Concrete

**Reinforced concrete:** It was developed to add the tensile strength of steel to the compressive strength of mass concrete. It was invented in 1849 by Joseph Monier. He promoted reinforced concrete for use in railway ties, pipes, floors, arches, and bridges. **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.
 * Concrete:** Is a manufactured mixture of cement and water, with aggregates of sand and stones, which hardens rapidly by chemical combination to a stone-like, water-and-fire-resisting solid of great compressive but low tensile strength.

**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.


 * What is the difference between tiltwall construction, tilt-up panel construction and pre-cast concrete construction? **

Tilt-up affords more flexibility; it is the method of choice in locations where the weather allows it, while precast concrete is a suitable choice in circumstances where environmental factors and the construction schedule preclude tiltwall as a viable option.

The environmental impact of concrete is a complex mixture of not entirely negative effects; while concrete is a major contributor to greenhouse gas emissions, recycling of concrete is increasingly common in structures that have reached the end of their life. Structures made of concrete can have a long service life. As concrete has a high thermal mass and very low permeability, it can make for energy efficient housing.