Strength Iso-Responses of Shear-Deficient Ultra-High Performance Fiber Reinforced Concrete Beams

Abstract

The development of sustainable construction methods can be achieved by improving the performance of reinforced concrete elements, resulting in an increase in structural life expectancy. This paper presents a study of the structural performance of shear-deficient ultrahigh-performance concrete (UHPC) concrete beams to produce sustainable construction materials. In the first phase of the experimental campaign, performance-based optimizations were implemented for UHPC. The characteristic compressive strength of all mixes was kept at 130 ± 10 MPa. The elastic modulus of plain UHPC was obtained at 8 GPa, and for the fiber-reinforced one was 40 GPa. Additionally, 18 sets of reinforced UHPC beams were investigated for their structural behavior based on the overall depth, reinforcement ratio (ρ), and the shear-span-to-depth ratio (λ) as key variables. Here, λ was varied between 1 and 2 and ρ was varied between 0.56% and 3.15%. The experimental study determined the lowest shear strength as 4.56 MPa, and the highest shear strength was calculated as 11.34 MPa. The database of the current shear strength results and similar literature results were used to develop models for predicting shear capacity. This research focused on applying a statistical approach using neuro-fuzzy logic, the robust analytical model. The ratio of the experimentally calculated shear strength and the predicted shear strength for different values of λ and ρ was obtained between 0.75 and 1.25, which was in good agreement with the results of similar literature. The results of this study suggest that high-strength fiber may extend structural lifetimes in UHPC applications.