Determining the effective service life of silane treatments in concrete bridge decks

Silane is a commonly used surface treatment to reduce water entry into concrete. Only limited work has been done to show the effective lifespan of silane treatments. This work uses 360 cores taken from 60 bridge decks treated with silane that have been in-service between 6 and 20 years. Optical staining techniques showed that the average silane thickness started decreasing after 12 years of service. The deterioration primarily occurs from the bulk of the concrete towards the surface. This suggests that deterioration from the alkali pore solution of the concrete may be important.