Abstract: In order to clarify the influences of typical harsh marine environments on the performance evolution of silane-impregnated concrete, three different simulated environmental experiments were designed, including immersion, ordinary wet/dry cycling, and irradiation wet/dry cycling. After exposure to these environments for 90 and 180 d, experiments on contact angle, water absorption ratio, alkyl content and chloride content were carried out. The results indicate that the performance evolution of silane-impregnated concrete is closely related to the exposure environment and the action time. The silane gradually fails and destroys in the typical marine environments. The initial contact angle of freshly impregnated concrete is 97.0°, which decreases to 73.1°, 46.4°, 28.2° after 180 d of immersion, ordinary wet/dry cycling, and irradiation wet/dry cycling, respectively. The alkyl content at 1 mm of silane-impregnated concrete is lower than that at 2 mm. Compared with immersion, short-term irradiation wet/dry cycling reduces the water content in surface pores of concrete, facilitating the dehydration condensation reaction of silane, reducing the early water absorption ratio and improving the chloride resistance of silane-impregnated concrete. Specifically, the irradiation wet/dry cycling group exhibits the lowest water absorption ratio and chloride diffusion coefficient at 90 d. However, with the extension of irradiation wet/dry cycling, the degradation of silane accelerates, and the water absorption ratio and chloride diffusion coefficient at 180 d both increase significantly.

Key words: silane-impregnated concrete, irradiation, wet/dry cycling, alkyl content, chloride diffusion coefficient