变温场和恒温场条件下外掺MgO混凝土弹性模量和极限拉伸变形性能的对比研究

外掺MgO砼材料性能指标是坝体设计、应力计算、温控计算、原形观测资料分析时不可缺少的重要参数。以往采用的材料参数是取自恒温试验结果,而大坝是变温场,该文通过对变温场和恒温场条件下外掺MgO砼弹性模量和极限拉伸变形性能的对比试验研究,结合长沙拱坝对外掺MgO砼在变温场和恒温场条件下的弹性模量和极限拉伸变形性能进行了对比试验研究,其试验研究方案、试验方法和数据处理严格按照有关规程规定进行,试验结果准确、规律性好,建立了相应的试验曲线数学公式,理论值与实测值拟合较好,相对误差较小,能为坝体的仿真计算分析提供比较可靠的计算参数。对比分析变温场与恒温场试验研究结果可知,两者的试验参数相一致,即可用恒温场的试验结果来计算变温场的实际材料性能参数。因此,在坝体仿真计算中,外掺MgO砼的力学性能参数可选用恒温条件下的试验结果。最终得出反映客观情况的、可供大坝仿真计算应用的、真实可靠的材料性能参数,对发展MgO砼筑坝技术和加速我国水电工程建设具有十分重大的现实意义。

Comparative Study on Elastic Modulus and Ultimate Tensile Deformation of Concrete Mixed with MgO under Variable Temperature Field and Constant Temperature Field

The performance index of the mixed magnesium oxide concrete is the important parameter which is indispensable when the dam design, stress calculation, temperature control calculation and prototype observation data are analyzed. In this paper, by comparing the elastic modulus and the ultimate tensile deformation performance of the mixed magnesium oxide concrete under the condition of variable temperature field and constant temperature field, the experiment is carried out with the experimental results. The experimental results, test methods and data processing are carried out in strict accordance with the relevant regulations, and the experimental results are carried out in the same way as the experimental data. Accurate and regularity, the mathematical formula of the corresponding test curve is established. The theoretical value agrees well with the measured value, and the relative error is small, which can provide reliable calculation parameters for the simulation calculation and analysis of the dam. Compared with the experimental results of the temperature field and the constant temperature field, it can be seen that the experimental parameters of the two are consistent, and the actual material performance parameters of the temperature field can be calculated by the test results of the constant temperature field. Therefore, in the simulation of dam simulation, the mechanical performance parameters of MgO concrete can be selected under the condition of constant temperature. And finally come to the objective performance, which can be used for the simulation and application of dam simulation, which is of great practical significance for the development of MgO concrete dam construction technology and the acceleration of hydropower project construction.