Prospective study on the behaviour of composite beams with an indented shear connector Alves Ana Rita a , B. Valente Isabel a, ⁎, B. Vieira Washintgon b , S. Veríssimo Gustavo c a ISISE – Institute for Sustainability and Innovation in Structural Engineering, University of Minho, School of Engineering, Department of Civil Engineering, Campus de Azurém, 4800-058 Guimarães, Portugal b Universidade Federal de Itajubá, Campus de Itabira, Rua Irmã Ivone Drumond, 200, Distrito Industrial II, 35903-087 Itabira, MG, Brazil c Universidade Federal de Viçosa, Department of Civil Engineering, 36570-000 Viçosa, MG, Brazil abstract article info Article history: Received 28 November 2017 Received in revised form 3 May 2018 Accepted 10 June 2018 Available online xxxx This paper presents a prospective study on the behaviour of steel and concrete composite beams in which a linear indented continuous shear connector, called Crestbond, is used to establish the connection between the steel beam and the concrete slab and ensure the joint behaviour of these two elements. The work includes an exper- imental campaign developed at the Structural Laboratory of University of Minho, Portugal, and a numerical study developed with the ATENA 3D software. The experimental tests and the numerical models were developed to evaluate the behaviour of the composite beam and particularly the indented shear connector in analysis. The tested specimens consist on a steel beam with a continuous indented connector, positioned on the upper flange of the beam and continuously welded in its development, and a reinforced concrete slab, in a total span of 3000 mm. During the tests, the connector provided high stiffness and a full interaction between the concrete slab and the steel beam. The beams failure was determined by crushing on the upper part of the concrete slab. © 2018 Elsevier Ltd. All rights reserved. Keywords: Steel and concrete composite beams Indented shear connector Four-point bending tests Numerical analysis 1. Introduction 1.1. The Crestbond shear connector By the end of the 80s, the poor performance of stud connectors under fatigue motivated the search for new connection mechanisms for steel and concrete composite structures. Several alternative connec- tors were developed consequently, and some of them were based in the concept of a steel plate with slots that are filled by concrete. One of the first examples of these connectors is the Perfobond, developed by Leonhardt Andrä und Partner [1], with a focus on bridges and viaducts applications, which was the object of several subsequent research stud- ies across the globe [2], [3], [4], [5], [6], [7], [8]. Nonetheless, constructive and structural aspects still motivate the search for better performance solutions resulting in the continued development of many other con- nectors based on the dowel-effect concept [9–37]. While researchers from Northern Europe focused their studies on bridges and viaducts [1,2,3,9,10,17–21], Canadians [4, 5], Brazilians and Portuguese [13–16, 28, 29], studied solutions for building struc- tures. In the first studies, the failure mechanism observed was associated with the failure of the concrete by shear at the openings of the connectors. For this reason, for a while, these connectors were called concrete dowels. Subsequently, other studies have demonstrated the possibility of other failure modes, including failure of the steel due to the force exerted by the concrete on the protrusions of the connector. From this, these connectors came to be called composite dowels (Fig. 1). Different connector shapes were analyzed within a European project called PreCo-Beam (prefabricated composite beam) [22, 23]. This pro- ject involved researchers from Germany, France, Belgium, Sweden, Poland and Luxembourg, as well as partnerships between universities and construction companies. The studies carried out consider the behavior of the connectors under static and cyclic loadings for applica- tion in industrial floor systems and bridges. After extensive investiga- tion, three connectors stood out due to their structural performance: (a) the puzzle-shaped connector (Fig. 1.n); (b) the clothoidal connector (Fig. 1.p) and (c) the saw-tooth connector (Fig. 1.o). Further studies on puzzle-shaped connectors and clothoidal connectors were developed by other authors and analytical approaches were derived, [30–37]. Crestbond is a notched steel-plate connector with a configuration that facilitates its fabrication and the disposition of transversal rein- forcement [13,14,15],. In addition, it is a very rigid connector for service loads and ductile in ultimate limit state, constituting an interesting alternative for steel and concrete composite structural systems sub- jected to cyclic loads, or for those with a limited installation space for Journal of Constructional Steel Research 148 (2018) 508–524 ⁎ Corresponding author. E-mail addresses: isabelv@civil.uminho.pt, (B.V. Isabel), vieira@unifei.edu.br, (B.V. Washintgon), gustavo@ufv.br (S.V. Gustavo). https://doi.org/10.1016/j.jcsr.2018.06.015 0143-974X/© 2018 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Journal of Constructional Steel Research