Advancing Geopolymer Technology: The Impact of Rice Husk Ash on the Mechanical Strength of M40 Concrete

Abstract

This research explores the role of concrete as a pivotal construction material and introduces geopolymer concrete as an environmentally friendly alternative to ordinary Portland cement (OPC). Utilizing industrial by-products such as fly ash and rice husk ash (RHA) mixed with alkaline solutions, geopolymer concrete emerges as a sustainable option to mitigate the carbon footprint of the construction sector. This paper reports on the mechanical behavior of steel-reinforced geopolymer concrete composites incorporating varying proportions of RHA as a partial substitute for cement. It was observed that the compressive strength tends to diminish with an increase in RHA content, suggesting an optimal replacement threshold. The study finds that up to 20% of fly ash can be effectively replaced with RHA in the geopolymer mix without compromising structural integrity. While the addition of RHA impacts the initial workability of the concrete mix, this can be counteracted through specific chemical additives. The overarching aim is to enhance resource recovery and recycling in construction materials, aligning with sustainable development practices.