钢丝网地质聚合物砂浆约束混凝土圆柱体的高温后轴压力学性能

AXIAL COMPRESSION BEHAVIOR OF CONCRETE CYLINDERS CONFINED BY FERRO-GEOPOLYMER AFTER EXPOSURE TO ELEVATED TEMPERATURES

通过对钢丝网地质聚合物砂浆和钢丝网聚合物水泥砂浆约束素混凝土圆柱体在常温下和高温后的轴压力学性能进行试验,表明:当经历500℃及以下的高温后,钢丝网地质聚合物砂浆约束混凝土圆柱体的约束效果与钢丝网聚合物水泥砂浆的相当或稍高,但700℃高温后钢丝网地质聚合物砂浆的约束效果明显优于后者;随着温度升高,钢丝网砂浆的约束效果先减后增,常温时2层钢丝网地质聚合物砂浆和2层钢丝网聚合物水泥砂浆约束试件的承载力相比于未约束试件分别提高了37%和21%,300℃时提高幅度仅为11%和12%,而700℃时的提高幅度分别达272%和188%。基于试验结果和现有的常温计算模型,通过回归分析建立了钢丝网砂浆约束混凝土的高温后抗压强度计算模型,模型计算结果与试验结果吻合较好。

Axial compression tests were conducted on plain concrete cylinders confined by ferro-geopolymer and ferrocement at room temperature and after exposure to elevated temperatures.The test results showed that the confinement effects of ferro-geopolymer and ferrocement were comparable at temperatures below 500℃,but the confinement of ferro-geopolymer was better at 700℃.With an increase in exposure temperature,the confinement of ferro-geopolymer and ferrocement decreased first and then increased.At room temperature,the axial bearing capacity of concrete cylinders confined by two layers of ferro-geopolymer and two layers of ferrocement was increased by 37% and 21% respectively,compared to that of unconfined concrete cylinders;but after exposure to 300℃,the enhancements were only 11% and 12%.When the exposure temperature rose to 700℃,the enhancement of bearing capacity of ferro-geopolymer and ferrocement confined cylinders reached 272% and 188%.Based on the test results and existing prediction model for ambient conditions,a calculation model describing the residual compressive strength of confined concrete after exposure to elevated temperatures was built through regression analysis,and the calculation results from the model agreed well with the test results.