Impact of wetting and drying cycles on the mechanical behaviour of a cement-treated soil

Abstract

The core objective of this study is to analyse the impact of the wetting/drying protocol on the mechanical behaviour of a cement-treated sand. The impact of two types of wetting and drying cycles of different magnitudes was evaluated with a quantitative approach based on the stress-dilatancy approach. The main effect of the wetting/drying cycles is to alter the bonds and consequently diminish the mechanical performance. The weathering effect is shown to be dependent on the cement dosage but also on the intensity of the cycles. For the samples treated with 4% cement, the very first cycles seem to bring the most alteration of the mechanical performance. For those treated with 1% cement, however, the accumulation of multiple cycles leads to more progressive degradation. The evaluation of the bonding ratio permitted the quantitative assessment of the treatment effect and the weathering progress with cycles. The results highlight the role of the imposed wetting/drying cycle technique for a better assessment of the long-term performance of treated soils, even if the definition of an adequate weathering protocol that makes sense with regard to the real solicitation endured by engineered structures deserves additional investigation.