The use of small diameter whole-culm (bars) and/or split bamboo (a.k.a. splints or round strips) has often been proposed as an alternative to relatively expensive reinforcing steel in reinforced...

The past five decades have witnessed an unprecedented growth in population. This has led to an ever-growing housing demand. It has been proposed that the use of bio-based materials, and specifically bamboo, can help alleviate the housing demand in a sustainable manner. The present paper aims to assess the environmental impact caused by using four different construction materials (bamboo, brick, concrete hollow block, and engineered bamboo) in buildings. A comparative life cycle assessment (LCA) was carried out to measure the environmental impact of the different construction materials in the construction of single and multi-storey buildings. The LCA considered the extraction, production, transport, and use of the construction materials. The IPCC2013 evaluation method from the Intergovernmental Panel on Climate Change IPCC2013 was used for the calculations of CO₂ emissions. The assessment was geographically located in Colombia, South America, and estimates the transport distances of the construction materials. The results show that transportation and reinforcing materials significantly contribute to the environmental impact, whereas the engineered bamboo construction system has the lowest environmental impact. The adoption of bamboo-based construction systems has a significant potential to support the regenerative development of regions where they could be used and might lead to long-lasting improvements to economies, environments, and livelihoods.

Current design and construction codes and standards for bamboo do not contain strength grading procedures beyond cursory visual inspections. This deficiency arguably limits the safe and economic use of the material. This paper presents findings from an international research project which seeks to develop a strength grading system for bamboo culms. Over 200 four-point bending tests were carried out on Guadua angustifolia Kunth culms for which numerous mechanical and physical properties were measured. Correlations between flexural strength, static modulus of elasticity, dynamic modulus of elasticity from stress waves and density provided mediocre results, with R² ranging from 0·27 to 0·47. However, properties such as flexural stiffness, flexural capacity and mass per unit length, which are less dependent on geometric properties, provided much stronger correlations, with R² ranging from 0·86 to 0·92. The quality of these correlations indicates that these could be used as indicating properties for flexural capacity in a simple yet reliable strength grading procedure for bamboo. The findings of this paper invite a reconsideration of the extant stress-based approach for bamboo design, and instead a move to a capacity-based approach, as is often used with engineered timber products.

Bamboo is a functionally graded, sustainable construction material that has evolved to resist its primary loading in nature. This study focuses on the effects of geometric and material property variation along the culm length on the capacity of an axially loaded member. Conservatively, compression capacity may be calculated using the smallest section of the member; however, this results in an inefficient use of the culm and may limit the use of long compression members. A more realistic estimate of capacity is obtained by considering the effects of culm taper on buckling capacity. In this work, culm taper was experimentally investigated for three representative bamboo species. The effects of culm section gradient on geometric properties were examined followed by an assessment of geometric variation along the culm height. Following this, a series of buckling analyses of tapered culms was conducted to illustrate the significant effects of taper on culm compression capacity. This analysis was supplemented with comparisons with experimental culm buckling data. Beyond compressive capacity, the paper discusses the implications of culm taper in terms of flexural behaviour, the design of gridshells (involving pre-bent axial load-carrying members), visual grading of bamboo and, ultimately, classification of the many species of bamboo presently used in construction worldwide.

Laminated bamboo is becoming an increasingly widespread commodity, even for structural applications, but it does require considerable transformation of the raw material. The aim of this LimesNet mission to Colombia was to observe how bamboo that has undergone minimal transformation may be used for structural applications. Significant achievements have been made in architecture, academic research and structural engineering with bamboo in Colombia. These are discussed. Observations of numerous bamboo structures are also reported. Bamboo is a promising renewable resource with a low environmental impact, and lightly modified bamboo is an exciting and nascent form of using this material that reinforces its sustainability credentials.