Performance deterioration rule for fiber reinforced ground granulated blast furnace slag concrete subjected to high temperature

To solve the performance deterioration of fiber reinforced ground granulated blast furnace slag(GGBFS) concrete subjected to high temperature,the influence of temperature,granulated slag content,steel fiber content,polypropylene(PP) fiber content and concrete strength grade on the mass loss and ultimate compressive strength loss of concrete subjected to high temperature was investigated.The results indicate that with increasing the heating temperature,both appearance characteristics and compressive performance of fiber reinforced GGBFS concrete deteriorate continuously.In addition,the ignition loss rate and strength loss rate show a rising trend.The addition of hybrid fiber can effectively prevent the high-temperature decrepitation of GGBFS,and maintain the integrity of the specimen.The GGBFS,steel fiber and PP fiber can remit the strength deterioration of the concrete subjected to high temperature.However,the change in their content has little effect on the mass loss.When the strength grade of concrete is C60,the compressive strength loss of the fiber reinforced GGBFS concrete is lowest.Moreover,a high-temperatue deterioration model for the compressive strength of fiber reinforced GGBFS concrete was proposed with considering the influence of temperature,GGBFS content and steel fiber content.