Geopolymer Concrete Incorporating Fly Ash: A Comprehensive Review on Mix Design Strategies, Engineering Performance and Environmental Sustainability
Recent concern over the shortage of driving sustainable construction material has catalyzed the level of attention that has been given to Geopolymer concrete (GPC), especially those based on the use of fly ash which is a by-product of coal combustion as a major cementing agent. This review analyses the use of fly ash in Geopolymer concrete by critically looking into the mix design strategies, engineering performance as well as environmental sustainability. The underlying chemical composition of fly ash, size and shape of the particles and reactivity play an important role in Geopolymerization and end concrete properties. Important variable parameters including alkaline activator concentration Si/Al ratio and curing conditions are expounded on in regards to their role in the strength and endurance of the mechanical processes. Fly ash GPC shows high resistance to chemical attacks, low permeability as well as thermal performance over the conventional OPC concrete. In addition, production places tremendous benefits on the environment by way of carbon emission, energy requirement and efficient use of industrial wastes. Real life applications and case studies emphasize the implementation potential of best fly ashbased GPC, some obstacles being variable material, standardisation, and cost. Key gaps in current research and future directions are established in this review to provide future sense in terms of commercialization of Geopolymer concrete in supporting the construction of sustainable infrastructure.