Experimental study on bonding mechanism between corroded bolts and grout

Bolts are always subjected to corrosion due to complicated and unfavorable environmental factors such as aggressive medium,alternation of wetting and drying,permanent immersion,stray earth and bimetallic corrosion.Corrosion might make the bonding mechanical behavior inferior,and even make bolts disabled.Pullout tests were carried out to investigate the mechanism of influence on the bond property and uplifit resistance of bolts in terms of corrosion and its position.It was demonstrated that the ultimate uplifit resistance of non-corroded bolts was evidently greater than that of corroded bolts,and that of the corroded bolts in the front part along the anchor was obviously smaller than that in the middle and rear parts.Therefore,the front part along the anchor was the key region to the bonding mechanical behavior between bolts and grout.It was also shown that corrosion products acted as lubricant,resulting in the degradation of bonding mechanical behavior by breaking the effective transfer of stress from bolts to grout.