PREDICTION OF CORROSION ACTIVITY LEVELS OF HYSD BARS IN OPC SCC AND GPC BY ELECTRICAL RESISTIVITY METHOD AND HALF CELL POTENTIAL METHOD

Reinforced concrete structures have good potential to be durable and capable of withstanding adverse environmental conditions. Failures in RCC structures will still occur as a result of premature reinforcement corrosion. Corrosion of steel has been recognized as one of the major durability problems in R.C.C structures. The damage caused by corrosion considerably reduces the strength, serviceability and life of structures. Inspection and continuous monitoring techniques necessarily have to be carried out, to assess the steel corrosion in R.C.C structural components in order to ensure their safety, serviceability and durability for a long time. They should be required for their easy maintenance and repairs also few investigations were carried out to study the corrosion level and flexural behavior of beams with corroded RCC beams. Very few investigations were carried out to study such corrosion characteristics in reinforcement in ordinary Portland concrete (OPC) beams, self- compacting concrete (S.C.C) beams and Geopolymer concrete (G.P.C) beams so far. Problems associated with corrosion of steel and possibility of its occurrence in ordinary Portland concrete, self -compacting concrete and geo polymer concrete were to be studied.In the present project work carried out the experimental studies on the corrosion of reinforced self- compacting concrete specimens and Geopolymer concrete of different grades (For example, M 25 and M 30 grades of conventional concrete) are carried out. In making self-compacting concrete and Geopolymer concrete, fly ash and GGBS are used as pozzolanic materials to replace cement partially. Specimens of size100 mm x 100 mm x 250 mm with centrally placed mild steel and HYSD bars are casted and immersed in acidic solutions HCl, H2O and MgSO4 solutions to promote corrosion. The specimens are cured for a period of 28days 60days and 90days respectively in those solutions. The corrosion levels in the specimens are assessed by measuring the potential difference between specific points of specimen by electrical resistivity Method (E.R Method) and half-cell potential method.