai

4. Andrew i. Neptune and Bradley J. Putman Effect of Aggregate size and gradation on

Pervious concrete mixtures

AUTHOR DETAILS

Nagireddigar.Madhava Reddy, pursuing M.Tech from Samskruti College of Engineering &

Technology, kondapur Village, Ghatkesar, RangaReddy District, TG, INDIA.

Kasireddy.prathap Reddy, working as HOD(Assistant Professor) from Samskruti college of