关键词: 硫酸腐蚀, 土与混凝土接触面, 剪切试验, 双曲线模型

Abstract: To investigate the effect of sulfuric acid corrosion on the mechanical behaviors of the pile-soil interface, large-scale direct shear tests were conducted on the interface between sand and concrete slabs under corrosion of 0, 31, 93, 154 days in sulfuric acid solution. Tests measured the relationship between shear stress and shear displacement of sand-corroded concrete interfaces after different corrosion durations. Experimental results indicate the hyperbolic relationship between shear stress and shear displacement. The shear failure of interface agrees well with the Mohr-Coulomb strength failure criterion. As the corrosion time increases, the cohesive force on the interface decreases, and the friction angle of interface, the shear strength and the shear displacement at the peak shear stress increase. Sand concrete interface failure tends to fail by sand itself under shearing. The shear displacement corresponding to the peak shear stress at interface between uncorroded concrete and sand is referred to as a standard. By comparing the interfacial shear stress with different corrosion times with the standard shear displacement, the shear stress after 5 months of corrosion is found to be smaller than that of uncorroded one. Finally, hyperbolic model is established and its parameters are obtained through the fitted relationship between tested shear stress and shear displacement, which provides a reference for further numerical simulation.

Key words: sulfuric acid, sand-concrete interface, shear test, hyperbolic model