The Corrosion Inhibition Effect of Forsterite (Mg₂SiO₄) Mine Tailings for Steel Rebar in Reinforced Concrete

摘要

In this study, the usability of forsterite mine tailings (FOT) to provide steel reinforcing bar corrosioninhibition effect was assessed. To this end, C30 grade concrete specimens were produced with andwithout forsterite mine tailings. FOT were used with 5%, 10%, 20%, and 40% by volume in150x150x150 mm cubic specimens, which then were subject to water curing for 28 days at 211temperature. At the end of the curing, the specimens with FOT were tested under compression. It wasseen the density and compressive strength of specimens with FOT were lower at different rates,depending on the amount of FOT. However, the specimens with 5%, 10%, and 20% FOT stillexhibited higher compressive strengths than that of C30 grade concrete. The concrete mixes withoutand with 5%, 10%, and 20% FOT were poured into 50x100 mm molds with centrally embedded 10mm flat steel reinforcing bars. The specimens were taken off the molds after 24 hours and subject tonormal curing for 14 days. Then the specimens were placed into a 5% NaCl solution to enhance thecorrosion in the reinforcing bars. Over the course of 17 weeks (approximately 120 days), the corrosionrate, Polarization resistance (Rp), Corrosion potential (E(I=0)), and Corrosion current (Icor) values ofthe specimens were measured on a weekly basis by means of the Linear Polarization method. Theresults showed that the corrosion rate of the specimens with 5% and 10% forsterite mine tailingsdecreased compared to the reference specimens without forsterite tailings.