Mechanical Performance of Slag-Based HPFRGC with Varying Silica Fume Replacement and Fiber Types

As Portland cement production greatly affects the environment, more focus is being placed on using geopolymer concrete (GPC) as an alternative. This study explores the mechanical performance of high-performance fiber-reinforced geopolymer concrete (HPFRGC) using slag-based binders partially replaced with silica fume at levels of ۰%, ۵%, ۱۰%, and ۱۵%. The effects of incorporating steel and glass fibers at ۰.۵% and ۱% volume fractions on compressive and splitting tensile strengths were also evaluated at ۷ and ۲۸ days. Results indicate that ۵–۱۰% silica fume replacement enhances compressive and tensile strength, with ۱۰% being optimal. Excessive replacement (۱۵%) reduced strength due to dilution of reactive content. Steel fibers were more effective than glass fibers, particularly at ۱% content, yielding up to ۱۲.۷% and ۳۸.۶% improvements in compressive and tensile strengths, respectively. Moderate benefits were seen from using glass fibers, mainly in tensile performance. Failure pattern analysis showed that fiber-free specimens experienced brittle fractures, while fiber-reinforced mixes exhibited improved crack control and ductility. Overall, the combined use of ۱۰% silica fume and ۱% steel fiber offers the best enhancement in mechanical performance, suggesting an effective approach for developing sustainable, high-performance geopolymer concretes.

Keywords:

Performance Evaluation , High performance fiber reinforced geopolymer concrete , Slag , Silica Fume