一种用于测量混凝土试件温度应力的温度荷载施加方法

A Temperature Loading Method for Measuring Thermal Stress of Concrete Specimen

采用电热带缠绕混凝土试件的加热方法,设计了一种用于测量试件温度应力的温度荷载施加方法.混凝土试件为圆柱体,内部中心位置埋设混凝土应变计和温度传感器,电热带外侧用隔热保温性能良好的聚氨酯泡沫填缝剂密封.试验时把试件置于普通压力试验机的上下承压板之间,温度传感器控制升温幅度,压力传感器测定温度应力,内埋的混凝土应变计和外设的千分表测量试件的温度变形.试验结果表明,该方法能够给混凝土试件施加较为均匀的温度荷载,升温幅度可达70,℃;与水浴、油浴等其他加热方法相比,该方法不仅结构简单、试件受热均匀,而且能在普通压力机上进行温度应力测定,为温度应力的试验研究提出了一条技术思路.

A temperature loading method for measuring thermal stress of concrete specimen was proposed. The tem- perature load was applied by the electric heater cable wrapped on the lateral surface of the specimen. A cylinder con- crete specimen was prepared with a concrete strain gauge and a temperature sensor embedded in the center. The elec- tric heater cable was covered and sealed by a layer of polyurethane foam, which has an excellent heat insulation property. The specimen was placed between the top and bottom bearing plates of an ordinary testing machine, the temperature rise was controlled by the temperature sensor, the thermal stress was detected by the load cell and the thermal deformation was measured by both the embedded strain gauge and the dial gauges installed on the testing ma- chine. Test results show that a relative uniform temperature distribution can be obtained by this temperature loading method and the temperature can be raised up to 70 ℃. Compared to the other heating methods such as water bath method and oil bath method, this method is not only simple in structure, even in heating effect, but also make it possible to measure thermal stress with normal testing machines. This temperature loading method proposes a techni- cal idea for the experimental study of thermal stress.