Perry Home no rebar in driveway concrete? (Houston, Roma: townhome, buyers)

[PedroMartinez]

When I had my circular driveway done, they used a combination of rebar and mesh. The rebar was in (about) a 3' grid with mesh on top.

I put rebar in the concrete base for the ornamental light I installed.

[thomasINtexas]

i bought a Perry in CCR built about the same time, plus Ive watched a dozen more go in on my street,
they all have rebar in the driveways...

[piyf]

Originally Posted by Judy Kay

We're in Long Meadow Farms, 3 miles South on 99 from Westpark Toll. We have a Lennar Home, no rebar in the driveway. We just had a Pool put in. Had to replace 4 sections of the driveway, after it was cracked from the Bobcat. Could not believe it. I was told no home builder in this area, put rebar in the driveway.

I hope your pool installer gave you a discount.

[Rayford Sawdust]

Rebar and/or mesh will NOT prevent a driveway from breaking. Its only purpose is to keep all the pieces together when it DOES break.

[PedroMartinez]

Originally Posted by Rayford Sawdust

Rebar and/or mesh will NOT prevent a driveway from breaking. Its only purpose is to keep all the pieces together when it DOES break.

Interesting, I did not know that. I had always assumed that it gave additional strength and support.

I'm not saying you are wrong, but are you able to back this up? (Either by a link to the information or by stating that you are an engineer that works with concrete structures)

Edit: Well, I decided to do some quick research, and apparently, you are wrong.

Every source I found stated that rebar in concrete does not add to its tensile strength; however, it does add to its compression strength preventing damage from crushing loads.

I found this in multiple sources, but the best place was probably on the American Concrete Institute's site in this document on page 3 - http://www.concrete.org/general/fE2-00.pdf

[thomasINtexas]

Originally Posted by Rayford Sawdust

Rebar and/or mesh will NOT prevent a driveway from breaking. Its only purpose is to keep all the pieces together when it DOES break.

Im sorry, you're incorrect.

its called "Reinforcing bar/steel" for a reason.

is it required in a driveway ?
not really, but it doesnt hurt.

here's some lighter reading...
Rebar - Wikipedia, the free encyclopedia

[marksmu]

Originally Posted by Rayford Sawdust

Rebar and/or mesh will NOT prevent a driveway from breaking. Its only purpose is to keep all the pieces together when it DOES break.

We need a most uninformed post award as well. This would be waaaaaay up there.

[Rayford Sawdust]

The wiki link and ACI pdf are interesting, but not really applicable to our residential driveways. Yes, rebar as used in structural concrete is a necessity and not in dispute.

I should have made myself more clear. A typical 4" thick driveway in Houston with the typical 1/2" rebar on 18" or even 12" centers is not made any stronger or will handle a heavier load with the addition of the rebar. Have ever seen 1/2" rebar being delivered on the back of a trailer going down the road? The stuff sags under its OWN weight....how is it going to bear a load? If you don't believe that, next time you see rebar being set in a driveway before pouring, step out onto it and walk around. It will sag some under your weight, even after being wired to cross bars and sitting on bar support chairs. It simply does not add any significant structural load bearing strength to Houston driveways. Yes, it would be possible to get enough rebar in the concrete to help, but in practical applications, it does not.

My original statement is especially true when the driveway has mesh and no rebar. There is NO load bearing ability in that product.

After all that and back to the original post, I would not want a driveway that didn't have rebar. It serves a purpose, but not the one most people believe.

[Hangster]

Originally Posted by Rayford Sawdust

The wiki link and ACI pdf are interesting, but not really applicable to our residential driveways. Yes, rebar as used in structural concrete is a necessity and not in dispute.

I should have made myself more clear. A typical 4" thick driveway in Houston with the typical 1/2" rebar on 18" or even 12" centers is not made any stronger or will handle a heavier load with the addition of the rebar. Have ever seen 1/2" rebar being delivered on the back of a trailer going down the road? The stuff sags under its OWN weight....how is it going to bear a load? If you don't believe that, next time you see rebar being set in a driveway before pouring, step out onto it and walk around. It will sag some under your weight, even after being wired to cross bars and sitting on bar support chairs. It simply does not add any significant structural load bearing strength to Houston driveways. Yes, it would be possible to get enough rebar in the concrete to help, but in practical applications, it does not.

My original statement is especially true when the driveway has mesh and no rebar. There is NO load bearing ability in that product.

After all that and back to the original post, I would not want a driveway that didn't have rebar. It serves a purpose, but not the one most people believe.

This is not true. The fact that rebar sags under its own weight does not mean it does not provide support / strength for the concrete. Concrete is very strong in compression strength. However, it is very weak when it comes to shear strength. This is where the rebar comes into play. The fact that rebar sags does not come into play. The reason for this is that once the rebar is encased in the concrete, the rebar is supported along its length by the concrete, However, when a force that is perpendicular to the concrete is applied (shear force), the force is transferred through the concrete to the rebar inside, where the rebar's strength against shear forces provide the strength against the shear force, preventing the concrete from breaking.. (For what its worth, I have a background in civil engineering)

[houstonfan]

I think you're both sorta right? Maybe we're disagreeing on semantics here? Concrete has excellent compression strength. A truck driving over a driveway is adding compression strength, so "in theory", rebar is not needed assuming you have a very solid base underneath. Reinforced bars are useful for increasing tensile strenth and for keeping the driveway from warping/buckingling/becoming uneven at joints (flexion strenghth).
What I understand is the rebar is needed more because the base is not solid, the soil in Texas is mostly clay, it shifts and expands and contracts a lot. The rebar resists these shear and tensile forces. Also, if the base is not rock solid, a heavy truck on the driveway can become problematic bc now it will introduce flexural stress where the base gives. So you can either add more thickness to your concrete, use fiber reinforced concrete (not sure how much strength this adds), or use rebar. On the flip side, too many rebar rods can weaken the concrete.