CORROSION BEHAVIOUR of DUAL-PHASE and GALVANIZED STEEL in CONCRETE
Reinforced concrete is established and well accepted throughout the world as a construction material due to proven track record serving mankind. However, problem can arise from time to time during services either due to weakness in materials itself or negligent during construction. One of the major problems suffered by reinforced concrete structure is corrosion of reinforcement. Reinforcement can be corroded either due to carbonation of concrete or chloride attack on the reinforcement. The objective of this research is to evaluate the potential of dualphase and galvanized steel reinforcement to survive in corrosive environment. Low carbon steels were intercritically annealed at 740o C followed by water quench to obtain dual-phase structures with 37% volume fraction of martensite dispersed in ferrite matrix. Dual Phase and Galvanized steel rebars were embedded in concrete and immersed in 5% NaCl solution for 100 days. Half-cell potential test was carried out during the 100 days of immersion to monitor the corrosion activity of the rebars. Corrosion rate of bare metals were measured in accordance to electrochemical method. Dual phase steels exibit better corrosion resistance compared to galvanized steels. Therefore dual phase steels have great potential as reinforcement in concrete.