Materials+Review

**-What are the advantages and disadvantages of this material?**
=== This material has the advantage that it be can found everywhere, it can be used naturally and is very good at working in compression, but has the disadvantage that it is weak in tension, difficult to transport and cut. ===

-next we are going to listen to ADRIAN LOBO with his speech about concrete and reinforced concrete.
===** Concrete is composed of cement, water and small rock. The advantages of concrete are that is resistant to fire and water, and is very economical. This material can be molded in any way and is resistant to compression. Some of the disadvantages of this material are that it cannot withstand tension, also this material was used for the arches of the bridges and domes. **===

-How is the reinforced concrete?
===** Reinforced concrete is composed of steel bars hidden in concrete, the advantages of this material is that it is economical, can be molded in any way, and resists compression and tension. This material is used in the construction of bridges, beams and columns of building and skyscrapers. **===

-Ok let’s begin with iron:
===** It is a very strong material under compression and it is very economic, but it is weak in tension, also when it is extremely cold it may be broken. Iron was used in construction to make bridges and columns. **===

-Finally we conclude the program by talking about steel:
===** It is an alloy consisting mostly of iron, with carbon content between 0.2% and 2.1% by weight, depending on the grade. It is one of the strongest materials used in construction; it is very strong under compression and tension. It rusts and loses strength in very high temperatures. Used widely in the construction of roads, railways, other infrastructures and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges, and airports, are supported by a steel skeleton. **===