Utilization of waste rice husk ash for sustainable geopolymer: A review

Abstract

The paddy farming countries generate enormous amounts of by-products, i.e., Rice husk (RH), through the milling process. It is typically utilized in the boiler as a fuel that produces a solid waste, i.e., Rice husk ash (RHA). It retains a high amount of biogenic silica and has shown good pozzolanic reactivity that can be used as a sustainable construction material. Consequently, over the last decade, a large number of investigations have been performed to utilize RHA for the production of cementitious materials, e.g., geopolymer. The geopolymer technology offers numerous advantages Over ordinary portland cement (OPC), such as reducing CO2 emission, excellent physico-mechanical properties, and feasibility to utilize waste ingredients. The present study reviews the utilization of waste RHA about the cleaner production of geopolymer. The effects of RHA inclusion on key properties like workability, setting time, compressive strength, and durability are intensely discussed in this study. On evaluating the effect of RHA on geopolymer, the incorporation of 10–20 wt% RHA is ascribed to improve the short and long-term properties of geopolymer. Thus, the use of RHA is a sustainable and environment-friendly pathway for the construction industry. Furthermore, based on the present review, the article also provides future research directions for developing more sustainability and recommends utilizing the RHA for cleaner production of geopolymer. © 2021 Elsevier Ltd