Concrete

Concrete is a composite construction material in which cementitious paste binds particles of aggregate. It hardens through chemical reactions and can be shaped before setting.

Aggregate: Aggregate is granular material, such as sand or crushed stone, used in construction mixtures. Coarse and fine aggregate make up most of concrete’s volume.
Cement hydration: Cement hydration is the set of chemical reactions between cement compounds and water that form solid hydration products. Hydration creates the binding structure that hardens concrete.
Prestressed concrete: Prestressed concrete is concrete in which steel tendons introduce compressive forces before or during service. Precompression helps concrete span longer distances and resist cracking.
Mortar (masonry): Mortar is a workable mixture of binder, water, and fine aggregate used to bond masonry units or coat surfaces. Unlike typical concrete, mortar generally lacks coarse aggregate.
Cement industry: The cement industry produces cement and related materials for construction. Concrete demand makes cement production a major upstream industrial activity.
Water–cement ratio: The water–cement ratio is the mass of mixing water divided by the mass of cement in a concrete mixture. This ratio strongly influences concrete’s porosity and strength.
Curing (concrete): Curing is the practice of maintaining suitable moisture and temperature conditions while concrete gains strength. Early moisture loss can interrupt hydration and weaken the surface.
Shotcrete: Shotcrete is concrete or mortar conveyed through a hose and pneumatically projected onto a surface. Spraying allows concrete placement on tunnels, slopes, and complex forms.
Asphalt concrete: Asphalt concrete is a paving mixture in which bitumen binds mineral aggregate. Its bituminous binder differs from concrete’s cementitious paste.
Carbon dioxide emissions: Carbon dioxide emissions are releases of carbon dioxide into the atmosphere from natural or human activities. Cement production and concrete’s supply chain contribute substantial emissions.

Linked from 28 pages