Asphalt UPDATED ACTUAL Exam Questions and CORRECT
Answers
Asphalt vs PC conc - Asphalt weaker, more flexible therefore used in pavements
Conc stronger, stiffer; therefore used in structures
Type of asphalts cement (often called "binder") - Asphalt cement, liquid asphalts (cutbacks and
emulsions), air blown asphalt*
Asphalt cement - Primary residuum from refinery most commonly used for hot mix asphalt
(HMA)
Liquid asphalts (cutbacks and emulsions) - Liquid at room temperature, easy to mix with agg,
used primarily for road repairs and surface seals
Lighter and more volatile products such as gasoline, kerosene and diesel oil... - Are removed and
the residue is asphalt cement
Fractional distillation of crude petroleum - Different products are separated at various
temperatures
Some crude oil sources have more asphalt residue than others.. - And quality and characteristics
of asphalt will vary from source to source
Cutbacks - Asphalt cement mixed with volatile solvent
Emulsified asphalt - Asphalt cement mixed with water
Liquid asphalts - Often used for chip seals, microsurfacing, fog seals
, Cutback asphalts - Add solvents to asphalt cement to liquefy
Less frequently used now due to environmental and cost considerations
After placement, the volatile solven evaporates leaving a solid mass
Rapid curing - very volatile solvent
Medium curing - less volatile solvent
Slow curing - low volatile solvent
Emulsified asphalts - Water + finely divided droplets of asphalt (10^-4cm) and emulsifying agent
(soap) imparting either a positive (cationic) or negative (anionic) charge
Rapid, medium and slow setting grades
Coagulates and sets on the surface of the aggregate
PROPERTIES OF ASPHALT CEMENTS (5) - Aging, viscosity and consistency, stiffness and
resistance to permanent deformation, low temperature performance, resistance to fatigue
cracking
Aging or age hardening - heating and cooling occurs during mixing and curing
cyclical temp fluctuations occur during service life
this results in changes in structure and composition primarily due to volatilization, oxidation and
other processes
results in hardening which means incr viscosity and reduced ductility
volatization.. - of light hydrocarbons
oxidation.. - by reacting with oxygen in environment
aging and film thickness - asphalt cement exists as a thin film in asphalt conc
Answers
Asphalt vs PC conc - Asphalt weaker, more flexible therefore used in pavements
Conc stronger, stiffer; therefore used in structures
Type of asphalts cement (often called "binder") - Asphalt cement, liquid asphalts (cutbacks and
emulsions), air blown asphalt*
Asphalt cement - Primary residuum from refinery most commonly used for hot mix asphalt
(HMA)
Liquid asphalts (cutbacks and emulsions) - Liquid at room temperature, easy to mix with agg,
used primarily for road repairs and surface seals
Lighter and more volatile products such as gasoline, kerosene and diesel oil... - Are removed and
the residue is asphalt cement
Fractional distillation of crude petroleum - Different products are separated at various
temperatures
Some crude oil sources have more asphalt residue than others.. - And quality and characteristics
of asphalt will vary from source to source
Cutbacks - Asphalt cement mixed with volatile solvent
Emulsified asphalt - Asphalt cement mixed with water
Liquid asphalts - Often used for chip seals, microsurfacing, fog seals
, Cutback asphalts - Add solvents to asphalt cement to liquefy
Less frequently used now due to environmental and cost considerations
After placement, the volatile solven evaporates leaving a solid mass
Rapid curing - very volatile solvent
Medium curing - less volatile solvent
Slow curing - low volatile solvent
Emulsified asphalts - Water + finely divided droplets of asphalt (10^-4cm) and emulsifying agent
(soap) imparting either a positive (cationic) or negative (anionic) charge
Rapid, medium and slow setting grades
Coagulates and sets on the surface of the aggregate
PROPERTIES OF ASPHALT CEMENTS (5) - Aging, viscosity and consistency, stiffness and
resistance to permanent deformation, low temperature performance, resistance to fatigue
cracking
Aging or age hardening - heating and cooling occurs during mixing and curing
cyclical temp fluctuations occur during service life
this results in changes in structure and composition primarily due to volatilization, oxidation and
other processes
results in hardening which means incr viscosity and reduced ductility
volatization.. - of light hydrocarbons
oxidation.. - by reacting with oxygen in environment
aging and film thickness - asphalt cement exists as a thin film in asphalt conc
