www.conbam.info |
Construction with Bamboo
Diplom-Ingenieur Christoph Tönges |
guadua   |
NEW >>> www.bambus-conbam.de <<< NEW |
guadua |
Guadua angustifolia
The 'Guadua', which was first identified as 'Bambusa guadua' by Humboldt and later defined by Kunth as genus 'Guadua' (including eight subspecies of 'Guadua angustifolia'), usually grows from sea level up to 2.000 m altitude in little woods along brooks, but also on meadows or sloping sites. Each stem grows out of a reticular root system, the rhizomes. |
||
(5) Bamboo grove near Pereira | ||
The tips of the rhizomes curve upwards from the root network and form the new
culms. This superimposition of root systems over several hectares provides
good protection against erosion. Moreover, it works as moisture storage and
can be used as sewage treatment plant for settlements and farmsteads.
|
||
(6) Part of a root system | ||
Each sprouting shoot already contains all nodes, internodes and diaphragms,
which are telescope-like compressed.
|
|||
(7) Sprout | (8) Section through a root | ||
Harvesting
takes place after three to six years, harvest maturity is recognized by the
lichens on the culm. Bamboo can also be called a 'lignifying giant grass'
(Graminae) - harvesting by picking out the mature culms therefore does not
lead to the death of the entire plant.
|
||
(10) Bamboo forest | ||
It does not grow at locations with high soil wetness, but for example at bluffs
of rivers. It transports moisture by means of its tight and widely ramified root
system to the culms that are higher - and therefore drier - situated.
|
||
(11) Guadua with culm sheaths | ||
Fibres
The bamboo material consists of a basic substance that holds together the fibres. These fibres run strictly axial and condense in the upper part of the culm, as well as to the outer edge. Therefore the strongest fibre lines are situated in the edge zone, where the highest static requirement lies, similar to steel reinforcement in concrete construction. These reinforced materials are called fibre composite materials in modern materials engineering. At the nodes, the fibres bend into the diaphragm and there crosslink themselves. Radial fibre structures don't exist. |
||
(12) Cross-section of a bamboo culm wall | ||
The mass of the bamboo is mainly composed of 50 percent of cellulose and up
to 30 percent of lignin, the cell glue. Bamboo culms taper upwards, the wall
thickness decreases while the internodes get shorter.
| ||
(13) Exterior zone of culm wall | ||
The unlimited
longitudinal fissility of the bamboo culm wall
in the internodes is due to the strictly parallel fibres. The nodes with the
strongly silicified diaphragms increase interlaminar and buckling strength of
the tube. From mechanics we know that a cylindrical tube has four times the
bending strength of a full cylinder with the same cross section area.
|
||
(14) Longitudinal section | ||
Bibliography
|
Links
|
" The fine, polished surface of a bamboo rod is a
remarkable, almost unnatural quality. No man-made product is that hard and delicate at the same time." William Portefield |
guadua   |
NEW >>> www.bambus-conbam.de <<< NEW |