An Experimental Analytical Studies on Flexural Behaviour of Rcc Two Way Slabs

Abstract

Concrete is the most commonly used material because of its ease in getting required shapes in various types of constructions. The present day concrete demands high performance with economy. A huge quantity of concrete is consumed by construction industry all over the world. The demand of aggregate and cement used in concrete is increasing worldwide every year due to rapid industrialization and urban development. On the other hand, vast amounts of construction and demolition (C&D) wastes are generated due to demolition of existing structures and increased construction activities which create landfill problems worldwide. The excessive utilization of aggregate for concrete production leads to excessive exploitation of natural aggregate and environmental degradation from quarrying activities.

This has resulted in renewed interest in use of Recycled Aggregates (RA) as a viable source of concrete ingredients. The modulus of elasticity of concrete is a very important parameter reflecting the ability of concrete to deform elastically. Deflections and crack widths are the parameters which give us warning that the structure is about to fail so that there will be sufficient time to react. The aim of study is to verify the influence of steel reinforcement on the modulus of elasticity of reinforced concrete members and also to compare the parameters such as deflection, strains and crack width between the slabs that are laid by using complete natural coarse aggregate and 50% of recycled coarse aggregate.

Study carries casting and testing of two way slab specimens by using natural coarse aggregate and 50% replacement with recycled aggregate. The concrete grade considered for study is M25. In the experimental study the concrete mix has been designed as per the guidelines given in IS: 10262-2009 published by Bureau of Indian Standards. In slab specimens, the steel reinforcement varies from 0.3%, 0.4%, 0.5% in both the cases (natural and recycled) by using 6mm and 8mm diameter rebars. The size of two way slab is 600mm × 800mm × 90mm. The value of modulus of elasticity (E) is evaluated from the load vs. deflection curve of slab specimens.