Concrete surfaces cannot be repaired with concrete. Use a concrete repair mix instead; these are available at home centers and online. Options include epoxy compounds, latex patch material, and mortar mixes. The latter option works best for filling large cracks (or chipped edges), while the other products are suitable for concrete cracks -inch wide or narrower.
Narrow cracks in concrete can be filled with an elastomeric filler for masonry cracks that can be applied with a caulking gun. Alternatively, many products come in applicator tip bottles. Very small cracks, such as fine cracks, can be repaired with a vinyl concrete patch compound applied over the crack and then smoothed with a spatula or trowel. For fine cracks, applying repair putty or crack filling over cracks is generally not effective, as the putty tends to peel off the surface over time.
To fill narrow cracks in concrete 1/8 inch wide or less, use an epoxy compound or latex-based formulation to seal each crack. For larger cracks or chipped concrete edges, mortar mixes are the best choice, as they fill and seal cracks. If your driveway, patio, or other concrete surface has cracks, they can often be repaired. In some cases, repairing cracks in concrete may be a simple DIY project, in others it may require a professional concrete contractor to correct the damage, and in the most extreme cases, the concrete may need to be removed and replaced.
Cracks in concrete are caused by lateral expansion, poor drainage conditions, or sedimentation of the soil beneath the concrete. I'm going to take a chance and assume that most of you have a broom and a concrete crack filler (LOL, just kidding). Add water to the repaver mix to get the consistency of the pancake batter for filling concrete cracks. It is possible that the subgrade has compacted and the concrete has been subjected to extreme weight, causing the concrete to sag.
I made my crack in the driveway as you should with a rear road and a thick layer of quickrete concrete repair filler and from the surface it looks great but it is flexible after 24 hours and when pushed on wet compounds it leaks out.
