Tensile strength characteristics and calculation methods of the cement stabilized soil

Cement stabilized soil has the advantages of high strength, small deformation, simple construction operation, easy quality control and remarkable economic benefits. It is widely used in subgrade filling, foundation pit backfilling, slope protection and foundation replacement. Soil-cement cracks affect the normal operation of roadbed engineering and may even endanger the safety of railway roadbed. Therefore, the design of cracks and deformation structures of railway subgrade or foundation requires a certain degree of understanding of the tensile strength of the compact-filled soil, and it is of great significance to determine the tensile strength of the cement-improved soil. The crack resistance of the cement stabilized soil is an important factor affecting engineering application. Tensile strength is the key parameter to measure the crack resistance of the cement stabilized soil. In this paper, a direct test method to measure the tensile strength of the cement stabilized soil is designed in the conventional unconfined compression apparatus. The effects of cement content, curing age, water content and dry density on the tensile strength of the cement stabilized soil are systematically studied. The tensile strength of the cement stabilized soil increases with the increasing cement content, curing age and dry density, and decreases with the increasing moisture content. The exponential function relationship between the tensile strength and e_t/A (e_t is the void ratio of cement stabilized soil) is established. The correlation between the tensile strength and unconfined compressive strength and matrix suction is also statistically established.