Rotating a concrete slab?

If it doesn’t crack or break up while moving it it probably will later because the bottom side is never perfectly flat. Concrete is very brittle and has no shear strength that’s why we add rebar and wire mesh, even if you have reinforcements I would not try to move it.

Slab on grade is probably the kind of pour you are referring to.

The problem is only partially one of lifting the slab, the other half is having the slab rest again on the grade.

These kinds of concrete pours fill all the irregularities of the ground they are poured upon. If one could lift the slab without slab damage, the setting of the slab on a new position of the grade would likely not match the irregularities in the same exact positions. This means your slab would be unsupported in some spots, and have new pressure points in others.

While one would hope that the weight of the slab pushes down the high points. In reality, the weight of the slab does so by bending at the high points while applying pressure. Since typical formulations of concrete aren't designed to be heavily flexible, the bending introduces fractures and causes premature failure of the slab.

I would look into augmenting the existing slab without attempting to move it.

This is just a guess.

I don't think there's going to be any muscling this around or moving it with prybars or etc. It's going to weigh 9000 pounds or so. Realistically I don't think it's going to happen.

But anything's possible, of course. I tried to think of some ways this might be doable. Most of them were way more work than busting up the slab and starting over. One might actually work.

If you put nine 3/8" expansion anchors in the slab, in a 3x3 pattern, put eye bolts in them, and rigged chain sling to a big shackle, set up so they're all under equal tension, and picked it up by the shackle, maybe with an excavator, you could probably get it up off the dirt, spin it, hose down the dirt under it, and lower it.

So yeah probably best to learn to like the angle, or crack it up.

You might get some inspiration from some attempts at various slab moving jobs posted to YouTube. It's more translation than rotation in place but you can get a sense for how strong a slab is.

• Moving a Patio Slab -- fabricates a bolted down steel fixture pressed with a bottle jack, demonstrates the slab displaces. Sheers off a 1/2" 5/8" bolt, upgrades to 3/4" bolt. Zooms in on slab, you can see it actually move each pump of the jack. 10'x15' slab
• Moving a Concrete Slab -- a smaller slab, uses a pry bar to lift one edge, slips in bricks, uses a floor jack to lift, slides in some roller logs to move the slab. Approximately 3'x4' slab
• Moving a concrete slab -- Approximately 5'x6' slab moved using steel pry bars, something like 5" metal pipes as rollers, and a piece of plywood to roll onto.

Definitely out of reach but this so called slab crab attachment to a digger shows how robust a slab can be Slab Crab moving Concrete Slabs - Kenco

Not quite related, but a great company service where folks lift sunken slabs with hydraulic jack and drills holes into the slab to inject some expanding foam Lifting Sunken Concrete Driveway Pads

I believe if you get the geometry right so the forces are oriented properly you should be able to make a configuration of those steel fixtures and bottle jacks to push at the right places to achieve a rotation. It may also be possible to push in one place and pull in another with like a snatch block pulley arrangement with a come along or something.

I'm not sure how feasible this is but, here's an idea: you might want to look around for a 'mudjacking' service. Here's a video isn't great but should be enough to understand the process.

This kind of service is typically used to level concrete but perhaps the approach could be used to float the slab. Then the slab could be rotated by other means.

If the entire slab can be floated in this way, it would address the issue of uneven support that is described in other answers. If this is even possible, it might raise the entire slab a bit which may present other issues.

I once moved an 8x12 slab (~4 inches) about 20 ft and 90 degrees from the original pour. Builder put a shed up when we built the house. It was 10+ years old when I moved it. Dug two holes under one edge and put bottle jacks. Surprisingly, the slab did not break when lifted clear of the soil - no stones just poured on the dirt so yeah the bottom was uneven (and I would doubt there was any rebar or wire in it). When I moved it I put it on a bed of sand hoping that would be soft enough to be stable. It worked for well enough for a tool shed. I took the structure (in tact) off the slab before moving. Lots of one foot 3" dia pvc pieces for rollers on boards worked for the shed and then the slab. BTW if you make a large airbag out of duct tape and plastic sheet or tarps and inflate it with a leaf blower you can lift the slab off the supports so you can rearrange them. I did this move by myself, so it took a while. Probably should have paid to have the old one broken up and poured a new one properly - but just so you know it can be done.