Abstract：In order to increase the use of the recycled resources and reduce potential impact of the wasted tires on the environment，the strength of expansive soil improved by wasted tire rubber powder was studied. The expansive soil is mixed with wasted tire rubber powder in a different proportions of 10，20，and 30%，and a different water proportions，which are about 15%，18% and 21%. Then consolidation fast shear tests were conducted. During the tests，impact of normal stress and the amount of rubber powder on the shear strength of the expensive soil are considered. The relationship between shear displacement and the corresponding shear stress relationship are also taken into account. Tests present the characteristics of the improved expansive soil shear strength. It was shown that the internal friction angle and the shear strength of the expansive soil increases as the amount of the wasted tire rubber powder increases；and the internal friction does not have a remarkable change，while the cohesion changes obviously. It confirms the assumption that wasted tire rubber powder can improve the expansive soil greatly. It provides a new improving method to reduce the engineering disaster caused by the expansive soil.
