Sometimes conventional reinforcement isn't enough. The basics of prestressed concrete. Prestressing reinforcement doesn't necessarily make concrete stronger. But, it does increase the serviceability of concrete members by reducing the amount of deflection under load. This video explains the two most common types of prestressed concrete: pre-tensioned and post-tensioned. Prestressed concrete is used in all kinds of structures from bridges to buildings to silos and tanks. It’s a great way to minimize cracking and take fuller advantage of the incredible strength of reinforced concrete.
This video shows more destructive testing to answer your questions about concrete. Concrete's greatest weakness is its tensile strength, which can be less than 10% of its compressive strength. So, we often reinforce it to create a composite material strong against all types of stress. This video briefly touches on conventional rebar and prestressed/post-tensioned reinforcement.