Experimental Assessment of Alternative Shear Connections in Cross-Laminated Timber-Concrete Floor Systems
Publication: Journal of Structural Engineering
Volume 149, Issue 5
Abstract
New building code changes enable mass timber panels (MTP), including cross-laminated timber (CLT), to be used in moderate and tall buildings as a floor system, usually with a concrete topping. A floor system of CLT composite with a reinforced concrete topping slab can provide increased stiffness and strength, making the system more advantageous. Present connection methods used to produce composite action within timber-concrete composites (TCC) have limitations when considering constructability or performance. This study presents experimental results from four (4) shear connectors for CLT-concrete composite floor systems, including three developed for this study. The connectors included self-tapping screws (STS) at 45-degrees, a modified lag screw with an integral plate washer that bears on the CLT surface at installation, a steel angle anchored only at the end of the span, and an inverted-T steel section with stem perforations. Different tests were performed on the different connectors including individual fastener tests, push-off group tests, and full-scale one-way bending tests. The push-off group tests showed that the proposed washer-screw exhibited higher stiffness and strength than a conventional STS. The full-scale one-way bending testing showed that the STS specimen exhibited the lowest strength of the alternatives. The inverted-T section exhibited the highest stiffness, while the other three connections had similar stiffness to the STS.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This work was financially supported by the USDA Agricultural Research Service in cooperation with the Tallwood Design Institute under Grant No. 58-0204-6-002. Additional thanks to Jeff Gent, Milo Clauson, Lance Parson, and Yasmeen Al-Sakin for their assistance in testing. The first author would also like to extend a deep thanks to ARCS for their support as an ARCS Scholar.
References
ACI (American Concrete Institute). 2019. Building code requirements for structural concrete. ACI-318-19. Farmington Hills, MI: ACI.
Al-Sammari, A. T., P. L. Clouston, and S. F. Breña. 2018. “Finite-element analysis and parametric study of perforated steel plate shear connectors for wood–concrete composites.” J. Struct. Eng. 144 (10): 04018191. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002188.
APA (The Engineered Wood Association). 2018. Standard for performance-rated cross laminated timber. ANDI/APA PRG 320. Tacoma, WA: APA.
Appavuravther, E., B. Vandoren, and J. Henriques. 2021. “Behaviour of screw connections in timber-concrete composites using low strength lightweight concrete.” Constr. Build. Mater. 286 (Jun): 122973. https://doi.org/10.1016/j.conbuildmat.2021.122973.
ASTM. 2012. Standard test method for mechanical fasteners in wood. ASTM D1761. West Conshohocken, PA: ASTM.
ASTM. 2014. Standard specification for carbon steel bolts, studs, and threaded rod 60 000 PSI tensile strength. ASTM A307. West Conshohocken, PA: ASTM.
ASTM. 2016. Standard test method for tension testing of metallic materials. ASTM E8. West Conshohocken, PA: ASTM.
ASTM. 2017. Standard test method for splitting tensile strength of cylindrical concrete specimens. ASTM C496. West Conshohocken, PA: ASTM.
ASTM. 2018. Standard test method for compressive strength of cylindrical concrete specimens. ASTM C39. West Conshohocken, PA: ASTM.
ASTM. 2021. Standard specification for high-strength low-alloy columbium-vanadium structural steel. ASTM A572. West Conshohocken, PA: ASTM.
Auclair, S. C. 2020. Design guide for timber-concrete composite floors in Canada. Montreal, QC, Canada: FPInnovations.
AWC (American Wood Council). 2018. National design specifications for wood construction. Reston, VA: AWC.
Barbosa, A. R., L. G. Rodrigues, A. Sinha, C. Higgins, R. B. Zimmerman, S. Breneman, S. Pei, J. W. van de Lindt, J. Berman, and E. McDonnell. 2021. “Shake-table experimental testing and performance of topped and untopped cross-laminated timber diaphragms.” J. Struct. Eng. 147 (4): 04021011. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002914.
Boccadoro, L., and A. Frangi. 2014. “Experimental analysis of the structural behavior of timber-concrete composite slabs made of beech-laminated veneer lumber.” J. Perform. Constr. Facil. 28 (6): A4014006. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000552.
