Concrete

== 1.- According to the text c oncrete 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 resistingsolid of great compressivebut low tensile strength. == ==2.- T ilt-up panel construction, tiltwall construction, precast concrete building construction are terms used for cement building processes. Tilt-up and tiltwall are two terms used to describe the same process. For a tilt-up concrete building, the walls are created by assembling forms and pouring large slabs of concrete called panels directly at the job site. Tiltwall panels can sometimes be extremely wide and/or tall. Tilt-up panel have been measured at just over 69 feet across and almost 93 feet from top to bottom.== ==The precast concrete building process is similar to tilt-up construction, work crews don't set up forms at the job site to create the panels. Instead, workers pre cast concrete panels at a large manufacturing facility. Because the precast concrete forms are poured indoors, this activity can take place regardless the weather conditions.==

=Conclusions= ==Concrete is a very durable and cheap construction material. It was employed in ancient Egypt, and after that concrete have be changing by the time. Thanks to this procedure, the concrete is transformed into a mass that can be molded easily. Over time, this material loses its plasticity becoming completely harden. However turns out to be the ideal material for outdoor work this is the element that gives strength to our homes, streets and many places in which we conduct our lives. ==