control/contraction joints should always be diamond sawed as soon as possible to prevent random cracking,,, when sawing, the current spec calls for thickness ./. 3 OR 1.3" deep if its a 4" thick floor,,, despite what you were told, fibre won't help much to control random cracking,,, i'd guess your only hope to save it now is full-depth sawing of a proper joint pattern.
why sand & not compacted fill as sand shifts ? gravel / graded aggregate base / nys dot item #4 is always recommended but never sand,,, if a 4" floor, 1 1/2" rock may be too large,,, rebar adds flexural but NOT compressive strength,,, conc likes to be square which's why we saw it,,, you shouldda listened to your contractor & let him saw,,, personally i wouldn't use fiber or wire mesh in 4" but that's often argued,,, as i recall, aci sez any steel/mesh's gotta be at the vertical midpoint +/- 5% which, in a 4" slab, is .2",,, by the time the jabonies finish tramping back& forth, guess what those odds are.
who designed this job ? your contractor SHOULD know why the cracks occurred - the joints should've been cut when the conc needed them - NOT when the owner sez,,, the next day is often too late. :furious:
why sand & not compacted fill as sand shifts ? gravel / graded aggregate base / nys dot item #4 is always recommended but never sand,,, if a 4" floor, 1 1/2" rock may be too large,,, rebar adds flexural but NOT compressive strength,,, conc likes to be square which's why we saw it,,, you shouldda listened to your contractor & let him saw,,, personally i wouldn't use fiber or wire mesh in 4" but that's often argued,,, as i recall, aci sez any steel/mesh's gotta be at the vertical midpoint +/- 5% which, in a 4" slab, is .2",,, by the time the jabonies finish tramping back& forth, guess what those odds are.
who designed this job ? your contractor SHOULD know why the cracks occurred - the joints should've been cut when the conc needed them - NOT when the owner sez,,, the next day is often too late. :furious:
