石灰膨胀土团聚体微结构的扫描电镜分析

SEM ANALYSIS OF MICRO-STRUCTURE OF THE PARTICLE CLUSTERS IN LIME-TREATED EXPANSIVE SOILS

石灰改良土为团聚体骨架结构,骨架是由团聚体构成,孔隙是由团聚体间的孔隙和团聚体内部微孔隙组成,粒间孔包括胶结物孔隙和压实时团聚体之间形成的孔隙。实验证明团聚体越小越有利于石灰与土的结合,微结构为链状结构;石灰掺量主要影响团聚体的表面微结构。在饱和状态时,钙离子浸入团聚体的内部,团聚体的内层也出现与外层类似结构。相同石灰掺量的样品,饱和状态和非饱和状态时钙的重量相对含量的分布有不同,非饱和状态时表面的钙相对较多,越往内部越少,内外差异很大;而饱和状态时,外层的钙比内层稍多,内外差异较小,团聚体内部形成较大的微集聚体。

Lime - treated expansive soil is of cluster structure. The micro - strcuture is made of particles, and the pole is made of micro - pole of inner of particle and the poles between particles , including a part of cementation material＇s poles. The test results show that the smaller of particle, more helpful for combining of lime and soil. Micro - structure is the chain structure ; the quantity of lime mainly effect micro - structure of the surface of soil particle. Ca^2＋ can immerge to inner of the particle saturation, and there is a similar structure in out layer with its inner layer. The samples with the same quantity of lime, there are different distributions of weight relative contents of Ca for saturated and unsaturated conditions. At the unsaturated condition, the content of Ca^2＋ is relatively more on the surface and less in the inner, aeat. At the saturated that in the inner , and the particles can be larger. condition, the mount of Ca on the surface is slightly more than