Review on Application of Rice Husk Ash for Production of Hollow Sandcrete Blocks: Towards Sustainable Construction

The search for cement substitutes will significantly lower building costs and contribute to a decrease in greenhouse gas emissions from cement production. In mortar and concrete, rice husk ash (RHA) has been extensively researched as a partial cement substitute. The improper usage and disposal of recyclables (rice husk and RHA) produced during rice production is one of the main issues that negatively impact the rice industry. One way to address this is by incorporating waste into construction materials. In this study, past research on sandcrete blocks was reviewed to ascertain the suitable use of RHA for producing sandcrete blocks for sustainable construction. Specific gravity, oxide compositions, X-ray diffraction (XRD), and scanning electron microscopy (SEM) of RHA were reviewed, while strength comparisons between conventional blocks and RHA-blocks were also reviewed. The physio-chemical outcome of the RHA revealed it as a good binding material. The study concluded that hollow sandcrete blocks produced with RHA could be used as non-load-bearing walls and for lightweight construction. Hence, the fineness of RHA and the longer curing age of blocks will determine RHA’s usefulness for producing load-bearing walls. The application of RHA for producing hollow sandcrete blocks will lead to sustainable construction, thereby reducing environmental pollution posed by the rice industry.