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本文利用实测大体积混凝土表层的温度发展规律曲线进行混凝土匹配养护,测试不同龄期混凝土静弹性模量和劈裂抗拉强度。利用实测温度校正的ANSYS数值分析的大体积混凝土温度场和混凝土静弹性模量等作为模拟参数,进行ANSYS数值分析大体积混凝土温度应力场。实验结果表明,混凝土在匹配养护条件下,静弹性模量早期发展很快,之后增长速率逐渐减小,3d可达28d的80.4%,同样,混凝土的3d劈裂抗拉强度(fts)可达84.5%。模拟结果显示:承台表面混凝土温度应力S1的最大值3d时达最大,为4.46MPa;3d时fts/S1值最小为1.12,此后逐渐增大,说明3d是混凝土最易开裂的时刻。对于底面全约束混凝土,温度应力最大值均集中在承台底部四周,这些部位为最易开裂部位。在混凝土表面养护条件良好的情况下,当fts/S1值大于1.12时,大体积混凝土表面不会开裂。
In this paper, the curve of mass concrete’s surface temperature development was used to test the concrete’s static modulus and splitting tensile strength at different ages. The temperature field of mass concrete and the static elastic modulus of concrete are taken as simulation parameters by ANSYS numerical analysis of measured temperature. Numerical analysis of temperature stress field of bulk concrete by ANSYS is carried out. The experimental results show that under the condition of matching curing, the elastic modulus of the concrete develops rapidly in the early stage, and then the growth rate decreases gradually, reaching to 80.4% of the 3d in 28 days. Similarly, the 3d splitting tensile strength (fts) of the concrete reaches up to 84.5%. The simulation results show that the maximum value of temperature stress S1 on the cap surface reaches the maximum of 4.46MPa in 3d, and the minimum value of fts / S1 is 1.12 in 3d, then increases gradually, which shows that 3d is the most easily cracked moment of concrete. For the fully confined concrete on the bottom, the maximum temperature stress is concentrated around the bottom of the cap, which is the most easy to crack. In the case of concrete surface curing conditions are good, when the fts / S1 value is greater than 1.12, the mass concrete surface will not crack.