Shear Behavior of High-Strength Concrete Column: A Review of Mechanisms, Design Models, and Experimental Evidence

Abstract

High-strength concrete (HSC) lets columns carry more load in a smaller section, but its gain in compressive strength is not matched by a proportional gain in tensile capacity, and HSC columns therefore remain prone to sudden, low-ductility shear failure rather than the gradual, flexure-dominated failure that seismic design prefers. This paper reviews the mechanics, design-code treatment, and experimental evidence for the shear behaviour of HSC columns (nominal f′c ≥ 40–50 MPa) under monotonic and cyclic loading. Section II summarizes the shear-transfer mechanisms specific to reinforced concrete columns and the scope and approach used for the review. Section III compares the governing shear-strength expressions of ACI 318, the UCSD/Priestley degrading-truss model, the Sezen–Moehle model for lightly reinforced columns, and recent data-driven formulations, and evaluates three representative code-type expressions for the concrete contribution, Vc, over a realistic range of axial load ratio. Section IV synthesizes the reported effects of concrete strength, axial load ratio, transverse reinforcement ratio and spacing, longitudinal and transverse steel grade, steel-fibre addition, and composite confinement on shear strength, failure mode, and ductility, drawing on studies published between 1994 and 2024. Section V presents a detailed case study: a cyclic-loading test programme on large-scale 70 MPa columns, in which shear-reinforcement ratio, longitudinal steel grade (CRB735 versus HRB400), stirrup spacing, and axial load ratio were varied, and the reported findings are compared against an 86-column literature database and against ACI 318's shear provisions. Across the reviewed evidence, higher axial load consistently raises shear strength while steepening the critical crack and reducing deformation capacity; closer or higher-grade transverse reinforcement delays, but does not eliminate, brittle shear failure; and the reporting of ductility and post-cracking deformation remains inconsistent across studies, which limits like-for-like comparison. Section VI compares these trends against code predictions, and Section VII proposes a small set of reporting items that would make future HSC column shear studies directly comparable, most of which are already measured in typical test programmes but not always published. The review concludes that shear design of HSC columns is best treated as a strength-ductility trade-off rather than a strength-maximization problem alone.