Concrete

__ Concrete __



Concrete is a mixture of cement, water and some aggregates of sand and stones that hardens rapidly by chemical combination to a stone-like, water and fire resistance solid. Great compressive but low tensile strength. It can fit in different forms (depending of the mold) while it is liquid and this way produce a wide variety of structural elements.

Concrete was used in ancient Egypt, and for the Romans allowing the expansion of architectural methods, developing domes, vaults, covering large areas, foundations, and structures like bridges and sewerage system.
 * __Reinforced concrete:__ was developed to add the tensile strength of steel to the compressive strength of mass concrete. Usually used on railways ties, pipes, floors, arches and bridges. The steel reinforcement is employed to take full advantage of the plastic or sculptural characters of concrete.
 * __Precast-concrete construction:__ employs brick, 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 contraction.
 * __Prestressed concrete:__ provides bearing members into which reinforcement is set under tension to produce a live force to resist a particular load.

Post-.reading activity

__Definition__

Concrete: it is a mixture of water, cement and aggregates of stones and sand that hardens rapidly by a chemical combination, creating a strong, stone-like and water and fire resistant solid.

__**Reinforced Concrete:**__

__**Pre-cast concrete:**__



__**Prestressed concrete:**__



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

Tiltwall construction = Tilt-up construction:__

Tiltwall and tilt-up panel are two different terms to refer to the same process. Walls are created by assembling forms and pouring large slabs of concrete called panels directly at the job site. This process is poured for outdoors this is why contractors are at the mercy of climate conditions. Climate condition could affect the way that concrete reacts so tiltwall construction is usually use in southern areas where the climate is warmer than in north parts

Pre-cast concrete process is very similar to tiltwall construction but the difference is that pre-cast concrete is made in manufacturer facilities so it is not exposed to the weather conditions. Pre-cast concrete is only for indoor and after being cured panel are trucked to the job site. From this point, pre-cast concrete buildings are assembled in much the same manner as tiltwall buildings.

Reply to the podcast

Concrete is a construction material so important today and in the ancient world. It is strong compressive solid but low at tensile strength. From the history to now, concrete and techniques to work with concrete has been changing to improve the quality of the constructions, this is why we change from mixing water with cement to apply the technology and start developing the reinforced concrete, precast-concrete and prestressed concrete, these three so important nowadays in any construction.

Thanks for the information Grace