Title: Theoretical and Experimental Study on Minimum Shear Reinforced Ratio in Concrete Beams

Author(s): S. L. Garcia, J. Ferreira, D. Dias, J. Sousa, P. Figueiredo, and J. Trindade

Publication: Structural Journal

Volume: 121

Issue: 1

Appears on pages(s): 47-59

Keywords: beam; geopolymeric concrete; minimum shear; reserve strength

DOI: 10.14359/51739184

Date: 1/1/2024

Abstract:
Failure in beams reinforced with a small amount of transverse reinforcement is brittle due to reinforcement rupture after critical shear cracking occurs. To eliminate this problem, standards recommend formulas to calculate the minimum amount of transverse reinforcement in reinforced concrete structures. Reinforcement can resist loads after the first crack’s appearance, preventing beam rupture from being brittle but making it somewhat ductile. This paper presents a theoretical experimental analysis to determine the minimum transverse reinforcement ratio in beams of high-strength ordinary portland cement concrete (BHSOPCC), low-strength ordinary portland cement concrete (BLSOPCC), and low-strength geopolymeric concrete (BLSGC). The beam dimensions were 150 x 450 x 4500 mm. They were subjected to a four-point bending test to assess shear failure. The transverse reinforcement ρsw,minfyk ranged from 0 to 1.16 MPa, in the ranges provided by ACI 318-19, AASHTO LRFD, fib Model Code, and ABNT NBR 6118:2014. This paper investigates the minimum shear reinforcement ratio for various types of concretes with different strengths and attempts to reevaluate the associated standards that have already been established. The parameter τwy*/τwcr proposed in this paper to define whether or not a beam has minimum transverse reinforcement is more appropriate.