Bamboo is a material with good tensile and flexural resistance. As a construction material with structural capacity, using bamboo implies considerable environmental advantages in relation to other typical materials such as steel or concrete. For its correct implementation, it is necessary to define its mechanical properties and durability. Bamboo is susceptible to degradation due to the lack of natural toxins and thin walls, which means that shallow decomposition processes can imply appreciable reductions in its mechanical capacity. The main degrading agents considered in this study were beetles, termites, and xylophagous fungi. The aim of this study was to analyze the durability of three different species: DS, PA, and AA. Durability and mechanical tests results after 6 months of exposure to biotic and abiotic agents were compared with their original properties and chemical composition. In this study, durability was analyzed in two ways. Firstly, the loss of mass due to fungal infection was investigated. The results obtained were based on the standard EN 113 using the fungus CP. Secondly, bending and compressive strength was evaluated after a durability test according to the standard EN 335:2013 for the CU3.1 use class after a 6 month period in the city of Donostia/San Sebastian, Spain. The DS and AA varieties were rated as very durable CD1, while the PA variety is durable CD2, thus proving to be an attractive material for construction.
A new structural typology of a hybrid purlin, made of type C cold steel and rectangular laminated wood (SWP), is presented in this paper. As a result, improvements on the most commonly used steel purlins are achieved, by substituting some of the steel sections for wooden sections. Although the wooden section is weaker and has a lower elastic modulus than the steel, the overall dimensions of the SWP are no larger than the type C steel purlin. In comparison with the steel ones, SWP purlins achieve a far better performance in terms of sustainability and are of lower weight, so less material will be needed for the main structure of the building. The behavior of each material in its position and the improvements in terms of sustainability and lower weight are analyzed as a function of span length, slope, and design load. To do so, the influence of both tensile stress and deformation design criteria in each section and the influence of those criteria on the choice of material and the lengths of each section are all examined. Finally, a design guide for the SWPs is presented that applies the proposed technical specifications.