To repair concrete driveway cracks, clean the crack, fill the crack using textured caulk or pourable grout, and allow it to dry. After the crack is repaired, apply a concrete sealer to help keep water out and prevent future cracks.
Before filling in the crack, clean it to ensure the repair material creates a good seal. Remove any loose pieces of concrete, using a screwdriver or chisel if necessary. Brush the crack with a wire brush, and remove any small particles. Use an air compressor, shop vacuum or small can of compressed air to thoroughly clean any remaining pieces from the crack.
Fill smaller cracks with textured caulk, concrete sealer or pourable grout. Wet the crack with a small spray bottle of water if using the sealer or grout, but apply the caulk to a dry crack. Use a trowel to fully fill the crack, and if using caulk, overfill by a small amount to allow for shrinking as it dries.
Fill larger cracks with sand until the depth of the crack is 1/4 inch, or apply layers of pourable grout or vinyl patch material in 1/4-inch increments, and allow to dry between applications. Smooth out the repair material with a trowel to create a good seal with the surrounding concrete. To help prevent future cracks due to water damage, apply a concrete sealer.