温度一应力试验能够较好地评价混凝土抗裂性,但因其耗用时间长、试验成本大而制约温度一应力试验法的发展。本试验应用温度一应力试验法得到线膨胀系数、自生体积变形、徐变等变形参数随成熟度发展的函数关系,并用B4Cast温度应力分析软件模拟实际浇筑过程中混凝土的温度发展历程,通过仿真计算,对比实际工况下不同配合比混凝土的抗裂性。结果表明:应用B4Cast仿真计算软件可以得到不同温控措施下混凝土内部的温度历程,采用与实际情况接近的温度历程进行温度应力分析,才能客观评价混凝土的抗裂性;在温度应力试验结果的基础上,通过拟合得到混凝土的热膨胀系数、收缩变形、弹性模量、抗拉强度等参数随成熟度的变化规律,再将其用于B4Cast计算出的温度历程,可以对混凝土的开裂风险进行仿真分析;应用此方法得出在同等级下低热水泥的混凝土抗裂性高于中热水泥的混凝土。
The temperature-stress testing machine can be used to evaluate crack resistance of concrete, but because of the disadvantages of long time, costs much restrict the development of temperature-stress test method.Getting the deformation parameters such as coefficient of thermal ex- pansion, autogenous volume deformation and creep with maturity development functions through the temperature-stress test here, then be used in the temperature history calculated by B4Cast simulation software to compare crack resistance of different concretes under actual condition.The re- suits showed that:the B4Cast simulation software can be used to get different concrete internal temperature histories under different temperature control methods,using the temperature history close to the real condition can evaluate the crack resistance of concrete objectively; on the basis of the temperature stress test results,via fitting obtained concrete thermal coefficient of expansion, contraction deformation, elastic modulus, tensile strength and other parameters with maturation changes, then be used in the temperature history calculated by B4Cast,the concrete cracking risk can be simulation analyzed.Using the simulation analysis method derived that the crack resistance of tow heat cement concrete is better than that of middle heat cement concrete under the same strength grade.