Formstress has a large range of precast concrete products.
Contact our friendly and professional team to discuss your needs or to provide a quotation.
Click on any of the products below to find out more.
Double Tees
Double Tee flooring units consist of two prestressed ribs and a connecting top slab. The ribs can vary in depth from 200 to 500mm. The connecting slab is 2400mm wide x 50mm thick. Double Tees are ideally suited for larger spanning floors with a wide variety of services suspended from the flooring system. Double Tees can easily accommodate large floor voids/penetrations through the slab region.
Product Specifications
A major practical benefit of a concrete floor is its ability to reduce noise transmission. Double Tee concrete floors are quiet and do not creak with temperature and moisture changes. The table below shows sound transmission ratings achieved by Double Tees.
Double Tee Concrete Strength = 42 MPa
Topping concrete strength = 20 MPa
Topping thickness = 65mm.
Fire Resistance rating, 2400 wide unit = 90 minutes
For fire ratings or loads in excess of the allowable, please contact your Formstress engineer.
Installation & Construction
Where high shear loads are combined with support beams or walls of low material strength, a bearing capacity check according to NZS3101 should be made; e.g. masonry bearing walls.
Lift Double Tees only at the lifting points provided. Chains or strops must be of correct length to carry equal load and must not be more than 30 degrees of vertical.
Double Tees if stored on site must be supported at their ends on firm ground. Bearers between layers in a stockpile must be vertically above each other and units of varying length should not be stacked upon each other. Ensure the bottom bearers are not pushed into the ground, resulting in the bottom unit being supported near midspan.
Flange supported Double Tees must be bedded on a sand cement mortar (the consistency of block-laying mortar). This must be evenly spread just prior to the unit being placed. Double Tee legs should be placed on cement mortar or on plastic bearing pads. Formstress Double Tees are designed as pre-stressed sections as per NZS3101 : Part 1 : 1995. For minimum seating requirements refer to NZS3101 : Part 1 : 1995 section .3.6.4.
General Notes
Specifications for the manufacture, transport and erection of Double Tee units, and standard details for typical situations, are available from your Formstress branch. Experienced and qualified staff will be pleased to discuss design and fixing details.
Before manufacture can commence, the contractor shall sign off the Formstress shop drawings as dimensionally and structurally correct. All Formstress units are provided with lifting eyes. Do not hesitate to contact Formstress about any specialist needs you may have.