Expected life of silane water repellent treatments on bridge decks phase 2 / M. Tyler Ley, Mehdi Khanzadeh Moradllo.

Abstract

This report outlines the investigation of the service life of silane sealers on Oklahoma bridge decks as well as laboratory investigation of a silane sealer and a two part sealer that uses both silane and epoxy. The performance of silanes on bridge decks was completed on 60 bridges that were in service between 5 to 20 years. Samples were taken from the travel lane and the shoulder. The work found that after 12 years that 100% of the silane applications were effective. By 15 years then only 68% were still effective and between 17 to 20 years then only 16% were still effective. The investigations suggest that abrasion was not a major deterioration mechanism; instead, deterioration from the high alkaline pore solution is suggested to be of importance. This work goes on to investigate a two part system of silane and epoxy sealer, a silane, and then a control sample and their resistance to chloride penetration. Both sealers show improved performance over the sample with just concrete. Additionally, a new experimental technique is presented that is capable of non-destructively imaging the penetration of external fluids into paste and mortar. This test is rapid, accurate, and can be used for in-situ testing. This test method again shows that the silane investigated was effective at reducing the ingress of ions.