高温对活性粉末混凝土抗压强度和热膨胀性能的影响

摘要

研究了不同钢纤维掺量的活性粉末混凝土(RPC)高温后的抗压强度和20 ～800℃温度段内的线膨胀系数,借助TG-DSC测试手段对RPC热膨胀性能变化规律进行机理分析.结果表明:随温度升高,RPC抗压强度呈下降趋势,在200℃内下降缓慢;200℃以上下降较快;钢纤维掺量越高,剩余抗压强度越高;线膨胀系数总体呈现先升高后下降的趋势,钢纤维掺量为1％时较素RPC大,钢纤维掺量大干等于2％时较素RPC小.%The compressive strength and the linear expansion coefficient in the temperature ranges from 20 ℃ to 800 ℃ of reactive powder concrete (RPC) with different content of steel fiber were studied.The thermal expansion behavior of RPC was studied by means of TG-DSC.The results show that the compressive strength of RPC decreases with increasing temperature,it decreases slowly before 200 ℃ and decreases rapidly after 200 ℃,the higher steel fiber RPC contains,the higher the residual compressive strength is;linear expansion coefficient increases first and then decreases.When the content of steel fiber is 1％,the coefficient of linear expansion is larger than that of RPC with 0％ steel fiber content,when the content of steel fiber is more than or equal to 2％,the linear expansion coefficient of RPC is smaller than that of RPC with 0％ steel fiber content.