Study On Performance And Test Method Of Concrete Protective Coating

At present, comprehensive durability of cement and concrete are becoming more and more prominent. Damage of construction induced by comprehensive durability is serious, which bring huge economic loss to our society. As a kind of materials improving comprehensive durability of cement and concrete, concrete protective coatings are paid more and more attention. But now, the test and evaluation methods about capabilities and protective effect of this kind are not mature, which restricts the benign development and engineering application.Firstly, in this paper water absorption of concrete protective coatings hi different corrosive medium is studied. Research results show that concrete protective coatings could markedly decrease water absorption of mortar and concrete. After mortar is dealt with concrete protective coatings, the percent of water absorption of mortar submits direct ratio to W/C. They also show that water absorption could availably evaluate the waterproof ability and resistance to acid and alkali corrosion of concrete protective coatings.Secondly, the author studies the resistance to chloride penetration of concrete protective coatings by diffusion cell test and rapid chloride penetrating test. Research results show that concrete protective coatings could increase the resistance to chloride penetration of mortar and concrete. And resistance value reduces with the W/C accretion of mortar and concrete. Diffusion cell test has good pertinence with rapid chloride penetrating test, and they could availably evaluate resistance to chloride penetration of concrete protective coatingsThe application of AC Impedance Spectroscopy in study of concrete protective coating is discuss in this paper. "Series-wound Brick" model is applied firstly to describe the ACIS behavior of concrete protective coatings system. It is deduced that the high frequency arc of concrete protective coatings system is a semicircle, which has been approved by testing results. Besides, the parameter used to describe concrete protective coatings increasing materials close-grained capability is fixed on.Lastly, the influence induced by concrete protective coating on reinforcement corrosion is discussed using electrochemical method. Test results show that in salt-immersed-placement and salt spray-placement corrosive environment, concrete protective coating could put off the activation time of passivating film, decrease the corrosion rate. And that the corrosion rate of concrete protectivecoatings is different in the two corrosion environment.The above researches provide theory reference and technology support for establishing test and evaluation methods about capabilities and protective effect of concrete protective coatings, and accelerate the development and engineering applications of concrete protective coatings.