Tangshan bridge bearing manufacturer procurement tells you how to repair the bridge expansion joint?

Expansion joint is one of the important components of bridge structure. The main function of the bridge expansion joint is to adjust the displacement between the superstructure caused by temperature changes, vehicle load environmental characteristics and physical properties of the building. Generally speaking, the expansion joint should have good durability, driving comfort, good waterproof, convenient construction and simple maintenance.

In recent years, with the development of science and technology and the continuous increase of traffic, most of the bridge expansion joints are exposed to nature. Due to the influence of various natural environments, they often produce different degrees of damage. The damage of the bridge deck expansion joint affects the normal use of the bridge, so it is necessary to repair the bridge expansion joint.

So how should bridge expansion joints be repaired? The specific steps are as follows:

1. Cleaning:

First of all, clean the broken slab of the cement concrete pavement or the seriously damaged part of the concrete structure, break the broken slab into small pieces with a pneumatic pick, then clean it up, remove the loose matter on the surrounding slab base surface, and use an air compressor to blow the dust on the base surface and groove.

2. Base surface penetration:

Secondly, 2-3 hours before pouring, wet the base surface with sufficient water to remove the exposed moisture; During winter construction, warm water not exceeding 65 ℃ shall be used to sufficiently wet the base surface, and the exposed water shall be removed before pouring.

3. Interface processing:

Then evenly coat a layer of polymer interface agent on the base surface.

4. Formwork support:

Next, for the cement concrete pavement slab in the middle of the road to be repaired, the three edges of the slab can be used as templates, and wooden or steel molds can be erected at the edges, and anti-leakage measures can be taken. For the parts with serious damage to the concrete structure, the formwork shall also be erected and anti-leakage measures shall be taken.

5. Mixing:

Then, according to the number of buildings to be poured on the site and the pouring speed, put the repair materials into the forced mortar mixer manually, dry mix for 10s, weigh according to the water volume specified by the product, and then add water to mix twice in sequence: add 2/3 of water once, mix for 30s, add 1/3 of water again, and mix for 150s. After mixing, the repair material shall be left standing for 2~3min, and then poured after the bubbles disappear. During winter construction, warm water not exceeding 65 ℃ shall be used for mixing, and the pouring temperature shall be above 10 ℃.

6. Pouring:

Next, use the pouring container to pour slowly and evenly to avoid hollowing during pouring. After pouring, grind the top surface of the repair material. From the beginning of mixing to the end of pouring, each mixing of repair materials shall not exceed 30 minutes. If the overtime or fluidity of the repair material cannot meet the pouring requirements, it shall not be used again.

7. Maintenance:

Then the maintenance of bridge expansion joints after repair. At the initial stage of maintenance, it can be completed by sprinkling water on the surface and covering with straw mats. The oxidation time at this stage should be controlled at least seven days. In addition, traffic control should be strengthened and road protection should be done well, such as setting up relevant warning signs, prohibiting vehicles and pedestrians from passing, so as to ensure that the quality of concrete will not be affected.