Effective Sealing and Monitoring of Small Movement Expansion Joints in Connecticut Bridges

016506082017Final ReportPDFTech ReportJHR 17-329;CCTRP 15-02AdhesionBridgesExpansion jointsField testsFoamsLaboratory testsSealing compoundsSiliconesUnited StatesConnecticutConnecticut. Dept. of TransportationMalla, Ramesh B.Shaw, Montgomery T.Kruszewski, DominicUniversity of Connecticut. Connecticut Transportation InstituteConnecticut. Dept. of TransportationUniversity Transportation Centers Program (U.S.)US Transportation CollectionOne in nine bridges in the United States is rated as structurally deficient by the 2013 Infrastructure Report Card published by the American Society of Civil Engineers. One of the primary degradation factors that contribute to compromising the structural integrity of bridges involves leaking joints, which allow water, debris and deicing corrosive materials to penetrate below the deck and damage the substructure. Currently, poured silicone sealants must be replaced every 2-3 years in Connecticut mainly due to delamination of the sealant from the substrate. A novel silicone foam sealant has been previously developed at the University of Connecticut to provide a long term, cost-effective sealing method for small-movement expansion joints. This report summarizes the laboratory testing, field installation, and in-service monitoring of the novel foam sealant, with and without primer in bridges, including wider gap joints and higher traffic volume than used in the earlier studies. As part of the laboratory testing, tension and adhesion tests were conducted to examine the general mechanical behavior of the foam sealant under uniaxial tension. Additionally, an aging study was conducted to determine the performance of the foam and solid sealants when exposed to accelerated laboratory aging, salt exposure, and primer application. The results of these tests showed that the foam sealant performed better than the commercial solid sealant in adhesion to the substrate and reduced the modulus (stress at 100 percent strain), therefore, decreasing the stresses at the interaction surface). Next, the foam and solid sealants were installed on three in-service bridges in Connecticut to examine their performance in a real operating environment. During the 6-month monitoring period, in general, fewer failures were observed on the foam sealant than the commercial solid sealant