Performance of Rice Husk Ash Concrete in Acidic Environment

As a suitable supplementary cementitious material with high pozzolan reactivity, low energy requirements, and minimal greenhouse gas emissions during production, rice husk ash (RHA) concrete has gained recognition. In relation to the silica dissolution from RHA, RHA's pozzolanic reactivity is affected by its amorphous silica content, fineness, mix proportions, alkaline media availability and temperature. This paper discusses mainly the strength performance of RA blended concrete in plan water (PW) and acidic environment. Five different cement replacement levels by RHA (i.e., 0%, 10%, 15%, 20% and 25%) were selected to make blended concrete specimens. A total of 500 nos 100 mm cubical specimens were cast for M28 grade concrete. All the specimens were precured for 7 days in PW and then exposed to PW and acidic environment (5% H2SO4 solution) over the period of 14, 28, 60 and 180 days. Different tests including visual examination, compressive strength, split tensile strength, porosity, alkalinity (PH levels) at different depth levels of the specimens were conducted to observe the strength properties and alkaline conditions of the concrete. RHA concrete showed significant resistance against strength deterioration. Among the various RHA concretes, 10–15% cement replacement level is found effective from strength and durability point of view.