What is the quality of bridge bearing replacement related to? The bridge bearing supplier directly tells you

Bridge is an important part of highway, and the quality of bridge bearing replacement is directly related to the safety and smoothness of highway traffic. At present, bridge bearing replacement may face the following problems. Let's take a look with the bridge bearing supplier.

(1) Insufficient durability of bridges: due to insufficient design considerations, reinforcement corrosion, freeze-thaw damage, alkali-aggregate reaction, chemical erosion, environmental impact and other reasons, the bearing capacity of the structure will decrease with time. Especially when the concrete cover is exposed and the reinforcement is corroded, the effective sectional area will continue to decrease, making the bearing capacity of the structure decline rapidly and cannot be restored, and the reinforcement will even break in serious cases. When the residual bearing capacity of the structure is lower than the action load, the bridge structure may be damaged. Therefore, the durability of bridges caused by steel corrosion has become a very prominent disaster.

(2) Excessive fatigue: The materials used for bridges often contain small defects. Under cyclic load, these tiny defects (microcracks, micro-pores) will nucleate, develop, merge and form damage, and gradually form macroscopic cracks in the material. If macro cracks are not effectively controlled, it is likely to cause brittle fracture of materials and structures. Fatigue damage is the core problem of steel bridge design. There are many cases of bridge collapse caused by fatigue fracture. Early fatigue damage is often difficult to detect, but its consequences may be catastrophic.

(3) Bearing capacity of traffic volume: the problem of traffic volume is increasing, and the bearing capacity of the old bridge can no longer meet the requirements of the new load level.

(4) Management is not strict: small and medium-sized bridges are widely distributed, difficult to track, diverse management forms, diverse bridge structures, and uneven maintenance technologies.

(5) Serious bridge overload: bridge overload is an objective phenomenon, which is very prominent in some sections. There are two situations: first, the old bridge built in the early stage is over-aged and overloaded; The other is the existence of illegally overloaded vehicles. The former is mainly caused by the change of design specifications, the increase of traffic volume and the development of heavy vehicles, which is inevitable; The latter is due to the overloading of vehicle users in violation of traffic regulations, which is very common in China's road transportation. Overload will aggravate bridge damage and cracks, and even cause some structural damage accidents due to overload.

(6) Late maintenance lag: small and medium-sized bridges account for 90% of the total number of bridges, with large number, wide distribution, difficult supervision, high maintenance investment and complex situation. In particular, low-grade highways distributed in rural areas in remote areas lack necessary maintenance funds and technical support, and it is difficult to guarantee bridges.