Bamboo in Bioconstruction

Would you like to build your own Bamboo house?

Bamboo can have different uses in construction:

– It can be used as submerged foundation reinforcement in concrete (with cement or lime) as an alternative to steel.
– The complete supporting structure can be constructed, from the columns to the beams/ribbings, including the roof battens.
– Can be combined with any type of wall and insulation: straw, straw/mud, vegetable fibres, mineral wool.
– Can be built on any load-bearing wall (brick, thermo-clay, etc.)

For the dimensioning of our Guadua structures we have a solid calculation base that can be used as a reference in Europe; Colombian Standards of Earthquake Resistant Construction in Guadua NSR-10, title G12.

At the fireproof level, we assume that bamboo is classified as a building material in the German standard DIN 4102 with class B2 (low flammability).

Static resistance

Bamboo has very high resistance values to all types of longitudinal stresses parallel to the fiber. In bending, tensile and parallel compression, their strength values or elastic limits are generally higher than those of wood normally used in construction (pine, spruce), in some cases approaching steel.

Earthquakes behaviour

The proper nature of bamboo, its cylindrical shape with fiber accumulation on the outer face, and its high degree of elasticity make it especially suitable for seismic-resistant constructions.

Historically, bamboo constructions have always had a high degree of safety in addition to this good resistance to earthquakes because, in addition to their great elasticity, the structures are particularly light and have a high capacity for absorbing energy.

General Properties of Bamboo for Construction

· Density (dry): 500-800kg/m3
· Culm height: 6-25m
· Internodal space: 250-500mm
· Diameter: 50-200mm
· Modulus of elasticity E: ~7000-17 000N/mm2
· Wall thickness: >10% of outside diameter

Structural bamboo species used worldwide

Scientific name (local)

Guadua angustifolia Kunth

Dendrocalamus strictus (Calcutta)

Bambusa Vulgaris

Phyllostachys edulis (Moso)

Dendrocalamus asper (Petung)

Bambusa blumeana (Spiny/Thorny)

Gigantochloa apus

Zones

America

Asia

Asia, America

Asia

Asia, America

Asia, Pacific Asia

Asia

Max diámeter.

120-160 mm

25-80 mm

80-150 mm

120-180 mm

80-200 mm

60-150 mm

40-100 mm

Comparison of characteristic design forces of dry bamboo* and free of visual imperfections (cracks, etc.)
10 minute load test (Kg/cm2)

*Moisture content 12% /”Mature” crops ( 3-5 years)

icon3-02

Guadua Angustifolia Kunth

Flexure

365/5090%

Traction

4070%

Compresssion

2030%

Design values

Flexure

3050%

Traction

4070%

Compresssion

2030%
pines-trees-forest

 C24 Softwood

Flexure

2500%

Traction

1420%

Compresssion

2240%
Bamboo elastic modulus with 12% and 19% moisture content

Moisture content

12%

19%

Average Elasticity Modulus (N/mm2)

10.000/17.000

8.500/15.000

Reduced modulus E0.05 (N/mm2)

7.500/13.000

6.700/8.000

Fire resistance

Bamboo is a material classified as suitable for construction according to German Standard DIN4102 with class B2 (low flammability). The high concentration of silica on the outside slows down the propagation of the flame and can thus be assimilated to wood when carrying out fire resistance calculations. The reaction to fire value is very similar to wood and is set at 0.6mm/min.

The preservation treatment by immersion in Borax salts and boric acid that our Guadua bamboo canes receive, adds an extra fire resistance, because this mixture acts as a fire retardant.

For exposed bamboo structures, a fire retardant coating material similar to those applied to wood structures will be applied to increase its resistance to combustion without the need to thicken its section.

Bibliographic references:

– Gernot Minke, (2010), Manual de Construcción con Bambú

– Oscar Hidalgo López, (2003), Bamboo, the gift of Gods

– Oscar Hidalgo López, (1978), Nuevas técnicas de construcción con bambú
.

– Arce, (1993) Fundamentals of the design of bamboo structures – Tesis doctoral Eindhoven University of technology

 

Bamboo on the net

– International Network of Bamboo and Rattan – www.inbar.int

– Bamboo Arts & Craft Network – www.bamboocraft.net

– European bamboo society – www.bamboo-society.org.uk

– American bamboo society – www.americanbamboo.org

– Sociedad Colombiana de Bambú – www.bambuguadua.org

– AsIB Asociación Ibérica del Bambú – asibambu.org

 

Referencias bibliográficas para el método de cálculo:

– ISO 22156:2004 Bamboo – Structural design.

– ISO 22157-1:2005 Bamboo – Determination of physical and mechanical properties.

– NSR-10: Normativa Colombiana de Construcción Sismo Resistente en Guadua NSR-10, G12.: Estructuras de madera y estructuras de Bambú Guadua angustifolia Kunth.

– EN 384:1996 Madera estructural. Determinación de los valores característicos de las propiedades mecánicas y la densidad.

– EN 1995-1-1:2006 Eurocódigo 5. Proyecto de estructuras de madera.