Experimental Analysis on Steel Corrosion in RCC Structures by Impressed Current Technique, using FRP Mats to Inhibit Corrosion

Concrete is a unique material which contain high compressive strength and can mould in various shape and sizes, when a system of steel bars or a steel mesh is incorporated in the concrete structure in such a way that the steel can support most of the tensile stresses and leave the immediately surrounding concrete comparatively free of tensile stress, then the complex is known as “reinforced concrete�. The steel bars, however, undergo corrosion in due course of time due to a variety of factors, which decreases the strength of the bars leading to a net decrease in the capacity of the structure as a whole. The project aims at finding the impact of different factors on the extent of corrosion as well as developing ways to inhibit rebar corrosion using Fiber Reinforced Polymer (FRP) sheets. FRP mats when installed on the surface of the concrete, increase the strength of the structure and has been in use for strengthening purposes for long in India. However, its property of acting as a barrier for the chloride ions and carbon dioxide molecules to prevent corrosion of the reinforcement bars has not been studied. In this dissertation corrosion inhibiting capabilities of FRP is determined in concrete and also most economical pattern of FRP is decided which serves determining the corrosion inhibiting capabilities of FRP and deciding the most economical pattern of FRP that serves the purpose of strengthening as well as corrosion inhibition by acting as a barrier for the corroding agents. For this purpose, 20 RCC beams and concrete cubes each of M 20 grade will be cast with similar reinforcements provided in each of the beams. The effect of corrosion will then be studied on uncovered beams using impressed current technique where the beams will be exposed to a DC current of 15 V for a period of 150 hours and the decrease in strength of unexposed and exposed beam would be noted. Further, each of the patterns of FRP demonstrated later would be tested for flexural strength and compressive strength before and after exposure to the same conditions as for the uncovered beam so as to derive a comparison for estimating the effectiveness of FRP in providing strength as well as preventing the decrease in strength due to corrosion.