Mechanical and micro-structure characteristics of cement-treated expansive soil admixed with nano-MgO

Because of some limitations in engineering applications of cement-treated expansive soil, nano-MgO (NM) is used to improve its mechanical characteristics and micro-structure. NM-modified cement-treated expansive soil (NMCS) was analyzed by using unconfined compressive strength (UCS) tests, and NM contents were 0%, 0.5%, 1%, 1.5%, and 2%, respectively. Results of the test suggested that (1) a new statistical method was proposed to better correct the UCS test error of NMCS. (2) The stress-strain curve of NMCS was characterized by softening type. (3) The compressive strength, stiffness, and toughness of cement-treated soil were improved after adding NM, and the optimal NM content was 1%. (4) Microscopic tests showed that NM promoted the cement hydration reaction and filled the pores of soil samples, making the internal structure of cement-treated soil more compact. Accordingly, it is feasible to investigate the applicability of NMCS in engineering.