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模拟高坝混凝土工作环境,将混凝土标准试件浸没于高压水体中,在混凝土内造成高渗透孔隙水压,研究高孔隙水压作用后混凝土产生的强度、弹性模量,含水量和声速等宏观指标的变化。试验中具体开展了混凝土试块外不同水压(孔隙水压)、不同时间、不同混凝土等级、不同最大骨料粒径4个因素的影响研究。试验采用正交试验设计法进行设计,关于高渗透孔隙水压对混凝土抗压强度、含水量变化和声速的影响研究共进行了28组试验,而抗拉强度试验进行了9组。研究表明,随着渗透孔隙水压的增加,混凝土的抗压强度、劈裂抗拉强度和弹性模量逐渐降低,其损失率逐渐增大。其中外界水压(孔隙水压)、粒径和混凝土强度等级对混凝土抗压强度损失有显著的影响。在同一孔隙水压作用下,粒径越大、混凝土等级越小,其损失率越大。混凝土含水量随着外界水压(孔隙水压)的增加而增加,并与孔隙水压的作用时间和混凝土等级有关,时间越长、强度等级越低,含水量越大。混凝土波速随着外界水压(孔隙水压)的增加,波速呈现波动性变化。
Simulation of high dam concrete working environment, the concrete standard specimen immersed in high pressure water, resulting in high permeability pore water pressure in concrete, the effect of high pore pressure concrete strength, elastic modulus, water content and sound velocity macro Changes in indicators. In the experiment, the influence of different hydraulic pressure (pore pressure), different time, different concrete grades and different maximum aggregate particle size outside the concrete test block was studied. The experiment was designed by orthogonal test design. Twenty-eight groups of tests were carried out on the influence of high-permeability pore-water pressure on the compressive strength, water content and sound velocity of concrete, while the tensile strength test was carried out in nine groups. The results show that as the pore water pressure increases, the compressive strength, splitting tensile strength and elastic modulus of concrete gradually decrease, and the loss rate increases gradually. Among them, external water pressure (pore water pressure), particle size and concrete strength grade have a significant impact on the compressive strength loss of concrete. Under the same pore water pressure, the larger the particle size, the smaller the concrete grade, the greater the loss rate. Concrete water content increases with the increase of external water pressure (pore water pressure), and is related to pore water pressure action time and concrete grade. The longer the time, the lower the strength grade, the greater the water content. As the external water pressure (pore water pressure) increases, the wave velocity of the concrete fluctuates.