Composite reinforcement of timber in bending

A promising use for high performance composite materials is to reinforce timber beams. The present paper studies the use of carbon and glass fibres to reinforce sawn timber sections. Consideration is given to strength phenomena of commercial timber alone and in reinforced sections in bending and shear. Anchorage length considerations for composite strips applied to the underside of simple beams are discussed. Experimental results are presented for three geometries of reinforcement using matched samples of 25 pairs of beams, reinforced and not. Results establish that the wood itself in the composite section shows strength increase, and that the increase in moment resistance of the reinforced beams is far greater than that predicted by simple models.