海水冻融后轻骨料混凝土的双轴压压强度和变形性能

Strength and deformation characteristics of lightweight aggregate concrete under biaxial compressive stress after freeze-thaw cycling in seawater

针对我国渤海湾北部海域轻骨料混凝土结构的工作环境和受力状态,进行了海水中不同冻融循环次数后轻骨料混凝土的双轴压压强度试验,考察了试件的破坏形态和表面裂缝的走向特征。根据试验结果,分析了极限抗压强度随冻融循环次数和应力比的变化规律,并在此基础上建立了考虑海水冻融影响的双轴压压强度准则。探讨了冻融循环作用后轻骨料混凝土的双轴压压变形性能,包括峰值应变、应力-应变关系随冻融循环次数和应力比的变化规律。研究结果说明,随冻融循环次数的增加各种应力比下的应力-应变关系曲线均逐渐扁平,峰值应力点明显下降并右移,说明混凝土的极限抗压强度逐渐降低。

The biaxial compressive strength of lightweight aggregate concrete after various cycles of freezethaw in sea water is experimentally studied and the failure characteristics of specimens as well as the direction of surface cracking are investigated. Based on the test data, the ultimate compressive strength varying with freeze-thaw cycles and stress ratio are analyzed. The biaxial compressive strength criterion with consideration of cyclic freezing and thawing in seawater are proposed. It is found that following the increase of freeze-thaw cydles, the curves of stress-strain relationship under various stress ratios tend to mild and the peak stress remarkably decreases, it means that the ultimate compressive strength is gradually reduced.