Techniques for retrofitting and strengthening decayed timber beams use fibre reinforced polymer (FRP) materials, either externally bonded or inserted in grooves. This allows restoring the static efficiency of timber structures. A critical factor in designing bonded reinforcement is the evaluation of anchorage force which can be transferred at the FRP/timber interface. Failure often occurs in a thin wood layer wetted by the resin, thus the shear strength of fibre is determinant. A simple technique able to detect separation failure in fibre aligned fracture surfaces uses double cut “S” shaped prismatic specimens obtained by two parallel cuts orthogonal to the fibre direction. In a wide laboratory study carried out at Bologna University, double cut specimens were compared to FRP shear delamination tests on several 200-year old beams. The correlation was very good and the double-cut prism compression tests allowed direct characterization of interface properties.
STRENGTHENING OF OLD TIMBER BEAMS BY MEANS OF EXTERNALLY BONDED REINFORCEMENT / Benedetti A.; Colla C.. - STAMPA. - 3:(2010), pp. 2053-2058. (Intervento presentato al convegno WCTE 2010, 11th World Conference on Timber Engineering tenutosi a Riva del Garda, Italy nel 20th - 24th June 2010).
STRENGTHENING OF OLD TIMBER BEAMS BY MEANS OF EXTERNALLY BONDED REINFORCEMENT
BENEDETTI, ANDREA;COLLA, CAMILLA
2010
Abstract
Techniques for retrofitting and strengthening decayed timber beams use fibre reinforced polymer (FRP) materials, either externally bonded or inserted in grooves. This allows restoring the static efficiency of timber structures. A critical factor in designing bonded reinforcement is the evaluation of anchorage force which can be transferred at the FRP/timber interface. Failure often occurs in a thin wood layer wetted by the resin, thus the shear strength of fibre is determinant. A simple technique able to detect separation failure in fibre aligned fracture surfaces uses double cut “S” shaped prismatic specimens obtained by two parallel cuts orthogonal to the fibre direction. In a wide laboratory study carried out at Bologna University, double cut specimens were compared to FRP shear delamination tests on several 200-year old beams. The correlation was very good and the double-cut prism compression tests allowed direct characterization of interface properties.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
