高温对活性粉末混凝土抗压强度和热膨胀性能的影响

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TGDSC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,钢纤维掺量大于等于2%时较素RPC小。

Study on Compressive Strength and Thermal Expansion Properties of Reactive Powder Concrete

The compressive strength and the linear expansion coefficient in the temperature ranges from 20°C to 800°C 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°C and decreases rapidly after 200°C, the residual compressive strength at 200°C is 96%-97% compressive strength at room temperature, 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.