Performance of rice husk ash (RHA) and recycled coarse aggregate (RCA) for sustainable concrete: A review
Raymond Wellington Suomie, Biraja Prasad Mishra, Swagato Das
Abstract
In recent years, researchers have explored more sustainable substitute materials for conventional concrete components. The present review examines the application of Rice Husk Ash (RHA) and Recycled Coarse Aggregate (RCA) in combination with each other in making concrete. By analyzing over 50 published studies, this paper evaluates how these materials affect workability, strength, durability, and environmental performance. The results show that RCA can sometimes lower performance due to its high porosity, but RHA helps counter this by improving the concrete's internal structure through its pozzolanic reaction. Overall, the review points to the need for better mix design strategies and material handling to make concrete both stronger and more sustainable. Furthermore, the review points out that the dual application of RHA and RCA remains under-explored in existing research, particularly regarding long-term stability and environmental analysis. The majority of studies isolate these materials from each other, losing the synergy they can acquire from interaction. This review bridges the critical knowledge gap for the combined application of RHA and RCA in concrete, illustrating their synergistic opportunities towards sustainable augmentation with the offsetting of individual limitations. It highlights the most significant research gaps, such as a lack of standardized processing and long-term durability studies, and recommends optimal mix designs to enable structural viability. Closing these gaps may result in more uniform performance results and increased use of these materials in actual construction. Finally, the review helps add to increasing literature that seeks to minimize the carbon intensity of the construction sector through the use of agricultural waste and construction demolition waste. It further stimulates subsequent research on optimizing proportion mixes, enhancing quality control, and assessing lifecycle performance.