Experimental investigation of Rice Husk Ash on compressive strength, carbonation and corrosion resistance of reinforced concrete

Reinforcement corrosion in concrete has become a major factor affecting durability of reinforced concrete structures. Corrosion of reinforcement is a continuous process. It cannot be eliminated completely. But its rate can be prevented with the help of corrosion inhibitors, either by acting as a barrier, by forming an adsorbed layer on the reinforcement surface or by retarding the cathodic or anodic processes of corrosion. The hazardous effects of synthetic inhibitors have led to the utilisation of alternative non-toxic, eco-friendly plant extracts, generally known as green corrosion inhibitors. The study aims to investigate the effect of Rice Husk Ash (RHA) as a green corrosion inhibitor on the durability of reinforced concrete. The compressive strength, carbonation depth and corrosion rate of RHA concrete has been studied. The results showed that the compressive strength increased with the increase in percentage of RHA upto 15% replacement of cement. However, a decrease in compressive strength was noticed from 15 to 20% replacement. It was also observed that the carbonation depth gets increased with the increase in percentage of RHA. From the corrosion tests, it was observed that the corrosion rate decreases with the increase in RHA percentage, hence increasing the inhibition efficiency of the concrete.