Influence of different curing conditions on water absorption of cement-based materials under dry and wet cycles

Abstract As the main structural material of a subway, the precast concrete segment is produced under the steam-curing condition, and frequently experienced dry–wet cycles environment. In this study, steam-curing and dry–wet cycling methods were used to simulate the water absorption process of cement-based materials under special circumstances. The results showed that the water absorption in cement-based materials decreased with an increase in the number of dry–wet cycles. Based on a micro-analysis, the proportion of large capillary pores (dimension >0.1 μm) in the steam-cured mortar increased during the water absorption process with the increase in the number of dry–wet cycles compared with the standard cured mortar. Through thermodynamic and kinetics analysis, the mechanism and model were calculated to explain the component transformation mechanism of cement-based materials under dry and wet cycles.