Cradle-to-gate assessment and optimization of sustainable geopolymer concrete

Geopolymer concrete (GPC) is a sustainable alternative to Portland cement concrete by eliminating Portland cement. However, using alkaline activators compromises the sustainability of GPC. This paper presents a comprehensive assessment of the cradle-to-gate life cycle cost, carbon footprint, and energy consumption of 2304 GPC mixtures which represent the state-of-the-art dataset, aiming to establish a holistic understanding of the impacts of GPC design parameters on mechanical and sustainability performance. The cost-benefit characteristics of solid wastes are considered, and strength-normalized sustainability parameters are discussed. Results reveal that the formulation of GPC plays critical roles in mechanical and sustainability metrics. Inappropriate use of alkaline activators and solid wastes can largely compromise both mechanical strength and sustainability metrics, lower than their Portland cement counterparts. Based on the large dataset, this paper identifies the appropriate upper and lower bounds for various ingredients to guide the design of GPC for balanced mechanical strength and sustainability metrics.