人工气候环境下考虑荷载应力影响的混凝土温度响应研究

摘要

The different levels of tensile or compressive stress were applied to the concrete specimens by self-made continuous loading device,and the influences of different stress levels on the temperature response for micro environment concrete were studied by temperature rise experiment under artificial climatic conditions.Based on the experimental results and the theory of heat transfer, the thermal conductivities of concrete with different stress levels were calculated,and the prediction model of thermal conductivity of concrete considering the influence of load stress was established.The results show that under the constant artificial weather conditions,the higher the compressive stress level of concrete is,the faster the internal temperature response rate is,but the higher the tensile stress level of concrete is,the slower the internal temperature response rate is.For the same stress level,the effect of compressive stress on the temperature response for concrete is more significant.T he research results can lay a theoretical foundation for the prediction of the internal temperature response of concrete structures in practical engineering.%通过自制的持续加载装置对混凝土试件施加不同水平的拉应力或压应力,并在恒温恒湿箱模拟的人工气候条件下进行混凝土试件的升温试验,研究不同应力水平对混凝土微环境温度响应的影响;通过对试验结果的分析,并结合混凝土传热学的相关理论,计算出不同应力水平下混凝土的导热系数,进而建立考虑荷载应力影响的混凝土导热系数预测模型.结果表明:在恒定的人工气候条件下,混凝土的压应力水平越高,其温度响应速率越快,而拉应力水平越高,其温度响应速率越慢;对于同样的应力水平,压应力对混凝土温度响应的影响更显著;所得研究成果可以为实际工程结构中混凝土内部温度响应的预测奠定一定的理论基础.