Evaluation the Performance of Concrete Containing Coarse Steel Slag Aggregate When Exposed to High Temperatures.

Abstract

Annually more than 100 thousand tons of steel slag are produced in the Syrian Arab Republic. And it is stored in large areas around the factories, caus

ing negative environmental and health effects. This research aims to evaluate the effect of using steel slag as coarse aggregates on the thermal properties of concrete. Three concrete mixtures M1, M2, and M3 were prepared using steel slag from the Syrian Steel Factory as a partial and total replacement for coarse natural aggregates. The replacement percentages were as follows (0 - 50 - 100)%, The studied replacement percentages were (0 - 50 - 100)% of the weight of the coarse aggregates. These mixtures have been tested at temperatures (20 - 400 - 800) . The mechanical properties and microstructure of concrete have been studied before and after heating, and compare the results among themselves. The results showed that the use of dolomite aggregates in concrete reduced the effect of high temperature on the compressive strength, where the decrease was by 9.6% at 400  temperature and 60% at 800  temperature, while the partial use of steel slag aggregates improved the compressive strength by 12% At the temperature 400 , and the value of the decrease in the tensile strength for all mixtures was 12% at the temperature 400, while the decrease for the reference mixture was 66% at the temperature 800 and 89% for the mixture containing steel slag aggregates, Thus, steel slag coarse aggregate can be used as a substitute for natural coarse aggregate in concrete exposed to temperatures up to 400°C.