多向压复合应力状态下A-E-C的强度性能研究

Study on strength of air-entrained concrete under combined multriaxial compression stresses

为准确认识引气混凝土(A-E-C)在多向压复合应力状态下的强度性能,通过试验对立方体强度为C30的A-E-C进行了单向压、双向压(应力比α=σ2∶σ3=0.25∶1.0,0.50∶1.0,0.75∶1.0,1.0∶1.0)以及三向压(应力比α=σ1∶σ2∶σ3=0.1∶0.25∶1,0.1∶0.5∶1,0.1∶0.75∶1,0.1∶1∶1)加载状态下的强度特性研究.对试件的破坏形态以及6个面上裂缝的走向进行了观察描述,根据试验结果,分析了应力比对多向压复合状态下A-E-C的极限强度的影响规律;并与在单向压、多向压(双向压以及三向压)复杂荷载作用下普通混凝土的研究内容进行了比较分析.在此基础上,建立了相应的破坏准则,为A-E-C结构的有限元分析提供了试验、理论依据.

To accurately understand the strength performance of air-entrained concrete （A-E- C） under combined multiaxial compression stresses state, properties of C30 air-entrained concrete under uniaxial compression, biaxial compression （stress ratio a=σ2 ：σ3 = 0. 25 ：1.0, 0.50 ： 1.0, 0.75 ： 1.0, 1.0： 1.0） and triaxial compression （stress ratio a= σ1：σ2 a2：σ3= 0.1 ： 0.25 ： 1,0.1 ： 0.5 ： 1, 0.1： 0.75 ： 1, 0.1 ： 1： 1） are investigated in this paper.The failure characteristic of specimens and the direction of superficial cracking are observed. Based on the test data, the influence of stress ratio on the ultimate compressive strength is analyzed respectively. The comparison and analysis between the experimental results in this paper and the experimental results got by other authors are given. The failure criterion withconsideration of the influence of stress ratio is proposed which provides the experimental and theory founda- tions for strength analysis of air-entrained concrete structures subject to complex loading in cold marine environment.