Options for filling cracks in concrete depend on the width of the crack, but it is possible to fill narrow cracks using masonry crack filler. This material comes in a tube the manufacturer designs for use in a caulking gun. For wider cracks, vinyl concrete patching material is an option.
Before filling the cracks, the repairman should remove any loose material from the opening, using a wire brush and a broom. Proper preparation is essential to ensure the material bonds to the existing concrete. He then places the cartridge of crack filler into a caulking gun, cuts the tip of the cartridge to the appropriate size, and punctures the inner seal. He uses the caulking gun to disperse the filler into the crack.
Larger cracks require more preparation to ensure the patch remains in place. The process begins by using a hammer and chisel to undercut the crack so the base of the patch inside the existing concrete is wider than the top of the opening. This prevents the patching material from falling out of the crack. The user mixes the vinyl patching material according to the manufacturer's directions and applies it to the opening. He smoothes it with a trowel and uses a brush to match the finish to the existing material.