Can new concrete be poured on top of existing concrete patio?

yes you can . Just ensure you have beat the sides of the forms with the broad side of a hammer to get the concrete down into any cracks.

And be sure the new patio floor is level all over, since the old patio has probably shifted and settled some. 😇

No! New concrete will not adhere to old concrete. It will just float on top. The old concrete will absorb the moisture from the new and it will fail. Any movement of the old concrete will transfer to the new. If your just resurfacing the old you need to use a latex modified concrete resurfacing compound which can be up to a maximum of 1/2" thick.

No. Won't stick. You need a new slab.

Short answer... yes. Long answer... Read CAREFULLY the instructions listed on the container of "Muriatic Acid" Other than a ph controller for your swimming pool it's used for cleaning and etching concrete,

It can work, but also has a very good likely hood of cracking. My fathers monument foundation was poured to small. They company tried to cap it. It cracked very badly. They had to remove it and start again. Seeing this and the problems it caused I would be consulting a concrete company or figuring doing some hard research with experts.

Good luck!

I recently had a foot-thick patio removed because the same thing was done at my house. The cracks in the original patio telegraphed through the new slab. If cracking is the reason for pouring a new slab the extra expense to remove the original and properly prepare the base with tamped crushed stone is a good investment.