热活化非高岭石质粘土制备水泥混合材的探索研究

以欧洲某国储量丰富的非高岭石质粘土为原料,研究了其煅烧活化制度,并以热活化非高岭石质粘土和石灰石作为混合材制备了复合水泥。研究结果表明:非高岭石质粘土以石英、绿泥石和白云母等矿物为主,其最佳活化制度为850℃煅烧3h,获得的热活化非高岭石质粘土28d活性指数为83%,以其与石灰石共同作为混合材可配制熟料含量50%~70%且力学性能等级32.5MPa及以上的复合水泥。复合水泥水化进程和水化产物与石灰石煅烧粘土水泥相类似,均含有碳铝酸盐、Ca(OH)_(2)等水化产物。

Evaluation of Effective Stresses and State Surfaces for Unsaturated Clayey Silt

Terzaghi had established soil mechanics as an academic scholarship due to the discovery of the principal of effective stress for saturated soils when he considered the consolidation theory of saturated clay. The reason of the existence of the effective stress is that soil particles and water are composited by incompressible solid and liquid. Although air is very compressible fluid, the principle of effective stress is also used in unsaturated soils in the resent developed numerical analyses. Schrefler＇s equation is most frequently used, but the effective stress is not verified by the experimental results. In this study, the equations for unsaturated soils proposed by Schrefler, Aitchison, Khalili and Khabbaz and Kohgo are compared with using the results of suction controlled consolidometer tests. As a result, the effective stress for unsaturated soils calculated by Schrefler＇s equation was average of them.