Which material is strong and durable and used for buildings, bridges, roads, dams, and kerbs?

• A. Concrete
• B. Carbon fibre
• C. Smart materials
• D. Advanced metal alloys

Answer: (A)

Concrete is the material that fits these roles because it is a cement-based composite designed for mass structural elements. It can be formed into large shapes for buildings, bridges, roads, dams, and kerbs, and its high compressive strength lets it bear heavy loads. When reinforced with steel, it also resists tensile stresses, which is crucial in bridges and similar structures. It remains durable under weathering and abrasion and is cost-effective, contributing to long service life with relatively straightforward construction and maintenance.

Carbon fibre is extremely strong for its weight but costly and not economical for large-area infrastructure like roads or dam bodies. Smart materials are designed to react to stimuli and are used for sensing or actuation rather than as the primary load-bearing material for vast infrastructure. Advanced metal alloys can be strong but are expensive and less practical for broad surfaces like roads and kerbs, where a cheaper, abundant material is preferred.

So, concrete best fits the described uses.