Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS

GRD Journals- Global Research and Development Journal for Engineering | Volume 3 | Issue 3 | February 2018 ISSN: 2455-5703

Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS Chandrashekar V C Assistant Professor Department of Civil Engineering Dayananda Sagar College of engineering Bangalore, Karnataka, India Tejashwini P S Assistant Professor Department of Civil Engineering Dayananda Sagar College of engineering Bangalore, Karnataka, India

Madhu KS Assistant Professor Department of Civil Engineering Dayananda Sagar College of engineering Bangalore, Karnataka, India

Deepa T Assistant Professor Department of Civil Engineering Dayananda Sagar College of engineering Bangalore, Karnataka, India

Poornima KB Assistant Professor Department of Civil Engineering Dayananda Sagar College of engineering Bangalore, Karnataka, India

Abstract 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. 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, Basketball and volley ball courts etc. In this study experimental investigation is carried out to study the properties of Pervious Concrete by partial replacing cement with different percentages of GGBS (0%, 20%, 40%, 50%, 60%, and 80%). To achieve optimum concrete mix various trial mixes are done by varying cement, coarse aggregate, water and super plasticizers. Once getting the optimum mix, six mix design are done by replacing cement with GGBS at 0%, 20%, 40%, 50%, 60%, 80 %. The pervious concrete mix is produced by using conventional cementitious materials, aggregates, and water. This concrete is tested for its Fresh properties such as workability and Hardened Properties such as density, void ratio, compressive strength, and water permeability.

The most important property of pervious concrete is its water permeability. Currently, there is no standard experimental procedure to determine to this property. A method was therefore developed to determine the water permeability.

Keywords- GGBS, Super Plasticizers, Optimum Mix, Workability Density, Void Ratio, Compressive Strength, Water Permeability, Binder to Coarse Aggregate Ratio

I. INTRODUCTION A. General Conventional normal weight Portland cement concrete is generally used for pavement construction. The impervious nature of the concrete pavements contributes to the increased water runoff into the drainage system, over-burdening the infrastructure and causing excessive flooding in built-up areas. Pervious concrete has become significantly popular during recent decades, because of its potential contribution in solving environmental issues. Pervious concrete is a type of concrete with significantly high water permeability compared to normal weight concrete. It has been mainly developed for draining water from the ground surface, so that storm water runoff is reduced and the groundwater is recharged.

Pervious concrete has been developed in the USA in order to meet US Environmental Protection Agency (EPA) storm water regulation requirements. The American Society for Testing and Materials (ASTM) Concrete Committee (C09) has focused on this concrete and formed a subcommittee to deal exclusively with pervious concrete production, properties and usage. European countries have developed pervious concrete, not only for water permeability but also for sound absorption. In Japan, pervious concrete has been researched for the usage in not only for road surfaces but also to support vegetation along river banks.

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Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS (GRDJE/ Volume 3 / Issue 3 / 001)

In 2003, the world’s Portland cement production reached 1.9 billion tonnes as the demand for concrete increases, current Portland cement production will be substantially increased. Since one tonne of cement production releases 0.93 tonnes of CO2 into the atmosphere, cement production contributes significantly to global warming which leads to undesirable climate change. Hence it is essential for the concrete industry to be aware of the consequences of utilising environmentally unfriendly cement.

Many efforts should be made to minimize the use of Portland cement in concrete mixes. In concrete mixes Portland cement should be partially replaced with a variety of proven supplementary cementitious materials, such as natural pozzolans, fly ash and ground-granulated blast furnace slag. Substantial use of these cementitious materials will help to produce environmentally friendly concrete mixes.

B. Properties of Pervious Concrete and Mortar Strength and permeability of pervious concrete are found to be affected by several factors including binder types, aggregate type, aggregate grading, mix combination and compaction.

Fig. 1: too little water

Fig. 2: proper amount of water

Fig. 3: too much water

C. Workability Even though a few researchers have reported slump values for pervious concrete, the standard slump test is not suitable for pervious concrete to assess its workability because of lightweight nature of pervious concrete was too small. Tennis et. al. recommended that workability for pervious concrete should be assessed by forming a ball with the hand to established mouldability of pervious concrete Mouldability of pervious concrete is quite sensitive to water content, hence the amount of water should be strictly controlled.

D. Unit Weight (Density) Due to high porosity, pervious concrete is a lightweight concrete. The unit weight of pervious concrete is between 1,500 kg/m3and 2,200 kg/m3.

