STUDY OF ENGINEERING PROPERTIES OF RECYCLED CONCRETE AGGREGATE CONCRETE

Abstract

In the present age, sustainability has become an important aspect of the construction industry. The use of huge quantities of concrete around the globe for construction and demolishing of old and deteriorating buildings has left us with no option but to consider alternatives for concrete manufacturing using Recycled concrete aggregates. RCA is not widely used in new concrete mixtures, largely because RCA concrete has been reported to be of inferior quality to concretes produced with virgin aggregates. In the present work, a new mix proportioning method has been proposed and experiments on engineering properties of RCA concrete have been conducted to determine the suitability of the proposed method. A series of experiments were conducted on two grades of concrete namely M25 and M40 with three nominal replacement ratios each. The nominal replacement ratios used were 0%, 25% and 50%. The RCA concrete was obtained using a new mix design as proposed in the thesis work of Mr. Ziyad A.K.R. Kubba, PhD student, Department of Civil Engineering, Indian Institute of Technology Roorkee. For the above six mixes, tests were conducted to determine the engineering properties of the RCA concrete and the results were compared to that of the natural aggregate concrete. A total of 72 specimens were cast and tested. The tests conducted included Slump, Density, Non-destructive testing, Compressive strength, Splitting tensile strength and Elastic modulus.