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Proceedings of the Institution of Civil Engineers Structures and Buildings 163 October 2010 Issue SB5 Pages 317–330 doi: 10.1680/stbu.2010.163.5.317 Paper 800002 Received 14/12/2007 Accepted 30/10/2009 Keywords: bridges/concrete structures/concrete technology & manufacture Chul-Hun Chung Professor, Department of Civil and Environmental Engineering, Dankook University, GyeonggiDo, Republic ofKorea Chang-Su Shim Professor, Department of Civil and Environmental Engineering, Chung-Ang University, Seoul, Republic of Korea Byung-Hak Hyun Researcher, BNG Consultants, Gyeonggi-Do, Republic of Korea Young-Jin Kim Research Fellow, Daewoo Institute of Construction Technology, Suwon, Republic of Korea

Shear connections in prestressed beams with precast slabs
C.-H. Chung
PhD,

C.-S. ShimPhD,

B.-H. Hyun

PhD

and Y.-J. Kim

PhD

The prefabricated bridge is an attractive system that can efficiently ease and accelerate the construction and replacement of bridges in urban areas. In order to contribute to its implementation, details of precast slabs for prestressed concrete girders were developed and static tests were conducted in order to propose design equations for theshear connection. Stirrups and stud connectors, used as shear connectors, were fabricated to insert embedded nut-type devices in prestressed concrete girders. Non-shrink mortar was adopted as a filling material in the shear pockets for the connectors. Evaluation of the shear strength developed by the shear connection considering the chemical bond, friction and mechanical connectors was performed toderive an empirical equation for the horizontal shear design of prestressed concrete girders. The presence of mechanical connectors increased the ultimate slip capacity of the shear connection so as to allow the redistribution of shear load, and the suggested details of the shear connection exhibited good performance in terms of strength and ductility. Three composite beams were tested to verify thesuggested equation, which revealed that the use of the empirical equations produces a conservative design for horizontal shear of prestressed concrete beam bridges. 1. INTRODUCTION This study is intended to contribute to the extension of the implementation of the emerging and growing technology of the innovative prefabricated bridge by pioneering bridge owners, engineers and builders. The featuresoffered by innovative bridge elements and systems help to sustain bridges by making bridge building safer and less disruptive to the environment and travelling public, by making bridge designs more constructible and by improving the quality and durability of the bridge by shifting work to a more controllable environment. The full-depth precast slab system for prestressed concrete (PSC) girderbridges, illustrated in Figure 1, is a very attractive design alternative for the rehabilitation of deteriorated concrete slabs as well as newly constructed bridges. A new shear connection detail, which optimises the efficiency of precast slabs to PSC girders, is suggested as presented in Figure 2. The horizontal shear strength at the interface between the two interconnected elements is of primaryimportance to achieve Structures and Buildings 163 Issue SB5

PSC girder Shear connector Precast slab Rubber strip Shear key

Shear pocket

PSC girder

Figure 1. Precast slabs system for PSC girder bridges

sufficient composite action. Generally, shear stirrups are used for shear connectors in PSC girder bridges with cast-in-place (CIP) concrete slabs. In this system, stirrups and studs areused for the shear connectors, and a detail that eases the installation of precast slabs is proposed. In order to accommodate girder elevation change along the bridge span, it is necessary to place a bedding layer. Owing to filling material in shear pockets for connectors and the bedding layer, a new empirical equation for the evaluation of static strength of the shear connection needs to be...