Deck 26: Bituminous Materials

Question 1

____ tests determine the flow properties of asphalts at application and service temperatures. A) Ductility
B) Flash point
C) Viscosity
D) Specific gravity

Answer 1

,C

Question 2

Describe what an asphalt ductility test measures and how it is conducted.

Answer 2

The ductility test is used to determine how much an asphalt sample will stretch at various temperatures below its softening point. A standard briquette is molded, brought to the specified test temperature, and pulled at a specified rate until the sample completely separates. The elongation in centimeters, at which the final thread of asphalt breaks, is used to indicate ductility.

Question 3

Explain how a hot bitumen built-up roof membrane is created and why this specific technique is used.

Answer 3

​ A built-up roof consists of alternate plies of organic or fiberglass roofing felt with a hot bitumen coating mopped over each layer. The design of the roof varies by situation but generally consists of three or more layers of felt with a bitumen layer over each and a bitumen topcoat with aggregate rolled on top.
Felts provide the needed reinforcement to keep bitumens in each layer from alligatoring. Alligatoring refers to surface cracking caused by oxidation and shrinkage stresses, which can result in a repetitive mounding of the asphalt surface similar to an alligator's hide.

Question 4

____ asphalts have the advantage of being applied cold, eliminating the need to heat the asphalt to bring it to a fluid condition. A) Plastic
B) Emulsified
C) Quick-setting
D) Cutback

Question 5

Describe in general how asphalts are graded.

Question 6

What is fiberglass sheet material?

Question 7

Type 1 roofing asphalt is ____. A) dead level
B) flat
C) steep
D) special steep

Question 8

____ roofing is composed of polymer-modified bitumen reinforced with one or more plies of fabric, such as polyester glass fiber. A) Modified asphalt roll
B) Conventional hot built-up
C) Cold-applied asphalt
D) Fiberglass shingle

Question 9

Name the most significant property of bitumens and explain why that is the case.

Question 10

____ is made using asbestos fibers either in a pressed mat-like felt or in woven sheets. A) Ice and water shield
B) Fiberglass
C) Coal tar pitch
D) Fireproofing paper