General Post-tensioning System Material Details

Post-tensioning systems are a sophisticated assembly of components which have been tested and proven to work together. It is not permissible to mix and match components from different sources as it is likely that such a "system" will under perform and not provide the client/customer with the required quality and durability of construction.

It is for this reason that post-tensioning contractors which are certified by CARES to PT 1 and PT 2 are required to supply and install the whole of the post-tensioning system. 

Tendons

Bar should CARES approved and comply with BS 4486.

Strand should be CARES approved and comply with BS5896 (prEN10138 is not acceptable).

Anchorages

Anchorages, including bursting reinforcement, should comply with EN 13391 "Mechanical tests for post-tensioning systems" or post-tensioning kits should comply with ETAG013.

The characteristics of anchor/wedge type and strand types vary and it is not possible to "pick & mix" components. It is therefore necessary to seek evidence of load efficiency and dynamic testing for specific anchors/wedge/strand combinations.

Grout

Grout should contain no materials which will adversely affect the steel tendons and shall have a chloride ion content of less than 0.1% by mass of cement. Grout should be batched to an accuracy of +/- 2% for dry materials and +/-1% for mixing water. Grout should exhibit the correct characteristics and, prior to contract, should be subject to suitability testing to determine its properties:

• Fluidity,
• bleed,
• volume change,
• density,
• strength,
• setting time .

For Further information please contact Richard Digman:
UK CARES
Tel : +44 (0) 1732 450000
Fax : +44 (0) 1732 455917
E-mail : RichardDigman@UKCARES.COM

UK Certification Authority for Reinforcing Steels Copyright © 1998-