Comparison of built up timber beams with timber trusses

Abstract

The following work is based on a comparison of timber box beams with parallel chorded timber trusses. Box type built up box beams have been adopted based on past research conducted in the Sri Lankan context. Two types of parallel chorded trusses have been compared with a box beam, where the trusses are of the same overall dimensions. Built up box timber beams are found to be the most effective and efficient solution compared to parallel chorded timber trusses of same depth as an alternative for heavy timber beams. Since the serviceability limit state governs the design criteria, load carrying capacities at allowable deflection were concerned. Built up box beam performed 2 to 2.5 times when compared to the Pratt and Warren trusses in terms of load carrying capacity per unit timber cost at allowable deflection.