高温后混凝土三轴压的强度及破坏准则研究

Strength and failure criterion research of concrete under triaxial compression after high temperature

利用大型混凝土静、动三轴试验系统,对经历了200、300、500、600℃高温后的普通混凝土进行了三轴抗压试验,应力比设为0.1∶0.25∶1、0.1∶0.5∶1、0.1∶0.75∶1和0.1∶1∶1,测得了混凝土的强度,并根据试验结果,系统地探讨了应力比和温度对处于常规三轴和真三轴受压下混凝土强度的影响。发现随温度的增加,混凝土三个方向极限抗压强度均相应降低,但在相同温度下,混凝土的极限抗压强度比单轴时增大。建立了三轴压混凝土在高温后的破坏准则。

Triaxial compressive tests on normal concrete subjected to 200,300,500,600 ℃ were performed,using a large-scale dynamic-static triaxial concrete test system.The concrete strength was measured with different stress ratio 0.1∶0.25∶1,0.1∶0.5∶1,0.1∶0.75∶1 and 0.1∶1∶1.Discussed the influence of stress ratio and temperature on concrete strength under conventional triaxial and true triaxial compression.With the increase of temperature,the concrete ultimate compressive strength in three directions was corresponding decrease.At the same temperature,the ultimate compressive strength of concrete was bigger than that under uniaxial compressive.The failure criterion of triaxial compressive concrete after high temperatue was established.