What are those bright criss-crossing items strewn across the formwork?
One of the the readers, Glen, asked the following question -
Any idea what the bright coloured items are that can be seen criss crossing the formwork on the corner of Ann & George St and you can also seen it being used on other formwork.
You can see what Glen is talking about in the photo below (bottom right):
At first I wasn't sure but after a bit of research I believe these are post-tensioning cables
. More info can be found about that here
, but here's a little snippet…
Post tensioning is a technique for reinforcing concrete. Post-tensioning tendons, which are prestressing steel cables inside plastic ducts or sleeves, are positioned in the forms before the concrete is placed. Afterwards, once the concrete has gained strength but before the service loads are applied, the cables are pulled tight, or tensioned, and anchored against the outer edges of the concrete.
Please leave a comment if you can provide more information or if I got this one wrong.