Ämmässuo waste-sorting station

Construction waste is going to be recycled more and more and, to this end, a new canopy has been built at the Ämmässuo sorting station to allow construction waste to be handled while protected from the weather. The unheated canopy is substantial in size, 63 metres x 53 metres, with an unrestricted height of around 12.5 metres.

The canopy is constructed of pre-waterproofed LVL (laminated veneer lumber) box elements approximately 10 metres long, with a rainwater gutter already installed.

The canopy is supported on specially shaped cross-beams and a ridge beam to give it a double pitch. Because the column grid is 16.7 metres x 20 metres, specially shaped beams are installed as primary beams between the columns and secondary beams. These are made up of two separate beams joined together in the factory.

Due to the wide spans, the column-to-beam and beam-to-beam support loads are transferred using separate steel components. The dowels for the steel components are glued to the contact surface of the beam. The supporting dimension of the roof elements is increased by a continuous shoe fixed along the top edge of the laminated beam.

The 430 mm x 675 mm laminated columns, which are made up of two parts in the factory, stiffen the frame of the canopy in a transverse direction together with the reinforced concrete columns in the central area. The 430 mm x 430 mm columns carry beams where the reaction at the top is transferred to the stiffening columns by the roof, which acts as a flat plate.

The roof elements on each side make up a uniform plate which transfers the horizontal loads. The horizontal loading is divided by the reinforced concrete and laminated timber columns in relation to their stiffness. Because of the height and location of the canopy, the columns are dimensioned according to Use Class 3, while the rest of the timber structure is dimensioned according to Class 2.