Behaviour of built up nailed timber box beams

Abstract

Timber is unique among construction materials in that it is a renewable resource. It has an added advantage that the manufacture of timber from the tree consumes less energy and causes less pollution when compared to other construction materials. However, today, timber is increasingly becoming a scarce resource due to indiscriminate felling of trees. An endless supply of timber and timber based materials can be ensured with the adoption of prudent forestry management techniques and using timber with care so that its full potential is realised. The size of a tree determines the maximum dimensions of the timber section that are produced. Large cross sections of timber are difficult to obtain and are very costly. Adopting the familiar structural principle of the I beam (a pair of flanges separated by a web) as the most efficient cross sectional profile for bending action, timber and plywood have been combined to build up beams that span distances that solid timber beams alone cannot.