极细颗粒黏土的比表面积测试与分析(英文)

Experiment and Analysis of Specific Surface Area of Tiny-particle Clay

软黏土如淤泥和淤泥质土的固相物质主要由极细粒径的黏土矿物和胶状物质组成,其力学性质、渗透性以及流变性等与颗粒的比表面积及表面电荷性质和密度密切相关。因而,比表面积测试对分析极细颗粒土的物理力学性质具有重要作用。采用乙二醇乙醚(EGME)吸附法和氮吸附(BET)法分别对膨润土、高岭土、石英和长石以及其混合土、深圳土、科威特土等极细颗粒土的比表面积进行测试和分析。比表面积测试结果表明,对于同样颗粒尺度的土情况,比表面积膨润土远大于高岭土,石英与长石相近;深圳土小于科威特土;随着膨润土相对含量的增加,试样的比表面积迅速增加;EGME法与BET法能够分别测出膨润土的总比表面积与外比表面积,高岭土的总比表面积与外比表面积相当接近,石英与长石的测试结果也比较接近。文中的比表面积测试和分析对深入了解影响软黏土的渗流固结与流变性等物理机制具有指导意义。

Solid-phase material in soft clay, such as slit and mucky soil, is mainly composed of tiny-particle clay minerals and colloids. Its mechanical and rheological properties, permeability are closely related to specific surface area（ SSA for short）, surface charge property and charge density. Hence, SSA test has great influence to analysis of physical and mechanical properties of tiny-particle clay. EGME method and BET method are adopted to carry tests on bentonite, kaolinite, quartz, feldspar and their mixtures, Shenzhen soil and Kuwait soil. The results show that the SSA value of bentonite is much higher than kaolinite,quartz is close to feldspar; Shenzhen soil is smaller than Kuwait soil. The SSA values of samples increase rapidly with the augment of bentonite relative content. Total and external SSA of bentonite can be measured respectively by EGME and BET method ,while the two methods are nearly the same for kaolinite, and SSA of quartz is close to feldspar. The test and analysis of SSA in this paper possess guiding significance for further understanding of physical mechanism that influence the seepage consolidation and rheology in soft clay.