Title:
From Steel to Synthetic: Unlocking the Potential of PVA and Carbon Fibers in Ultra High Performance Concrete
Author(s):
Meghana Yeluri
Publication:
Web Session
Volume:
ws_F25_MeghanaYeluri.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/26/2025
Abstract:
Ultra-high-performance concrete (UHPC) is widely recognized for its exceptional strength and durability, making it a preferred material for structural applications. However, the high cost and limited availability of steel fibers hinder its broader adoption. This study investigates the partial replacement of steel fibers with synthetic alternatives—polyvinyl alcohol (PVA) and carbon fibers (CF)—as a strategy to enhance sustainability and reduce material costs. Seven UHPC mixtures were developed with a total fiber volume of 1.5%, incorporating PVA and CF at steel fiber replacement levels of 0%, 33%, 50%, and 75%. All mixtures were proportioned to achieve a target flow of 8 ± 1 inches by adjusting the dosage of high-range water-reducing admixture, while maintaining a constant water-to-cementitious materials ratio of 0.20. All mixtures met the target compressive strength of 17,500 psi under standard moist curing, with a maximum strength reduction of approximately 10% observed at the 75% replacement level. The modulus of rupture across all mixtures ranged from 1,450 to 2,300 psi. In contrast, the modulus of elasticity and splitting tensile strength declined by up to 5% and 40%, respectively, with increasing levels of synthetic fiber substitution. Notably, the inclusion of PVA fibers in combination with steel fibers proved effective in mitigating drying shrinkage, with a 32% reduction observed at 33% replacement level after 91 days. Additionally, Durability was assessed using sorptivity, rapid chloride permeability, and surface resistivity. Linear regression analysis revealed strong correlations among sorptivity, charge passed, and surface resistivity in UHPC mixtures containing synthetic fibers.