To ensure the structural integrity of an Interbloc® structure with vertical reinforcing, it is vital to follow the correct process for installing the starter bar. Deviation from this procedure may result in structural failure. It is ultimately the responsibility of the installer to ensure the process is followed correctly.
Marking The Location of Holes:
The location of the starter bars first need to be marked out on the foundation. Unless otherwise specified in the design, the location of the starter bars should be a minimum of 300mm from the nearest edge of the concrete foundation.
The space between each hole is a minimum of 603mm for 600 series blocks, and 403mm for 400 series blocks; this allows for creep in blocks as they’re placed. The table on the following page provides an example of the spaces required between holes.
If the wall requires more than 20 holes, at the 21st hole re-calibrate your measuring tool to ensure accuracy.
Drilling The Holes:
Drill holes in the concrete at the marked points along the centre line, and to the correct diameter and depth for the size of rod specified to be used. For best results a diamond tipped drill bit should be used.
Cleaning The Holes:
Use the Blow-Brush-Blow method to clean the hole.
Blow air into the whole to remove cement dust. The hole should then be brushed to loosen cement dust and loose aggregate followed by blowing the debris from the hole using compressed air. Where the hole is wet, use water followed by compressed air.
The following tables provide the minimum depth and quantities specifications for Interbloc® wall structures. Engineers should specify structure specific requirements as part of the design process.
Epoxying the Bar:
Once cleaned, the epoxy should be injected into the hole, followed by the starter bar. This should be allowed to set for the required time before installing the blocks.
Use a long nosed epoxy dispenser to ensure the hole fills from the bottom up.
Inserting the Bar:
Slowly rotate the starter bar as it is inserted into the hole, this ensures the epoxy fully coats the bar and prevents air bubbles forming.
Once cured, ensure the bars are cemented in place by conducting a pull test on the bar.