What are the common causes and effective solutions for repairing cement cracks?

Common causes of cement cracks include shrinkage, settlement, and external factors like temperature changes or heavy loads. Effective solutions for repairing cement cracks include filling them with epoxy or polyurethane sealants, using cementitious patching compounds, or applying overlays to strengthen the surface. Proper preparation of the crack and choosing the right repair method are crucial for a successful repair.