Structural use of DÚO and TRÍO beams. Glued laminated beams composed of two or three lamellas: for light and esthetically high quality structures

Abstract

The modern world of construction is getting more and more complex. Building technicians and professionals have to fulfil the always more demanding standards, the objective of which is to guarantee the final quality of a building. At the same time there is a parallel progress which has an effect on the whole spectrum of building materials and systems, timber being one of them. Standardisation or harmonisation of timber, which is known to be very heterogeneous material, is a complicated matter and requires highly intelligent solutions. DÚO and TRíO as a concept is another proof of material engineering, which surges from an adequate realization of a characteristics analysis and from a technical application to create a new industrial product with an added value.

DÚO beam is produced by gluing large size timber lamellas together. Glued surfaces are the tangentially sawn pieces from the outer part of the log and the outer part of the lamellas (which can be seen) are the sawn surfaces from inner part of the log. The glue line is in vertical direction, whereas in glued laminated beams glue lines are horizontal. Several advantages can be gained by doing this. From the esthetical point of view, the advantage comes from less knots and defects, due to the fact that the outer surface of the DÚO (or TRÍO) lamella has been sawn from internal part of the log. Other visual effects are the solid appearance of DÚO, as there is just one glue line (in case of DÚO), and almost no shakes in the surface. Mechanical properties are improved by using sideboards which have high strength values. From the geometrical aspect of the beams, the deformations can be minimized by using glued structure and well dried lamellas. Gluing two or three sideboards together, also large cross sections can be produced. All these advantages give architects and other specifies a lot of flexibility and new possibilities in design of buildings.