Driveway

[Keith Laufenberg]

I'm getting ready to pour a driveway. I dug it out, so far, with a back-shovel (my back, my shovel) and got haphazard results, 2" here and maybe 6" there, because of the uneven site and presence of limestone rocks, and am getting ready to rent a bobcat to finish grading the site. I've got the forms dug & recessed into the ground; 4", 2X4's & 6", 2X6's for the swale only, but am wondering if I should remove the 2x4's & 2x6's before I attempt to scrape it or do the opposite, take a transit & shoot them in at the right slope height and then try to scrape the rest of the site up to the forms. If I shoot them I'd put some rebar behind them and nail them in before scraping with the bobcat. Right now I'm leaning towards the latter but I'm not a heavy equipment operator so I'm wondering if I'd be good enough to not smash up the forms? I'm also wondering about cutting expansion joints to protect from cracks; I know you've got to do it as soon as it dries.
Any thoughts would be greatly appreciated.

Keith G.

[Scott Patterson]

I'm getting ready to pour a driveway. I dug it out, so far, with a back-shovel (my back, my shovel) and got haphazard results, 2" here and maybe 6" there, because of the uneven site and presence of limestone rocks, and am getting ready to rent a bobcat to finish grading the site. I've got the forms dug & recessed into the ground; 4", 2X4's & 6", 2X6's for the swale only, but am wondering if I should remove the 2x4's & 2x6's before I attempt to scrape it or do the opposite, take a transit & shoot them in at the right slope height and then try to scrape the rest of the site up to the forms. If I shoot them I'd put some rebar behind them and nail them in before scraping with the bobcat. Right now I'm leaning towards the latter but I'm not a heavy equipment operator so I'm wondering if I'd be good enough to not smash up the forms? I'm also wondering about cutting expansion joints to protect from cracks; I know you've got to do it as soon as it dries.
Any thoughts would be greatly appreciated.

Keith G.

Keith, if you have never placed this much concrete you might want to consider getting some help. What are you doing in the way of reinforcement for the driveway?

The proper forms and foundation will determine the entire outcome.

[Keith Laufenberg]

Scott,

What exactly do you mean by reinforcement? It's fiber-cement so I don't need any rebar. I've got a couple of concrete guys helping me with the pour when I get ready. I've done a lot of pours but I just did the footings and formwork; this is my personal driveway so I'm the only one responsible for the outcome.

The ground is a combination of limestone rock, hard clay and dirt and I was going to scrape it with a bobcat and then drop the shovel to compact it.

[Scott Patterson]

Scott,

What exactly do you mean by reinforcement? It's fiber-cement so I don't need any rebar. I've got a couple of concrete guys helping me with the pour when I get ready. I've done a lot of pours but I just did the footings and formwork; this is my personal driveway so I'm the only one responsible for the outcome.

The ground is a combination of limestone rock, hard clay and dirt and I was going to scrape it with a bobcat and then drop the shovel to compact it.

I would consider using welded wire reinforcement just as an extra added measure. The fibers in the mix help, but they are not as strong as steel. I do not know anything about the soils in your area, but in my area everything is pretty much on rock after a few inches or feet of dirt and WWR is still the norm for driveways and most flat work.

[Keith Laufenberg]

Scott,

I was thinking of putting some in the 6" swale.

[Dom D'Agostino]

I would consider using welded wire reinforcement just as an extra added measure. The fibers in the mix help, but they are not as strong as steel. I do not know anything about the soils in your area, but in my area everything is pretty much on rock after a few inches or feet of dirt and WWR is still the norm for driveways and most flat work.


Not here in Florida, Scott. WWR is almost never used for any walkway or driveway, and the long term results are pretty good around here if the person placing the concrete knows what their doing...

Otherwise, Keith, call in a pro who, thanks to our economy, has no jobs scheduled. You'll be happier in the long run with a driveway that performs as intended.

Dom.

[Keith Laufenberg]

Dom,

I'm in Florida, Hernando Beach, and as far as I know, as long as I've got a couple of guys with me making sure the concrete doesn't set-up too soon and as long as we screed it in time, with a long 2x4, and cut the expansion lines, there shouldn't be any problems. And, there may be a lot of guys out of work but you wouldn't know it by the prices they throw out at you; that's why I'm doing it myself.

Keith G.

[Tim Spargo]

I generally use the ole flying groover and put my joints right on in there while finishing the concrete. <-- It's a real tool BTW.

As Scott mentions WWR, and it's a good suggestion, we use 6-6-10 around here. 6" square and 10 gauge wire. I'd have to agree it's use in a driveway is a requirement in my book.

Fiber cement is fine, but in a driveway I recommend wire or #3 rebar, as in my experience ALL concrete cracks via shrinkage, soils conditions etc WWR or rebar can help LIMIT cracks and displacement is all.

I like to know where my joints are going ahead of time, symmetry... what can I say? I also have a thing about where an "inside corner" comes into flatwork and lacks a control joint. Just like stucco around windows, concrete cracks where it intersects a corner.

I haven't seen a bobcat grade while forms are in place... An occasional string-line is not a bad idea.

Good Luck!

Don't put your steel too close to the sides... this (the attached pic) can happen to you!

[Jerry Peck]

we use 6-6-10 around here. 6" square and 10 gauge wire.


I believe you meant 6-6-10-10 for 6" spacing by 6" spacing with 10 gage by 10 gage wire.

When used in slabs on grade down here, 6-6-10-10 is what is used.

Many times they will use fiber mesh and then use the 6-6-10-10 WWM (welded wire mesh) anyway.

quote]Don't put your steel too close to the sides... [/quote]

WWM is steel reinforcement, and all steel reinforcement is required by code to have a minimum of 3" of concrete cover when placed in concrete in direct contact with earth. That means the WWM should be 3" above the bottom and 3" in from all edges.

[Tim Spargo]

3" Sure.. tell that to the guy who built the house... wait a minute, I told the buyer that :D