Expansion joint design points

It is extremely important to reasonably select the appropriate amount of expansion and contraction gap. The larger the gap, the more easily the expansion device will be damaged. The gap is too large or too small, and the gap is adjusted without considering the temperature at the time of installation. Especially for the plate type rubber expansion device, it is easy to cause damage. Even with continuous bridge decks, cracks often appear in the surface pavement. therefore. To take pre-cut bridge deck, set joints, or use a softer pavement to absorb cracks, or install small expansion devices to solve. In the case of a large longitudinal slope, if a structure that considers vertical displacement is not set up, it is easy to produce defects and cause damage. The telescopic device is along the longitudinal direction of the bridge deck. Even if the amount of expansion and contraction is small, there is a problem of large deflection difference. Therefore, attention should be paid to the structure of the telescopic device. The combination of the telescopic device and the beam body to form an equal-strength whole is undoubtedly an important means to improve its use efficiency. In addition to modular expansion devices, other types of bridge expansion devices are often insufficiently fixed and combined with the bridge deck, and the effect is not ideal. Generally, the size of the structure is small, the rigidity is insufficient, and the characteristics and coordination of new materials are not enough. The research is not deep enough, so a full comparative study should be done in the selection. In order to prevent water leakage caused by rain, although in some steel expansion joint devices, the sealing rubber is inserted into the matching part or the drainage device or the pavement layer is used as an easy-to-clean type, or the whole gap is filled with filling. Practical form of waterproof material. For the rainwater on the bridge deck, a centralized drainage outlet should generally be set up near the expansion device; for components that are not painted multiple times for daily maintenance, high-quality and durable protective materials should be used for effective treatment in design.