ULTIMATE SHEAR CAPACITY AND FAILURE OF SHEAR KEY CONNECTION IN PRECAST CONCRETE CONSTRUCTION
DOI:
https://doi.org/10.11113/mjce.v26.15900Keywords:
Shear key, ultimate shear capacity, failure mechanism, precast connectionsAbstract
This paper presents the experimental results on the strength of shear key connection in precast concrete construction. The use of shear key is to connect two separate precast components to increase the shear resistivity of the joint surfaces. The proposed shear key shape in this study comprises of triangular, composite rectangular, semi-circle and trapezoidal. In addition, the trapezoidal shape is made up with 3 different key’s angles. All specimens are tested using the “push-off†method to obtain the ultimate shear capacity of which is due to the failure of the connection. From the analysis, stiffness, elastic and plastic behaviour, and the mode of failure is discussed to determine the most effective shape of the proposed shear key. From the findings, semi-circle shear key produced the highest shear capacity at 62.9 kN compared to that of the other shapes. Meanwhile, the trapezoidal shape at an angle of 45 produced the highest shear capacity at 44.1 kN. Together in the aspect of stiffness, the 45 trapezoidal shapes produced the highest resistance towards slip at 166.7 kN/mm. Failure mode are mostly due to shear, sliding and diagonal tension crack. Large slip of 7.35 mm is recorded from the triangular shape. The large slip is maybe due to sliding since the angle of the key faces to the shear plane is 45° which indicates to less interlocking compared with the other shapes they form an angle of 90° with the shear plane.References
Bakhoum, M. M. (1991). Shear Behavior and Design of Joints in Precast Concrete Segmental Bridges. PhD Thesis. Massachusetts Institute of Technology.
Buyukozturk O., Bakhoum M. and Beattie S. (1990). “Shear Behaviour of Joints in Precast Concrete Segmental Bridgesâ€. Journal of Structural Engineering. 12. pp: 3380-3401.
Chatveera B. and Nimityongskul P. (1994). “Vertical Shear Strength of Joints in Prefabricated Loadbearing Wallsâ€. Journal of National Research Council Thailand. 26(1). pp: 11-36.
Kaneko Y., Connor J. J., Triantafillou T. C. and Leung C. K. (1993a). “Fracture Mechanics Approach for Failure of Concrete Shear Key. I: Theoryâ€. Journal of Engineering Mechanics. 119(4). pp: 681-700.
Kaneko, Y., J.J. Connor, T.C. Triantafillou, and C.K. Leung (1993b). “Fracture Mechanics Approach for Failure of Concrete Shear Key. II: Verificationâ€. Journal of Engineering Mechanics. 119(4). pp: 701-719.
Koseki K. and Breen J. E. (1983). “Exploratory Study of Shear Strength of Joints for Precast Segmental Bridgesâ€. Research Report No. 248-1 Re-evaluation of AASHTO Shear and
Torsion Provisions for Reinforced and Prestressed Concrete. The University of Texas at Austin.
Lim, C. P. (2011). Response of Shear Key Connection with Different Key Shapes. Master Thesis. Universiti Teknologi Malaysia.
National Precast Concrete Association (2008). The Little Book of Concrete. London: British Precast Concrete Federation Ltd.
Rizkalla S. H., Serrette, R.L., Heuvel J. S. and Attiogbe E. K. (1989). “Multiple Shear Key Connections for Precast Shear Wall Panelsâ€. PCI Journal. March-April.
Rombach G. A. (2002). “Precast Segmental Box Girder Bridges with External Prestressing – Design and Constructionâ€. INSA Rennes: Segmental Bridges. February. pp: 1-15.
Rombach G. A. (2004). “Dry Joint Behaviour of Hollow Box Girder Segmental Bridgesâ€. FIB Symposium: Segmental Construction in Concrete. New Delhi: India.
Sullivan S. R. (2003). Behavior Transverse Joints in Precast System. M.Sc. Thesis. Ohio University
