Investigation of the performance of brick aggregate concrete incorporating rice husk ash in the corrosive environment

Abstract

Brick aggregate concrete (BAC) is susceptible to rebar corrosion due to its porous nature. Rice husk ash (RHA) has the potential to improve a few properties of concrete by replacing ordinary Portland cement (OPC) including porosity and permeability. In this experimental work, BAC samples with different percentages of RHA have been cast and exposed to corrosive mediums such as concentrated chloride and concentrated carbon-di-oxide environments. The periodic observations in terms of non-destructive tests such as the half-cell potential test and resistivity test have been conducted to measure the probable chloride-induced corrosion that occurred in the specimens. The samples were also kept exposed to the concentrated CO₂ medium and subjected to periodic carbonation depth tests to monitor the CO₂ penetration into the concrete samples. Additionally, sorptivity and permeability tests have been conducted on concrete specimens to reveal the effectiveness of RHA in reducing the porosity and permeability of concrete. In the experimental studies, 5% RHA was proven to be optimum for the lower w/b ratio and 10% RHA was proven to be optimum for the higher w/b ratios in chloride-induced corrosion as well as carbonation depth test. Finally, the correlation between the non-destructive methods and the degree of corrosion of the rebar has been established from the values of the experimental studies.