International Research Journal of Engineering and Technology (IRJET) Volume: 04 Issue: 02 | Feb -2017
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e-ISSN: 2395 -0056 p-ISSN: 2395-0072
A Study on Strength Properties of Concrete Replacing Partially the Natural Coarse Aggregates with Recycled Aggregates Surendra . B.V1, Rajendra T N2 1Associate
Professor, Department of civil Engineering New Horizon college of Engineering, Bengaluru, Karnataka, India 560103 2 Assistant Professor, Department of civil Engineering New Horizon college of Engineering, Bengaluru, Karnataka, India 560103 ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract – Some of the important issues are the reduction in the consumption of energy and natural raw materials, as well as the increase in consumption of waste materials. The use of recycled concrete aggregates (RCA) form construction and demolition waste (C&DW) in construction, as an alternative to natural aggregates, has strong potential. The use of RCA preserves the natural resources and reduces the space required for the disposal of RCA in landfill. The quantity of C&DW is also increasing rapidly every year finding their way to landfill sites. It will be an important breakthrough for our society if a solution for excess waste production is found by means of utilizing RCA and C&DW with an improvement in their final qualities. The aim of the study is to determine the suitability of using RCA in structural concrete based on its strength, stiffness, dimensional stability and durability. Three types of RCA designated as RCA1, RCA2 and RCA3 in this study, were taken from three different sources. These materials were tested to establish their mechanical properties for use as aggregate in concrete. In the experimental programme, RCA was used at replacement percentages of 0%, 10%, 20% and 30% concrete and to determine what level of NA replacement is satisfactory for structural application.
industry uses vast amounts of natural stone from quarries a aggregate all around the world. Both these practices are damaging to the environment and are no longer considered sustainable. 2. MATERIALS AND METHODS 2.1. Materials 2.1.1 Cement: Ordinary Portland cement of 43 grade confirming to Indian Standards was used in the present investigation and the specific gravity of the sample was evaluated. The results have been tabulated in table2.1. 2.1.2 Fine aggregates: River sand with fineness modulus 2.92 conforming to zone II was used in the present investigation and the specific gravity of the sample was evaluated. The results have been tabulated in table2.1. 2.1.3 Coarse aggregates: NA used are Crushed granite with fineness modulus 7.1 having size between 20 mm and 4.75 mm was used in the present investigation and the specific gravity of the sample was evaluated. RCA is produced by crushing sound & clean demolition waste. The size of RCA varies from 20 mm to 10 mm and the specific gravity of the sample was evaluated. The results have been tabulated in table 2.1.
Key Words: Cement concrete, Recycled Aggregates, Construction & Demolition waste, M.Sand Compressive Strength, Split tensile strength, Flexural Strength.
2.1.4 Water: Drinking water was used for the experimental study
1. INTRODUCTION All over the world many old buildings, concrete pavements, bridges and other superstructures have reached the end of their design life. The condition of some of them is beyond repair and they need to be demolished. The structures are not serving preset day needs, and demolishing them is often the only way for meeting the demand. Economic growth in many countries needs new construction methods with better performance. Natural disasters such as earthquakes, tsunamis, cyclones, tornadoes and floods cause structures to collapse turning them into debris. Manmade disasters such as war create waste from buildings and infrastructures. The disposal of these huge amounts of waste material places strain on landfill sites. On the other hand, the concrete
Š 2017, IRJET
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Table 2.1: Significant properties of materials used Materials
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Specific gravity
Cement
3.12
Fine aggregates (M.Sand)
2.51
Natural Coarse aggregates
2.75
Recycled Coarse Aggregates
2.68
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