perry

hey, folks. I'm about to pour a driveway section that slopes six feet in twenty... what is that, 30% or something.... I've done a lot of gentler slopes and just gone with a drier mix, but are their some tips out there for doing something this steep? (sorry if this is an old topic; I looked through the forum but didn't see anything)

thanks, -pj

kapena

Does the truck have to back down that driveway section?
A fully loaded concrete truck might have problems backing down on a six feet in twenty slope. I've been on some jobs where the truck's front tires kept lifting until some of the load was dropped.

Make sure whoever is operating the chute does not rush the job. Stop now and then to make sure. It is way easier to pull or dump some extra mud down than to pull any upwards. I hate when some clown dumps too much because he wasn't paying attention.
Expect the final thickness to be more than the forms indicate. It ain't as precise as flatwork.

CaliDesigns

Use rebar, it will help hold the mud in place.

perry

Thanks. No, the chute will almost reach the bottom so the truck will be almost level... and I had planned to use a standard four inch mesh instead of rebar... think that's ok?

How dry should I go (slump)? It's only about 300 sq ft of surface area, so I'm not worried about it going off before I can finish...

I'm also worried about the tamping- standing uphill and holding that sucker at such an angle will be difficult... any thoughts on standing below the tamper and filling in the boot holes with the float?

Anyone ever start at the top and tamp downhill with a dry mix?

Thanks a lot.

(Great website, BTW)

-p

kapena

I always use the 6x6 10/10 w.w. mesh. Don't let the truck back onto it though. I also lay 1/2" rebar about 8"-12" alongside the edges.

I don't recall ever tamping (except for the edges), but maybe the concrete you use requires it. Usually the bullfloat gets everything down.
A slope like that gets at least a rough-broom finish for traction.

The truck drivers over here are pretty good about getting the right mix.
It's stiff, but it flows enough to keep it easy enough to work.
There is some movement on steep slopes, but it isn't that bad. Your tamping might make it worse though.
We always use 3000psi mix for slopes.

I have done some steep driveways from the top down, but I didn't tamp.

CaliDesigns

Mesh will work if you get it chaired up enough. I find it easier to chair up rebar.

perry

Thanks for the input... I guess I've never considered not tamping flatwork... I don't think the mud is anything special though. Maybe I'll just give it a try and if the mud slumps too much I'll just float it.

And yeah, I use the two-inch blocks to raise the mesh.

Thanks again, -p

jcalvin

Might be costly, but how about forming the surface and using a concrete vibrator down in the forms. They pour walls all the time and they are straight up.

__________________
Cal


You hired WHO

Hoven

Just lay the mesh and tie it all together. As the truck pulls into the area have him dribble some concrete on the ground and pull the wire up as he does this. Once the wire is up it should stay. Forget the tamper it will make your life miserable here. Use a screed, pull downhill and slowly don't try to rip it. Then go backwards with the screed to fix any crete that fell off grade. Pick up your screed and move to next area to place. Only pour out 2 to 4 feet at a time and enough that your screed will span that area . 3 1/2 to 4 inch slump max and don't use small aggregate in the mix, 3/4 is ok. Fiber mesh will also help you with this application. Chairs in this area will make walking on the wire dangerous for you and your help. There are plenty of ways to skin this cat, this is just how I have tackled a similar driveway I installed last year. Your gonna sleep like a baby that night, I promise.

mdshunk

There's a development over in Lancaster PA that has some curiously steep driveways. The pictures have been around the 'net a bit, and they have been accused of being PhotoShop'd. They are not.

perry

Thanks, folks... very useful stuff. -p

Hoven

WOW, they are steep, that cant be code lol, You would have to send your kids out to play with a parachute.