高温后机制砂混凝土抗压性能试验研究

Experimental study on compressive properties of concrete with manufactured sand after high temperature

以受热温度T为变化参数,对高温后机制砂混凝土试块(立方体和圆柱体各48个样本)进行抗压强度试验,分析不同温度下试块的表观变化、裂缝分布、破坏形态、质量烧失率、残余强度等影响规律。研究表明:不同高温后机制砂混凝土的表观颜色和裂缝分布差异明显;T≥500℃时,混凝土爆裂机率随温度升高而增大,其中圆柱体相比立方体更易爆裂;质量烧失率随温度升高而呈线性增长趋势,圆柱体质量烧失率低于立方体;T<600℃时,试块抗压破坏过程中脆性特征显著;高温后机制砂混凝土抗压强度不断减小,其中圆柱体抗压强度劣化更严重。

Taking the heating temperature as the variable parameter,the compressive strength test of manufactured sand concrete specimens(48 samples for each cube and cylinder)after high temperature was carried out,the influence laws of apparent change,crack distribution,failure mode,mass loss on ignition and residual strength of specimens under different temperatures were analyzed.The results show that the apparent color and crack distribution of manufactured sand concrete are significantly different after different high temperatures.When T≥500℃,the probability of concrete bursting increases with the increase of temperature,and the cylinder is more likely to burst than the cube.The mass loss on ignition increases linearly with the increase of temperature,the mass loss on ignition of cylinder is lower than that of cube.When T<600℃,the brittleness of the specimen is obvious.After high temperature,the compressive strength of manufactured sand concrete decreases,and the cylinder compressive strength deteriorates more seriously.