Balancing structural capacity and sustainability in composite Bamboo shear walls. Effects of cement and earth plaster on overturning performance and carbon emissions

Abstract

This study investigated the overturning and environmental performance of composite bamboo shear wall panels constructed from Bambusa blumeana bamboo poles, with emphasis on the influence of the cladding. Three cladding systems, i.e. (a) cement plaster on rib lath matrix, (b) cement plaster on flattened bamboo matrix, and (c) earth plaster on flattened bamboo matrix, were examined and compared against a bare-frame panel without plaster. Structural performance was assessed in terms of maximum overturning capacity following ISO 21581:2010 Method II, while environmental performance was quantified through life cycle assessment. The results showed that cement plaster was critical in mobilizing the nailed frame to cladding connections. In turn, the cement plastered panels achieved the highest overturning resistance, with the flattened bamboo matrix configuration reaching the greatest capacity under monotonic loading. Under cyclic loading, the difference between the two cement-plastered configurations was reduced. Although earth-plastered panels achieved the lowest carbon emissions and highest biogenic carbon storage, they showed lower overturning resistance, due to excessive plaster cracking and inability to fully mobilize the nailed frame to cladding connections. Overall, among the examined specimens, the cement plastered flattened bamboo panels offered the most balanced solution, combining the highest structural capacity with moderate emissions and substantial biogenic carbon storage. The findings identify cladding selection as a key design variable for achieving structurally efficient and environmentally sustainable composite bamboo shear walls. The study provides baseline evidence that could support the improvement of existing standards and the development of new design provisions for composite bamboo shear wall systems.