温度、应变率对地质聚合物混凝土抗压强度的影响

Effects of temperature and strain rate on compressive strength of geopolymeric concrete

采用自主研制的高温SHPB试验系统，对高温条件下地质聚合物混凝土的动态抗压强度进行了试验研究。结果表明：200℃时地质聚合物混凝土的动态抗压强度较常温时有所增长，800℃时强度则急剧下降；应变率随弹速近似线性增长；同一弹速水平下，200～600℃时的应变率与常温接近，800℃时较常温提高明显；高温条件下，由侧向约束引起的附加应力可以忽略不计，试验所测得的动态强度增长因子（DIF）的应变率增强效应反应了材料的本质属性；在30～30s^-1范围内，高温下地质聚合物混凝土的DIF与应变率的对数呈线性关系，且温度越高，应变率效应越明显。

The dynamic compressive strength of using a self-designed high temperature SHPB system. geopolymeric concrete under high temperatures was investigated The results showed that the dynamic compressive strength of geopolymeric concrete at 200℃ is higher than that at room temperature, but it drops dramatically at 800℃ ; the strain rate increases approximately linearly with increase in projectile velocity. At a given projectile velocity, the strain rate changes slightly at 200 - 600℃ and rises evidently at 800~C compared with that at room temperature ; under elevated temperatures, the additional stress of geopolymeric concrete specimens caused by lateral confinement can be ignored, thus the strain rate effect on the dynamic increase factor （DIF） obtained from test data can reflect the inherent nature of geopolymeric concrete; DIF increases linearly with increase in the logarithm of strain rate over the strain rate range of 30 - 130 s^-1 ; the higher the temperature, the more obvious the strain rate effect.