A study of dowel action in reinforced concrete beams

Abstract

This paper reopens the question concerning the contribution of dowel action to the shear capacity of reinforced concrete beams. First, a literature survey on the subject reveals that, despite the implicit belief in much of the current design thinking that dowel action can play a significant role in the mechanism through which shear is carried in a beam, opinion on the matter is divided and often contradictory. Secondly, a programme of beam tests in which the total amount of main steel remains constant but the number of bars (and hence their diameter) is varied is reported, the results showing that the bar diameter has no effect on the load-carrying capacity of the members, suggesting, therefore, that dowel action is unlikely to be a significant factor in the internal load-transfer mechanism leading to final collapse. Faunally, these experimental findings are confirmed by an established finite-element package which faithfully reproduced the experimental results, on the basis that the numerical model makes no allowances for the so-called dowel-action effect.

Shear strength of concrete members without transverse reinforcement: A mechanical approach to consistently account for size and strain effects

“…However, when spalling cracks can develop parallel to the bending reinforcement ( Fig. 2c) as for slender beams without transverse reinforcement, this action is significantly decreased, and even considered as negligible by many researchers [29,4,15,28]. -Residual tensile strength of concrete (Fig.…”

“…2c). The longitudinal bars of a reinforced member also have the possibility to transfer shear forces acting as dowels between the lips of a crack [25][26][27][28][29]. This action has shown to be efficient in regions were concrete cannot develop spalling cracks.…”

Analysis of shear-transfer actions on one-way RC members based on measured cracking pattern and failure kinematics

“…Another action reported in the scientific literature is the dowelling strength provided by flexural bars (Chana, 1987;Dei Poli et al, 1992, 1993Jelic et al, 1999;Thurston Charles, 1966a, 1966b;Taylor, 1969;Zararis, 2003). This action depends mostly on the diameter of the flexural bars, the presence of transverse reinforcement, the concrete cover and its strength, and the distance of the critical shear crack to the support plate.…”

“…Other researchers have focused on developing physical models to assess the amount of shear force that can be transferred (locally or by a structural member) under a specific shear-transfer action (or a combination of them) assuming given kinematics at failure. Some significant works in this field have been performed on the aggregate interlock action (Dei Poli et al, 1987;Paulay and Loeber, 1974;Sagaseta and Vollum, 2011;Taylor, 1970;Ulaga, 2003;Walraven, 1980;Zararis, 1997), the dowelling action (Chana, 1987;Dei Poli et al, 1992, 1993Jelic et al, 1999;Thurston Charles, 1966a, 1966b;Taylor, 1969;Zararis, 2003), the influence of the residual tensile strength of concrete (Bažant and Kazemi, 1991;Bažant and Yu, 2005a, 2005b, 2009Hillerborg, 1983;Hordijk, 1992;Kotsovos, 1983Kotsovos, , 1986) and the contribution of the compression zone to carry shear forces (Tureyen and Frosch, 2003).…”

Study on Load-Slip Characteristic Curves of Perfobond Shear Connectors in Hybrid Structures

“…The adhesion force from the aggregate interlock is relevant to the root of the concrete strength, c f (Bentz et al 2006). The dowel action of the perforated rebar under shear failure is relevant to / 3 y f (Jelic et al 1999). When subjected to the limit load, the perforated rebar is already yielded but the transverse reinforcement remain elastic.…”