Does concrete adhere to old concrete?
Then, does mortar stick to concrete?
Concrete, mortar or similar materials are not designed to stick or bond to old surfaces. You will not get any satisfactory results if you simply add new mortar to old. It just doesn't work. Using a modified thinset mortar would be the preferred method for this type of installation.
Beside above, can you pour a thin layer of concrete over existing concrete? Yes, you may pour a concrete pad overlay over an existing slab. You need to consider the added height and weight of the overlay on the existing structure. Overlays may include polymers, portland cement concrete, or epoxies. You should improve the drainage of the slab by having a good slope on the overlay.
Similarly one may ask, can you pour new concrete over existing concrete?
Placing New Concrete Over Old. If done properly, new concrete can often be poured right over an existing slab. For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete.
Does concrete resurfacer really work?
Concrete resurfacer is a very strong product, rated for a compressive strength of about 4,500 psi. This is actually stronger than the slab itself, so properly applied, resurfacing layers can be very durable.