Since this thread is going good, I have question regarding cracks NOT inside an expansion joint. I had my concrete put down in 2011 and this year with the extremely cold winter the frost heave gave me a crack (in the smallest section, which is triangular) for my outside pad.
It is hairline NOW and I was thinking it should be filled with some thin liquid that would penetrate down into it. It has a top cure coat that was sprayed on the day of the pour but no other coating & is standard whitish concrete with fiber 6000 psi mix. The separation is flat 5.5" thick and width of crack is from nothing to maybe 20 thousands wide, depth unknown, length maybe 8 feet.
Suggestions as to what to fill it with. Also I have not filled the expansion joints but would think this year of doing that on the outside slab sections. They are typical and only 3 of them that form a triangle and a square pad across the front of the barn.
about best pic of the spot, it comes from the man door towards the spot I was standing taking the photo.
other pics and videos there if you click on above pick U can scroll thru the pour and what it looks like now, no pics of the crack (still on the phone tho.)
mark