Bridge expansion joints: In order to meet the requirements of bridge deck deformation, expansion joints are usually set between two beam ends, between beam ends and abutments or at the hinged position of the bridge. Expansion joints are required to be parallel and perpendicular to the bridge axis. It can expand and contract freely in all directions, is firm and reliable, and the vehicle should run smoothly without sudden jump and noise; it should be able to prevent rainwater and garbage soil from infiltrating and blocking; installation, inspection, maintenance, and removal of dirt should be easy and convenient to set up bridge expansion and contraction At seams, railings and bridge deck pavement should be disconnected. Expansion joints are used in: bridges, sidewalks, highways, expressways, high-speed rails, subways, viaducts, buildings and other areas.