CONCRETE


 * DEFINITIONS**


 * 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 strengt.


 * Reinforced concrete** was developed to add the tensile strength of steel to the compressive strength of mass concrete, which means concrete with steel bars, mesh, etc., embedded in it to enable it to withstand tensile and shear stresses.


 * Concrete shell **also commonly called //thin shell concrete structure//, is a structure composed of a relatively thin shell of concrete, usually with no interior columns or exterior buttresses. The shells are most commonly flat plates anddomes, but may also take the form of ellipsoids or cylindrical sections, or some combination thereof.

**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 lifted into place.


 * Prestressed concrete ** is a method for overcoming concrete's natural weakness in tension. It can be used to produce beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. Prestressing can be accomplished in three ways: pre-tensioned concrete, and bonded or unbonded post-tensioned concrete

REINFORCED CONCRETE



PRECAST CONCRETE



•  PRESTRESSED CONCRETE

CONCRETE SHELL

=Precast Concrete, Tilt-up Construction and Tiltwall =

 The basic differences between these terms are based on the place of execution of the concrete. Sometimes, the weather can complicated the construction, so there are two ways to built. At first, Tilt-up and tiltwall which are two terms used to described the same process allow to tilt-up concrete buildings, it means the walls are created by assembling forms and pouring large slabs of concrete directly at the job site. In the other hand is the precast concrete building process which is similar to tilt-up construction, but it addresses the challenges presented by weather. For precast concrete buildings, work crews do not set up forms at the job site to create the panels, but at a large manufacturing facility. Because the precast concrete forms are poured indoors, this activity can take place regardless the weather conditions. After curing, the precast concrete panels are trucked to the job site. From this point, precast concrete buildings are assembled in much the same manner as tiltwall buildings. The fact that precast concrete walls are formed at a manufacturing facility resolves the weather issue, but presents a different limitation not found in tilt-up construction. Because the panels must be transported places a substantial limitation on how wide or tall each panel can be.  Both process have their advantages and disadvantages, but the most important is that precast concrete is a perfect choice in bad enviromental circumstances but it has to be transported sometimes over long distances, in contrast to the tilt-up process, which is the opposite. 

**GLOSSARY **
 * HARDEN: to make hard or harder. To make resistant to hardship, especially through continued exposure.
 * STONELIKE: (of bone especially the temporal bone) resembling stone in hardness.
 * COMPRESSIVE: compressing or having the power or capacity to compress.
 * TENSILE STRENGTH: the resistance of a material to a force tending to tear it apart, measured as the maximum tension the material can withstand without tearing.
 * POURED: To pass or proceed in large numbers or quantity.
 * FUSE: A cord of readily combustible material that is lighted at one end to carry a flame along its length to detonate an explosive at the other end.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;">SPRING: An elastic device, such as a coil of wire, that regains its original shape after being compressed or extended.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;">DECK: <span style="font-family: Arial,sans-serif; font-size: 9.5pt;">A platform extending horizontally from one side of a ship to the other. A platform or surface likened to a ship's deck. A roofless, floored structure, typically with a railing, that adjoins a house. The roadway of a bridge or an elevated freeway.
 * <span style="font-family: Arial,sans-serif; font-size: 9.5pt;">STRESS: <span style="background-color: white; font-family: Arial,sans-serif; font-size: 9.5pt;">The force per unit area applied to an object. Objects subject to stress tend to become distorted or deformed.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 9.5pt;">SEWERAGE:the removal of surface water or sewage by means of sewers.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 9.5pt;">BEAM: A squared-off log or a large, oblong piece of timber, metal, or stone used especially as a horizontal support in construction.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 9.5pt;">PIPE: A hollow cylinder or tube used to conduct a liquid, gas, or finely divided solid.
 * MESH: An openwork fabric or structure.
 * SLAB: An outside piece cut from a log when squaring it for lumber.