Influence of embedded length on strength of BFRP rods bonded parallel to the grain in low grade timber by pullout-bending tests

Caoimhe O'Neill, Daniel McPolin, Su Taylor, Annette Harte

    Research output: Contribution to conferencePaper

    Abstract

    Bonded-in rod connections in timber possess many desirable attributes in terms of efficiency, manufacture, performance, aesthetics and cost. In recent years research has been conducted on such connections using fibre reinforced polymers (FRPs) as an alternative to steel. This research programme investigates the pull-out capacity of Basalt FRP rods bonded-in in low grade Irish Sitka Spruce. Embedded length is thought to be the most influential variable contributing to pull- out capacity of bonded-in rods after rod diameter. Previous work has established an optimum embedded length of 15 times the hole diameter. However, this work only considered the effects of axial stress on the bond using a pull-compression testing system which may have given an artificially high pull out capacity as bending effects were neglected. A hinge system was utilised that allows the effects of bending force to be taken in to consideration along with axial forces in a pull-out test. This paper describes an experimental programme where such pull-bending tests were carried out on samples constructed of 12mm diameter BFRP bars with a 2mm glueline thickness and embedded lengths between 80mm and 280mm bonded-in to low-grade timber with an epoxy resin. Nine repetitions of each were tested. A clear increase in pull-out strength was found with increasing embedded length.
    Original languageEnglish
    Number of pages5
    DOIs
    Publication statusPublished - Aug 2014
    EventCivil Engineering Research in Ireland Conference (CERAI) - QUB, Belfast, United Kingdom
    Duration: 28 Aug 201429 Aug 2014

    Conference

    ConferenceCivil Engineering Research in Ireland Conference (CERAI)
    CountryUnited Kingdom
    CityBelfast
    Period28/08/201429/08/2014

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