MBT meets NTZA Bridge Manual requirements for seismicity, slip and brittle fracture

Ancon is pleased to confirm that its MBT range of mechanically bolted couplers and anchors, in the most common reinforcing bar diameters (12mm to 25mm), provide ultimate tensile strength to 690MPa and comply with NZTA Bridge Manual (SP/M/022) requirements for seismicity, slip and resistance to brittle fracture.

MBT Couplers are suitable where it is not convenient to have the bar ends prepared (threaded) for the Ancon RT System. The bars are supported within the coupler on two serrated saddles. Bars are locked in place by a series of special lockshear bolts, the heads of which shear off when the predetermined tightening torque is reached, providing a visual check of correct installation.

The MBT system can be used to join imperial, plain round or deformed reinforcing bars and is ideal for repair work.

For applications involving the replacement of corroded or damaged bars, the replacement bar is cut approximately 5mm shorter to allow clearance for insertion between the sound ends of the original bars. MBT couplers are pushed fully over both ends of the replacement bar and temporarily held in position. The replacement bar is then correctly positioned and the couplers moved to a previously marked position on the existing bars indicating half the length of the coupler. The lockshear bolts are tightened to complete the installation.

MBT Headed Anchors create an anchorage in the concrete, replacing the need for cogged or hooked bar ends. They can simplify scheduling and bar placement, and reduce congestion in the concrete.

MBT Couplers

The following sizes provide ultimate tensile strength to 690MPa:

• 12mm
• 16mm
• 20mm
• 25mm

MBT Headed Anchors

The following sizes provide ultimate tensile strength to 690MPa:

• 12mm
• 16mm
• 20mm
• 25mm

Larger Sizes

Larger coupler/anchor sizes are available to suit reinforcing bar above 25mm diameter. Contact Ancon for details.

NZTA Bridge Manual

The NZTA Bridge Manual is a key engineering document for practitioners involved with infrastructure works around New Zealand. The manual sets the criteria for the evaluation of existing bridges and the design of new structures and earthworks. First published in 1994 and revised for a first time in 2003, the current revision was produced in 2013 and reflects advancing engineering knowledge and expectations.

Among the many changes to the previous edition, section 4.2.1 of revision 3 demands higher standards for the mechanical coupling and anchorage of reinforcing bars.

Please contact Ancon for more information.