不同水灰比混凝土冻融循环后双轴压试验研究

对水灰比为0.45、0.55的普通混凝土试块分别进行0、25、50、75和0、25、50次冻融循环作用后双轴压荷载试验,测得了试块的双轴压强度.通过对试验结果进行分析,讨论了水灰比、冻融循环次数及中间应力对双轴压强度的影响,发现双轴压强度高于单轴压强度,且随冻融循环次数的增加而降低;在分析试验资料的基础上,建立了冻融循环作用后普通混凝土在主应力空间的破坏准则,可为复杂应力状态下可能经受冻融循环作用的普通混凝土结构的设计、维修提供参考.

Experimental investigation on different w/c concrete under biaxial compression after freeze-thaw cycles

The experimental study of plain concrete specimens of water cement ratio 0. 45, 0.55 under biaxial compression after 0, 25, 50, 75 and 0, 25, 50 cycles of freeze-thaw respectively was completed. The biaxial compressive strength behavior of concrete after different cycles of freeze-thaw was tested. The influences of w/c, freeze-thaw cycles and the stress ratio on the biaxial compressive strength were analyzed. It is tested that the biaxial compressive strength is larger than the uniaxial compressive strength and decreases as freeze-thaw cycles increase. Based on the test data, the failure criterion expression in terms of principal stress after different cycles of freeze-thaw is proposed, which is essential to economical and reliable design of plain concrete structure suffering from freeze-thaw cycles under complex stress condition.