改善仿真混凝土塑性的两种方法

Experimental Research on Two Methods to Improve Plasticity of Emulation Concrete

针对仿真混凝土材料脆性过大的特点,通过一系列的试验研究,提出了在原料中添加黏土或细橡胶颗粒来改善其脆性的2种方法.结果表明:与普通仿真混凝土相比,添加黏土可以改善仿真混凝土的脆性,增强其变形能力;依据黏土仿真混凝土的各力学参量随黏土含量变化规律的理论拟合曲线,可以确定符合某仿真试验模型所需要的黏土仿真混凝土的配合比;橡胶仿真混凝土在破坏过程中表现出良好的变形协调性,在承受最大荷载时未产生脆性断裂,而是呈现出经过较大塑性变形后的延性破坏现象.

Emulation concrete（EC） is a kind of concrete with low elastic modulus and low strength and used to perform the dynamic failure test on simulation model. Since emulation concrete is quite brittle, a series of tests were carried out to evaluate two methods of improving the brittleness of the material with adding clay and fine rubber particles in emulation concrete. The test results of clay emulation concrete with differ- ent clay contents are compared with those of standard emulation concrete, and it is found that clay mixed in emulation concrete can improve its brittleness and the deformability. The mathematical model is estab- lished to well estimate the mechanical parameters for any clay emulation concrete with respect to clay con- tent. The functions presented are helpful in establishing the targeted basic engineering properties of the clay emulation concretes for the mix design purposes. According to that, the researchers can find the mix proportion of the clay emulation concrete for the need of the test. Another way to improve brittleness of emulation concrete is to add fine rubber particles in the emulation forming rubberized concrete. By analy- zing test results of rubberized emulation concrete, it is found that the material shows good deformation compatibility in fracturing process of specimens. The specimens do not show brittle fracture under the maximum load, but rather show ductile failure with large plastic deformation.