论文部分内容阅读
通过给定配合比混凝土的低温劈拉试验,考察混凝土不同低温作用工况下的受拉性能变化规律。结果表明,不同低温下混凝土立方体试件劈拉破坏形态相似;混凝土低温受拉强度离散性虽较大,但基本经历损伤阶段、快速增长阶段和平稳波动阶段。约-10℃时混凝土受拉强度达到极小值,相对常温降幅达5.7%;约-120℃时达到极大值,相对常温增幅达42.6%。随温度降低,混凝土拉压比减小、脆性增强。根据试验结果和已有的研究结果拟合的混凝土低温相对受拉强度计算公式可为工程实践提供参考。
Through the low-temperature splitting test of concrete with specific mix proportion, the change law of tensile behavior of concrete under different low temperature working conditions was investigated. The results show that the splitting tensile behavior of concrete cubes at different low temperatures is similar. The discrete tensile strength of concrete at low temperature is quite large, but it basically experiences the damage phase, the rapid growth phase and the steady fluctuation phase. At about -10 ℃, the tensile strength of concrete reaches the minimum value, which is 5.7% lower than that of normal temperature. It reaches the maximum at about -120 ℃ and increases by 42.6% at room temperature. With the decrease of temperature, the tensile ratio of concrete decreases and the brittleness increases. According to the test results and the existing research results, the formula of relative tensile strength at low temperature can be used as a reference for engineering practice.