Cracks in concrete are typically caused by subgrade failure. Some will say pour consolidation or inadequate curing methods. Either way you have two simple choices. You can break it out, replace with new concrete or apply a resin/hardener mix called Epoxy. A product I have used with great success is Crack Bond LR-321 by Adhesive Technologies.
Crack-Kit is for the small job, 8 to 10 LF based on 8" thick concrete. For the larger projects look at purchasing the 16 oz tubes, individual ports, nozzles and Miracle Bond past.
Crack Injection Video
Keys to Success:
- Clean surface
- PPE; i.e. safety glasses, gloves, ear plugs, dust mask and knee pads
- The RIGHT tools
- Hepa Filter Vac
- Battery Caulk Gun
- Wire Brush
- Compressed Air
Allow three days for scope of work.
Day One: Prep and Paste
Day Two: Inject and cap ports
Day Three: Break off ports and grind surface smooth