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. He exhibited his invention at the Paris Exposition of 1867. Besides his pots and Tubs, Joseph Monier promoted reinforced concrete for use in railway ties, pipes, floors, arches, and bridges.


 * 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.


 *  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.

   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 