SPR 14-492: Improved Bridge Joint Materials And Design Details

Objectives: 1) Review current closed joint types/seal materials. Identify seals currently using neoprene and seek substitute materials offering better long-term flexibility. Identify seal reinforcing fibers to resist punctures. 2) Work with joint/seal manufacturers and material suppliers to introduce better performing joint types/seals and improved small deck movement joint seals (including both preformed and poured seals). 3) Inspect recent large bridge designs with finger joints to determine trough designs. Inspect existing troughs under open joints and assess performance. Provide feedback on performance of existing trough systems to the Division of Bridges along with recommendations for modifications (if necessary). Investigate the performance of flexible self-purging troughs used by the Kansas DOT (including joint designs and trough material). 4) Review recent designs for troughs/gutters to be used with closed joints. Review the potential use of diverters in place of troughs for large finger dams. Work with the Divisions of Bridges and Maintenance to develop experimental projects using those. 5) Interface with AASHTO to develop a test program for evaluating joint seals and proprietary joints modeled after the NYSDOT joint qualification procedure. Background: Most KYTC bridges have some type of deck joints (open or closed). Open joints commonly have troughs to prevent leakage onto underlying bridge components (beam ends, bearings and pier caps/abutments). Closed joints are sealed with a flexible material (e.g. preformed or poured seals) to accommodate deck movement and to keep out rainwater which is commonly contaminated with corrosive deicing salts. Troughs frequently collect debris hindering their function. Seals of closed joints typically fail after a few years and permit rainwater to seep onto underlying bridge elements where it causes considerable damage. While the initial cost of joints/seals is low relative to the cost of a bridge, they have a major cost impact on follow-on maintenance. Better performing joints/seals will extend their service lives and minimize maintenance expenditures.