1. Tower in the Sky
Bill Baker
Chapter 12

2. Steel and iron manufacturing techniques
Allowed for the production of long steel beams in the Industrial Revolution.
These could be used to create tall steel-frame buildings.

3. Most modern skyscrapers
Are constructed around a strong reinforced core.
Reinforced core is a long reinforced column that acts like a building’s spine.
Floors extend from the core with supporting columns around the perimeter.
This allows for the outer walls of the structure to be made of glass.

4. Steel and concrete Are common skyscraper building materials.
Concrete resists compression very well, but does not perform as well under tension.
For this reason, it is often reinforced with steel rebar, which holds up well under tension.

5. Shear
Is a force that results in the deformation of an object such that the object’s parallel planes move past each other.

6. A truss
Is a triangular arrangement of structural members that reduces the effects of shear and bending.

7. Concrete is Good with compression, not-so-good with tension
Modern concrete uses
fly ash from coal-fired power plants,
Ground up blast furnace slag from steel manufacturing, and
Silica dust from computer-chip manufacturing
As substitutes for some of the cement.
These waste makes concrete stronger.
Steel bars (called rebar) reinforces concrete, which is very fragile under tension or bending

8. Who is Bill Baker? Field engineer Structural engineer Urban planner
Software engineer

9. What limited the height of the structures in the Middle Ages?
Because people were not educated back then.
Because the structures were supported by woods.
Because they were afraid of height.
Because the structures were supported by thick stone walls.

10. What manufacturing breakthrough led to the development of taller structures in the 1800s?
New manufacturing process for making…
Long steel and iron beams
A truss
A strong reinforced core.
Steel and concrete

11. What is a truss and how does it minimize the effects of a shearing force?
A truss is a triangular arrangement of structural members.
A truss prevents the joints of a structure from sliding apart.

12. Why did Bill need to design the Burj Dubai to confuse the wind?
The wind can get very strong at high altitudes.
It starts crating spinning vortices at the sides of a building.
This can cause the building to start rocking back and forth dangerously.
If the shape of the building changes, not enough vortices can build up along the structure’s side to cause a problem.