Potential and production of pervious concrete incorporating rice husk as a partial aggregate replacement
Abstract
Pervious concrete is produced by utilising cement, coarse aggregate, and water. Industrial or agricultural waste products contribute significantly to environmental problems, such as air pollution and carbon dioxide emissions. Therefore, these waste products should be reused or recycled within construction or infrastructure activities to reduce their impacts on the environment. To address environmental problems, this study investigates an agricultural waste product, particularly rice husk (RH), in order to replace natural coarse aggregate in pervious concrete. This research addresses the research gap of employing unprocessed RH as a direct coarse aggregate replacement in pervious concrete. Its novel contribution is the empirical identification of a suitable replacement percentage that balances environmental waste valorisation with the preservation of structural integrity. Pervious concrete was prepared with a proportion of 1:3 (cement to coarse aggregate) and a water–cement ratio of 0.5, with RH replacing coarse aggregate by weight at 2%, 4%, 6%, and 8%. This study aims to investigate the potential of RH as a partial aggregate replacement by producing pervious concrete and assessing its behaviour. Two main experimental activities were conducted: RH surface morphology and elemental analysis, as well as analysis of compressive strength of pervious concrete cubes at 7, 28, and 40 days, with a total of 45 specimens. The design standards for determining the compressive strength were in accordance with BS EN 12390-3. The results indicated that the specimen with 2% RH replacement exhibited the highest compressive strength among all specimens, achieving 13.4 MPa at 7 days, 16.3 MPa at 28 days, and 18.0 MPa at 40 days. Overall, the compressive strength of pervious concrete decreased as the proportion of coarse aggregate replaced by RH increased. Therefore, it can be concluded that RH has the potential to replace coarse aggregate at proportions of less than 4% in pervious concrete based on the testing.