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Experimental investigations on the pull-out strength of steel rods bonded in Douglas fir roundwood specimens with polymer concrete

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European Journal of Wood and Wood Products Aims and scope Submit manuscript

Abstract

The current market of timber products shows a clearly identifiable dominance of rectangular crosssections in modern timber buildings. To promote roundwood as addition to commonly used wood and wood products, this paper presents experimental investigations serving for axial connectors in roundwood truss structures. Glued-in threaded rods, bonded parallel to grain into Douglas fir (Pseudotsuga menziesii) softwood, represent the basis of this research. To increase the load-carrying capacity and usability of this connection technique in roundwood, a resin-bonded polymer concrete (PC) with an increased bondline thickness and contact surface to timber was investigated. The pullout strength and embedment stiffness of the new modified bonded-in rod connection was studied on Douglas fir roundwood specimen exposed to different service conditions. The study also determined the influence of wood defects and moisture content before testing. The results show a larger single-fastener capacity, also for higher moisture content applications, compared to traditional glued-in rods. The quality of the adhesive bondline, for example bonding length, hardening process and homogeneous adhesive bond could be verified by visual inspection.

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Acknowledgements

Parts of the presented research were funded by the German Federal Ministry for Economic Affairs and Energy according to a decision of the German Federal Parliament (Grant Agreement No. ZF4119606). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the funding agency.

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  1. Timber and Plastics Research Group, Mainz University of Applied Sciences, Holzstraße 36, D-55116, Mainz, Germany

    Tarick Chahade & Kay-Uwe Schober

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  1. Tarick Chahade
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  2. Kay-Uwe Schober
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Correspondence to Tarick Chahade.

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Chahade, T., Schober, KU. Experimental investigations on the pull-out strength of steel rods bonded in Douglas fir roundwood specimens with polymer concrete. Eur. J. Wood Prod. 81, 439–450 (2023). https://doi.org/10.1007/s00107-022-01855-x

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  • DOI: https://doi.org/10.1007/s00107-022-01855-x

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