Application of rice husk ash in brick aggregate concrete to improve the permeability and resistance against acid and sulfate attack

Abstract

AbstractBrick‐aggregate‐concrete with a greater permeability is susceptible to decay at a faster rate under the action of acid and sulfate. This study tries to improve the durability of brick aggregate concrete by the addition of rice husk ash, which has been termed brick‐ash concrete in this paper. The permeability and sorptivity of stone‐aggregate‐concrete, brick‐aggregate concrete, and brick‐ash concrete samples with different percentages of rice husk ash and different water‐to‐binder ratios were investigated. The concrete samples were also exposed to 1.5 % hydrochloric acid and 5 % sodium sulfate along with periodic drying and wetting cycle and periodic observations in terms of compressive strength, weight loss, and ultrasonic pulse velocity test for 360 days. 5 % to 10 % rice husk ash can significantly improve the permeability and resistance to the harsh environment of brick aggregate concrete. Additionally, this study also presents the equations to predict the actual strength from ultrasonic pulse velocity values for the brick ash concrete specimen exposed to acid and sulfate environments.