EXPERIMENTAL STUDY AND ANALYSIS ON DETERIORATION MECHANISM OF DAMAGED CONCRETE INDUCED BY MECHANICAL LOAD
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摘要: 在分析混凝土荷载损伤后混凝土劣化机理的基础上,通过短期轴拉和短期轴压静载后混凝土抗氯离子侵蚀和抗冻性性能试验,研究荷载损伤对混凝土长期耐久性能的影响。结果表明:受压荷载作用下混凝土依次经历可逆、不可逆和加速劣化三个劣化阶段,受拉荷载下混凝土表现为耐久性持续劣化。在65%和75%轴拉荷载水平,混凝土表观氯离子扩散系数分别增加了6.4%和34%,表面氯离子浓度分别增大了10%和40%,显现出轴拉荷载的负效应;随着轴压荷载水平的增加,混凝土抗冻性能经历一个正效应到负效应的转变。Abstract: The durability failure mechanism of damaged concrete induced by mechanical load was analyzed firstly in this paper.Then through the chloride penetration test and freezing-thawing test of concrete specimens after direct uniaxial tensile or compressive loading,the load-induced damage influence on the long-term durability of concrete was investigated.The results indicated that concrete changed from reversible phase,irreversible phase to accelerated degradation phase under the action of compressive load.But the concrete under tension load experienced continuous degradation.When the uniaxial tensile load level reached the 65% and 75% of ultimate capacity,the apparent chloride diffusion coefficient of concrete increased by 6.4% and 34%,and the surface chloride concentration increased by 10% and 40% respectively,which showed the negative effect.But with the increasing of uniaxial compressive load level,the influence on frost resistance of concrete experienced from a positive effectto a negative effect transformation.
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