Experiment of swelling properties of improved typical expansive soil in Yunnan by industrial alkali residue
1. College of Architecture and Planning, Yunnan University, Kunming，Yunnan 650000, China； 2. China Railway Tunnel Group Co., Ltd., Sanhe， Hebei 065200, China
Abstract：The laboratory test was used to study the typical expansive soil in Mengzi area of Yunnan Province improved by industrial alkali residue. The effects of cement amount, industrial alkali residue amount and cementindustry alkali residue amount on the expansion characteristics of expansive soil were investigated. The test results show that industrial alkali residue, cement and cementindustry alkali residue can all reduce the free expansion rate of pure expansive soil. The minimum expansion rate of industrial alkali residue modified soil is 0.77 times of that of cement. When the modified expansive soil admixture ratio of industrial alkali residue and cement are respectively more than 30% and 6%, the displacement curve of expansion and shrinkage is not change. When the optimum mixing ratios of industrial alkali residue and cement are respective 30% and 6%, the minimum expansion force of industrial alkali residue modified soil is only 0.33 times of that of cement modified soil and 0.05 times of that of pure expansive soil.The optimum ratio of industrial alkali residue admixture to expansive soil cohesion and internal friction angle is from 30% to 40%.