Brunner, M., M. Romer, and M. Schnüriger. 2007. “Timber-concrete-composite with an adhesive connector (wet on wet process).” Mater. Struct. 40 (1): 119–126. https://doi.org/10.1617/s11527-006-9154-4.
Capozucca, R. 1998. “Bond stress system of composite concrete—Timber beams.” Mater. Struct. 31 (9): 634–640. https://doi.org/10.1007/BF02480615.
CEN (European Committee for Standardization). 2004. Design of timber structures—Part 1-1: General—Common rules and rules for buildings. EN 1995-1-1. Brussels, Belgium: CEN.
Clouston, P., L. A. Bathon, and A. Schreyer. 2005. “Shear and bending performance of a novel wood–concrete composite system.” J. Struct. Eng. 131 (9): 1404–1412. https://doi.org/10.1061/(ASCE)0733-9445(2005)131:9(1404).
Deam, B. L., M. Fragiacomo, and A. H. Buchanan. 2008. “Connections for composite concrete slab and LVL flooring systems.” Mater. Struct. 41 (3): 495–507. https://doi.org/10.1617/s11527-007-9261-x.
Fitzgerald, D., A. Sinha, T. H. Miller, and J. A. Nairn. 2021. “Axial slip-friction connections for cross-laminated timber.” Eng. Struct. 228 (Feb): 111478. https://doi.org/10.1016/j.engstruct.2020.111478.
Fragiacomo, M., C. Amadio, and L. Macorini. 2007. “Short- and long-term performance of the ‘Tecnaria’ stud connector for timber-concrete composite beams.” Mater. Struct. 40 (10): 1013–1026. https://doi.org/10.1617/s11527-006-9200-2.
Frangi, A., M. Knobloch, and M. Fontana. 2010. “Fire design of timber-concrete composite slabs with screwed connections.” J. Struct. Eng. 136 (2): 219–228. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000101.
Gelfi, P., and E. Giuriani. 1987. Corso di Perfezionamento per le Costruzioni in Cemento Armato Fratelli Pesenti. Milan, Italy: Politecnico di Milano.
Gelfi, P., E. Giuriani, and A. Marini. 2002. “Stud shear connection design for composite concrete slab and wood beams.” J. Struct. Eng. 128 (12): 1544–1550. https://doi.org/10.1061/(ASCE)0733-9445(2002)128:12(1544).
Gerber, A. R. 2016. “Timber-concrete composite connectors in flat-plate engineered wood products.” M.S. thesis, Dept. of Civil Engineering, Univ. of British Columbia.
Girhammar, U. A. 2009. “A simplified analysis method for composite beams with interlayer slip.” Int. J. Mech. Sci. 51 (7): 515–530. https://doi.org/10.1016/j.ijmecsci.2009.05.003.
Gutkowski, R., K. Brown, A. Shigidi, and J. Natterer. 2008. “Laboratory tests of composite wood–concrete beams.” Constr. Build. Mater. 22 (6): 1059–1066. https://doi.org/10.1016/j.conbuildmat.2007.03.013.
Higgins, C., A. R. Barbosa, and C. Blank. 2017. Structural tests of concrete composite-cross-laminated timber floors. Corvallis, OR: Oregon State Univ.
Higgins, C., and H. Mitchell. 2001. “Behavior of composite bridge decks with alternative shear connectors.” J. Bridge Eng. 6 (1): 17–22. https://doi.org/10.1061/(ASCE)1084-0702(2001)6:1(17).
Hossain, A., M. Popovski, and T. Tannert. 2019. “Group effects for shear connections with self-tapping screws in CLT.” J. Struct. Eng. 145 (8): 1–9. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002357.
ICC-ES (International Code Council Evaluation Service). 2021. Evaluation service report 3179. Subject: SWG ASSY 3.0 wood screws. Washington, DC: ICC.
ICC (International Code Council). 2021. International building code. Washington, DC: ICC.
Lukaszewska, E., H. Johnsson, and M. Fragiacomo. 2008. “Performance of connections for prefabricated timber–concrete composite floors.” Mater. Struct. 41: 1533–1550. https://doi.org/10.1617/s11527-007-9346-6.
