水泥混凝土早期温度应力的计算方法

Calculation of Thermal Stress of Cement Concrete at Early Stage

混凝土早期迅速而复杂的体积变化可立即引起开裂或在混凝土中作为残余应力存在,影响其耐久性、整体性、力学性能等,尤其是抗裂性。在收缩、强度、弹性模量、徐变等处于动态发展的混凝土早期,受温度变化产生温度应力及其发展是非常复杂的,不能套用已硬化混凝土的计算方法。全面分析了早期混凝土的特点,总结了温度应力的两种计算方法(全量法和增量法),并指出其各自的优缺点和应用范围。

Complicated volume changes of early-stage concrete may cause immediate cracking or residual strains damaging concrete durability, integration and mechanic properties, among others especially cracking resistance. At early stage of concrete, when the shrinkage, strength, elastic modulus, creep and other properties are in drastic dynamic evolution, the generation and development of thermal stress induced by temperature changes are very sensible, and the computation methods of hardened concrete can hardly be used here any more. In this paper, the authors analyze the features of early-stage concrete, and (summarize) two computation methods of thermal stress and shrinkage stress——the superposition and the (increment) methods. Their advantages and disadvantages as well as the application scopes are also provided.