EFFECT OF PARTIAL REPLACEMENT OF AGGREGATES BY RECYCLED CONCRETE DEBRIS ON STRENGTH OF CONCRETE

Abstract

Lot of construction debris are generated during the construction and demolition of any concrete structure like buildings, roads, bridges etc. and sometimes, even from catastrophes like wars and earthquakes. Discarding these wastes is a very serious problem because it requires huge space for its disposal and very little demolished waste is recycled or reused. This debris after recycling can be used as aggregates in fresh concrete in order to protect natural resources and to reduce the space required for the landfill disposal thus minimising environmental pollution. In recent times, scarcity of river sand is also another major problem faced by the construction sector in India. In this paper, experimental investigations have been carried out to gauge the effect of partial replacement of natural coarse aggregates (NCA) and natural fine aggregates (NFA) by recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) on compressive strength, tensile strength and flexural strength of recycled concrete. 10%, 20%, 30% of NCA and NFA were replaced with RCA and RFA respectively & the results obtained from compressive strength test, split tensile test and flexural test were compared with the conventional concrete. From the experimental study, it was observed that compressive strength & tensile strength of concrete with recycled aggregates increased up to 20% replacement of natural aggregates with recycled aggregates whereas the flexural strength of recycled concrete was found to decrease with increase in percentage of RCA & RFA. In this paper, feasibility of utilizing concrete debris after recycling in the construction industry from strength point of view has been studied.