Laboratory assessment of the FRP to timber bonding force for ancient beams showing biological attack

Title: Laboratory assessment of the FRP to timber bonding force for ancient beams showing biological attack
Author(s): A. Benedetti, I. Brosio, F. Simonelli
Paper category : conference
Book title: RILEM Symposium on On Site Assessment of Concrete, Masonry and Timber Structures - SACoMaTiS 2008
Editor(s): L. Binda, M. di Prisco, R. Felicetti
Print-ISBN: 978-2-35158-061-5
e-ISBN: 978-2-35158-075-2
Publisher: RILEM Publications SARL
Publication year: 2008
Pages: 1091 - 1100
Total Pages: 10
Nb references: 9
Language: English

Abstract: The techniques used in the last 30 years for retrofitting and strengthening old deteriorated timber beams, have been overridden by the use of fibre reinforced polymer (FRP) materials.
Many techniques based on the external bonding of sheets and laminas, or on the insertion in grooves of bars and prisms, allow restoring the static efficiency of many timber structures.
A critical factor in the design of the bonded reinforcement is the evaluation of the anchorage force which can be transferred between the FRP – timber interface. In particular,
the failure very often occurs in a thin wood layer wetted by the resin, and thus the shear strength fibre wise is determinant.
A very simple technique able to detect the separation failure in fibre wise aligned fracture surfaces is based on the use of double cut “S” shaped prismatic specimens obtained by executing in a timber prism a system of two parallel cuts orthogonal to the fibre direction.
In a wide investigation carried out at the DISTART Department, the double cut specimens were compared to FRP shear delamination tests carried out on several 200 years old small section beams. The correlation between the two types of tests was very good and the double cut prism compression tests allowed a direct characterization of the interface properties.

Online publication: 2009-05-26
Publication type : full_text
Public price (Euros): 0.00