Evaluation of different coating materials to protect against corrosion of reinforcing rebar in concrete by accelerating the electrical reaction.

Abstract

This article tested the efficiency of the corrosion protection system of reinforced rebar using corrosion inhibitors of the coating type. It considers comparing the performance of different types of coatings, including coatings on reinforced steel surfaces, concrete surfaces, and the combined use of both. When using different admixtures, type 5 cement, fly ash at 35%, coarse rice husk ash, and fine rice husk ash at proportions of 10%, 25%, and 40% by weight of cement, a total of 36 samples were prepared. The reinforced steel was installed in cylindrical concrete specimens with a diameter of 10 centimeters and a height of 20 centimeters. After 28 days of concrete curing, the reinforced concrete corrosion was accelerated in a solution containing 4% sodium chloride using the electrochemical cell method. Following the corrosion acceleration, the weight loss rate of the reinforced steel due to corrosion was examined. Additionally, the chloride penetration at distances of 2.5 centimeters and 5 centimeters from the concrete surface was investigated using the titration method. The test results revealed that the corrosion protection efficiency of the coated steel surface was most effective in preventing corrosion. As for the chloride content, the concrete samples with Type 5 cement and mixtures of 35% fly ash and 10%-40% coarse rice husk ash showed lower chloride content than those with Type 1 cement. The coatings used in the tests effectively prevented chloride permeation, similar to the use of admixtures.