Effects of fibres and rice husk ash on properties of heated HSC

This paper describes experimental research to study the influence of rice husk ash and polypropylene fibres of different lengths (6 and 24 mm) on the residual fracture mechanical behaviour of high-strength concrete (HSC). The evolution of residual mechanical properties with temperature (room temperature, 100 degrees, 300 degrees, 500 degrees and 700 degrees C) was analysed in various HSCs and compared with a non-reinforced reference concrete. The evolution of pore level with temperature was also studied and subsequently compared with the effect of adding fibres to HSC on preventing spalling at high temperatures. Concrete ductility was analysed through the residual characteristic length of concrete, as the characteristic length of HSC increases with high temperatures. Further study of the rice husk ash and other materials used in this study did not reveal any environmental problems.