混凝土双轴压缩徐变实验初步研究

为完善大体积混凝土仿真应力计算以及确切了解混凝土徐变性质 ,设计研制了机电伺服混凝土双轴徐变仪 ,采用高精度位移传感器测量徐变变形 ,和传统的混凝土徐变测量仪器及方法做了对比 ;获得了混凝土双轴压缩徐变实验曲线 ,与单轴徐变曲线相比 ,早龄期混凝土双轴压缩徐变比单轴徐变小 30 %左右 ;测定了多轴徐变试件的强度 ,并比较了同龄期未受力的强度 ,研究了微观切片混凝土双轴压缩应力下裂缝发展情况 ,认为低应力水平下压缩徐变试件强度并不降低 ,低应力下压缩徐变变形并非以试件损伤为代价

Preliminary study of concrete creep under biaxial compression

The biaxial creep mechanical electrical servo machine is manufactured to make sure the property of concrete creep and to complete the simulation calculation of mass concrete. High accuracy displacement sensor is used in the measurement of the creep strain. The contrast is made between the new creep machine and the traditional ones, together with the new method of the measurement with the conventional ones. Biaxial concrete compression creep curves are acquired with the help of the new machine. The biaxial creep of the early concrete is 30% less than the uniaxial ones. And the strengths of the creep specimens after loading are also measured, which are not less than the ones before loading with the same age. The microscopic conditions of the crack of the concrete under the biaxial compression are also studied which lead to the conclusion that the creep strain of concrete under low stresses is not at the expense of damage.