中国红土的微结构和工程性质

为了研究红土的高强度、低压缩和高孔隙的工程特性,我们系统地分析了我国各类红土的物理力学性质,物质成分和微结构特征。我们发现红土强度主要来源于粒间残存或新生的化学键力、晶质氧化铁的胶结力和胶态含水氧化铁的影响。长期处于湿润条件下,赋存于孔隙溶液中的游离胶态氧化铁,虽能对粘土表面斥力起一定抑制作用,但还是不能完全阻止红粘土的胀缩行为。

The Microstructures and Engineering Properties of Red Soil in China

In order to study special engineering properties （high porosity, high strength and low compressibility） of red soils, the physico-mechanical properties, chemical composition, mineralogical composition and microstructure features of samples of red soils in China have systematically analysed with SEM, EDAX, XDA and by conventional physico-chemical test.It has been found that the strength of red soil come mainly from chemical （atomic and molcular） bonds residual or regenerated between the particles, from cementing force of crystalline ferric oxide and from influence of colloidal ferric hydroxide.Though free colloidal ferric hydroxide existed in the pore solution under the humid condition have the certain restraint on clay surface activity, they can not prevent all swell-shrink behavior of clay.