Spaceframes based on bamboo

Bamboo Space Frames

Lombok International Bamboo Architecture Festival, Indonesia,
Dec 2013

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.

The first space frame of "bois de brousse", local round wood, Ouagadougou 1975

Local round wood with resistance to termites was the first concept. The idea was to replace imported metal trusses for schools, ware houses, meeting halls etc. The similarity to bamboo was obvious: 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 via the connector nodes.

Cantine, École Suédoise, Pointe Noire, Congo, 1987 Bois résistant de la forêt tropicale Mayombe

Bamboroo Workshop , Thailand, Nov 2013

A combination of bamboo + mortar + rebar makes a robust transfer of forces. A Ø10mm rebar with hook should reach beyond the first node diaphragm covered with mortar padding. This is to prevent the wine-cork effect for components exposed to tension.
Waste, shredded polystyrene or Leca clay pebbles can be mixed with the mortar to reduce the weight. 20 MPa compression allowance is enough. On the rebar a Ø8 mm nut is welded-on. Care must be taken not to fill the threads of the nut.

"PetCrown" uses plastic bottle cut-offs to contain the mortar.

The mortar must be quite fluid to fill out inside the bamboo node. A simple vibration device is useful.

"PetCrown", a new connector design

It narrows 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. Ø8x15 mm bolts connect to the nuts welded on the rebars.

Bamboo space frame structures.pdf

Saevfors Consulting

Saevfors Consulting

Bamboo Space Frames