Timber-Limecrete Composite Floors Using Timber Connectors Sloped toward or against Slip
Publication: Journal of Structural Engineering
Volume 136, Issue 12
Abstract
Building floors comprising timber joists connected to limecrete (lime concrete) slabs via timber headed studs have low carbon footprints. Such floors are not yet used owing to lack of underpinning research. This paper presents results from large-scale joint tests which show that by sloping the timber studs at 45° against the sense of slip so that the slab lifts off the joists during slip, not only does the joint exhibit good stiffness and strength, but also the joint fails in a highly ductile manner by double curvature hinging of each stud and by crushing of the adjacent limecrete and glulam near the slab-joist interface. With the studs sloped at 45° toward the sense of slip, joint ductility drops significantly while joint stiffness and strength rise dramatically. Test data are also given for a 4.6 m long timber joist-limecrete slab composite specimen with studs sloped at 45° against slip and loaded in four-point bending to failure. Nonlinear finite-element analysis (FEA) using the measured joint and material constitutive data is seen to reliably predict this specimen’s load response. The verified FEA is used to compare the effects of the two stud layouts on the specimen’s structural characteristics. An equivalent rectangular stress block is derived for the limecrete based on a polynomial fit of that material’s compressive stress-strain test data and assuming that the neutral axis of the timber-limecrete section lies in the slab. Finally, suggestions are made for future studies of this composite system.
Get full access to this article
View all available purchase options and get full access to this article.
References
Ball, R. J., El-Turki, A., Allen, W. J., and Allen, G. C. (2007). “The stress cycling of hydraulic lime mortars.” Proceedings of the ICE, Journal of Construction Materials, 160(2), 57–63.
Bilodeau, A., Sivasundaram, V., Painter, K. E., and Malhotra, V. M. (1994). “Durability of concrete incorporating high volumes of fly ash from sources in the USA.” ACI Mater. J., 91(1), 3–12.
Brunner, M., Romer, M., and Schnüriger, M. (2007). “Timber-concrete composite with an adhesive connector.” Mater. Struct., 40, 119–126.
Clouston, P., Bathon, L. A., and Schreyer, A. (2005). “Shear and bending performance of a novel wood-concrete composite system.” J. Struct. Eng., 131(9), 1404–1412.
Clouston, P., and Schreyer, A. (2008). “Design and use of wood-concrete composites.” Pract. Period. Struct. Des. Constr., 13(4), 167–174.
Davids, W. G. (2001). “Nonlinear analysis of FRP-glulam-concrete beams with partial composite action.” J. Struct. Eng., 127(8), 967–971.
Deam, B. L., Fragiacomo, M., and Buchanan, A. H. (2008). “Connections for composite concrete slab and LVL flooring systems.” Mater. Struct., 41(3), 495–507.
Dias, A. M. P. G., Lopes, S. M. R., Van de Kuilen, J. W. G., and Cruz, H. M. P. (2007). “Load-carrying capacity of timber-concrete joints with dowel-type fasteners.” J. Struct. Eng., 133(5), 720–727.
Foschi, R. O. (1985). “Wood floor behavior: Experimental study.” J. Struct. Eng., 111(11), 2497–2508.
Fragiacomo, M. (2006). “Long-term behaviour of timber-concrete composite beams. II: Numerical analysis and simplified evaluation.” J. Struct. Eng., 132(1), 23–33.
Fragiacomo, M., Amadio, C., and Macorini, L. (2007). “Short- and long-term performance of the ‘Tecnaria’ stud connector for timber-concrete composite beams.” Mater. Struct., 40, 1013–1026.
Fragiacomo, M., and Ceccotti, A. (2006). “Long-term behaviour of timber-concrete composite beams. I: Finite element modeling and validation.” J. Struct. Eng., 132(1), 13–22.
Frangi, A., and Fontana, M. (2003). “Elasto-plastic model for timber-concrete composite beams with ductile connection.” Struct. Eng. Int. (IABSE, Zurich, Switzerland), 13(1), 47–57.
Gelfi, P., Giuriani, E., and Marini, A. (2002). “Stud shear connection design for composite concrete slab and wood beams.” J. Struct. Eng., 128(12), 1544–1550.
Gutkowski, R. M., Brown, K., Shigidi, A., and Natterer, J. (2004). “Investigation of notched composite wood-concrete connections.” J. Struct. Eng., 130(10), 1553–1561.
Hodsdon, T., and Walker, P. (2006). “Study of round-wood timber-limecrete composite panels.” Struct. Eng. Int. (IABSE, Zurich, Switzerland), 16(3), 245–251.
Pritchett, I. (2003). “Into the limelight.” The Architects’ Journal, July, 34–35.
Sebastian, W. M., and McConnel, R. E. (2000). “Nonlinear finite element analysis of steel-concrete composite structures.” J. Struct. Eng., 126(6), 662–674.
Seshasayi, L. V. A., Ramaseshu, D., and Shankaraiah, R. (2001). “Effects of cement replacements by fly ash and silica fume on compressive strength of concrete.” ACI Special Publication, 199, 581–584.
Steinberg, E., Selle, R., and Faust, T. (2003). “Connectors for timber-lightweight concrete composite structures.” J. Struct. Eng., 129(11), 1538–1545.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 136 • Issue 12 • December 2010
Pages: 1585 - 1595
Copyright
© 2010 ASCE.
History
Received: Apr 28, 2009
Accepted: May 9, 2010
Published online: May 28, 2010
Published in print: Dec 2010
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.