Plain cement concrete (PCC):

• Very high compressive strength (~20–50 MPa for standard mixes)
• Very low tensile strength (~1/10th of compressive = 2–5 MPa)
• This is why steel reinforcement is added (RCC) — steel handles tension, concrete handles compression.

Structural steel has high strength in both tension and compression. Timber has moderate strength in both. RCC is a composite with improved tensile properties.

Among single materials, PCC best demonstrates this extreme disparity.