A review of cement-soil in engineering geological applications: mixing mechanisms, mechanical behavior, and constitutive models

Abstract Cement-soil stabilization is a fundamental ground improvement technique in engineering geology, critical for constructing foundations, embankments, and infrastructure on weak or problematic soils. By incorporating cementitious materials with in-situ soil, this method increases bearing capacity and minimizes settlement, thereby increasing the safety and longevity of geotechnical structures. This review comprehensively examines the mechanisms of cement-soil stabilization, including cement hydration and the complex interactions among clay particles, inorganic salts and organic matter, which together form a strengthened soil matrix. The mechanical performance behavior of cement-soil is influenced by binder and soil properties, as well as mixing and curing conditions. Advances in constitutive modeling transitioning from empirical to sophisticated frameworks, are reviewed and highlighted for their ability to capture the multifaceted behavior of cement-soils under diverse conditions. The review identifies key future research directions, including the development of novel materials and additives, refinement of constitutive models and simulation techniques, and comprehensive evaluation of long-term durability and environmental impacts. Emphasis is placed on in-situ testing techniques, particularly for offshore engineering applications, and on the adoption of sustainable alternatives to Ordinary Portland Cement in light of its high energy demands and carbon emissions. Promising substitutes such as alkali-activated binary blended mortars and belite-ye’elimite-based binders are suggested for their potential to strengthen soft soil, reduce emissions, and shorten curing times. This review provides a critical foundation for advancing sustainable and effective cement-soil stabilization strategies in engineering geology.