Strain-hardening ultra-high performance concrete (UHPC) with hybrid steel and ultra-high molecular weight polyethylene fibers

• Published in: Construction & building materials 2024-08, Vol.438, p.136716, Article 136716
• Main Author: Chu, S.H.
• Format: Article
• Language: English
• Subjects: Direct tension; Fiber factor; FRC; Steel fibers; UHPC; UHWMPE fibers
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2024.136716

This study addresses the advancement of strain-hardening ultra-high performance concrete (UHPC) by investigating its tensile behavior with hybrid steel and ultra-high molecular weight polyethylene fibers. Through direct tensile testing of UHPC samples with varying volumes of steel and polyethylene fibers (totaling 2.0%), significant improvements in tensile strain capacity and energy absorption capacity (tensile toughness) were observed upon replacing steel fibers with polyethylene fibers. Despite marginal variations in first cracking strength and ultimate tensile strength, these properties could be finely tuned by tailing fiber length and hybrid ratio. Quantitative analysis established correlations between the hybrid fiber factor and key mechanical properties, advancing a deeper understanding of UHPC behavior. The findings underscore the benefits of multiscale fiber hybridization in UHPC, offering scientific insights into predicting and optimizing its performance for structural applications. This study helps close the gap in UHPC development, emphasizing the potential of multiscale fiber hybridization to achieve concurrently high tensile strength and strain capacity. •Concurrent ultra-high tensile strength and strain fiber composites were developed.•Effect of the combination of steel fibers and polypropylene fibers was evaluated.•Modeling of the tensile performance was performed based on hybrid fiber factor.•The tensile strength, tensile strain capacity and energy dissipation were analyzed.