Concrete

**Reinforced concrete : ** is concrete in which reinforcement bars (" rebars "), reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension . 
 * Concrete : **is acomposite construction material, composed primarily of aggregate, cement and water. There are many formulations that have varied properties. The aggregate is generally coarse gravel or crushed rocks such as limestone or granite<span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, along with a fine aggregate such as sand<span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">. <span style="font-family: Arial,sans-serif; font-size: 10pt;">Concrete is widely used for making architectural estructures<span style="font-family: Arial,sans-serif;">, foundations,<span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;"> brick/block <span style="font-family: Arial,sans-serif; font-size: 10pt;">walls, pavements <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, bridges/overpasses, motorways/roads, runways, parking <span style="font-family: Arial,sans-serif; font-size: 10pt;">structures, dams<span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, pools/reservoirs, pipes, footings <span style="font-family: Arial,sans-serif; font-size: 10pt;">for gates, fences <span style="font-family: Arial,sans-serif; font-size: 10pt;">and poles <span style="font-family: Arial,sans-serif; font-size: 10pt;">and even boats <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">.

**<span style="font-family: Arial,sans-serif; font-size: 10pt;">Concrete shell **<span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">: also commonly called <span style="font-family: Arial,sans-serif; font-size: 10pt;">// thin shell concrete structure // <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, is a structure composed of a relatively thin shell of concrete <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, usually with no interior columns <span style="font-family: Arial,sans-serif; font-size: 10pt;">or exterior buttresses <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">. The shells are most com <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">monly flat plates and domes <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, but may also take the form of ellipsoids <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">or cylindrical <span style="font-family: Arial,sans-serif; font-size: 10pt;">sections, or some combination thereof. The first concrete shell dates back to the 2nd century. **<span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;">Precast concrete <span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">: **<span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;"> is a <span style="font-family: Arial,sans-serif; font-size: 10pt;">construction product produced by casting concrete in a reusable mold <span style="font-family: Arial,sans-serif; font-size: 10pt;">or "form" which is then cured in a controlled environment, transported to the construction site and lifted into place. In contrast, standard concrete <span style="font-family: Arial,sans-serif; font-size: 10pt;">is poured into site-specific forms and cured on site. ** Precast stone ** is distinguished from precast concrete by using a fine aggregate <span style="font-family: Arial,sans-serif; font-size: 10pt;">in the mixture, so the final product approaches the appearance of naturally occurring rock or stone. <span style="font-family: Arial,sans-serif; font-size: 10pt; line-height: 0px; overflow-x: hidden; overflow-y: hidden;"> **<span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;">DIFFERENCE BETWEEN TILT-WALL CONSTRUCTION, TILT-UP PANEL CONSTRUCTION AND PRECAST CONCRETE CONSTRUCTION. ** <span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;">Tilt-up and tilt-wall are basically the same process. A tilt-up concrete building has walls created assembling forms and pouring panels of concrete called directly at the construction site. The panels are then tilted up (as the name says) into position to form the walls according to the plans for the building. The precast concrete building is a process similar to tilt-up construction, but it can suffer changes depending to the weather. For precast concrete, work crews don´t set up forms at the job site to create the panels, the panels are made in a fabric or other environments, because they has to be poured into a mold and cured to be transported to the construction place latter. And they’re assembled just like tilt-up panels. <span style="font-family: Arial,sans-serif; font-size: 10pt;">Finally we can say that tilt-up concrete construction and precast concrete are similar processes. But when can we use each one will depend of the weather. And the other important difference between them is that the panels made of tilt-up concrete can be created and assembled directly at the construction site and the panels of precast concrete are made in a fabric and then transported to the construction site.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 10pt;"> Prestressed ****<span style="font-family: Arial,sans-serif; font-size: 10pt;">concrete <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">: **<span style="font-family: Arial,sans-serif; font-size: 10pt;"> is a method for overcoming concrete <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">'s natural weakness in tension <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">. It can be used to produce beams <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">, floors <span style="font-family: Arial,sans-serif; font-size: 10pt;">or bridges <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">with a longer span <span style="font-family: Arial,sans-serif; font-size: 10pt;">than is practical with ordinary reinforced concrete <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">. <span style="font-family: Arial,sans-serif; font-size: 10pt; text-align: -webkit-auto;">[[image:prestressed-concrete-t-beam-126833.jpg]]