Strength development of cement-treated soils: Effects of water content, carbonation, and pozzolanic reaction under drying curing condition

•The strength under the drying condition was attributed to carbonation and suction.•The contributions of the chemical reactions to strength were quantitatively understood.•The relationship between the strength and the water content was well established.•Carbonation could increase the strength at the early age of cement-treated soils.

This study investigates the effects of carbonation, water content, and pozzolanic reaction under the drying condition on the strength development of cement-treated soils. Two soil specimen types (i.e., sand mixture and sand-loam mixture) were cured under sealed, drying, and changing water content conditions. The measured compressive strength of the specimens under the drying condition was higher than that under the sealed condition because of carbonation and suction. The relationship between the strength and the water content under the drying condition was established. The progress of the chemical reactions in the specimens was also evaluated. The contributions of cement hydration, carbonation, pozzolanic reaction, and suction to strength development under the drying condition were then quantitatively analyzed. The results indicated that not only cement hydration and pozzolanic reactions, but also carbonation and changes in the water content, substantially contributed to the strength development of cement-treated soils.