钢纤维混凝土结构温度应力特性

Study on thermal stress properties of steel-fiber concrete

通过早期水化热及外界温度影响下的钢纤维混凝土模型试验,得出钢纤维混凝土比普通混凝土具有更好的热传导性,可以减小钢纤维混凝土内部的温度梯度,进而降低表面应力的结论。在试验的基础上进一步通过有限元数值模拟,计算钢纤维混凝土在不同热导率下的温度及温度应力,给出了钢纤维混凝土热导率与温度梯度和温度应力之变化关系。数值计算结果表明,钢纤维混凝土热导率变大,结构内部温差变小,温度应力减小,验证了模型试验所得的结论,表明了钢纤维混凝土的实际抗裂作用。

Model tests on the thermal stress properties of steel-fiber concrete under influences of hydration heat at the early stage and external temperature were performed. It is concluded that the steel-fiber concrete is of high thermal conductivity as compared with ordinary concrete, which is helpful for steel-fiber concrete to reduce its internal temperature gradient, and further to decrease the thermal stress in the surface. By use of FEM model, the temperature and thermal stress of steel-fiber concrete with different thermal conductivity were calculated, and the relationships between thermal conductivity, temperature gradient, and thermal stress were obtained. The calculated results show that, the higher the thermal conductivity, the smaller the difference between internal temperatures and the smaller the thermal stress. The numerical result accords with that of the model test, and the research demonstrates the anti-cracking function of steel-fiber concrete.