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对经历冻融循环和海水浸泡交替作用后含气量为5.9%的引气混凝土试件进行抗压强度、质量损失、相对动弹性模量及扫描电子显微镜检测,以研究冻融循环和海水浸泡交替作用下引气混凝土的劣化机理.通过观察引气混凝土试件表面和中间处的微观结构,发现未受到冻融循环时,几乎不见裂缝和晶体,随着冻融循环次数增加,微裂缝逐渐发展,当冻融循环达到300次时,主裂缝深入发展,并有晶体产生.可见海水侵蚀和冻融循环交替作用,导致微裂缝产生并发展,同时化学反应产生了晶体.物理和化学损伤累积导致引气混凝土抗压强度降低达8.5%,但是相对动弹性模量和质量损失在冻融循环和海水浸泡交替作用前后均变化较小.
Compressive strength, mass loss, relative dynamic elastic modulus and scanning electron microscopy were used to test the air-entrained concrete specimens with 5.9% air content after alternating freeze-thaw cycles and seawater immersion to study the effect of freeze-thaw cycles Degradation mechanism of air-entrained concrete under the action of air-entrained concrete specimens was observed by observing the microstructure on the surface and middle of air-entrained concrete specimens, and it was found that there were almost no cracks and crystals during the freeze-thaw cycles. Microcracks gradually developed with the increase of the number of freeze- , When the freeze-thaw cycle reaches 300 times, the main fractures develop in depth and crystals are produced, showing that seawater erosion alternates with the freeze-thaw cycles, resulting in the generation and development of microcracks and the chemical reactions that produce crystals. The accumulation of physical and chemical damage results in The compressive strength of air-entrained concrete decreased by 8.5%, but the relative dynamic elastic modulus and mass loss changed little before and after the interaction between freeze-thaw cycle and seawater immersion.