Iron+&+Steel

Eiffel Tower, Paris

Notes Iron & Steel!!
-Cast Iron is brittle, it snaps very easily. -Cast Iron is strong in compression, therefore old arch bridges were made of cast iron. -Cast Iron is very flexible. -Cast Iron is very weak in tension. -Cast Iron is very heavy. -Cast iron is used in arch bridges, cannons, historic domes.

-Steel is stronger than any material in tension, therefore the cables in the Golden Gate Bridge were made of steel. -Steel is stronger than any material in compression, therefore steel supports most skyscrapers. -Steel is very heavy. -It is one of the strongest materials used in construction. -It rusts and loses strenght in high temperatures. -It is used in bridges, trusses, beams and columns and roller coasters.

** [|Building Big: Materials Lab] **

**Post- reading activities:**
====On your wiki, write your opinion about this quotation from the recording: //"the old cast iron buildings died out. I'm not really sure whether the new skyscrapers killed them, or the new esthetics //" ====

In my opinion, the phrase “//the old cast iron buildings died out. I'm not really sure whether the new skyscrapers killed them or the new aesthetics //” refers to when the terrible Chicago fire of 1861 wiped out most of the iron buildings of the area and had to be rebuilt immediately, so by then America has just started manufacturing steel, and they used it quite well allowing much higher buildings with a new aesthetic of modernity rapidly replacing the old iron ornament. Today, large steel structures are hidden behind a glass cover, this material, helped create much higher building, however, the aesthetic took another direction to modernism.

** 1. Find the meaning of "Wrought Iron" and its uses **
Wrought Iron is a term that can be discomposed into two words. The word “wrought” is a very old way of referring to the verb “to work”, so the term Wrought Iron really and literally means worked iron which means that the iron is mixed with slag and other impurities. Because it is relatively brittle cast iron, it has relegated the use of this material to secondary o decorative uses in construction, such as railings and other parts.

** 2. Answer: Do you think metals are "cold" materials? Explain **
I believe the metal, more that a cold material is a good conductor of heat, that is, metal can easily acquire warmth of another body by contacting, to achieve a balance between the temperatures of the 2 bodies.

Reading: BRICK

** [|this recording] ** on Iron by John H. Lienhard.