Epoxy Adhesives Modified With Nano- And Micro-Particles for In-Situ Timber Bonding: Effect of Microstructure on Bond Integrity.
Ahmad Z., and Ansell, M.P. , and Smedley, D. , (2010) Epoxy Adhesives Modified With Nano- And Micro-Particles for In-Situ Timber Bonding: Effect of Microstructure on Bond Integrity. International Journal of Mechanical and Materials Engineering, 5 (1). pp. 59-67. ISSN 1823-0334
Official URL: http://ejum.fsktm.um.edu.my/ArticleInformation.aspx?ArticleID=858
Universiti Technologi MARA. Faculty of Civil Engineering
University of Bath, UK
Rotafix (Northern) Limited, UK.
The bond integrity of thixotropic, shear-thinning epoxy adhesives for in situ bonding of FRP connections into timber was investigated. The manufacture of such joints requires adhesives which can produce thick bond-line where the bonding environment does not allow any use of pressure and heat. Four adhesives were evaluated based on a standard adhesive to which nano-silica, nano-rubber and ceramic micro-particles were added to modify rheology and improve adhesive bonding. Viscosity and shear stress of the adhesives were measured as a function of shear rate. The rubber-modified formulation was found to possess the highest viscosity and required higher shear stress to reduce its viscosity. The wettability of nano-modified adhesives on timber substrates was assessed by contact angle measurements and the rubber-modified formulation possessed the highest contact angle which was expected from viscosity measurements. The shear strength of timber to adhesive interfaces was measured using block shear tests and pull-out tests on FRP rods bonded into timber. The addition of nano- and micro-filler additions increased the bond strength of the base adhesive by up to 20%. However the measured contact angle negatively correlated with measured bond strength. Overall, the less ductile micro-particle-filled adhesive delivered the highest shear strengths when bonding timber and FRP rods.
|Additional Information:||The work reported here was financially supported by the Malaysian government. The provision of epoxy adhesives by Rotafix Ltd is gratefully acknowledged. We wish to thank technical staff in the materials engineering group and the Centre for Electron Optical Studies at the University of Bath for their assistance and support.|
|Keywords:||micro- and nano-particle-reinforcements, shear strength, wettability, thixotropy.|
|Subjects:||T Technology, Engineering|
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