Cracking in Post tension slab

[seminole22]

I have project that has a longitudinal crack in the PT slab The crack runs along a single curved strand line near the longitudinal center of the rectungular slab (280'x100'). The crack is <1/16" wide and is not vertically offset. The crack runs the entire width of the slab and.

The slab is ~10" thick and contains regularly spaced strands which span the longintudinal direction (16k/ft) and curved bulk strands along the column lines in the transverse direction (~425 k) A drive lane and parking area are located above with no unusual loading near the crack line.

Any thoughts as to the source of the cracking? Is it better to repair with an elastic sealant or rigid epoxy?

 

[rowingengineer]

1. We need more info, ie bonded/unbonded, restraint layout, type of slab, photo's, ect.

2. After you have established that the cracking is not structural and this is not a movement joint created by the slab, then I would recommend a cementitious grout that closely matches your concrete used for the PT slab.


A clear conscience is usually the sign of a bad memory

 

[Ron]

S22...the crack is too narrow to use anything cementitious. It is most likely a shrinkage crack that occurred prior to stressing the strands.

I would use a semi-rigid epoxy. W.R. Meadows Company makes one...I'll see if I can get the specifics.

 

[rowingengineer]

Thanks fo the pick up ron, 1/16 of an inch did compute well in my head.

A clear conscience is usually the sign of a bad memory

 

[Ron]

S22--here's the material I was thinking of. I've used it before in residential applications for interior slabs.

http://www.wrmeadows.com/wrm00055.htm