Anticorrosive coating for concrete structure reinforcing bars and preparation method thereof

Abstract

The invention relates to an anticorrosive coating cured at the room temperature and used for concrete structure reinforcing bars and a preparation method thereof. The coating system comprises a priming paint and a finish paint, wherein the priming paint and the finish paint respectively comprise a component A and a component B which are used in a mixed manner; the component A in the priming paintcomprises the following components in parts by weight: 1:10-30 parts of epoxy resin by weight, 2:5-15 parts of epoxy resin by weight, 30-55 parts of pigment and filler by weight, 0.5-1 part of additive by weight and 20-40 parts of solvent by weight; the component A in the finish paint comprises the following components in parts by weight: 1:10-30 parts of epoxy resin, 2:5-10 parts of epoxy resin,10-30 parts of pigment and filler by weight, 10-30 parts of glass flakes by weight, 0.2-1 part of additive by weight and 20-40 parts of solvent by weight; and the component B of the priming paint andthe component B of the finish paint are the same and are at least one of fatty amine, aromatic amine and polyamide. The coating can be cured at the room temperature, the cured coating has good adhesion, impermeability, alkali resistance, saltfog resistance and wear resistance, can effectively prevent the reinforcing bars in concrete from rusting and further prolongs the service life of the reinforcing bars.

Description

technical field [0001] The invention belongs to the field of anti-corrosion coatings, in particular to a room-temperature-cured anti-corrosion coating for concrete structure reinforcement and a preparation method thereof. Background technique [0002] The corrosion of steel bars by chloride ions is one of the most important causes of corrosion damage to coastal concrete structures. Due to the porosity of the concrete material, chloride ions will continue to enter the interior of the concrete, destroying the passivation film on the surface of the steel bar, causing corrosion of the steel bar and cracking of the concrete. In order to solve the problem of corrosion of steel bars in reinforced concrete structures, common measures include increasing the thickness of the concrete protective layer, adding admixtures to the concrete, cathodic protection, and developing new coated steel bars or plated steel bars, etc. In the United States, Canada and Europe, there are many studies o...

AI Technical Summary

Problems solved by technology

However, since the preparation of epoxy-coated steel bars requires electrostatic spraying of epoxy resin powder onto the steel bars preheated to 230°C for curing, the requirements for temperature and environmental cleanliness make it difficult to complete the pre-production on the construction site, which not only greatly increases The use cost of steel bars is reduced, and it is easy to collide and scratch during transportation, loading and unloading, and storage, causing coating defects and directly affecting the anti-corrosion quality of steel bars

Chinese patents CN1687269A and CN1962779A disclose two kinds of anti-corrosion coatings for steel bars. The coatings both use epoxy resin as the base material, but the coatings are all powder coatings and need to be cured at a temperature above 200 ° C, which is not suitable for on-site construction.

Under the action of inorganic acid, active pigments and antirust pigments form nitrogen base ion groups that absorb and stabilize rust, transform rust into a beneficial and stable protective layer, and firmly adhere to the metal surface to prevent corrosion of steel bars in concrete, but the patent does not have Mention the influence of the coating on the bonding strength between the steel bar and concrete and whether the coating meets the requirements of the bending degree of the coated steel bar when it is bent in use

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