Performance of Laced Steel–Concrete Composite (LSCC) beams under monotonic loading

Abstract

In this paper, a new Laced Steel–Concrete Composite (LSCC) system1Patent filed and is in process.1 is proposed. LSCC system comprises of thin steel cover plates provided with apertures / perforations, through which reinforcements in the form of lacings are introduced and held in position with the help of transverse / cross rods, after which concrete is filled in between the cover plates. This method of fabrication avoids welding in total. Paper presents the details of experimental investigations carried out on two beam specimens, which are representative of proposed LSCC system. Monotonic load testing under four point flexure on two specimens, one with 45° lacing and another with 60° lacing, are conducted under displacement control mode. Experimental results indicate that both the beams exhibit almost similar strength performance, while the one with 60° lacing perform better in terms of deformation. Failure modes could not be ascertained, since the experiments were stopped due to limitations in test set-up. At this stage, maximum support rotations achieved by LSCC beams with 45° and 60° lacings are 13° and 16° respectively. Responses of LSCC, Laced Reinforced Concrete (LRC) and conventional Reinforced Concrete (RC) beams are compared. It is estimated that RC, LRC and LSCC beams can achieve a maximum support rotation of 3.5°, 7° and 15°, respectively. Thus, the proposed LSCC system is found to possess high rotation capacity, and maintain structural integrity even at large deformation. Comparison of performance of the LSCC beams in terms of support rotation with that of Steel–Concrete Composite (SCC) beams having other forms of connectors indicate that LSCC beams exhibit relatively high support rotations. Thus, proposed LSCC system has potential for use in structures subjected to suddenly applied dynamic loads, especially blast loads.