Life Cycle Assessment and Impact Correlation Analysis of Fly Ash Geopolymer Concrete

Geopolymer concrete (GPC) has drawn widespread attention as a universally accepted ideal green material to improve environmental conditions in recent years. The present study systematically quantifies and compares the environmental impact of fly ash GPC and ordinary Portland cement (OPC) concrete under different strength grades by conducting life cycle assessment (LCA). The alkali activator solution to fly ash ratio (S/F), sodium hydroxide concentration (C(NaOH)), and sodium silicate to sodium hydroxide ratio (SS/SH) were further used as three key parameters to consider their sensitivity to strength and CO(2) emissions. The correlation and influence rules were analyzed by Multivariate Analysis of Variance (MANOVA) and Gray Relational Analysis (GRA). The results indicated that the CO(2) emission of GPC can be reduced by 62.73%, and the correlation between CO(2) emission and compressive strength is not significant for GPC. The degree of influence of the three factors on the compressive strength is C(NaOH) (66.5%) > SS/SH (20.7%) > S/F (9%) and on CO(2) emissions is S/F (87.2%) > SS/SH (10.3%) > C(NaOH) (2.4%). Fly ash GPC effectively controls the environmental deterioration without compromising its compressive strength; in fact, it even in favor.