Influence Of Surface Impregnation With Silane On Corrosion Of Steel In Concrete

The degradation of concrete durability which can reduce the reliability and security of constructures notably,have endangered the normal use greatly.Also durability of concrete has already become a severe problem that the field of engineering construction in our country has faced. There are numerous factors leading to the degradation of concrete durability,and among them the corrosion of reinforcing bar is one of the main reasons causing reduction of concrete structu re durability.Because of the corrosion of reinforcing bar,a lot of concrete structures have to maintain or remove,even collapse,and cause enormous economic losses.Therefore,detection and evaluation in steel corrosion,and taking effectual mearsures to repair and pretect have great significance in improving concrete structure durabilities.Regarding to the steel corrosion of concrete,this paper outlines state of the art in this field comprehensively both at home and abroad,and analyze s the corrosion mechanism correspondingly. Half cell potential,polarisation resistance and mass loss methods are adoptted to study the influence of corrosion development and silane liquid surface impregnation on the steel corrosion under singly and complex action among external chloride ingress,initial chloride,drying and wetting circle,crack and carbonization.Especially,the influence of silane liquid surface impregnation on steel corrosion of concrete in different environmental conditions was studied in details.Corresponding results indicts:(1) Silane liquid surface impregnation concrete can prevent external chloride penetration,so that the treated concrete has good effect on reducing the probility and rate of steel corrosion,delaying the time of initiated corros ion and lowing the mass loss ratio of corroded steel.(2) Silane liquid surface impregnation concrete can not influence corrosion in concrete with initial chloride abviously;however,it can reduce the corrosion rate and degree of initial chloride ingree concrete in drying and wetting cycle actions.(3) Steel corrosion in concrete, for which silane liquid surface impregnation is carried on first and then induce crack,is more severe than the ones crack inducing first and silane liquid surface impregnation later.The mass loss ratio of above treatment in two W/C ratios from max to rain is given as following: MWC4-0.6＞MCW4-0.6＞MWC4-0.4＞MCW4-0.4＞MWC1-0.6＞MWC1-0.4＞MCW1-0.6＞MCW1-0.4. (4) In the complex action of carbonization,crack and drying and wetting cycle s of water,also silane liquid surface impregnation can reduce corrosion rate to a certain extent,thus improve the durability of concrete;(5) For untreated concrete,the corrosion degree acclerates with increase of W/C, corrosion rate of concrete with W/C=0.6 is two times higher than 0.4 ones.But for silane treated concrete,the effect of water to cement ratio to steel corrosion is not notable.