Interlocking Connections  

Woodcore connection. A piece of wood can be used and glue can be employed to stick it to the inner surface of the bamboo. Any normal glue provides a capaity far larger than that of bamboo in the tangential direction.

Two slots are needed in the bamboo cane to control cracking during the insertion of the wood cylinder.

The wood fitting can be extended outside the culm to meet the outcoming piece of wood from other elements, then normal wood construction methods can be used for connection.

Woodcore connection. The steel plate C is introduced in the slot of the wood cylinder and glued to it with a mixture of epoxy resin and portland cement. The plate is projected, so that its outer extreme can be adapted for different applications, as indicated in the details D and E.

Systemadvantages are its low price and the availibilty of the parts.

In plane or space trusses, the plates from two or more incoming elemets can be pre-welded to eachother and then the rest of the connection can be assembled.

The figure shows a connection in which a small box is made of steel plates, so that the faces are prependicular to the axis of the incoming elements. The steel tips are then welded directly to those surfaces. Welding is thought of here because it is cheaper than machining of the tips, but in some cases tis can be achieved as well.

Information: Fundamentals of the Design of Bamboo Structures [pdf]

by Oscar Antonio Arce-Villalonos (Costa Rica/ at TUEindhoven)

constructionelements made of Bamboo

Constructionelements made of Bamboo that can be used for various tasks. Bamboo often grows slightly bend, the diameter of the bamboo cane varies and it is a little oval. At the knots it is a little thicker. If you try to skrew or wedge the bamboo its high strength won´t be transfered. Bambu - Tec constructionelements eleminate these weak points. - The bamboo canes are cut into the desired, unique length (e.g.0.5m,1m,2m). Both ends are covered with caps that are connected with artificial resin or another fillingmass. To give the connection cap/bamboo a high tensile strength the bambooends are given circular grooves and the inner cap is covered with circular notches, so the connecting mass acts like a claw between bamboo and cap.

The capfastening is done with a gauge, so the caps are aligned exactly parrallel and in a reproducable distance. The caps can be made of synthetic, aluminium or steel. It is even possible to produce them, by using the synthetic spray technique, directly on the bamboo. There can be bores, threads or flanges fixed to the caps. If you use steel or aluminiumcaps they can even be welded to other metalparts.

used for: . . . scaffolding, tentconstructions, house building, roof and half-timbered constructions,...

Information: Bruno Huber - Ordenslandstr.39 - 82140 Olchingen, Germany

drawings from the patent.

legend:
1 single strunt
2 free end
3 connectionelement
4 bore
5 struntaxis
6 adhesive
8 notches
9 notches
10 threadbore
11 crossbore
12 jointelement
13 sphere
14 rotationaxis

Transportation armature with pressed concrete. The sytemstrength depends on the concrete/bamboo connection, on the concretes (or fillingmass) compressive strength, on the thread diameter, the production series (long or short shaft, straight model) aswell as on the tractive direction (axial, slantwise , athwart) and the jointdesign.

Systemadvantages are its price and its deliverability from stock. The installation can start immediately without long prefabrication of the dowels.

Information: Firma Friedrich Schroeder GmbH & Co.KG

Reinforcement Continuity Screw Connection System. The optimal sollution for all static component connections. Static, constructive and economically. The sleevestick (with sleeve and connectionflange) - and the connectionstick (with furled metric thread) are sheded with the bamboo and therefore reach an interlocking connection. The connection is carryed out via an adapter with right/left outerthread for the doublesided sleeveconnection.

Systemadvantages are [like transportation armature] its price and its deliverability from stock. The installation can start immediately without long prefabrication of the dowels.

Information: Halfen GmbH & Co. KG

Induo-anchor. For big bamboodiameters the Induo-anchor can transfer nearly 100% of the maximum load of the cane cross section.

The Induo-anchor consists of a cast iron core with connectionteeth on its sides. It can easily be sheded with a bamboo cane. Concrete or artificial resin can be used for that.

Information: In-Duo.de

Advantage of Induo is that any available knot-connection-system can be used with it (e.g. Mero, Pan).

A simple connection can be manufactured with a threaded bar and two counter nuts. Steelballs with threadbores are used as jointpoints.

Disadvantage of Induo-anchor is its high price.

If used with the Induo-anchor the cast iron core is drilled in the perpendicular axis with fitting diameter to connect the screwbolt.

Information: mero.com

Steel-neb-connection - This connection method uses the Induo-anchor in its usual state with bores and threads. The base element of this connection is a conical steelconnecter which is centric screwed from the inside to the Induo-anchor bore on the one side and to the threadbore of the jointelement on the other.

Pan-spacetruss. Small bamboo canes (diameter up to 80mm) can transfer ca.50% of the maximal tensile force if threaded bars are glued or sheded into the caneends. For compressive forces the maximum force is where the cane breaks if connected with a headplate. If overhead working is necessary tests by an officially recognized material-testing-institution and special permission of the building departement are required. (germany)

Pan-spacetruss consist only of two elements - the Pan-ballknot and the cane with sheded threadrod. That means more economic statics, drawings and production. Furthermore they can be dismantled and reused.

Information: Panholz.de