B RANGE FLAT ANCHORAGES - FREYROM

Freyssinet - 1 bis rue du Petit-Clamart - 78140 Vélizy-Villacoublay - Tel : +33 (0)1 46 01 84 84 - Fax : +33 (0)1 46 01 85 85 - www.freyssinet.com

Technical Sheet Reference : FT A 0030 - 2009-11-01

SUBJECT

In order to offer a range of small tendons with flat anchorages especially adapted for the post-tensioning of buildings or thin elements (slabs, floors), Freyssinet developed the system B prestressing anchorages.

The system B is suitable for traditional internal post-tensioning using tendons made up of high-strength steel strands, in accordance with NFA 35-045 or pr EN 10138 or other relevant stan-dards, with the characteristics mentioned below:

Diameter Type Designation Fm max

Ø 12.7 T13 Standard strand 183.7 kN

Ø 12.9 T13S Super strand 186 kN

Ø 15.2 T15 Standard strand 260 kN

Ø 15.7 T15S Super strand 279 kN

The strands are anchored individually, in cylindrical-co-nical holes in the anchorages, by conical wedges com-posed of three parts (Freyssinet “Unigrip” wedges).

5B15 anchorage with sheath

A distinction is made between two family units, depending on the prestressing application: • Bonded post-tensioning units (most current), composed of bare strands protected by a flat sheath, usually made of smooth or corrugated steel or high density polyethylene (HDPE) pipe injected with cement grout bonding the concrete structure and protecting the tensioned strands. • Unbonded post-tensioning units made up of unbonded strands. The strands are individually protected by grease and a HDPE sheath, so that the strand is free to slide inside the sheath without being bonded to the structure.

Both families use tendons composed of 3, 4 or 5 strands.

B RANGE FLAT ANCHORAGES

ANCHORAGE dimENSiONS

(All the values in mm)

B RANGE FLAT ANCHORAGES

All rights reserved by Freyssinet. The product names are Freyssinet Trademarks. The Information contained in this document is subject to change. Although best efforts were made to ensure maximun accuracy of this information, Freyssinet may not be held liable for this accuracy in any respect.

B RANGE FLAT ANCHORSiNSTALLATiON

The post-tensioning equipment is generally installed as follows:

• Ducts and trumplates installation

• Placement of tendons and anchorages

The threading of the strands is carried out before concreting. When the concrete reaches a sufficient resistance, the recess formwork is removed to allow the assembly of the anchorage blocks and wedges.

• Tensioning

The stressing of the tendons is carried out strand by strand using a monostrand jack with a specific adaptation allowing the correct alignment of the jack and a mechanical wedges adjustment.

Where the tensioning of anchorages is not possible from slab edge a specific adaptation with a curved nose shall be used.

• Final protection of tendons and anchorage zones

After tensioning, cement grout is injected (bonded post-tensioning) into the duct through the injection pipe attached near the top of the anchorage. The recesses are packed with mortar (after the ends of the strands have been cut off), troweled smooth and allowed to cure prior to the grouting.

Note: The B range anchorage allows all of the usual options of prefabrication:

• In internal (bonded) prestressing, installation in the formwork either by entirely prefabricating the cable fitted with its two anchorages either by fixing the duct on its supports and threading the strands before concreting.

• In unbonded prestressing, installation in the formwork of the individually sheathed and greased strands, fitted with their anchorages and fixed on their supports.

pERFORmANCES

Approval static tests according to BS 4447 have been carried out on the anchorages of the B range.

They can be used with all classes of standard or super strands (T13, T13S, T15, T15S), in concrete structures. B range anchorages can be used on slabs with a minimal thickness of 180 mm. The minimal concrete compressive strength at stressing shall be the following depending on the strand type :

Strand type Minimal cylinder concrete compressive strength

Minimal cube concrete compressive strength

T13 S 20 MPa 25 MPa

T15 21 MPa 26 MPa

T15 S 23 MPa 28 MPa

BURSTiNG REiNFORCEmENT

The recommended bursting reinforcement is described in the sketch below.

mANUFACTURiNG

PPCZA du Monay - BP 18 - Saint Eusèbe71210 MONTCHANIN - FranceTel.: + 33 (0) 3 85 73 69 00Fax: + 33 (0) 3 85 73 69 01

Sales manager:Bernard CADOT or Bruno ZACCAROTel.: + 33 (0) 3 85 73 69 49 / + 33 (0) 3 85 73 69 [email protected] / [email protected]

Technical contact:Nicolas DEMEYTel. + 33 (0) 1 46 01 85 [email protected]

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