Effect of Surface Applied MCIs and Sealants on the Durability of Reinforced Concrete in Rigorous Chloride Conditions

摘要

The effect of surface applied inhibitors and waterrepellent coats on the durability of concrete have been carried out. The charges passed through the surface coated C30 concrete have been measured based on ASTM C1202. The results show that the average charges of concrete painting MCIs alone can be reduced to about 55.6% of the control sample's, in particular the lowest value of concrete painting BT100 is only 45% of the control one's. While the average charges in concrete coated inhibitors and resin emulsion sealant prepared in lab are 41.9% of control sample', and the composite use of inhibitors and styrene acrylic emulsion on the surface of concrete gives a lowest charge which is only 21.4% of the control one's. The EIS, LPR. and corrosion current of steel bars in concrete coated MCIs and resin emulsion sealant experienced in 30 dry-wet cycles (3%NaCl solution) were also measured. The results make out that surface painting MCIs only is not enough to protect the steel bar in concrete at dry-wet cycle chloride conditions, and composite use of inhibitors and resin sealant (No 4) gives the best inhibition effect. The investigation illustrates that the amine carboxylate based inhibitors can provide hydrophobic coat or pore-blocking effect in concrete which improve the ability of anti-chloride ion penetration, and an additional sealant is helpful for improving the ability of anti-chloride ion penetration and preventing proliferation of inhibitor outward from the concrete surface.