Steel bridge expansion joints
Modular bridge expansion joints are expansion devices used in bridge structures, mainly used to solve the expansion and contraction displacement problems caused by temperature changes, concrete shrinkage, creep and load. It consists of multiple modular units, each of which includes side beams, middle beams, sealing rubber strips, support systems and anchoring devices.
Modular expansion joints have a large expansion adjustment range, which can adapt to the displacement requirements of different bridges and are widely used in various large and medium-sized bridge projects.
Structural composition
– Side beams: usually made of hot-rolled integrally formed special-shaped steel, located on both sides of the expansion joint, mainly play a connecting and supporting role, connecting the expansion joint to the main structure of the bridge, and bearing part of the vehicle load.
– Middle beam: used in conjunction with the side beam, it plays a role in sharing the load and transmitting force in the expansion joint, and is also an important component for the expansion joint to achieve a large displacement.
– Cross beam: connects the side beam and the middle beam, transfers the load to the beam body and the abutment, so that the entire expansion joint structure forms a stable whole, ensuring the uniformity and stability of the expansion joint when subjected to force.
– Displacement control system: generally composed of elastic elements such as rubber springs and PTFE pressure bearings, which can ensure the uniform displacement of the expansion joint during the expansion and contraction process, so that the displacement of each middle beam is coordinated and the expansion and contraction friction resistance is small.
– Sealing rubber belt: embedded in the groove of the steel section, mostly made of chloroprene rubber and other materials, using its good elastic deformation ability to play a waterproof and dustproof role, preventing rainwater, garbage, etc. from entering the expansion joint and affecting its normal use.