Effect of fire extinguish methods on RHA-concrete strength

During the few past years reuse these materials to enhancement the mechanical properties of concrete are one of the aims of concrete technology. The previous researches turn the rice hulls into rice husk ash by different methods. In this research, RHA were prepared by two methods which are oven burning at 200°C and exposure to direct flame. Concrete cubes with 4%, 8%, 12%, and 16% by weight of cement were prepared and tested under compression test to achieve the optimum percentage of replacement and RHA preparation method. Then, three groups of RHA concrete cubes were casted and exposed to direct fire for one hour. One group of them tested directly to study the enhancement of fire resistance of RHA concrete and act of RHA in concrete fire resistance while, the other groups extinguished by two different methods (Water, and Powder) to study the effect of fire extinguish method on concrete strength. The results found that oven burning rice husk produce RHA better than direct flam. Effect of fire extinguish method has nearly the same effect on the reduction in concrete compressive strength and flexural strength. Concrete fire resistance for RHA concrete is higher than the conventional concrete. © Published under licence by IOP Publishing Ltd.