Jean-François Jullien

Experimental study of a composite wood–concrete beam with the INSA–Hilti new flexible shear connector

Abstract Recent advances in modern construction have led to the frequent use of combined concrete slab and timber beams as a horizontal load-bearing structural component as a result of the development of appropriate connecting devices. Several of such devices are now available, some allow for limited interlayer slip, while others prevent separation of the partial girders. Installation speed and working conditions on site are the two major criteria that dictate their market prospects. The connector described here was developed with the paramount objective of breaking the speed barrier by using modern fixing techniques such as the multi-purpose Hilti cartridge-operated gun. Results from tests show that the new shear connector possesses higher rigidity, ductility and ultimate strength than a limited range of Hilti shear connectors used in both composite wood–concrete and concrete–steel construction.

Buckling of Axially Compressed Imperfect Cylinders and Ring Stiffened Cylinders Under External Pressure

The main purpose of this paper is to present the experimental device which has been developed at INSA LYON (Ref. 1), in order to study the buckling behavior of cylindrical shells under axial loading or lateral pressure.

An Experimental and Analytical Study of a New Shear Connector for Composite Steel-Concrete Beams

Publisher Summary Numerous types of shear connectors have been developed since the introduction of composite steel–concrete construction in buildings. The headed studs, which are attached to the steel beam by a fillet electric-arc welding running all around the connector, are the most widely used ones. The horizontal shear force acting at the steel–concrete interface is transmitted principally by the studs root while the head is provided for preventing uplift of the slab. The shear strength of a stud connector is directly proportional to its cross-sectional area and its ultimate shear strength is primarily influenced by the compressive strength and the elasticitys modulus of concrete. This chapter presents a report of the preliminary results of an experimental and analytical study designed to develop a new shear connector for composite steel–concrete beams. The innovative characteristic of this stud proposition patented by Spit, lies in the design features of the connectors base, which presents a special cold formed shape. The push-out test is employed to assess the shear strength and the load-slip characteristics of the Spit connector. A remarkable ductile behavior is observed in all of the push-out tests. These results are compared with those issues from a three-dimensional finite element method (FEM) analysis.