Dowel action of the tensile reinforcement in RC beams without shear reinforcement: Novel experimental investigation and mechanical modelling. (15th March 2023)

• Record Type: Journal Article
• Authors: Autrup, Frederik; Jørgensen, Henrik Brøner; Hoang, Linh Cao
• Is Part Of: Engineering structures. Volume 279(2023)
• Publication Date: 2023-03-15
• Subjects: Reinforced concrete -- Shear -- Shear-transfer actions -- Dowel action -- Experimental investigation -- Mechanical modelling -- Linear elastic modelling -- Rigid plastic modelling; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2022.115471
• Languages: English
• ISSNs: 0141-0296

Abstract

Abstract: Dowel action is a well-known phenomenon in shear-related problems within structural concrete. The tests previously reported in the literature to evaluate this contribution in reinforced concrete beams without shear reinforcement were conducted without any initial activation of the tensile reinforcement. This paper presents the experimental results of dowel tests, performed in a novel experimental test setup. The test setup reflects more realistically the conditions of the tensile reinforcement in reinforced concrete beams without shear reinforcement. The test setup enables a realistic tensile activation of the longitudinal reinforcement before applying the dowel force. The tests show that even a low activation of the tensile reinforcement results in the development of horizontal- and inclined cracks, even before the dowel force is applied. This shows that the contribution from dowel action of the tensile reinforcement is not just simply governed by the splitting strength of the concrete cover. A method to determine the displacement of the dowel from photogrammetric measurements is presented. In addition, a linear elastic- and a rigid-plastic mechanical model are presented for estimating the shear force transferred by the tensile reinforcement in RC beams without shear reinforcement. The estimates are based on measurements of the dowel displacement. Comparison of the presented model and the experimental results shows fairly good agreement. Highlights: Presents a novel dowel test setup with a tensile activation of the reinforcement The tensile activation induces cracks before the dowel force is applied The shear force carried by dowel action depends on the dowel displacement An elastic- and a plastic mechanical dowel model is proposed Comparison of proposed models with the experimental results shows a good agreement