Mai, K. Q., A. Park, and K. Lee. 2018. “Experimental and numerical performance of shear connections in CLT–concrete composite floor.” Mater. Struct. 51 (4): 84. https://doi.org/10.1617/s11527-018-1202-3.
Mirdad, M. A. H., and Y. H. Chui. 2019. “Load-slip performance of Mass Timber Panel-Concrete (MTPC) composite connection with Self-tapping screws and insulation layer.” Constr. Build. Mater. 213: 696–708. https://doi.org/10.1016/j.conbuildmat.2019.04.117.
Möhler, K. 1956. “On the load carrying behavior of beams and columns of compound sections with flexible connections.” In Habilitation. Karlsruhe, Germany: Technical Univ. of Karlsruhe.
Müller, K. 2020. “Timber-concrete composite slabs with micro-notches.” Ph.D. dissertation, Dept. of Civil, Environmental, and Geomatic Engineering, ETH Zurich.
SAE (Society of Automotive Engineers International). 2014. Mechanical and material requirements for externally threaded fasteners. SAE J429. Warrendale, PA: SAE.
Shephard, A. B., E. C. Fischer, A. R. Barbosa, and A. Sinha. 2021. “Fundamental behavior of timber concrete-composite floors in fire.” J. Struct. Eng. 147 (2): 04020340. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002890.
Srivastava, M. 2021. “Structural design and testing of mass timber concrete composite floor solutions with acoustic interlayers.” M.S. thesis, Dept. of Civil and Construction Engineering, Oregon State Univ.
Stenson, J., et al. 2019. “Monitored indoor environmental quality of a mass timber office building: A case study.” Buildings 9 (6): 142. https://doi.org/10.3390/buildings9060142.
Tannert, T., A. Gerber, and T. Vallee. 2020. “Hybrid adhesively bonded timber-concrete-composite floors.” Int. J. Adhes. Adhes. 97 (Mar): 102490. https://doi.org/10.1016/j.ijadhadh.2019.102490.
Taylor, B., A. R. Barbosa, and A. Sinha. 2021. “In-plane shear cyclic performance of spline cross-laminated timber-concrete composite diaphragms.” J. Struct. Eng. 147 (10): 04021148. https://doi.org/10.1061/(ASCE)ST.1943-541X.0003127.
Uniform Evaluation Service. 2019. Evaluation report number 192, subject: Simpson strong-drive SDW22, SDWS22DB, SDWH19DB, SDWS22, SDWS19, SDWH27G, and SDWS16 wood screws. Ontario, CA: International Association of Plumbing and Mechanical Officials.
van de Lindt, J. W., J. Furley, M. O. Amini, S. Pei, G. Tamagnone, A. R. Barbosa, D. Rammer, P. Line, M. Fragiacomo, and M. Popovski. 2019. “Experimental seismic behavior of a two-story CLT platform building.” Eng. Struct. 183: 408–422. https://doi.org/10.1016/j.engstruct.2018.12.079.
Van Den Wymelenberg, K., D. Northcutt, M. Fretz, J. Stenson, and E. Zagorec-Marks. 2019. Acoustic lab testing (ASTM E492- 2016, ASTM E90-2016) of multi-family residential CLT and MPP wall and floor assemblies. Engineering Studies in Buildings Laboratory. Eugene, OR: Univ. of Oregon.
Wacker, J. P., A. Dias, and T. K. Hosteng. 2017. “Investigation of early timber–concrete composite bridges in the United States.” In Proc., ICTB 2017, 3rd Int. Conf. on Timber Bridges. Stockholm, Sweden: Research Institutes of Sweden.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 149 • Issue 5 • May 2023
Copyright
© 2023 American Society of Civil Engineers.
History
Received: Feb 24, 2022
Accepted: Jan 9, 2023
Published online: Mar 11, 2023
Published in print: May 1, 2023
Discussion open until: Aug 11, 2023
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.
Cited by
- Ian Morrell, Arijit Sinha, Christopher Higgins, Bulent Tunc, Andre R. Barbosa, Two-Way Bending Behavior of Cross-Laminated Timber–Concrete Composite Floors with Alternative Shear Connectors, Journal of Structural Engineering, 10.1061/JSENDH.STENG-13290, 150, 8, (2024).