Unearthing the potential of Geopolymer Concrete in sustainable underground construction

Underground construction, especially tunnelling, presents significant opportunities to reduce CO₂ emissions through material innovation. Geopolymer Concrete (GC), a low-carbon alternative to Conventional Concrete (CC) made of Ordinary Portland Cement (OPC), offers promising sustainability benefits. The study demonstrates that GC can be utilized as a prescribed performance-based concrete, assisted by testing, for its design and production, typically provisioned for CC in codes including EN 1990, EN 1992, and EN 206. It evaluates GC’s key physical and mechanical properties in comparison to CC, demonstrating excellent durability, superior chloride-ion resistance and improved abrasion resistance. With significant reduction in CO₂ emission and high resistance to carbonation and sulfate attack, GC can be a viable option for structures exposed to aggressive environments. With continued standardization and awareness, GC can become a mainstream sustainable solution for major underground construction projects.