冻融循环对混凝土静态双轴受压力学特性的影响  

Static Biaxial Compression Behavior Test of Concrete with Different Freeze-thaw Cycles

作　　者：刘苗苗 彭刚[1] 王乾峰[1] 孙尚鹏 LIU Miao-miao;PENG Gang;WANG Qian-feng;SUN Shang-peng(College of Civil Engineering&Architecture,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学土木与建筑学院

出　　处：《水电能源科学》2019年第12期86-90,共5页Water Resources and Power

基　　金：国家自然科学基金项目(51579139,51709155)

摘　　要：对不同冻融劣化程度的混凝土进行了不同侧压(0、0.06fc、0.12fc、0.18fc、0.24fc,其中fc为单轴抗压强度)下的静态(应变速率10^-5/s)单双轴压缩试验,分析了冻融次数和侧压力大小对混凝土的峰值应力、峰值应变及弹性模量的影响。结果表明,混凝土的单轴和双轴抗压强度均随冻融次数的增加而减小;冻融次数越多,混凝土峰值应力随侧压的增加,其增幅越大;混凝土单轴受压时的峰值应变随冻融次数的增加而增大;相同冻融次数的混凝土,其峰值应变随侧压的增加呈先增大后减小的趋势,冻融次数越多,峰值应变的拐点所对应的侧压越小,侧压对混凝土峰值应变的敏感性受冻融次数的影响越显著;混凝土的弹性模量随冻融次数的增加逐渐减小;混凝土未冻融时,弹性模量随侧压的增加而增大,而冻融劣化的弹性模量随侧压的增加无明显改变。The static(strain rate 10^-5/s)uniaxial and biaxial compression test of concrete lateral pressure(0,0.06 fc,0.12 fc,0.18 fc,0.24 fc,where fc is uniaxial compressive strength)were carried out under different degrees of freeze-thaw degradation.The impacts of the number of freeze-thaw cycles and lateral pressure on the peak stress,peak strain and elastic modulus of concrete were analyzed.The results show that the uniaxial and biaxial compressive strength of concrete decreases with the increase of the number of freeze-thaw cycles.The more number of the freeze-thaw cycles,the higher the peak stress of concrete increases with the increase of lateral pressure.The peak strain of concrete under uniaxial compression increases with the number of freeze-thaw cycles.The peak strain of concrete with the same number of freeze-thaw cycles increases first and then decreases with the increase of lateral pressure.The smaller the side pressure corresponding to the inflection point of the peak strain,the more sensitive the lateral pressure to the peak strain of the concrete is affected by the number of freeze-thaw cycles.The elastic modulus of concrete decreases with the increase of freezing and thawing times.When the concrete is not frozen and thawed,the elastic modulus increases with the increase of lateral pressure,while the elastic modulus of freeze-thaw deterioration does not change significantly with the increase of lateral pressure.

关 键 词：冻融 侧压 双轴 力学试验 

分 类 号：TU528[建筑科学—建筑技术科学]