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.

Guadua Angustifolia Kunth (Guadua) is a tropical species of bamboo endemic to South and Central America and widely used as a mainstream material for construction in Colombia. Its rapid rate of biomass production, renewability, high level of CO₂fixation and storage, wide diameter, long-length, and durability are distinctive and highly desirable features which can benefit the new built environment Research interest in Guadua construction increased significantly after many Guadua-constructed buildings withstood or suffered only minor damage during an earthquake which reached 6.2 on the Richter scale in 1999, resulting in the standardization of Guadua in the seismic-resistant Colombian code (NSR, 2010). However, Guadua buildings constructed in the Americas and other parts of the world, whilst considered to be sustainable, are not fully characterised in terms of the preparation, use and disposal of Guadua. Furthermore, workability, building durability and the construction process have not been specifically documented and evaluated. The structure, properties and availability of Guadua are described in this paper. A case study on a recently built holiday house is presented illustrating the architectural, structural, environmental and technical performance of a Guadua building. This paper presents the construction process, discusses difficulties encountered during the building life cycle and highlights the need for similar assessments. It is concluded that with the aim of achieving a low carbon construction system using Guadua bamboo, challenges regarding manufacture, bio-deterioration, integration with conventional systems, and environmental impacts must be addressed.

Whilst upcoming innovations on digital technology and renewable energy can have a significant impact on the reduction of operational carbon emissions in the construction industry, readily available fast-growing building materials like bamboo are already proving reductions in the embodied carbon of dwellings above 60% when compared to traditional brickwork in Colombia. This paper presents a like-by-like comparison of the environmental impact of a conventional clay brick house (CBH) and a bamboo house for social housing in Colombia, which was built using adapted vernacular technologies. The bamboo house uses bamboo species Guadua angustifolia Kunth as the main structural support for the light cement bamboo frame (LCBF) system, a.k.a. ‘cemented bahareque’, whilst the CBH combines clay bricks and steel for the load-bearing walls. Traditionally built Guadua angustifolia Kunth bahareque (GaKB) houses are a key part of the vernacular architecture in the ‘coffee cultural landscape of Colombia’ (CCLC) recognised by UNESCO. A life cycle assessment (LCA) was performed to calculate the carbon footprint of the houses following four phases: (1) definition of objective and scope; (2) inventory analysis; (3) impact assessment; and (4) interpretation of results. The results show that the carbon footprint of the GaKB house accounts for about 40% of the CBH, i.e., the GaKB generates a carbon footprint of 107.17 CO₂-eq/m² whilst the CBH results in a carbon footprint of 298.44 kg CO₂-eq/m². Furthermore, from a carbon balance calculation, the carbon footprint of the GaKB house is further reduced to about 36% of the CSB house. LCA results for the built GaKB house demonstrate that vernacular housing projects that preserve cultural heritage can also be resilient and climate-neutral. This paper sets a precedent for the establishment of targeted government policies and industry practices that preserve the cultural heritage and vernacular technologies in the CCLC region and in other emergent economies worldwide whilst promoting future-proof and net-zero carbon construction.

Guadua angustifolia Kunth (Guadua) was subjected to thermo-hydro-mechanical (THM) treatments that modified its microstructure and mechanical properties. THM treatment was applied to Guadua with the aim of tackling the difficulties in the fabrication of standardised construction materials and to gain a uniform fibre density profile that facilitates prediction of mechanical properties for structural design. Dry and water saturated Guadua samples were subjected to THM treatment. A densified homogenous flat sheet material was obtained. Mechanical properties of small clear specimens of THM modified Guadua were evaluated by testing in tension and compared to the results of the same test on a control specimen. Samples were tested in the elastic range to determine values for Modulus of Elasticity (MOE) and Poissons ratio. There was a significant increase in the tensile MOE values (parallel to the direction of the fibres) for densified samples. MOE values measured were 16.21 GPa, 22.80 GPa and 31.04 GPa for control, densified dry and densified water saturated samples respectively. Oven dry densities for these samples were 0.54 g/cm³, 0.81 g/cm³and 0.83 g/cm³. Despite a 50 % reduction in the radial Poissons ratio for the water saturated sample, no further variation in the Poissons ratio as a result of densification was observed for control and densified dry samples. This paper presents the results of the first phase of a study focussed on the manufacturing of flat Guadua sheet (FGS) by THM treatment and the characterization of its mechanical properties. The achievement of a dimensionally stable FGS by THM modification, with a uniform density and achieved with reduced labour effort during manufacture, will be of key importance for the development of structural applications, and could have a significant impact in the bamboo industry. The final aim of the research at the University of Bath is the development of Cross Laminated Guadua (CLG) panels using THM modified and laminated FGS glued with a high performance resin.

Novel cross-laminated bamboo panels comprising three and five layers (G-XLam3 and G-XLam5) were tested in compression along the main (0°) and the transverse (90°) directions. Linear variable differential transformer (LVDT) and non-contact three-dimensional digital image correlation (DIC) measuring techniques were used separately to measure deformation in the elastic region, and the elastic moduli, Ep_C,0and Ep_C,90, were derived. Mean elastic modulus values obtained using LVDTs exhibited a good match with analytically predicted values. In contrast, the elastic values obtained by the DIC method were considerably higher and presented a considerable scatter of results. For instance, the Ep_C,0for G-XLam3 and G-XLam5 panels were 17·22 and 15·67 GPa, and 14·86 and 12·48 GPa, using the DIC and LVDT methods, respectively. In general, G-XLam panels with a fifth of the cross-sectional thickness and twice the density of analogous cross-laminated timber exhibited an approximately two-fold increase in Ep_C,0and Ep_C,90. Overall, this research provides guidelines for the assessment and standardisation of the testing procedures for similar engineered bamboo products using contact and non-contact methods and highlights the potential of using G-XLam panels in stiffness-driven applications and in combination with wood for structural purposes.