Published Date doi:10.1016/j.ijadhadh.2008.04.008 Special Topic Issue on Structural Adhesive Joint Author
D Otero Chans,
J. Estévez Cimadevila
E. Martín Gutiérrez
Department of Construction Technology, Advanced Technical School of Architecture, University of A Coruña, Spain
Available online 15 April 2008.
Abstract
The use of glued joints offers an option with ample aesthetic and functional possibilities in the design of wood structures. This type of joint is used since years 1970 in countries of North and Central Europe, for the design and construction of glulam (glued laminated timber) structures. This has led to diverse investigations in the experimental analysis of joints made with steel bars glued-in glulam subjected to axial loads. It led to diverse formulae of empirical base for the design of the same ones. Of these empirical formulae, the proposal of Riberholt is considered to be a pioneer. Likewise, the Eurocode 5 has included in more recent years a formula for the design of these unions, though only as an Informative Annex.
From these precedents, our research equipment has developed an extensive experimental campaign directed to evaluating the adjustment of these proposals to the design of joints in elements made with hardwood saw timber. This can be of great usefulness in works of restoration, because glued joints have an enormous potential for repairing old structures.
In this paper, diverse experimental campaigns made with threaded steel bars glued-in hardwood saw timber of high density are described.
Published Date March 2009, Vol.29(2):101–110,doi:10.1016/j.ijadhadh.2008.01.006 Author
Gary M. Raftery
Annette M. Harte,
Peter D. Rodd
Department of Civil Engineering, National University of Ireland, University Road, Galway, Ireland
Accepted 23 January 2008. Available online 25 March 2008
Abstract
Fibre-reinforced polymer (FRP)-strengthened glulam would be a more economically viable product if a single adhesive type could be utilised at all the bonded interfaces. This paper describes a test programme that examines the hygrothermal compliance of five commercial wood-laminating adhesives when bonding commercially viable FRP materials to wood. It was seen that the integrity of the bond depended not only on adhesive type but also on the FRP type under consideration. For one of the FRP types, moisture-cycled FRP–wood bonded specimens obtained high wood failure percentages and good shear strength results that compared well with non-moisture-cycled FRP–wood specimens, non-moisture-cycled wood–wood bonded specimens and solid control specimens taken from the same board. This encouraging result suggests an alternative to the expensive structural epoxy adhesives, which are generally accepted as the appropriate adhesive in FRP-strengthened glulam.
Publish Date 1997, Vol.17(3):247–255, doi:10.1016/S0143-7496(97)00010-9 Author G. Davis TRADA Technology Ltd, Stocking Lane, Hughenden Valley, High Wycombe, Bucks HP14 4ND, UK Accepted 14 October 1996. Available online 7 June 1999. Abstract Structural adhesives can be used to bond two or more timber components together and to bond-in other materials in such a way that they transfer load between the elements. In addition to this, owing to the nature of timber, the adhesive will often have to possess some gap-filling properties. Traditionally, formaldehyde-based adhesives have been used, but these have limited gap-filling qualities and often require the application of pressure to the joint to achieve the required strength. Alternative structural timber adhesives, such as epoxy resins and polyurethanes, have been used in certain fields of timber engineering. One of these areas is in the repair of timber structures, where better gap-filling qualities are required and the application of pressure is not practical. TRADA Technology Ltd (TTL) has been investigating the application of epoxy resins in the repair of structural timbers. Initial research has examined the methods in which epoxy resin is used in such situations. Aspects such as the effect of timber moisture content on joint strength have been investigated. Forthcoming tests will examine the effect of surface preparation and the long-term performance of specimens under load in exposed conditions. Timber has a long history of use as a structural building material and finds its way into many varied applications, from shipbuilding and marine architecture to civil and structural engineering. Keywords
Published Date March 2009, Vol.29(2):173–185,doi:10.1016/j.ijadhadh.2008.03.002 Author
João Custódio a,,
James Broughton b,
Helena Cruz a,
aTimber Structures Division, Structures Department, Laboratório Nacional de Engenharia Civil, Av. Brasil 101, 1700-066 Lisbon, Portugal
bJoining Technology Research Centre, School of Technology, Oxford Brookes University, Wheatley Campus, Oxford OX33 1HX, UK
Accepted 15 March 2008. Available online 28 March 2008.
Abstract
Adhesive bonding technology has played an essential role in the development and growth of the rehabilitation and repair of timber structures. The ability of a structural joint to maintain satisfactory long-term performance, often in severe environments, is an important requirement of a structural adhesive joint, as the joint should be able to support design loads, under service conditions, for the planned life time of the structure. A number of factors determining the durability of structural adhesive joints have been identified and can be grouped in three categories: environment, materials and stresses. The environment is dominated by temperature and moisture. The materials category includes the adherend, the adhesive, and the inter-phase between them both. The last category refers to the stresses to which the bond is subjected during or after exposure to service environment, affecting both longevity and residual strength. Since this subject in relation to timber bonding is very disperse within the literature, this paper will focus briefly on each of the aforementioned factors, thus providing a general understanding on the factors that influence the durability of bonded timber joints.
