三向应力状态下混凝土强度和变形特性研究

对设计强度为１０MPa的混凝土立方体试件进行三轴压缩试验,系统研究了等围压条件下混凝土的强 度和变形特性,围压分别为０,４,８,１２,１６MPa５个量级;同时研究了不等围压条件下混凝土强度变化特性, 试验表明,随着围压增加,混凝土的极限抗压强度有明显增强的趋势;随着小主应力的增加,中主应力的影响 有减弱的趋势;峰值应力处应变随围压增加幅度显著。得出了在不同恒定围压下混凝土的应力应变全过程曲线; 通过与当前文献资料的对比分析,指出了在混凝土结构计算中适用的强度及变形表达式,为工程实践提供了 依据。

Behavior of Concrete Under the Triaxial Compression

Experimental tests on 10 mm cubic concrete specimens were carried out using the servo hydraulic testing machine. Specimens subjected to equal constant confining pressures of 0, 4 MPa, 8 MPa, 12 MPa and 16 MPa respectively were conducted to investigate the deformation and strength characteristics of concrete. In addition, strength properties of concrete under unequal confining pressures were also investigated. Based on the test results it was revealed that the ultimate strength increases dramatically with the increasing confining pressure and the strain at peak stress increases even more pronounced. With the increasing minor principal stresses, the enhancement effect of middle principal stresses on the ultimate strength became weak. The complete stressstrain curves were obtained at different confining pressures. By comparison with the current literature, appropriate formulas of concrete strength and deformation were proposed for the engineering purpose.