Hello: First I apologize for my poor English cause I don´t live in the USA.
My question is for a good contractor. I have to repair my concrete slab on my garage. It was originally built as a 4 inches “raft” concrete slab over the ground(without rebars). The walls are supported for properly foundations. The garages floor is so damaged due to subsidences and differential settlements. So. I want to build another slab using concrete and steel reinforcement. I intend to do it as “ flouting slab. As I think the fill that supported the original slab is already compacted, due to the traffic and the natural settlements. I would like just to put that reinforced slab without sub-base( as crashed stone, etc) and without additional compaction. Just to make the job easier. I inform you that is not expected using so heavy vehicle as trucks, pick –ups,etc just popular cars. I will summarize bellow the information and how I am planning to do it.
PS: We use here metric units but I am going to convert is, as possible, at Imperial ones.
1)Milded climate( South Brazil): no freezing, thawing. Not too much hot climate the garage has a good roof. No ground water table.
2)Light vehicles, at maximum 2 tons.( The total vehicle´s weight)
3)The dimensions are : 4 X 9 meters(13’ X 29’ feet)
4)I will use a 13 mm slab(5” inches) with 25 Mpa concrete(3625 psi)
5)We don’t use welded meshs here( just on big enterprises) so I will use :
a)6, 3 mm rebar each 20 cm at the bottom on both directions( ¼” bar each 8 inches). Rebars tied with steel wire.
b)To stiffer it, I will use each 2 meters(6 feet) beams (inside the slab on the minor dimension) for 30 cm to 13 cm( 12 X 5 inches), having 3 bars top and bottom of 10 mm( 3/8 inches), tied with 6,3 mm stirrups, each 20 cm( ¼” stirrups each 8 inches), These beans inside the mesh I have already mentioned.
c)I will put proper covering: 30 mm at the bottom and 10 mm on the top( cause it will be covering by mortar and ceramics) ( 1 X 3/8 inches)
d)No joints are planned. Except for external wall perimeter when pile foundations are provided.
I thank you in advance.
Fernando