Bridge Expansion Joint for Bridges with Expansion Joints in Deck Coatings

Protective deck coatings on bridge decks must be integrated with the expansion joint to provide continuous protection across the joint location. The coating must be applied to the joint components and the adjacent deck surface to prevent water infiltration and corrosion. Coating selection for expansion joint areas must consider the movement of the joint. Standard rigid coatings will crack at the joint location due to the movement. Flexible coating systems based on polyurethane or polyurea can accommodate the movement without cracking. The coating must be compatible with the joint materials and the deck surface. Coating application at the joint location requires careful preparation of the joint components and the adjacent deck surface. The surfaces must be clean, dry, and free of loose material. The coating must be applied in accordance with the manufacturer's instructions, including the correct film thickness and curing conditions. Coating thickness at the joint location must be sufficient to provide the required protection. The minimum coating thickness is typically 250-500 micrometers for protective coatings on bridge decks. Thicker coatings provide better protection but may crack more easily at the joint location due to the increased stiffness. Coating maintenance at the joint location requires annual inspection for cracking, debonding, and wear. Any damage to the coating at the joint location must be repaired promptly to prevent water infiltration. The repair must use a compatible coating material and must be applied in accordance with the manufacturer's instructions. Recoating of bridge deck expansion joints is required when the coating has deteriorated beyond the point where repairs are effective. The recoating process requires removal of the old coating, preparation of the substrate, and application of the new coating system. The joint must be temporarily sealed during the recoating process to prevent water infiltration.