BAMBOO SPACE FRAMES
As can be seen in airports, exposition halls, multipurpose facilities, space frame structures are often used to cover large roof spans. The design is based on nodes connecting pole members of a standard length in a way that resembles four-sided pyramids (halves of octahedrons) between two horizontal grids. The free space between the lower and upper decks is often used for conduits, sprinklers and ventilation systems. The lower deck, if not supporting ceilings, is often left open as a strong architectural expression.
Lombok International Bamboo Architecture Festival, Indonesia, Dec 2013
The first space frame of "bois de brousse", local round wood, Ouagadougou 1975
Bamboroo Workshop , Thailand, Nov 2013
Obviously bamboo is a perfect candidate for this concept with its tubular form. The challenge is to design a reliable pole connector to be produced at a reasonable cost.
The bamboo pole end is very vulnerable to cracking and great care must be taken when transferring loads to the connector nodes. A combination of bamboo + 20 MPa mortar + 10mm rebar with a welded-on nut is used. Waste, shredded polystyrene can be mixed in into the mortar reducing the weight.
"PetCrown", a new connector design, uses plastic bottle cut-offs to contain the mortar and narrow the ends of the space frame poles so as to converge up to 8 poles into one moment free point.
The connector is made of a simple standard steel pipe cut off and steel plate strips welded together by a local smith.