There are cracks on my driveway and backyard concrete. Is there a way to fix them without having to tear down the old concrete? What cost?

Follow the following steps:

1.Make your cracked surface clean so that it becomes ready to bond with the repair materials.

2.Start with breaking off any loose pieces of concrete.

3.Use a firm wired brush to remove any remaining debris.

4.Remove loose debris from within the cracks if possible.

After all those steps, follow these for repairing driveway cracks:

1.Consider any of the good ways to fix small concrete cracks viz. textured caulk, concrete sealer or pourable grout designed for repairing concrete.

2.With all the products, completely fill the cracks and use a pointing trowel to push the grout or sealer into the cracks.

3.You can refer to specific product manufacturer guidelines for application instructions.

Get a bag of quick drying ready-mixed concrete from a hardware store, add just enough water for the right consistency and fill the cracks. It will stay until freeze/thaw starts to break it down.

Ultimately the concrete must be relaid properly.

Bolted is correct....No matter what you do short of replacement, the cracks will remain and probably get worst. Freeze /Thaw, if you live in that climate will cause cracking and tree roots, if the slab was not properly, steel reinforced. You can put a bandaid on the cracks with more quickcrete or epoxy but the fix is in replacement.

The main reason it may crack again is if you have any nearby tree's, as these trees grow the roots gets so huge andit causes driveways to crack! And that my friend, is the culprit. Cut the trees down first. It will take time for the roots to deteriorate and your driveway will lay back down. Then recoat.

You can buy premixed concrete repair material. It's epoxy based and fairly expensive but you only do the job once. See link for UK example.

Piss in the cracks it will soften the concrete so you can smooth it out.