Research On The Effect Of Surface-film-forming Coating To The Performance Of Concrete Cover

Concrete is a kind of building materials that are widely used in civil engineering. At present ,comprehensive durability of cement and concrete are becoming more and more prominent.Damage induced by comprehensive durability is serious.The most important performance of concrete cover is to maintain the durability of concrete structure.This paper took four kinds of surface-film-forming coatings for research subject,studying the effect of surface-film-forming coating to the performance of concrete cover.Water absorption of concrete that is dealt with coatings is studied .Research results show that the percent of water absorption of concrete painted decrease dramatically. The percent of water absorption of bare concrete and concrete painted both increase with the increase of W/C. The percent of water absorption of concrete also decreases with the increase of painting times. The resistance to carbon dioxide diffusion of concrete painted is studied.Research results show that concrete painted could increase the resistance to carbon dioxide diffusion.Carbonation depth of concrete painted is increasing with the increase of carbonation time. Carbonation depth decrease with the increase of painting times,Finally carbon dioxide diffusion could keep relatively stable.The resistance value reduces with the W/C accretion of concrete. The resistance to chloride penetration of concrete painted is studied by rapid chloride penetrating test. Research results show that concrete painted could increase the resistance to chloride penetration. Electric quantity of bare concrete and concrete painted decreases with age,s growth. Electric quantity of concrete painted with RS22-1,BS-2,JF decreases with the increase of painting times.otherwise, painting times have no influence on concrete painted with S. The resistance value reduces with the W/C accretion of concrete. The resistance to chloride penetration of concrete could increase when concrete mixed fly ash.The resistance to acid,alkali and sulphate corrosion of mortar that is dealt with paint is studied. Research results show mortar painted could decrease acid corrosion in early age.With the increase of age,coatings appear peeling,the resistance to acid corrosion decreases. The resistance to alkali corrosion of mortar that is dealt with paint has no increase.The mortar and the mortar with fly ash that are painted have resistance to sulphate corrosion to some extent.