Fire Effect on Concrete Containing Red Clay (Homra ) as a Partial Replacement of Both Cement and Sand
The partial replacement of cement and sand with red clay (called also homra) in the concrete is investigated in this study, with reference to fire resistance. As a natural pozzolanic material commonly found in desert areas, homra is extensively used in brick manufacturing. As a waste material from this industry, homra is hazardous for the environment, and using homra in concrete production may reduce its environmental impact, with the plus that homra reacts with the lime resulting from the hydration of ordinary Portland cement (OPC). In this study, replacing OPC and sand (15%, 20 %, 25 and 30% by mass) with homra has been investigated to have information on the mechanical behavior of homra-modified concretes after being exposed to fire for half- an- hour or one-hour. After heating, the specimens were either quenched in water or cooled in air. The tests show that the optimal replacement rate is 15% for the cement and 25% for the sand, in terms of enhanced compressive, tensile and flexural strength.
