水泥加固漳浦滨海风积砂的细观结构分析

A Mesostructural Analysis of Cement Solidified Zhangpu Coastal Aeolian Sands

利用Olympus金相显微镜,对不同水泥剂量及养护龄期的水泥加固漳浦滨海风积砂进行了细观结构分析,从细观结构角度研究了水泥对滨海风积砂的强度及抗液化能力的影响。试验得出:水泥水化产物以絮状、片状相互交错重叠,发生了凝聚作用,从而形成团粒体;团粒体进一步发展形成空间网格状骨架密实结构,使得固化土的级配更加良好,提高了固化土的强度;水泥土密实的空间网格状结构使得孔隙水不易渗出,导致施加循环荷载初期动孔隙水压力急剧上升,同时,掺入水泥提高了水泥土试样的强度,因此施加循环荷载后期动孔隙水压力发展缓慢;低剂量水泥,7天内基本完成水化作用,龄期28天对细观结构影响不大。

The paper carries out amesostructural analysis of the reinforcement of Zhangpu coastal aeolian sand with the cement of different mixing amountand different curing periods using the Olympus metallographic microscope and studies the influences of cement on the strength and liquefaction resistance of coastal aeolian sand on the basis of mesostructure.The results show that the hydration products of cement,overlapping with each other in the form of flocculent and schistose shapes,have a great effect on the condensation to shape the granular structure.This condensation is enhanced with the increase of mixing amount of cement,and the granular structure is further developed to form a spatial grid-like skeleton.All of these contribute to perfecting the gradation of solidified soil,and hence improving its strength.Besides,the dense spatial grid structure of cement makes it difficult for pore water to sedate,resulting in a sharp rise in the dynamic pore water pressure at the initial stage under cyclic loading and the strength of cement soil sample is improved by adding cement,so the development of dynamic pore water pressure at the later stage under cyclic loading is slow.Even if the mixing amount of cement is not very high,the hydration of cement can also be basically completed within 7 days,so the curing period of 28 days has little impact on the mesostructure.