Flexural stiffness and strength enhancement of horizontally glued laminated wood beams with GFRP and CFRP composite sheets

Developments in the field of timber engineering have helped in the wise and economical use of timber for structural purposes. Glued laminated wood is composed of several layers of timber glued together with adhesives, forming large and strong structural members that can be used as beams and columns. This research study presents an experimental programme of strengthening laminated wood beams using carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP) composite sheets. Laminated wood beams were made using rubber wood, which is a plantation grown timber. The results of the study are encouraging with percentage increase in flexural stiffness as 26.29% and 45.76% respectively for 2.5% and 5% addition of GFRP composite sheet to the tension side of the beam. For the same percentage addition of GFRP the flexural strength increase was 36.91% and 40% compared to un-strengthened beam. For 1.67% and 3.33% addition of CFRP composite sheet to the tension side of the beam the percentage increase in flexural stiffness to un-strengthened beam was 36.19% and 64.12%. The increase in flexural strength for the corresponding percentage addition of CFRP was 45.86% and 50.62%. Theoretically predicted flexural properties were conferred with the experimental findings.