Betons

Betons, the term used in several languages for the construction material commonly known as concrete, is a composite made from a cementitious binder, aggregates (sand and gravel), and water that hardens through chemical hydration. Portland cement is the most common binder, and admixtures may be added to adjust workability, setting time, durability, or other properties.

Production and curing involve mixing the components to form a workable slurry, placing and compacting the material, and curing to retain moisture during the early hydration period. Hydration is exothermic and gradually develops strength over time, with concrete typically reaching most of its specified 28-day strength under proper curing.

Key properties include high compressive strength and good durability, but relatively low tensile strength. To carry tensile loads, concrete is often reinforced with steel (reinforced concrete). Variants include prestressed concrete, where reinforcement is pre-tensioned or post-tensioned to improve performance. Other characteristics are density, modulus of elasticity, thermal mass, fire resistance, and resistance to environmental exposure.

Common types encompass normal-weight concrete, lightweight concrete (using lighter aggregates), high-strength or high-performance concrete, self-compacting concrete, and fiber-reinforced concrete. Applications are broad, including buildings, bridges, pavements, dams, and marine structures, reflecting concrete’s versatility and relatively low material cost.

Environmental considerations focus on the energy-intensive production of cement and associated CO2 emissions. Mitigation strategies include using supplementary cementitious materials (e.g., fly ash, slag), recycled aggregates, alternative binders, longer service life, and methods for crushing and reusing demolished concrete. Historically, concrete has ancient roots and remains central to modern construction.