Yes, it is recommended to use rebar for a 4-inch slab to provide additional strength and prevent cracking.
You still need rebar, unless you are filling a drop in an existing slab that already has steel in it.
To pile rebar bent to a slab, first determine the required lengths and bends based on the slab design and structural specifications. Using a rebar bender, create the necessary bends at specified angles while ensuring the rebar is adequately supported. Once bent, position the rebar according to the slab’s layout, securing it with ties or supports to maintain proper spacing and alignment before pouring the concrete. Always follow engineering guidelines to ensure structural integrity.
2" based strictly on the slab thickness. However, it may be governed by form spacing, rebar spacing or rebar clearance to the forms.
As a guideline, 4 inches thick, but it would depend on what is going to be sitting on top of it. You may need thicker and/or to reinforce it with rebar.
There is no way to answer without a design and the square footage.
When the slab is loaded and force applied to it, the top of the slab directly under the load will be put in compression. However at the bottom of the slab. the concrete will pull itself in tension. Put the ends of your fingers together than flex your wrist up. You will feel the pressure at the top of your fingertips and you will see a gap open at the bottom. That is what is happening in a slab. Concrete is strong in compression, poor in tension. Rebar, or steel, is the opposite. By combining the two, you develop a product that is superior and complimentary to the strengths and weaknesses of the individual materials.
varies depending on load to be put on slab, local codes, lots of variables. Check with bldg. dept., better yet a structural engineer.
I assume they would be tied using tie-wire to the rest of the rebar cage.
No. There are plenty of complete driveways with no steel. Assuming you are refering to flatwork and not an actual building foundation.
If your peice of concrete does not have beams I consider that flatwork. So in flatwork with 3/8 rebar (#3) on 16" centers, for the 15 foot side you will have 8 pieces x 15' long. On the 10' side you will need 12 pieces x 10'. (6 bars cut in half) In all you will need 14 #3 x 20'
Rebar and Post Tension cable (PT) are two entirely different items. Rebar is the static steel bars placed in the concrete while the PT are high tensile strength cables that were placed in concrete than stressed under hydraulic jacking to a tension generally around 2500 to 3500 psi. As a result, the situations for repair are different. The exposed rebar can be cleaned and patched through approved methods. However the PT should be looked at by a professional as it is an integral part of the structure and, as mentioned before, is under tensioned stress. If the exposed rebar is in a PT slab, caution should be used and a professional consulted as well, due the rebar being integrated with the PT.
The essential steps for pouring a concrete slab are: preparing the site by leveling and compacting the ground, setting up formwork to contain the concrete, placing a layer of gravel for drainage, reinforcing the slab with rebar or wire mesh, mixing and pouring the concrete, leveling and smoothing the surface, and allowing the concrete to cure properly before using the slab.