Which material is known for high compressive strength with relatively low tensile strength and is often reinforced to improve tensile capacity?

• A. Cast in Place
• B. Pre-Cast
• C. Concrete
• D. Spalling

Answer: (C)

Concrete is renowned for its high compressive strength, meaning it resists crushing loads very well. But its tensile strength—the ability to resist being pulled apart—is relatively low, so it cracks under tension or bending. To handle those tensile forces, engineers reinforce concrete with materials like steel bars or fibers, creating reinforced concrete. The reinforcement takes the tensile stresses while the concrete takes the compression, giving a strong, durable composite used in most structures. Spalling isn’t a material; it’s a failure phenomenon where surface material flakes off under certain conditions. Cast-in-place and pre-cast describe how concrete components are manufactured or installed, but the fundamental property here is the concrete’s need for reinforcement to boost tensile capacity.