Bridge crack repair
Crack repair methods:

1. Surface plaster repair method

Cement mortar coating

For the concrete structure, the commercial concrete surface near the cracks can be gouged first, and then with 1:1 ~ 1:2 cement mortar daub on it, daub when there is no running water.
Daub total thickness is generally 10 ~ 20 mm, mortar sand should not be too thick, generally fine sand, cement strength grade should not be less than 32.
Level 5.

Apply epoxy mortar

First cut a v-shaped slot in the crack, brush with wire to clean the seam.
Apply a layer of epoxy mortar around the crack. If the crack is deep, static perfusion can also be carried out in the vertical direction. 0.
5 mm gap.
*** insert epoxy mortar and use a scraper to make the plane level with the original commercial concrete plane.
The epoxy resin can be applied after hardening.
The structure should not be subjected to vibration or moisture during maintenance to ensure the quality of repair.


2. Caulking and grooving

caulking

Caulking is a simple and convenient method to repair masonry cracks.
During operation, the gap is cleaned, and according to the width of the crack, tools such as a seaming knife, a spatula and a scraper are used for operation respectively. The mortar used is usually 1:2.
5 or 1:3 cement mortar, generally not less than the strength of masonry mortar.
After joint filling treatment, it can play a certain role in aesthetics, durability and so on, but it has little effect on the integrity and strength of masonry.

Chisel seam inlaying

Chiseling is a method of chiseling a deep groove along the cracks of commercial concrete and then inserting various bonding materials, such as epoxy mortar, asphalt, methacrylate lipids, etc.
Repair along the cracks gouge groove, groove shape according to the location of the cracks and fill material to determine, groove shape is usually used v-shaped groove.
Both sides of the trough of commercial concrete surface must be repaired flat, groove to clean, when necessary before the filler with acetone wipe.
If cement mortar or spraying mortar is needed outside the groove, the surface of commercial concrete outside the groove shall be gouged and cleaned at the same time.
Fill with cement mortar.
Keep the tank wet (there should be no water) in advance. When filling with asphalt or epoxy materials, keep the tank dry. Otherwise, take other measures to make the tank dry before filling.


3. The grouting method

Wide cracks should be treated by pressure grouting.
Generally, epoxy resin is used for grouting treatment.
The crack surface is processed and the /V0 groove or /U0 groove is chipped along the crack with steel. The width and depth of the groove can be determined according to the depth of the crack and the favorable sealing.
Chiseling cracks along the first crack open, and then to both sides of the width, after chiseling with steel wire brush and air pump will be commercial concrete debris, dust clearance.
The distance between the embedded grouting nozzle can be determined according to the depth of cracks. The grouting nozzle should be pasted on the predetermined position with epoxy resin cement before embedding.
After the crack is closed, pressure leakage test should be carried out to check the sealing effect after the sealing cement reaches a certain strength.
Grouting machines, tools and tools should be checked before grouting, and can only be used after normal operation.
Remove the pipe immediately after grouting and flush the pipe and equipment with acetone.
After grouting, the grouting place shall be smoothed with epoxy resin cement. After grouting, each crack shall be brushed with epoxy resin cement to ensure the sealing is tight and its color shall be consistent with the commercial concrete of the bridge as far as possible.