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

• Published in: Applied clay science 2020-07, Vol.192, p.105635, Article 105635
• Main Authors: Zhu, Jian-Feng, Xu, Ri-Qing, Zhao, Hong-Yi, Luo, Zhan-You, Pan, Bin-Jie, Rao, Chun-Yi
• Format: Article
• Language: English
• Subjects: Citric-acid-modified magnesium oxysulfate cement; Compressibility; Shear strength parameters; Soft clay; Stabilization; Unconfined compressive strength
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2020.105635

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. •The products of CMMOSC-S-C stabilized soft clay mainly consist of 5·1·7 phase, gel, dolomite, pyrophyllite, a few CaO and MgO.•Wg and T are beneficial to the evolution of qu, E50, c and φ of CMMOSC-S-C stabilized soft clay regardless of a2-4.•w plays an inhibiting role on the evolution of qu, E50, c and φ but behaves well in promoting a2-4.•Empirical relationships between qu, E50, a2-4, c, and φ values and w, Wg, and T are developed.