定侧压荷载作用下引气混凝土的强度性能

Strength of air-entrained concrete under compression with constant confined stress

为准确认识复杂应力状态下,引气混凝土材料的性能特征,对强度等级为C30的引气混凝土进行了双向非等比例加载下的受压试验,观察了引气混凝土试件在双向非等比例荷载作用下的破坏模式和试件表面裂缝的特征.结果表明:与单轴强度相比,引气混凝土在定侧压应力下双轴抗压极限强度有较大程度的提高,提高程度在侧压应力系数为0.50时达到最大,然后提高程度会随侧压应力的继续增加而有所降低;将本试验结果与其他试验结果进行了比较分析;在此基础上,建立了考虑侧压应力比影响的强度准则,为处于复杂受力状态下的引气混凝土结构的有限元分析提供试验和理论依据.

To accurately understand the properties of concrete materials under complex stress state, the compression tests of C30 air-entrained concrete under compression with constant confined stress were conducted. The failure characteristic of specimens and the cracking direction were observed. The results show that the strength under compression with constant confined stress was higher than the uniaxial compressive strength. The increasing value of strength reaches maximum when the lateral compressive stress ratio is 0.50, and the increasing value of strength decreases with the increasing of lateral compressive stress. The experimental results in the paper were compared with those in literature. The strength criterion with consideration of the influence of stress ratio was proposed to provide experimental and theory foundations for strength analysis of air-entrained concrete structures subjected to complex loading in cold environment.