Concrete

**Concrete**

 * definitions:**
 * Concrete** is a manufactured mixture of cement and water, with aggregates of sand and stones, which hardens rapidly by chemical combination.


 * Reinforced concrete** was developed to add the tensile strength of steel to the compressive strength of mass concrete.The creator promoted reinforced concrete for use in railway ties, pipes, floors, arches, and bridges.


 * 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.

**types of concrete** constructions:
- reinforced concrete



- Pre-cast concrete

- prestressed concrete

- concrete-shell =The diferent between tilt-up or tilwall and precast concrete= Tilt-up or tilwall and precast concrete are methods of constructions and their process is very alike only different in the place were they are made. First, til-up or tilwall concrete is a process that consists on build concrete panels in assembling forms directly at the job site, so this has some advantages like they don’t required transportation but also disadvantages like the climatic conditions that they can deteriorated the panels in their curing process.

Now about the precast concrete is a similar process only that this panels are made in other place different to the job site, this permits that the panel process of curing finished correctly, but this process has consequences which is the issue with the transportation, this condition also reduce the site of the panels because of the transportation trucks. So establishing the advantages and disadvantages I think that this process is very interesting especially for the unknown places were we know now.