AN EXPERIMENTAL STUDY TO PROTECT STEEL REINFORCING BARS FROM CORROSION | ||
| JES. Journal of Engineering Sciences | ||
| Article 4, Volume 37, No 2, March and April 2009, Pages 303-318 PDF (882.37 K) | ||
| Document Type: Research Paper | ||
| DOI: 10.21608/jesaun.2009.121219 | ||
| Authors | ||
| Sayed, A. E; Mohamed R. A. S. | ||
| Associate Professors, Civil Engineering Department, Faculty of Engineering, El-Minia University, El-Minia, Egypt | ||
| Abstract | ||
| Steel is an essential part of reinforcing concrete and the corrosion of steel is identified as single largest factor responsible for its deterioration. The alkalinity of concrete, which protects the steel, may be affected by carbonation of the concrete, or by ingress of chloride ions. These may arise from sea salts or environmental corrosives. The corrosion of steel in concrete leads to cracking and eventual spalling of concrete because the rust product has a greater volume than the steel and hence exerts considerable pressure on concrete which eventually leads to its disintegration. Since the 1970s, research projects and field studies have been conducted on different methods for protecting steel reinforcing in concrete constructions from corrosion damage. These methods include rebar coatings, concrete coatings, use of admixtures, methods for decreasing permeability, increasing concrete cover, cathodic protection, electrochemical method to remove chloride, and corrosion inhibitors. The purpose of this research is to implement three different protection methods on the reinforcing steel bars to prevent or minimize the occurrence of corrosion as well as to detect the most effective method in the protection technology of steel bars. The parameters studied in this research are the corrosion rate and percentage of chloride. The three protection methods are, coating the steel bars before embedding them in concrete using two different epoxy coating materials as well as using sodium nitrite (by 1% of cement content) to be added to the concrete mix to work as a corrosion inhibitor. Pullout tests have been carried out and their results are discussed to determine the effect of the implemented different methods for protecting steel from corrosion on the bond strength. The results indicated that the sodium nitrite give the best results as an anticorrosive material, adding 1% to concrete mix increases the pull-out load by value of 300% but the epoxy coating materials produced an increase in pull-out load by values 215 % and 240 % increase with the two Epoxy coating materials. Three reinforced concrete full-scale beams protected from corrosion along with a control beam were tested under flexure to study the effect of the applied corrosion protection methods on the mechanical behavior of R.C beams. | ||
| Keywords | ||
| Sodium nitrite; corrosion protection; epoxy-coated; reinforcement corrosion inhibitor | ||
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