Performance of Opuntia Ficus Indica Mucilage as Corrosion Inhibitor in Cement-Based Materials
摘要
Reinforcement corrosion in concrete structures is a world-wide problem and one of the main causes of loss of performance of concrete structures. One of the alternatives to face this problem is the use of corrosion inhibitors. Considering the actual seek for more eco-friendly materials, the use of bio-inhibitors has gained more strength in last years. The Opuntia Ficus Indica (OFI) mucilage arises in this scenario as one of these alternatives. In this work, reinforced mortar specimens with high early strength Portland cement and water to binder ratio of 0.5 were cast with different contents of OFI mucilage (4%, 6%, 8% and 10%). After that, they were cured in a humid chamber for 28 days and then were characterised on compressive strength and surface electrical resistivity. Another set of specimens was subjected to wetting and drying cycles in 1 Molar sodium chloride solution initially until reinforcement depassivation. Along this period, these reinforced mortar specimens were electrochemically monitored. Results show that although there is a delay in cement hydration and a slight decrease in compressive strength at earlier ages, it is not a worrying effect for the mucilage contents adopted in this work. Regarding the electrochemical performance, there is a better performance of mortar specimens with OFI mucilage, not only bringing the electrochemical parameters to better levels, but also extending the initiation corrosion period and not presenting reinforcement depassivation after two years of laboratory tests in chloride contaminated solution.