Publication

Abstract : Geopolymer concrete, also known as cementless concrete, is emerging in the field of civil engineering as one of the advanced construction materials. Sustainable construction demands geopolymer concrete as an eco-friendly and viable alternative to Portland cement. Although geopolymer concrete with fly ash and GGBFS as precursors has been extensively studied, the incorporation of industrial by-products, such as lime sludge, remains unexplored. This study investigated the synergistic effects of a ternary blend comprising fly ash, GGBFS, and lime sludge in producing M30 grade geopolymer concrete. In this study, 11 different mixes with various percentages of fly ash and GGBFS with lime sludge were analyzed in terms of mechanical properties, durability, microstructural characterization, and cost. Among the tested combinations, the mix with a composition of 60% fly ash, 30% GGBFS, and 10% lime sludge was found to be optimal, with significant improvements in the compressive strength (25.89%), flexural strength (26.67%), and split tensile strength (18.03%) compared to the control mix. This optimal blend was utilized as the base for the second phase of the study, which evaluated the influence of hooked-end steel fibers at volume fractions of 0, 0.25, 0.5 and 0.75%. The tests conducted on steel fiber geopolymer concrete include workability and mechanical properties. The results indicated that the incorporation of 0.75% steel fibers provided optimal results with 11.25% enhancement in compressive strength, 5.26% enhancement in flexural strength, and 46% enhancement in split tensile strength compared with the non-fibrous mix.