Effect of Eco-friendly Inhibitors on Corrosion Resistance of Rebar Reinforced Concrete

摘要

Corrosion of steel bars is one of the biggest problems facing many countries in the world having constructions like bridges in seashore areas and different other marine concrete structures which problem must be thoroughly studied first then also some economic solution needs to found and applied afterwards. Due to the high cost of repair of damaged constructions, some preventive measures, namely using, for example, rice husks as corrosion inhibitor admixtures were chosen as a prospective preventive technique. Along this approach, laboratory concrete samples were so prepared and sent to mechanical testing, and concurrently, the inhibitive potential of the rice husks suspended in electrolyte solution (water with dissolved sodium chloride of 3.5 wt.%) was also tested by using a standard electrochemical corrosion testing technique, i.e. the powdered rice husk was added to the electrolyte solution in different dosages (1%, 2% and 3%), then the corrosion currents of the steel samples were recorded by using a three-electrode cell assemblage. In these laboratory tests a quite steady decreasing tendency could be observed in the measured corrosion current densities (I_(corr)) compared to the case when the electrolyte solution did not contain any inhibitor admixture (I_(corr)=41.3 μA/cm~2; taken as the reference). For example, a corrosion current of I_(corr) = 28.5 μA/crrr was measured at 1% rice husk concentration, and only I_(corr) = 7.8 μA/cm~2 when the solution was mixed with 3% rice husk powder.