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What we do: concrete accessories
Dowels, Dowel Baskets and related
items:
CANZAC Speed Dowels round and square for load transfer in construction joints. Dowel baskets for bigger pours and Wide-Move Dowels for post tensioned and shrinkage compensating concrete floor slabs. CANZAC Fibre Dowel a corrosion proof dowel bar system.
CANZAC® Speed Plate System:
A new and economically smart choice for
Flat Plate Dowel Systems.
● ensure proper dowel alignment
● a dowel method recommended
by ACI 302-04 Guide for Concrete
Floor and Slab Construction
● one piece design with alignment marks and
pre-installed nails that makes installation quick
and easy |
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● integral, patented sleeve insert that eliminates lateral
restraint between slab panels
● non-tapered plate profile ensures consistent bearing stresses
at joint face and full depth of dowel
● larger steel plates (compared to competing plate dowels) provide greater
overall surface area to reduce bearing stresses on the concrete
● a system with a uniform plate width to ensure minimal bearing stresses at the
joint face and throughout the full embedded length of the dowel
SPEED PLATE reduces the number of dowels required when compared with conventional doweling systems. Fewer dowels and simpler installation means reduced cost of installation. The conversion chart below gives the equivalent size and spacing of SPEED PLATE dowels when substituted for conventional smooth round dowels.
Note: The spacing of SPEED PLATE dowels in any application should be as determined
by the structural engineer for specific load conditions.
Testing and Research:
Greenstreak’s engineering department dedicated numerous laboratory hours to investigate load transfer system.
Independent tests were conducted to provide an unbiased evaluation of all doweling methods available, including
round bar, square bar, flat plate, and diamond plate. The tests, which utilised a modified version of the AASHTO
T253 test for load transfer devices, were designed to determine the following:
● Total joint deflection under load.
● Bearing stresses imparted to the concrete at the joint face.
● Failure mode of each doweling system.
Conclusions:
● Tests of all dowel systems resulted in a tensile “pop-out” failure of the concrete.
● All dowel types provided deflections substantially less than the typically accepted value of 0.64mm when loaded to 907kg per dowel (equivalent to 4535kg axle load). Deflections greater than 0.64mm can lead to joint failure due to impact from wheeled traffic. Minimising deflection is the key to ensuring the durability of a control joint.
● Dowels with rectangular cross sections and larger widths are effective in reducing bearing stresses on concrete. Adding sleeves to dowels of all types also reduces the bearing stress on the surrounding concrete Speed Plate dowels produce the lowest bearing stress on the surrounding concrete. Bearing stress alone, however, does not predict ultimate dowel loads. All dowel systems tested failed at a wide range of bearing stress but at similar applied loads.
● Flat plates or square dowels with sleeves that allow movement in the direction of the joint, are effective eliminating lateral restraint between concrete sections. The Speed Plate sleeve incorporated an integral, custom insert that provides lateral movement capability between concrete sections.
● It is critically important to thoroughly vibrate the concrete around plate dowel.
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