Repairing concrete walkways can be a big project if the walkway has a lot of damage. If not, the process could go quickly. An assistant can help the whole project go much smoother. Concrete walkways typically begin to deteriorate when subjected to standing water or de-icing salts. Such salts are usually a necessary evil, but you can minimise the damage they cause by rinsing the residue off of your concrete walkways.
Build a boundary along the sidewalk by placing the 2x4 boards along the edges. Press the boards up against the sidewalk edge and hammer metal or wooden stakes into the ground to secure the boards. This will keep the boards from slipping while you are working with the concrete.
Examine your existing concrete walkway. Find and remove broken or chipped pieces of concrete. Leaving chipped and broken concrete in the sidewalk area will result in the repair being substandard and help the new concrete deteriorate much faster. The holes left by broken or chipped pieces of concrete being removed will be filled later in the process.
Sweep the concrete sidewalk completely to remove all dirt and debris. Then mop the sidewalk thoroughly. Make sure the sidewalk is dry before continuing. If you continue before the concrete is dry, then the water will have nowhere to go when it tries to evaporate.
Spread a generous layer of acrylic block fill primer over the existing concrete walkway with a paintbrush. Your assistant should smooth the primer into the pores of the concrete by spreading it with a paint roller immediately after you apply the primer. Let the acrylic block fill primer dry, which should take about 2 or 3 hours. You'll need to check the manufacturer's directions to be certain, however.
Combine the concrete according to the manufacturer's instructions in small batches in a bucket.
Pour the concrete over the existing sidewalk, making sure you stay inside the boundary boards. Work from one end of the sidewalk to the other end. Add extra concrete in places where you had to remove broken or chipped concrete, so that the holes will be filled. As you pour, the concrete will flow and level, so pour slowly and steadily until you reach a depth of about ½ an inch over the whole sidewalk.
Allow 3 days for the concrete to cure completely before walking on it. Rinse the walkway off with a water hose to remove any debris that may have accumulated during the waiting period.