The following principles should be followed in the treatment of concrete cracks

• Find out the situation: structure actual condition, the key character of cracks and development situation of cracks.
• Identify the nature of cracks: cracks that do not deteriorate in structure, then be treated after being clearly defined.
• Clear purpose: seal or reinforcement.
• Ensure structural safety: take urgent measures when necessary to prevent vicious collapse accidents.
• Meet the use requirements: stiffness, size, space and tightness, leakage prevention, cleanliness, aesthetics.
• Ensure durability: prevent steel corrosion and repair material durability.
• Determine the appropriate processing time: deal with as stable as possible.
• Prevent unnecessary damage: avoid artificial expansion and then repair.
• Improve the conditions of structural use, eliminate the factors causing cracks: ensure that cracks do not develop.
• The feasibility of the method is reliable, convenient, safe, economical and reasonable.
• Meet the design requirements and comply with the relevant provisions of the standard specification.

Crack repair method

• Compacting leveling method

Application: early shrinkage crack and shrinkage crack before hardening of concrete.

• Epoxy adhesive paste

Application: when the concrete is hardened, the width of the surface is <0.3mm, the depth is not large, and the cracks are more numerous.

Treatment points: first clean the surface that needs to be treated, remove oil stains and dirt, and use acetone to scrub, and then brush epoxy mortar repeatedly after drying, once every 3 to 5min, and the thickness of the coating is about 1mm.

Treatment effect: the penetration depth can reach 16 ~ 84mm, which can effectively prevent air and water from penetrating.

• Bonded fiber reinfroced polymer(FRP) compsoite materials

• Surface suture

• Concrete crack injection adhesive

• Strengthening and retrofitting measures