Strength Characteristics of Concrete with Recycled Aggregates Replacement

Abstract

This paper is based on the recycling of the rapidly increasing construction and demolition waste
and use of those recycled coarse aggregate (RCA) in concrete as partial and full replacements
to natural coarse aggregate (NCA) in concrete. Construction and demolition waste is waste
product arisen from construction of buildings and demolition of structures.
An experimental investigation is carried out by using demolition waste arisen from demolition
of 15 year old residential structure to review the strength characteristics of non-conventional
concrete (replacing NCA by RCA at different percentages) and hence to compare it with the
conventional concrete strength characteristics. In order to investigate properties of concrete which
observed from replacement of NCA with RCA, a design concrete mix(M20) with NCA replacement
with RCA at 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and full replacement is done.
The material properties on cement, fine aggregate, natural coarse aggregate and recycled coarse
aggregate are carried out to understand the similarity between NCA and RCA. The intrinsic
properties are determined by testing cubes, cylinders and prisms. In order to understand the load
deflection behaviour of reinforced concrete beams, model beams were cast and tested after 28
days curing. The results indicates that percentage replacement to an extent of 30% natural coarse
aggregate by recycled aggregates show better performance in terms of strength characteristic
and load deflection characteristics