A Study on Replacement of Coarse Aggregate with Recycled Concrete Aggregate (RCA) in Road Construction

Growth in population is influencing the construction activities in the recent times leading to higher demand for various construction materials. This has affected the environment in an adverse way due to the exploitation of depleting natural resources. Aggregate prepared by quarrying rocks and then crushed to various suitable sizes is one such material which is heavily used in construction industry. This procedure leads to serious occupational hazards and also causes disturbance in the ecosystem such as deforestation, air and noise pollution, necessitating the finding of substitute materials for natural aggregates. On contrary, millions of tonnes of concrete are produced every year as wastage due to dismantling of existing structures which are unconsciously dumped or used for filling lower areas. Since concrete acts like solid hardened material as rock, its suitability for use as an aggregate can be explored. In the present study, quarried coarse aggregates, used in both flexible and rigid pavement construction, are replaced with recycled concrete aggregate (RCA). Different strength tests such as toughness and hardness test of RCA along with compressive strength test of cube and tensile strength test of cylinder with 0, 25, 50, 75 and 100% RCA replacement have been performed and the results compared with natural aggregates and with IRC and IS codes. The findings showed that RCA and natural aggregates if mixed in a proportionate ratio can be used in both pavement and building construction.