Durability Evaluation of Outdoor Scrimbers Fabricated from Superheated Steam-Treated Bamboo Fibrous Mats

With natural texture and high performance, bamboo scrimber is one of the artificial lignocellulosic composites widely used in construction, furniture and other structural applications. However, it is vulnerable to the actions of water, ultraviolet radiation and fungus, which affect its durability, especially in the open. Here, bamboo was treated with superheated steam in an attempt to improve the durability of bamboo scrimbers. The chemical composition, mechanical properties, dimensional stability, aging resistance, decay resistance and anti-mildew properties were investigated at different temperatures (160~200 °C). After superheated steam treatment, the relative contents of holocellulose and α-cellulose in bamboo decreased. The bending strength and short-beam shearing strength slightly decreased as the temperature was raised while the modulus was essentially retained. The aging resistance in terms of thickness swelling rate (≤9.38%) was substantially improved. The decay resistance reached to the level of Grade I and can be dramatically enhanced by elevating temperature. The anti-mildew properties were also improved. To take together, superheated steam treatment remarkably improves the resistance of bamboo scrimbers to water, ultraviolet radiation, rot fungi and mildew with some concomitant reduction in mechanical properties. The results will permit outdoor construction using bamboo scrimbers more resistant to environmental damage.