黏土混凝土在土坝防渗墙中的应用

Clay concrete for cutoff wall in earth dam

本文在对黏土混凝土的原材料选用、配合比设计、拌合物性能、物理力学性能等进行试验的基础上,配制出了满足米家寨水库除险加固防渗墙工程需要的黏土混凝土,并成功应用于该工程。研究表明,黏粒含量较高的黏土对降低混凝土弹性模量效果显著,并使混凝土具有相对较高的强度和抗渗性能;通过调整水胶比、黏土掺量、不同外加剂的掺量,可以配制出不同性能的黏土混凝土;黏土混凝土抗压强度随龄期增长系数与普通混凝土在7d时基本一致,90d则明显高于普通混凝土;与28d相比,黏土混凝土90d弹性模量增长很少,但抗渗性能提高约5倍。

Based on the test results of raw material, mix design, workability and physical-mechanical performances a kind of clay concrete for cutoff wall in Mijiazhai Project is proposed. It is found that the clay remarkably reduces the elastic modular of the concrete and the concrete has relatively high strength and low seepage coefficient. Clay concrete with different performances can be obtained by regulating the ratio of water to cement and clay, amount of clay, and amount of additive. The compressive strength increasing coefficient of clay concrete is the same as that of ordinary concrete at 7d, but the coefficient of 90d is much higher than that of ordinary concrete. The elastic modulus of clay concrete at 90d is slightly higher than that at 28d, but the impermeability is raised by 5 times.