E. Porosity (Voids Content Or Void Ratio) Porosity for pervious concrete is ranged from 15 to 30%. Also, porosity of pervious concrete termed as void content or void ration in percentage. This high porosity leads to a high permeability for the pervious concrete.

F. Pore Structure of Pervious Concrete There are three different types of pores in the previous concrete, namely, pores in cement paste, aggregate voids, and air voids.

Gel pores in cement paste are smaller than capillary pores. Capillary porosity is affected by water/cement ratio and age. These types of pores are either discrete or connected. The air voids are bigger in size and may be connected and responsible for water permeability. It is mainly influenced by aggregate grading and degree of compaction. Aggregate voids vary in size and may or may not be connected and depending upon the types of aggregate used.

G. Compressive Strength Because of the high void content, the compressive strength of pervious concrete is lower than that for conventional concrete. The average compressive strength of pervious concrete is around 20 MPa, while the lowest strength of 2.5 MPa and the highest strength of 34.5 MPa are reported. The compressive strength for highly pervious concrete is half or one-third that of conventional concrete.

H. Water Permeability A wide range of values for water permeability of pervious concrete has been reported. Some researchers have claimed that water permeability of pervious concrete is 1 mm/s to 5 mm/s, and others have reported the permeability, between 20 mm/s and 45 mm/s.

Hence, the permeability of pervious concrete is typically between 5 mm/s and20 mm/s. The water permeability of pervious concrete was also reported as the permeability coefficient, intrinsic permeability and hydraulic conductivity.

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Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS (GRDJE/ Volume 3 / Issue 3 / 001)

II. METHODOLOGY Experimental investigation is carried out to study the properties of Pervious Concrete by partial replacing cement with different percentages of GGBS. To achieve optimum concrete mix various trial mixes are done by varying cement, coarse aggregate, water and super plasticizers. Once getting the optimum mix, six mix design are done by replacing cement with GGBS at 0%, 20%, 40%, 50%, 60%, 80%.

Table 1: Summarization of mix design ratio SL NO

% OF GGBS

BINDER TO COARSEAGGREGATE RATIO

MIX 1 MIX 2 MIX 3 MIX 4 MIX 5 MIX 6

0% 20% 40% 50% 60% 80%

1: 4.841 1: 4.832 1:4.824 1: 4.819 1: 4.815 1: 4.806

A. Details of Experimental Programme The experimental work has been divided into two stages: In the first stage of this investigation, preliminary tests are conducted on materials. Standard consistency, initial and final setting time, soundness, specific gravity and fineness of cement have been determined. Specific gravity, bulk density, water absorption, flakiness index and fineness modulus have been determined for coarse aggregate.

In the second stage of this investigation, the properties of the hardened concrete containing GGBS of 0%, 20%, 40%, 50%, 60%, 80% as a replacement of cement cube mould of size 150.150.150mm, cylindrical mould of size 150 mm diameter and 300 mm height confirming to IS: 10086-1982, beam mould of size 100mm x 100rnm x 500mm have been used. The properties of materials used in the present investigation are as shown in Tables3.1, 3.2, 3.3 and 3.4. properties like compressive strength, flexural strength and split tensile strength have been recorded at 7 days and 28 days of curing. The strength properties of concrete with particular percentage replacement of cement by GGBS are compared with that of Pervious Concrete which does not contain GGBS.

III. RESULTS A. Analysis of Concrete Cubes for the Compressive Strength The concrete cube of size150*150*150mm have been casted for normal mix and also mix with varying GGBS, Percentage (0%, 20%. 40%,50%,60%and 80%)for both ordinary curing. Concrete with mix different proportion. And water cement ratio 0.31 and Sp content = 0.4% totally 50 numbers of concrete cubes have been tested in order to determine the compressive strength.

Table 2: Summarization of Compressive strength results of pervious concrete Average comp.

