Sustainable approach of utilization of limestone and treated construction wastes as aggregates in the production of high temperature resistant green concrete

Natural gravel used as aggregates in the construction had a severe impact on the environment leading to scarcity in recent times. Furthermore, the resistance of such natural aggregates to crack at higher temperature zones was less. This paper investigates the above concerns on scarcity and meagre high-temperature resistance with the use of sustainable waste materials such as recycled aggregates and limestone as aggregates in the concrete. The natural aggregates were replaced with different proportions of limestone aggregates (LA), recycled aggregates (RA) and carbonation-treated recycled aggregates (CRA) to investigate their hardened properties and thermal properties at 200, 400, and 800 oC. The strength of recycled aggregate concrete (RAC) and carbonated RAC (CRAC)was reduced by 16.67% and 1.32%, while the strength of limestone aggregate concrete (LAC) was enhanced by only 2.3%. The RAC and LAC show better resistance to elevated temperature compared to control concrete and the residual temperature was observed between 200 to 400 oC.