Fundamental mechanical behavior of CMMOSC-S-C composite stabilized marine soft clay

Abstract This study aims to address the fundamental mechanical behavior of soft clay stabilized by the composite of citric-acid-modified magnesium oxysulfate cement, silica fume, and clinker (CMMOSC-S-C composite) at different initial soil-water contents (w), amounts of stabilizing agent (Wg), and curing time (T). X-ray diffraction analysis and Scanning electron microscopy indicate that the main products of the curing reaction can be summarized as 5·1·7 phase, gel, dolomite, pyrophyllite, and minor amounts of CaO and MgO, which could be attributed to the hydration, carbonation, ion exchange, and filling. The unconfined compressive strength tests, one-dimensional consolidation tests and unconsolidated undrained triaxial compression tests show that the unconfined compressive strengths (qu), secant Young's modulus (E50), and shear strength parameters (c and φ) are positively dependent on Wg and T. However, these parameters demonstrate a negative relationship with w. The compression efficient (a2–4) is positively and negatively related to w, Wg, and T. In view of these test results, empirical relationships between the fundamental mechanical parameters of CMMOSC-S-C composite stabilized soft clay and key effect factors (w, Wg, T) are developed to predict the qu, E50, a2–4, c, and φ values at any w, Wg, and T.