The influence of routed grooves on the bending behavior of old timber beams

In recent times, the methods and approaches used to assess and to maintain timber in historic buildings have evolved considerably and various techniques for timber repair and strengthening were developed and deeply investigated. A very common and widely used technique for the timber strengthening-repair is realized by inserting reinforcement materials in grooves cut in the original sound wood. The proposed reinforcement materials are various (fiber reinforced plastic materials, steel bar/s or plate/s, wood and wood products) and the grooves number and depth are variable. Several researches were conducted to determine the Modulus of Elasticity (MOE) of old timber members strengthened with the described techniques. A common approach is to consider the strengthened timber beam as a composite one and the MOE of the wooden part correspondent to the original. In practice, the timber members work together with strengthened materials, and the strengthening intervention is planned taking into account both original timber and strengthening material MOEs. The basic assumption of this approach is that the slots executed along the timber length have no effect on the timber MOE. The aim of this research is to investigate the effects of the routed grooves cut along the wooden beams, on the bending MOE of old timber members, to provide important information for the strengthening interventions plan.