Experimental and statistical analysis of spruce timber beams reinforced with CFRP fabric

Enhancement of timber beams with fibre reinforced materials gained momentum in the last few decades producing a wide range of materials, techniques and modelling methods. Experiments show that the potential improvement of structural behaviour is greatly affected by the type of reinforcement, wood species, etc. In this study a series of experiments were conducted on sawn Norway spruce beams reinforced with various amounts of CFRP sheets (carbon fibre reinforced plastic) followed by a statistical analysis. A moderate increase of load-bearing capacity and ductility (approx. 30%) and a small increase of elastic stiffness (approx. 16%) can be achieved. Statistical analysis of the results has shown that the performance of reinforced spruce beams is affected by the presence of knots in the material.