Cast-In Channels


In the construction of precast noise walls for the Gateway Bridge Duplication Project in Brisbane, a number of ALTAS Lifting and fixing systems were used, namely the ALTAS LIFTIFX TKA Anchor for lifting and transporting the walls, and the ALTAS RAILFIX system for securing the walls in their final positions. The precast elements were cast in the Eagle Farm Precast Facility in steel and rubber textured moulds. ALTAS LIFTIFX TKA Anchors were used for edge lifting the elements, with 2 anchors cast on either long edge. This provided for flat lifting and transportation, and then rotating off one edge at installation. ALTAS LIFTIFX TKA Anchors have the advantage over standard hairpin and foot anchors that while using a standard clutch, the geometry of the anchor prevents the clutch head from rotating in the void too far and thus preventing it bearing against the concrete. With standard lifting anchors, sometimes when the clutch bears on the concrete, the concrete will spall if it has not achieved sufficient strength or the impact of the clutch is too great. A variety of 1.3, 2,5 and 5.0T anchors were used on this job depending on the wall element required. Over 25,000 lifting anchors were supplied for this project.

The examples walls shown here are using the 5T TKA Anchor secured with a perimeter shear bar and an additional anchorage bar through the anchor. A variety of different ALTAS RAILFIX HDG anchor channels and styles were used on this project depending on the wall thickness of the precast element.

Standard ALTAS RAILFIX anchor channels having a minimum of 2 or 3 anchor legs were used for most of the precast walls. The channel has a foam filled uniform cross section with an open mouth that is located against the mould face. The anchorage pins are similar to ALTAS LIFTFIX foot anchor pins which are securely connected to the channel. Both the anchorage pins and the channel section work together to provide high pullout capacity for securing items to the finished precast element, or for securing the precast element to the rest of the structure, i.e. steel columns.

ACTECH was also able to provide a custom fabrication service of anchor channels with a slotted plate anchorage system for thin panels. Reinforcement bars transverse to the channel provided the anchorage in the element. (See opposite page - Special Channels)

On site, the panels were edge lifted into position and the secured using ALTAS RAILFIX T-bolts. These bolts were easily inserted into the anchor channel and rotated to lock into position connecting steel clip plates to previously installed steel columns. The length of channel provides for a high degree of variance in the final location of the T- bolt meaning standard clips plates could be used, and no welding required. The result is a clean and elegant connection that is easy to use, and very fast to install.