Composite Bamboo Shear Walls – a Shear Wall System for Affordable And Sustainable Housing in Tropical Developing Countries

Abstract

Composite bamboo shear walls (CBSW) are modern engineered vernacular-improved shear walls, that take the traditional Latin American wattle-and-daub known as bahareque, and engineer it, using modern materials and construction techniques. CBSWs consist of a frame made of timber and/or large diameter bamboo, upon which a matrix of cane, small diameter bamboo, flattened bamboo, bamboo laths or expanded steel mesh is nailed. The walls are then finished with cement or lime render to form solid shear walls. Over the past 30 years, at least 4000 one and two-storey homes utilising modern CBSWs have successfully been constructed in various countries around the world, including Costa Rica, Colombia, Nepal, Ecuador, Peru, Mexico, El Salvador and the Philippines. When properly designed and built, they have demonstrated their effectiveness as an affordable, hazard-resilient, low-carbon and durable form of housing. The system is now codified in the Colombian, Ecuadorian and Peruvian structural standards, as well as in ISO 22156. Efforts are currently underway to incorporate them into the Philippines, Mexican and Nepalese codes. This paper describes the history of the CBSW system, variations that exist across the world, the current state of knowledge with regards to codes, strength, ductility, sustainability and fire, and recommendations for areas of future research. The paper argues that the CBSW system is an effective way of creating low-carbon housing that provides excellent code-compliant strength, ductility, and durability, and has significant potential for affordable housing in lower and middle income highly seismic countries where bamboo grows.