三轴压缩荷载下高温处理后泡沫混凝土力学性能试验研究

Experimental investigation on the mechanical properties of the foamed concrete with thermal treatment under triaxial compression

为探究围压、高温处理以及加载速率3种因素对泡沫混凝土(FC)三轴压缩性能的影响,针对湿密度为500 kg/m3的FC(FC-500)开展高温后三轴压缩试验。研究结果表明:在低围压作用下,FC-500以剪切破坏为主;随着围压增加,FC-500出现局部压溃现象;在高围压作用下,FC-500主要以压溃破坏为主。FC-500三轴压缩应力-应变曲线在峰前表现为弹塑性特征,峰后表现为屈服平台特征;FC-500三轴压缩强度随着围压、加载速率的增加而增加,随处理温度的升高而减小;采用折减系数法可将FC-500的峰后应力-应变曲线简化为理想弹塑性模型。

To investigate the influence of confining pressure,thermal treatment and loading rate on the triaxial compression behavior of foamed concrete(FC),triaxial compression test was conducted on the thermally treated foamed concrete(FC-500),the wet density of which is 500 kg/m3.The results show that at low confining pressure,FC-500 presents characteristics of shear failure.With the increase of confining pressure,FC-500 shows shear failure accompanied by a phenomenon of local crushing.At high confining pressure,the failure behavior of FC-500 is dominated by crushing failure.The pre-peak stage of the triaxial compression stress-strain curve of FC-500.shows elastic-plastic characteristics and the post-peak stage shows yield plateau characteristics.The triaxial compression strength of FC-500 increases with the increase of the confining pressure and loading rate,but decreases with the increase of the treatment temperature.Furthermore,the post-peak stress−strain curve can be simplified into the elastic-plastic model by introducing a reduction coefficient.