Repairing large cracks in concrete

First, you must chisel along the crack to widen the bottom, not the top because undercutting helps bonding. Clean the debris with water from your hose and let it dry. Keep the concrete moist. Wear safety goggles as you clean out loose pebbles or chunks. Use a trowel, screwdriver or wire brush for this. Mix water for your concrete patch and stir consistently. Not too runny or thick, but make it pliable. Estimate just the right amount that you will need. Place it in a bucket, or in a disposable plastic container. For better bonding, add a concrete adhesive. This can be brushed on, and let it dry afterwards until tacky. Make sure that the crack is moist if you have decided not to use adhesive. Apply the mix into the crack by using a putty knife or a trowel. Smooth out any excess mix by running your trowel into it. After two hours, you may cover the repaired area with a board or plastic. Keep it covered for several days. Don’t forget to clean your tools after repairing. Remove the cover daily and lightly water the new concrete for this will improve its condition.