Tensile Tests on PediX Duo Post Supports

The Eurotec PediX Duo and PediX Easy are post supports that are ideal for building light wood constructions. After assembly, the height of the post supports can be changed: 45 mm or 80 mm for the PediX Duo, and 65 mm or 100 mm for the PediX Easy. Made of galvanised structural steel, the post supports can be mounted to the end grain of the supports using full thread bolts, without further joinery work, drilling or milling. The posts consist of a base plate with threaded rod, a top plate, a threaded sleeve with screwed joint and a protective sleeve. The PediX post supports can be used in usage classes 1, 2 and 3 according to DIN EN 1995-1-1.

As part of product development, tensile tests were carried out on the PediX Duo post supports to determine the load. The post support was screwed in using full thread bolts at an angle of 0-25° to the grain, allowing accurate readings of the behaviour of oblique set screws. In essence, high-quality screws can be screwed in at different angles from 0° - 90° to the grain.

The tensile test indicated was performed with a wooden post in conjunction with the PediX Duo post foot. The cross-sectional dimensions of the wood component are 100 x 100 mm.

After centring, two full thread bolts Ø 5.0 x 80 mm at 0° angle and 2 x 5 screws at 25° angle are used for the top plate. First of all, the load is distributed evenly across the 5 mm top plate. The two bolts in the centre area of the top plates initially take the greatest load and in terms of numbers, contribute only marginally to the tensile load capacity.

Through central tension, an almost direct plate bend occurs between the two rows of screws above 2.55 kN. Each row of screws will hold the wooden post on the left and right, each with 5 full thread bolts (5.0 x 80 mm) with a theoretical holding force of 7.14 kN x cos 25° = 6.47 kN.

The 2 x 5 full thread bolts at 25° angle alone produce a holding force of 2 x 6.47 kN = 12.94 kN. The rows of screws on the left and right have twice the tensile load capacity of the bending loading capacity of the top plate.

The experimental tensile test clearly shows that in this case, the weakest link is the buttoning of the upper bolt to the top plate. The bayonet lock was able to permanently withstand the forces. A bayonet lock enables easy assembly of the upper part with the mounted support and the anchored lower part. The connection is locked by plugging in and pulling up the lock.

The connection can transfer tensile forces from the support to the foundation specifically and is characterised by particularly high load absorption.

For more useful information and technical data on the PediX support feet from Eurotec, please visit our website.