The study of the effect of final tin slag as partial substitution in portland based concrete towards corrosion resistance of reinforcement steel against chloride environment with linear polarization method

The final tin slag is the final product of the tin smelting process which contains oxide compounds such as SiO₂, CaO, Al₂O₃, and Fe₂O₃ which have similarities to the content of the oxide compounds found in Portland cement (OPC). The existence of the final tin slag has not been widely used. For that reason, the final tin slag will be very useful if it is used as a cement substitute as a raw material for making concrete. This study aims to analyze the resistance of cement and steel reinforcement mixtures on concrete to a corrosive environment using linear polarization method. In this study, the composition of the final tin slag used was 10%, 20%, 30%, and 40%. The final tin slag used came from PT. Timah Tbk on Bangka Island Indonesia. Then, the 0.5 w/c ratio concrete will be cured for 28 days and will be immersed with a 3.5% NaCl solution for 6 days. The results presented that the reinforcement steel embedded in concrete OPC60-FTS40 was the sufferest towards corrosion since it had the highest corrosion rate in each immersion day among all the concrete samples and followed by OPC80-FTS20, OPC70-FTS30, OPC100, and OPC90-FTS10 in six days of immersion.