Roundowels
What is a Roundowel?
A Roundowel is a dowel bar of plain round reinforcing steel to NZS3402:1 989, with burr free ends, used for shear load transfer through joints in concrete structures. Roundowels are often used as an alternative to grease or Denso Tape.
Dowel bars must be free to slip within the concrete. Roundowels are shrink-wrapped in polythene plastic for easy slippage and convenient handling on site.
The plastic wrap is brightly coloured to enable easy visual checking of installation.
Sizes Available.
Lesa Roundowels are available in common sizes ex stock. A wide range of other sizes can be made to order.
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Standard Sizes |
16mm diam x 400mm long
20mm diam x 400mm long
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Special Sizes |
12 mm diam x 300mm, up to 1000mm long
16mm diam x 300mm, up to 1000mm long
20mm diam x 300mm, up to 1000mm long
25mm diam x 300mm, up to 1000mm long
32mm diam x 300mm, up to 1000mm long
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Spacing.
For common uses in floors and paving, and with a minimum concrete strength of 25 MPa at 28 days, the table below can be followed. These sizes and spacings are in accordance with recommendations of American Concrete Institute committees. If in doubt, refer to engineers' specifications.
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Slab thickness |
125mm |
Roundowels |
16mm diam at 300mm centres |
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150mm |
Roundowels |
20mm diam at 300mm centres |
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175mm |
Roundowels |
25mm diam at 300mm centres |
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200mm |
Roundowels |
25mm diam at 300mm centres |
Why use dowels?
In concrete floors and paving, joints are needed to control the cracking which results from shrinkage and thermal movement. The joints break the continuity of the concrete and create lines of weakness. Dowel bars restore the strength of the slab across the joints by transferring shear loads.
Dowels must be slip coated to allow movement of the concrete. This is provided on Roundowels by the plastic coating which covers the full bar length, therefore messy grease coating is avoided.
Dowels must be correctly aligned in the concrete, in a horizontal position and square with the joint to avoid restraining concrete movement. In many cases, this can be achieved by tying dowels to reinforcing mesh, or by using the LESA Dowel Cage.
Galvanising.
All sizes are available galvanised, to special order
Dowel ladders.
Lesa Roundowels are available pre-assembled in ladder form. Alternatively, ask for Lesa Load Plate baskets, which may offer a cheaper option.
Dowel ladders with Key Joint.
All Lesa dowels can be pre-assembled with Connolly Key Joint to create a movement joint with load transfer. This product provides certainty in movement joint location with accuracy of dowel alignment.