Effect of wetting on strength of cemented sands

When cemented sands were exposed to repetitive wetting and drying during curing, their 28-day unconfined compressive strength was evaluated experimentally. Weakly cemented sand with four different cement ratios was compacted at optimum water content and cured for 28 days. Wetting at last one day was found to decrease the unconfined compressive strength of cemented sand, whereas wetting in the middle of curing exhibited the strength increase. The strength reduction due to wetting at last one day decreases as a cement ratio increases. The strength of a specimen with repetitive wetting and drying during 28 days curing increases as the number of wetting increases until 3 cycles. After 3 cycles of wetting and drying, the strength becomes constant or slightly decreases due to insufficient water for hydration.