Concrete is a durable and long-lasting material, but it is not immune to damage. The most significant factor that damages concrete is the corrosion of reinforcing steel and other embedded metals. When steel corrodes, it expands and creates tensile stresses in the concrete, leading to cracking, delamination, and spalling. Corrosion can be caused by exposure to moisture, salt, and other chemicals that penetrate the concrete and attack the steel. Preventative measures such as protective coatings and proper maintenance can help minimize the damage caused by corrosion.