双向加载下混凝土的力学特性研究

Mechanical Characters of Concrete under Biaxial Compression

为了研究双向加载下混凝土的强度,采用河南理工大学的双向等刚度加载设备,对C50混凝土立方体试块进行了单向和双向σ_1∶σ_2=1∶1和σ_1∶σ_2=2∶1的加载试验,并将单轴下混凝土的强度与双轴下混凝土的强度进行了比较;得出了不同加载条件下的混凝土应力应变曲线,给出了实验过程中观察到的现象,探讨了双轴下混凝土的破坏机理.通过研究表明:单向加载下,混凝土的破坏属于剪切破坏,双向加载下,混凝土的破坏属于拉—剪破坏;双向加载条件下,混凝土的破坏强度比单轴破坏强度要高,主要是中间主应力的影响.

In order to study on the strength of concrete under biaxial compression,the uniaxial and biaxial compression σ1∶σ2=1∶1 and σ1∶σ2=2∶1 under the loading tests of C50 concrete cube specimens were carried out. We used the using sotropic biaxially loading system of Henan polytechnic university of China and compared the strength of concrete under uniaxial and biaxial concrete. The stress-strain curves of concrete under different loading conditions were obtained,the phenomena observed in the experiment were given,and the failure mechanism of concrete under biaxial loading was discussed. The research results indicated that the specimen failure modes were the shear failures under the uniaxial loading. The specimen failure modes under the biaxial loading were tension-shear failures. The damage strengh under biaxial loading of biaxial loading was serious than that of uniaxial loading and the mainly influence was intermediate principal stress.