Optimizing Fiber-Reinforced Geopolymer Concrete for Sustainable Construction Practices

Concrete production is a major contributor to environmental challenges, including high carbon dioxide emissions and depletion of natural resources. To address these issues, sustainable alternatives such as geopolymer concrete (GPC) and the use of manufactured sand (M-sand) have gained attention. GPC, utilizing industrial by-products like fly ash and ground granulated blast furnace slag (GGBS), offers a low-carbon alternative to conventional concrete (CC). Additionally, M-sand, a processed material, replaces river sand, reducing environmental degradation associated with excessive sand mining. Polypropylene (PF) and steel fibers (SF) further enhance the mechanical properties and crack resistance of concrete mixes. This study focuses on optimizing fiber content for improved performance in both CC and GPC mixes. In Phase 1, the optimal fiber content was identified as 0.5% PF and 2% SF based on slump and compressive strength tests for CC with M-sand and river sand. In Phase 2, these optimal fibers were incorporated into both CC and GPC mixes, and evaluated for mechanical and durability properties, including compressive strength, modulus of rupture, elasticity, water absorption, sorptivity, and rapid chloride permeability (RCPT). Results reveal that GPC with M-sand and steel fibers exhibits superior mechanical properties and durability, offering a sustainable and eco-friendly alternative to traditional concrete solutions.