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Concrete has been used since ancient times. Regular Roman concrete for example was made from volcanic ash , and hydrated lime. Roman concrete was superior to other concrete recipes (for example, those consisting of only sand and lime) [1] used by other cultures. Besides volcanic ash for making regular Roman concrete, brick dust can also be used.
Concrete is sometimes used as a fire protection for steel frames, for the same effect as above. Concrete as a fire shield, for example Fondu fyre, can also be used in extreme environments like a missile launch pad. Options for non-combustible construction include floors, ceilings and roofs made of cast-in-place and hollow-core precast concrete.
Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site and maneuvered into place; examples include precast beams, and wall panels, floors, roofs, and piles.
As concrete transforms from its plastic state, hydrating to a solid, the material undergoes shrinkage. Plastic shrinkage cracks can occur soon after placement but if the evaporation rate is high they often can actually occur during finishing operations, for example in hot weather or a breezy day.
The most common use for portland cement is in the production of concrete. [17] Concrete is a composite material consisting of aggregate (gravel and sand), cement, and water. As a construction material, concrete can be cast in almost any shape desired, and once hardened, can become a structural (load bearing) element.
Cement block construction examples from the Multiplex Manufacturing Company of Toledo, Ohio, in 1905 A cement is a binder , a chemical substance used for construction that sets , hardens, and adheres to other materials to bind them together.
Self-consolidating concrete or self-compacting concrete (SCC) [1] is a concrete mix which has a low yield stress, high deformability, good segregation resistance (prevents separation of particles in the mix), and moderate viscosity (necessary to ensure uniform suspension of solid particles during transportation, placement (without external compaction), and thereafter until the concrete sets).
Mass concrete is defined by American Concrete Institute Committee 207 as "any volume of concrete with dimensions large enough to require that measures be taken to cope with the generation of heat from the hydration of cement and attendant volume change to minimize cracking."