We are losing our country all around us yet you are posting a vanity about losing your stupid concrete driveway. Yeah. Like timing is everything.
Concrete does not bond well with itself. Add a primer layer before adding any more concrete.
I think you’ll want to use something like Polymer Modified Structural Repair concrete for that.
You should have filled the hole first with dead commies, and you probably would have needed less concrete.
Let the bonding agent become tacky and I would recommend drilling some 1/2×1” deep holes in existing for better bond. Use a masonry bit.
You should have made a youtube video showing how to screwup a screwed up driveway. You could have made a fortune!
Follow the instructions.
The recommendation to drill holes is good as well.
Do that before you apply the adhesive. (which I'm pretty sure you could figure out buuuut...just to be safe...LOL)(don't leave it puddled up in the hole)
Quikrete answers: concrete over concrete application tips @WOC2016
when is concrete dry
The general rule of thumb is that concrete takes about 30 days to dry for every one inch of slab thickness.
anything you do short of tearing out and replacing the slab is a crap shoot... good luck...
Just wet the spot you are going over and put down your top coat. It will stick. Sometimes if you only have 1/2 inch to work with don’t use rocks. Use mortar, thinset or portland and sand adjust as necessary.
When for example someone tiles a concrete floor, they don’t do an special prep except sweep.
You are working against all the laws of good concrete work. Thin cold joints are not optimal long term patches, they tend to crack under weight.
Use thinset.
If it were my driveway, I’d take a hammer and chisel and make the layer you need to add at least 3 inches. Paint the bonding agent on. Then I’d drill some holes for rebar, 1/2” rebar should do. Then pound the rebar in the four corners, making sure that the rebar does not come within an inch of the top of the hole. cut small pieces of rebar to make a grid in the patch, wire them together, and pour away.
If you wanted to really do it right, chisel out all the previous concrete, and re-pour using enough to this time, to reach the surface. Some people like to use hydraulic cement for hole patching, as hydraulic cement expands as it dries, whereas normal concrete shrinks.
Dig it all up. Go down about 8 feet by 8 feet wide, fill with corrupt Democrats and one Ga SOS Rino, cover with Quikrete until you fill the damned hole and everyone in it.
Then paint BLM letters on it and no one will dare touch it.
/SARC - Welcome to the Rotten Peace State, rotten to the pit.
Read the instructions on the bags. Regular Sakrete is good for a MINIMUM 2” thick application. You will need, as an earlier poster said, a mix intended for thinner applications. Make sure surface of concrete is clean, bonding agent applied per directions, and proper mix used for a thin (as you described 1/2” to 1”.
Sakrete has a website with characteristics of their different mixes, and something you should have used first, a concrete calculator. This is just a volume calculator, but gives the answer in the number of bags you need.
Keep it simple.
It reads as though your driveway is Portland Concrete, not Asphalt Concrete.
Doesn’t sound as though you have any need of rebar.
Don’t piddle with drilling holes less than about 2”-4” dia and for that size of patch, they won’t matter anyways.
The only concern is placing a shallow patch say less than 2x the size of your aggregate (gravel) in depth, the layer you are placing will tend to crack up and spall out. Also the surface on which you place the concrete just needs to be rough, like jagged gravel. That is all the concrete is adhering with anyways.
No problem if it rains, but if it freezes,then could cause some problems. Could mix some salt in with the water to reduce the freezing point. Salt isn;t good on rebar, but generally for a driveway, placed over the earth, you really don’t need any rebar or wire mesh anyways.
Concrete strength is important. Sackrete will tend to give you say 2000-2500 psi concrete, where institutionally we prefer 3000 psi default, and better policy of 4000 psi even for sidewalks if people drive their vehicles over it, to reduce chances of cracking.
Since you patch material is different in strength than the driveway, just plan on it cracking and perhaps spalling if less than 2” deep.
Simple solution, use an old hammer and rough up the surface of the patch, place the new patch so it is 2” deep, and when it cracks and spalls out over the next couple of years, replace with enough concrete all in one placement to lessen chances of spalling. You probably don’t want to bang on the existing patch too much as it will just become gravel, or if you do, then just remix and patch the whole thing.
Try to use a concrete similar in strength and expansion properties to the adjacent concrete.
Nothing wrong with just patching it with the new stuff and see if it lasts. If it doesn’t, just bang on it till it becomes gravel and remix a new batch of concrete and replace the patch, say over 2” thick.
There are lots of specialty concrete mixtures out there. I wouldn’t waste the time or effort or $$ on it. Use angular sand and gravel, for your cosmetic application, 1/2” aggregate is fine. 3/4” gravel has more strength, but your patch doesn’t sound large enough to worry about the difference.
You can probably get by with some gravel in the hole, unless you want cosmetic appearance to improve.
I found that link by doing this Google search => how to patch concrete driveway
LOTS of good ideas come up that I never would've dreamed possible, including the one having to do with the product Sakrete, which I'm not pushing one way or another.
Instead of searching on "patching concrete," you could search on "filling potholes in concrete," which may let you drill down to a more focused set of possible solutions for your paticular problem. Or, try some other search term you think is even more likely to lead you to the answer you're looking for.
All I'm saying is don't neglect "asking" a much larger group of experts than you'll find on FR which, as good as they are, may not be the best group to ask (and nobody will criticize you for NOT clutching your pearls 24/7 over the "end of the world"). Cheers and Good Luck!
This is a hard subject....
DIY guy for 50 years. IMHO you will not get the second pour to adhere to the first in a secure manner. Especially if vehicles drive on it. water infiltration will be an issue also. If it freezes in your area it will lift.