Title: Shear Behavior of Ultra-High-Performance Concrete Beams Reinforced with High-Strength Steel Bars

Author(s): S. Ahmad, S. Bahij, M. A. Al-Osta, S. K. Adekunle, and S. U. Al-Dulaijan

Publication: Structural Journal

Volume: 116

Issue: 4

Appears on pages(s): 3-14

Keywords: concrete beam; cracking pattern; high-strength steel; mechanistic model; shear capacity; ultra-high-performance concrete (UHPC); ultra-high-performance fiber-reinforced concrete (UHPFRC)

DOI: 10.14359/51714484

Date: 7/1/2019

Abstract:
This study was conducted to investigate the effects of key structural parameters on the shear behavior of non-prestressed ultra-high-performance concrete (UHPC) beams passively reinforced with high-strength steel bars. The parameters studied were shear span to effective depth ratio a/d; volume fraction of steel fibers Vf ; longitudinal reinforcement ratio ρ; and stirrups spacing s. Ten beam specimens with cross-section dimension (width x depth) 5.91 x 8.86 in. (150 x 225 mm) were quasistatically loaded to failure on a simple span length of 68.9 in. (1.75 m), under a four-point loading configuration. The statistical analysis of the experimental data indicated that a/d, Vf, and s have significant effects on the shear capacity of UHPC beams, while the effects of ρ are quite insignificant. A mechanistic model for estimating the shear capacity of reinforced UHPC beams was developed, validated, and shown to be reasonably accurate.