Adding a drive

[davidbrady]

I'd stick with rebar and I'd add lots of it like Bob suggested (on 6" centers). Use high tensile rebar (60,000psi), and place it 2" from the bottom of the slab, so if you have a 6" slab you'd have 2" of concrete, then rebar, then 4" of concrete. When the slab bends it's the rebar that goes into tension adding tons of strength. The top concrete goes into compression, also adding tons of strength, the bottom concrete beneath the rebar is there for show. :-) (actually it's there to protect the rebar and to transfer loads into it, but it does nothing for the flexural strength of the beam. Add soft cut's to control shrinkage cracking, (10' x 10' grid).

If you use wire mesh you need to calculate the cross section area and make sure you have enough. If you're using #5 rebar like Bob suggests then make sure the wire mesh has the same amount of steel in it; i.e., say you have #5 on 6" centers then for every 6" depth of concrete you have (pi*.098=0.31 sq in of steel) cross section area of rebar. Do the math with screen mesh and see if you get 0.31 sq inch in every 6" depth. (measure the wire diameter, take the cross section area, and add up the number of wires in a 6" depth).

Simplified Engineering for Architects and Builders, Ambrose, J. TripenyTripthy, 10th edition, John Wiley &HobokenHoboken, New Jersey.