béton

Béton, or concrete, is a composite construction material produced by mixing a cementitious binder with aggregates and water. After placement, the paste hydrates and hardens, binding the aggregates into a solid mass.

The most common binder is Portland cement. Aggregates typically include gravel or crushed stone (coarse) and sand (fine). Water initiates hydration. Admixtures can modify workability, setting time, and durability. Supplementary cementitious materials such as fly ash, slag, or silica fume may replace part of the cement to improve performance and reduce cement content.

Concrete varieties include normal weight and lightweight forms; reinforced concrete (béton armé) uses steel reinforcement to resist tensile stresses; prestressed concrete (béton précontraint) uses pre-tensioning or post-tensioning to improve performance. Other types include high-strength and high-performance concretes, as well as air-entrained or self-compacting variants.

Manufacture and curing involve batching, mixing, transporting, placing, compaction, and curing. Proper curing, including maintaining moisture and suitable temperature, is essential to develop strength and minimize cracking. Methods include water curing, curing compounds, or sealed environments.

Applications and history: Béton is the primary material in modern infrastructure, used in buildings, bridges, roads, dams, and foundations. The ancient Romans used hydraulic lime-based concretes; modern Portland cement was developed in the 19th century. Environmental considerations focus on reducing cement-related CO2 emissions, using supplementary cementitious materials, and recycling concrete as aggregates to extend service life and lower impacts.