Study On Practicability Of Concrete Protective Coatings Under Concentrated Seawater Condition

In recent years, owing to the shortage of fresh water resource and the increasing demand of environmental protection, seawater circulating has become the developing trend of electrical and chemical industry in the coastal areas, which brings the corrosion problem. Under the concentrated seawater condition, chloride ions concentration is many times to the normal seawater condition, and the highly concentrated chloride ions must corrode the concrete construction much more seriously ,which will bring much more severe damage and loss.As a kind of materials improving comprehensive durability of cement and concrete, concrete protective coatings are paid more and more attention. Meanwhile, many problems, such as the assorting of coatings and its practicability under the concentrated seawater condition are waiting to be studied and confirmed urgently.According to the criterion and the practical demand, this paper firstly selects out jotun(A1),euronavy (A2),HENGCHANG(A3) and sunrui (A4) these four kinds of appropriate coating materials. After detecting the basical quality of the coatings, this paper simulats the corrosive working condition of the reinforced concrete construction, rsearches the anticorrosion efficiency of the coating-protected-concrete samples, discusses the practicability of coating protection to the concrete that work under the concentrated seawater condition, and concludes in the followings:(1) The selected coating materials have favourable fundamental performances, which are differential but all can meet the demand of the criterion and test.(2) Most of the coating-protected-concrete samples show favorable resistance to acid and alkali corrosion, and also show well ability to water and chloride penetration resistance, this indicates that the coating protection is feasible and practicable to the concrete working under concentrated seawater condition.(3)Epoxy resin base coat+ epoxy resin middle coat+ acryl acid polyurethane finishing coat is an excellent combination system, it performs nice protection for the concrete which working under concentrated seawater condition.(4) The A3 coat protecting system shows worse protecting ability than the other three protecting systems, especially the resistance to alkali corrosion, which indicates this system need to be adjusted and optimized in order to get better protecting ability.The above researches provide theoretical reference and technical support for practical application of concrete coating protection under concentrated seawater condition, and accelerate the development and applications of concrete protective coatings.