Age of concrete in Sl. No Of Mix % of GGBS of strength in Days N/mm2 0 0% 0 1 7 0% 15.26 28 0% 21.50 0 20% 0 2 7 20% 14.82 28 20% 20.10 0 40% 0 3 7 40% 11.36 28 40% 15.20 0 50% 0 4 7 50% 8.72 28 50% 12.60 0 60% 0 5 7 60% 7.88 28 60% 11.30 0 80% 0 6 7 80% 6.54 28 80% 9.10

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Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS (GRDJE/ Volume 3 / Issue 3 / 001)

Fig. 4: Graphical comparison of Average Compressive Strengths of different % replacement of GGBS Table: 3 Summarization of Split tensile strength results of pervious concrete Average split tensile Age of concrete in Sl. No Of Mix % of GGBS of strength in Days N/mm2 1 28 0% 1.56 2 28 20% 1.10 3 28 40% 0.87 28 50% 0.67 5 28 60% 0.638 6 28 80% 0.541

Fig. 5: Graphical comparison of Average Split tensile strength of different % replacement of GGBS Table 4: Summarization of Flexural strength pervious concrete Average Flexural Age of concrete in SL NO OF MIX % of GGBS of strength in Days KN/mm2 1 28 0% 3.13 2 28 20% 3.4 3 28 40% 3.92 4 28 50% 3.57 5 28 60% 3.3 6 28 80% 3.21

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Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS (GRDJE/ Volume 3 / Issue 3 / 001)

Fig. 6: Graphical comparison of Average Flexural results of strength of different % replacement of GGBS Table 5: Graphical comparison of Average Void Ratio of different % replacement of GGBS of GGBS Volume of voids(ml) Volume of Solids(ml) Void Ratio(%) 0% 1350 3996.4 34.20% 20% 1450 3851.4 37.65% 40% 1400 3901.4 35.88% 50% 1325 3976.4 33.32% 60% 1300 4001.4 32.50%

Fig. 7: Summarization of Void Ratio results of different % replacement of GGBS pervious concrete Table 6: Graphical comparison of Average Density of Pervious concrete % of GGBS Avg. Weight(kg) Avg Density(kg/m3) 0% 6.56 1943.71 20% 6.483 1920.88 40% 6.523 1932.74 50% 6.483 1920.88 60% 6.583 1950.52

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Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS (GRDJE/ Volume 3 / Issue 3 / 001)

Fig. 8: Summarization of Density results of different % replacement of GGBS Table 7: Graphical comparison of Average Permeability of Pervious concrete % of GGBS of Discharge(cm3/s) or (ml/s) Permeability(cm/s) 0% 65.250 0.290 20% 63.675 0.283 40% 60.525 0.269 50% 55.125 0.245 60% 49.500 0.220 80% 41.175 0.183

Fig. 9: Summarization of Permeability results of different % replacement of GGBS

IV. CONCLUSIONS 1) The compressive strength of pervious concrete with 0% and 20% GGBS replacement is almost equal. It decreases gradually for further increase in replacement percentage of GGBS 2) For 0 and 20% of GGBS, the increase in percentage strength from 7 days to 28 days curing is almost same as that of normal concrete. But the percentage increase gradually decreases for further increase in GGBS content.

3) The workability and paste content increases for increasing percentage of GGBS 4) The split tensile strength follows the same pattern as compressive strength 5) The flexural strength pattern is observed to be different than that of compressive and split tensile strength. It increase from 0% GGBS to 40% GGBS and then decreases till 60% GGBS 6) The maximum flexural strength is observed for 40% GGBS mix.

7) The void ratio first increases from 0% to 20% of GGBS, then decreases gradually

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Effect on the Engineering Properties of Pervious Concrete by Partial Replacement of Cement with GGBS (GRDJE/ Volume 3 / Issue 3 / 001)

8) The density of concrete is almost same from 0%GGBS till 50% GGBS, but there is a sharp increase in density for 60% and 80% GGBS 9) Water permeability decreases gradually for increasing % of GGBS

REFERENCES [1] [2] [3] [4] [5] [6] [7] [8]

IS: 10262: 2009. Concrete Mix Proportioning- Guidelines, BUREAU OF INDIAN STANDARD, New Delhi.

NRMCA, ―What, Why, and How? Pervious Concrete, ―Concrete in practice series, CIP 38, Silver Spring, Maryland, May 2004, 2pp..

NRMCA, ―Freeze Thaw Resistance of Pervious Concrete,‖ National Ready Mixed Concrete Association, May 2004..

RMC Research Foundation Pervious Concrete Research Compilation: Past, Present and Future.

ACI 522R-10, ―Report on pervious concrete ‖ ACI Committee 522, March 2010” Concrete Promotional Group inc., ―Handbook for Pervious Concrete Certification in Greater Kansas City‖, CPG Pervious Concrete Certification Program National Concrete Pavement Technology Centre―Mix Design Development for Pervious Concrete in Cold Weather Climates‖, February 2006.

UltraTech Concrete Pervious, -Report on Permeable Concrete

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