Full scale tests of bamboo scaffolds for design development against instability

Abstract

Bamboo scaffolding is widely used in construction in the South East Asia, in particular, the Southern China, and Hong Kong for over the previous years. However, bamboo scaffolds are generally erected by scaffolding practitioners based on their intuition and experiences without any structural design. In order to standardize the design and erection of bamboo scaffolds and to improve the safety of bamboo scaffolds, a research and development program to promote the effective use of structural bamboo was carried out. Four full-scale bamboo scaffolds were built and tested to failure in order to examine the structural behavior of bamboo scaffolds in site condition. The first two tests were performed on double layered bamboo scaffolds (DLBS) with typical configurations commonly erected in building sites in Hong Kong, where Kao Jue and Mao Jue were used as the main posts of the inner and the outer layers respectively. From the four tests, the structural performance of all the DLBS was found to be satisfactory in terms of strength and deformation. Despite of large deformation in the posts due to axial buckling and flexural failure in the main ledgers over supports under large hogging moment, the scaffolds were found to be able to sustain additional loading without global collapse.