Quote:
Originally Posted by 1ajs
even at that thicknes that span needs the extra suport
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That's my point - it doesn't appear to require the assistance of PT. The tensile capacity of the material is more than adequate and even if you wanted to guard against a freak failure, why not just slide a few channel sections in under the slab hidden from view and doesn't involve the additional expense.
Span to depth is pretty modest (about 12 or 15 to 1), so it still defies logic. An FOS of 3 (or even more) is superb, so again PT appears to be an expensive solution with little reason to substantiate it. So the question remains - why PT it?
To expand on Vexx's question - a series of holes are drilled through the slab but each would also require a counter bore at each end in which to accept the strand anchors. The photo shows each strand pocket capped with an epoxy sealant to keep it air tight, so it (the strand) may not need to be grouted. However, it may not be prudent to rely on said sealant, so grouting the hole seems warranted. To do that though, there would have to be a second grout tube and vent drilled alongside each primary hole - which probably explains the oblong shape of the cap.