Longitudinal rebar for long & narrow (high aspect ratio) SOG
Longitudinal rebar for long & narrow (high aspect ratio) SOG
(OP)
We are assisting a local concrete/aggregate manufacturer with replacement of a 40 year old truck scale (pit type) with a new type - that 'sits' on a slab at four bearing/support points for each of multiple weigh-scale beam 'spans'. The truck scale is located under overhead aggregate storage bins.
The old scale has 8" RC perimeter walls about 9' apart, and the pit was about 5 ft deep. The 'pit' is being backfilled and will be topped with a new 12" thick RC slab.
Total length of new slab is more than 200 ft, with a width of 10'.
The scale manufacturer has a 'canned' slab design - thickness, rebar, etc, and a minimum bearing capacity requirement for any compacted backfill etc.
The new slab will be engaged into the existing perimeter scale walls, and this will provide significant restraint to shrinkage in the longitudinal direction. Coupled with such a high-aspect ratio of >20 and this is destined to crack, IMO.
So I was expecting to see a bunch of rebar in the long direction - but the 'canned' design has the equivalent of 0.13% rebar in the long direction. No joints detailed that I am aware of.

Expected service life is probably 15+ years.
Anyone venture a 'guess' on expected crack width and spacing?
The old scale has 8" RC perimeter walls about 9' apart, and the pit was about 5 ft deep. The 'pit' is being backfilled and will be topped with a new 12" thick RC slab.
Total length of new slab is more than 200 ft, with a width of 10'.
The scale manufacturer has a 'canned' slab design - thickness, rebar, etc, and a minimum bearing capacity requirement for any compacted backfill etc.
The new slab will be engaged into the existing perimeter scale walls, and this will provide significant restraint to shrinkage in the longitudinal direction. Coupled with such a high-aspect ratio of >20 and this is destined to crack, IMO.
So I was expecting to see a bunch of rebar in the long direction - but the 'canned' design has the equivalent of 0.13% rebar in the long direction. No joints detailed that I am aware of.

Expected service life is probably 15+ years.
Anyone venture a 'guess' on expected crack width and spacing?






RE: Longitudinal rebar for long & narrow (high aspect ratio) SOG
RE: Longitudinal rebar for long & narrow (high aspect ratio) SOG
You also have to sawcut it at the right time, too.
Dik
RE: Longitudinal rebar for long & narrow (high aspect ratio) SOG
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Longitudinal rebar for long & narrow (high aspect ratio) SOG
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