Long-Term Effect of Curing Temperature on the Strength Behavior of Cement-Stabilized Clay

The influence of curing temperature on the strength development of concrete, mortar, or cement-stabilized granular soils has been widely reported in the literature. However, there are fewer studies focusing on cement-stabilized clay. The key difference is the presence of pozzolanic reactions in cement-stabilized clay, which give rise to more complex strength-development behaviors than those of concrete, mortar, or cement-stabilized granular soils. This paper aims to clarify this difference using extensive data collected as part of a land reclamation project in Singapore. Five different mixes of cement-stabilized Singapore marine clay are cured under different temperatures. Their strength development with time is studied by testing the specimens under unconfined compression at various curing ages (up to 1 year). The experimental results show that a higher curing temperature gives rise to not only higher short-term strengths but also higher long-term/ultimate strengths. Based on the experimental results, a model is proposed that combines the maturity theory commonly used for concrete or mortar with a proposed temperature-enhanced strength factor, which takes into account the effect of curing temperature on pozzolanic reactions occurring in cement-stabilized clay. This proposed model is validated by another independent Singapore data set and data sets collected from the literature.