Reinforced concrete is a composite material in which concrete’s relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength and/or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars and is usually embedded passively in the concrete before it sets.
For a strong, ductile and durable construction the reinforcement needs to have the following properties at least:
• High relative strength
• High toleration of tensile strain
• Good bond to the concrete, irrespective of pH, moisture, and similar factors
• Thermal compatibility, not causing unacceptable stresses in response to changing temperatures.
• Durability in the concrete environment, irrespective of corrosion or sustained stress for example.
