Research On The Composition Of Expansive Soil Of He-Xu And He-An Expressway And Its Microstructure

By using X-ray Diffraction Analysis, Polar microscope, Scanning Electron Microscope(SEM) and Chemistry Analysis, the mineral compositions of the expansive soil of He-Xu and He-An expressways is determined in this dissertation. The clay minerals of it are tested to mainly be isinglass, montmorillonite and a little kaolin, and the oddment minerals are quartz, mica, calcite, feldspar etc. The relationship between the distensibility and shrinkage with the clay minerals, especially that of montmorillonite is studied in this paper. In addition to, the microstructure of expansive soil are also studied here through SEM. The relationship between the engineering properties of expansive soil and the microstructure is also studied here. Studies show the distensibility and shrinkage and the special properties of expansive soil are mainly controlled by its mineral composition(especially clay mineral), CEC and its microstructure.