Bamboo hybrids can bolster UK timber supplies

A relatively common material is not being embraced fully for building supplies. Interest in bamboo is growing, through research and media campaigning about the material’s environmental benefits, properties and its ability to replace wood, steel and carbon-fibre. But bamboo is not commonly used in high-performance applications or permanent structures, and its potential in construction remains untapped. Academic and industrial research carried out in the UK aimed to address the challenges associated with using bamboo in durable, safe and cost-efficient structures. Further combining the grass with UK-grown wood could maximise use of this material and make economic sense for the domestic forest secto

Limeboo: Lime as a Replacement for Cement in Wall-Framing Systems with Bamboo-Guadua (Bahareque Encementado)

Traditional construction systems with the bamboo species Guadua angustifolia Kunth (Guadua) are standardized under the Colombian code for seismic-resistant buildings '1'. These systems are regarded as highly environmentally friendly due to their intensive use of Guadua in the supporting structure and walls. In particular, the plastered cane building system or 'bahareque encementado', which provides a low-cost and low-technology alternative for two-storey dwellings, commonly uses round Guadua for the frame and riven Guadua boards (esterilla) for covering the frame. However, this wall-framing system relies heavily on cement renders for providing combined structural action to resist lateral loads, protecting the material against weathering and ensuring a flat surface for construction finishes. Thick cement renders contribute greatly to the wall mass and together with the foundations result on the highest negative environmental impact in traditional wallframing construction with Guadua. Therefore, the reduction of the use of cement or its complete replacement for alternative binders in the wall-framing 'bahareque' system is a key point for environmental improvement. Widely available materials such as lime, which have less energy intensive production-processes present an alternative to cement. Moreover, lime offers improved breathability within the building and behaves more elastically than cement. This paper explores the potential use of lime as a replacement for cement mortars in 'bahareque' systems and analyses Guadua's anatomical and chemical features when mixed with lime. The paper describes a 'cold process' in which no high temperatures are involved for the improvement of the bonding between lime and bamboo

Thermo-hydro-mechanically modified cross-laminated Guadua-bamboo panels

Guadua angustifolia Kunth (Guadua) is a bamboo species native to South and Central America that has been widely used for structural applications in small and large-scale buildings, bridges and temporary structures. Currently, its structural use is regulated within seismic resistant building codes in countries such as Peru and Colombia. Nevertheless, Guadua remains a material for vernacular construction associated with high levels of manual labour and structural unpredictability. Guadua buildings are limited to two storeys due to the overall flexibility of the slender and hollow culms and its connection systems. Its axial specific stiffness is comparable to that of steel and hardwoods, but unlike wood, Guadua’s hollow structure and lack of ray cells render it prone to buckling along the grain and to transverse crushing. As a result, Guadua’s mainstream use in construction and transformation into standard sizes or engineered Guadua products is scarce. Therefore, this work focussed on the development of standardised flat industrial structural products from Guadua devising replicable manufacturing technologies and engineering methods to measure and predict their mechanical behaviour. Cross-laminated Guadua panels were developed using thermohydro-mechanically modified and laminated flat Guadua strips glued with a high performance resin. 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 content profile that facilitated prediction of mechanical properties for structural design. Densified homogenous flat Guadua strips (FGS) were obtained. Elastic properties of FGS were determined in tension, compression and shear using small-clear specimens. These properties were used to predict the structural behaviour of G-XLam panels comprised of three and five layers (G-XLam3 and G-XLam5) by numerical methods. The panels were assumed as multi-layered systems composed of contiguous lamellas with orthotropic axes orientated at 0º and 90º. A finite element (FE) model was developed, and successfully simulated the response of G-XLam3 & 5 panels virtually loaded with the same boundary conditions as the following experimental tests on full-scale panels. G-XLam3 and G-XLam5 were manufactured and their mechanical properties evaluated by testing large specimens in compression, shear and bending. Results from numerical, FE predictions and mechanical testing demonstrated comparable results. Finally, design and manufacturing aspects of the G-XLam panels were discussed and examples of their architectural and structural use in construction applications such as mid-rise buildings, grid shells and vaults are presented. Overall, this research studies THM treatments applied to Guadua in order to produce standardised engineered Guadua products (EGP), and provides guidelines for manufacturing, testing, and for the structural analysis and design with G-XLam panels. These factors are of key importance for the use of Guadua as a mainstream material in construction

Low carbon construction using Guadua bamboo in Colombia

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 CO2 fixation 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

Solución habitacional para las comunidades del municipio de Ciénaga Magdalena en riesgo de inundación

La evolución territorial del municipio de Ciénaga está caracterizada por el predominio de las soluciones espontáneas y por la escasa intervención de las autoridades locales. Teniendo en cuenta la situación anterior, la alcaldía de Ciénaga adjudicó a la empresa Amphibia Ltda la elaboración de los estudios de viabilidad técnica, financiera y social para la construcción de vivienda de interés social para los habitantes en riesgo de inundación del municipio de Ciénaga – Magdalena; para la cual Amphibia se presentará una propuesta de solución habitacional innovadora para contribuir a minimizar las pérdidas de materiales y trastornos de evacuación que los fenómenos de inundación implican para la población del municipio de Ciénaga, este proyecto cuenta con las siguientes características: Unidad de Vivienda Flotante para comunidades residentes en cuerpos de agua: ciénagas, riberas, lagunas y humedales, vulnerables y/o marginadas con riesgo de inundación, en situación de pobreza, desplazamiento u informalidad. Tamaño Óptimo del Proyecto: Constituido por Unidades Habitacionales Flotantes, con un área de 60m2 cada una, proyectadas en paquetes anuales de 50 unidades, que para el cierre (al décimo período), sumará un total de 800 unidades