MATERIAL PROPERTIES
Bamboo has a robust natural fibre, which makes it a good candidate for construction. The compressive strength of bamboo can be brought close to that of concrete, while the tensile strength is close to that of mild steel. The bamboo fibre has a shear strength that is generally higher than timber's. Additionally, bamboo can be curved without breaking.
Bamboo has traditionally been used in building construction from time immemorial. It is used in foundations, frames, floors, walls, partitions, ceilings, doors and windows, roofs and sometimes as reinforcements in cement concrete.
Physical properties
The basic properties of bamboo used for structural purposes are as follows:
• Culm height ranges from 6m to 25 m
• Nodal spacing ranges from 250mm to 500 mm
• Diameters ranges from 50mm to 200 mm
• Wall thickness is ~10% of external diameter
Fire considerations
In case of fire, bamboo behaves similar to timber and char at a slow and predictable rate. It is also a poor heat conductor. Because of its thin culm walls, only after a few minutes of burning these wall starts losing their strength. The charring rate of bamboo can be considered similar to timber (0.6 mm per minute).
Behaviour during earthquakes
Historically, bamboo structures have performed well during the time of earthquakes because of the following major reasons:
With high strength-to-weight ratio bamboo structures are lightweight
Skeletal frames can be easily built with bamboo tying and carrying non-structural parts
Bamboo frames can absorb significant energy at connections
Structural Properties
The dry density of bamboo (ρ) ranges from 500–800 kg/m3.
Elastic modulus (E) ranges from 7,000–17,000 MPa
Compressive Strength ranges from 60- 80 MPa
Poisson's Ratio is 0.3