Concrete

=Concrete=

====Concrete :  **Concrete** is a manufactured mixture of cement and water, with aggregates of sand and stones, which **hardens** rapidly by chemical combination to a **stonelike**, **water-and-fire-resisting** solid of great **compressive** but low **tensile strength**. ==== ===Reinforced Concrete: was developed to add the tensile strength of steel to the compressive strength of mass concrete. It was invented (1849) by Joseph Monier, who received a patent in 1867. The metal is embedded by being set as a **mesh** into the forms before pouring, and in the hardened material the two act uniformly. The combination is much more versatile than either product; it serves not only for constructing rigid frames but also for foundations, columns, walls, floors, and a **limitless** variety of coverings, and it does not require the addition of other structural materials. The Falling-water house, by Frank Lloyd Right is made using Reinforced concrete ===

Concrete-shell construction: permits the erection of vast vaults and domes with a concrete and steel content so reduced that the thickness is comparatively less than that of an eggshell.

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Centre of New Industries and Technologies in Paris. Its architects were [|Robert Edouard Camelot], [|Jean de Mailly], [|Bernard Zehrfuss] accompanied by the engineer [|Jean Prouvé] for the exterior.=====

 Precast-concrete construction : employs bricks, slabs, and supports made under optimal factory conditions to increase waterproofing and solidity, to decrease time and cost in erection, and to reduce expansion and contractions.



Prestressed concrete:provides bearing members into which reinforcement is set under tension to produce a live force to resist a particular load. Since the member acts like a **spring**, it can carry a greater load than an unstressed member of the same size.