CE 382 HMA Final Exam UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Basic Philosophy of asphalt mixture design - CORRECT ANSWER Economical
Constructable
meet performance expectations
What are four present day asphalt products? - CORRECT ANSWER Asphalt Cements
Asphalt Emulsifiers (waterproofing
Cutback asphalt (waterproofing)
roof shingles
What is the difference between asphalt and tar? - CORRECT ANSWER asphalt is from
petroleum/crude oil
tar is from coal
Does viscosity increase or decrease as the temperature increases? - CORRECT
ANSWER Viscosity decreases (inverse relationship)
What effect does the rate of loading have on an asphalt pavement? - CORRECT
ANSWER High Temp + low rate = viscous
Low Temp or high rate = elastic
What statistical approach is used in selecting a binder and what are its benefits? - CORRECT
ANSWER A reliability bell curve is plotted to determine the reliability of temperature
ranges for a given region
What is the effective asphalt content? - CORRECT ANSWER Effective asphalt content
is the asphalt not absorbed by the aggregate
,What tests are used to analyze pavement deformation potential of an asphalt binder? -
CORRECT ANSWER Rotational Viscometer
Dynamic Shear Rheometer
Bending Beam Rheometer
Rolling Thin Film Oven
Pressure Aging Vessel
What does the rotational viscometer test help determine? - CORRECT
ANSWER Mixing and compaction temperature
What does the dynamic shear rheometer test help determine? - CORRECT
ANSWER Rutting and pavement deformation
What does the bending beam rheometer test help determine? - CORRECT
ANSWER Low temperature thermal cracking
What does the rolling thin film oven test determine? - CORRECT ANSWER Short
term aging (during mixing, compacting, placement)
What does the pressure aging vessel test determine? - CORRECT ANSWER long term
(10 year) aging
What are the different tests to use on an asphalt mix? - CORRECT ANSWER Rutting
(Hamburg wheel test, French wheel tracking test, asphalt pavement analyzer)
Fatigure (Bending beam rheometer)
Thermal cracking (semi-circular bending test, disc shaped compact tension test, DCT,
TSRST)
What device measures the creep potential of an asphalt binder? - CORRECT
ANSWER Bending beam rheometer
, What are the components of the dynamic modulus? - CORRECT ANSWER Apply a
repeated load at varying frequencies to a test specimen over a relatively short period of time
and measure the specimen's recoverable strain and permanent deformation. Some dynamic
modulus tests are also able to measure the lag between the peak applied stress and the peak
resultant strain, which provides insight into a material's viscous properties. Test results
correlate reasonably well with in-service pavement rutting measurements but the test is
somewhat involved and difficult to run.
How are air voids determined? Be specific about the tests and corresponding properties. -
CORRECT ANSWER Air voids are determined using the bulk and max specific
gravities of the mix, determined by obtaining weights of dry, saturated surface dry, and
submerged, and for max, taking a loose sample, and removing air voids (rice).
Phase diagram for HMA - CORRECT ANSWER Air
Effective asphalt
Absorbed asphalt
Aggregate
What does asphalt primarily consist of chemically? - CORRECT ANSWER 80% by
weight of carbon;
around 10% hydrogen;
up to 6% sulfur;
small amounts of oxygen and nitrogen;
trace amounts of metals such as iron, nickel, and vanadium.
What does a chart of binder susceptability look like? - CORRECT
ANSWER Rotational viscometer graph
Temperature (x-axis)
Log[viscosity] (y-axis)
inversely correlated
QUESTIONS AND CORRECT ANSWERS
Basic Philosophy of asphalt mixture design - CORRECT ANSWER Economical
Constructable
meet performance expectations
What are four present day asphalt products? - CORRECT ANSWER Asphalt Cements
Asphalt Emulsifiers (waterproofing
Cutback asphalt (waterproofing)
roof shingles
What is the difference between asphalt and tar? - CORRECT ANSWER asphalt is from
petroleum/crude oil
tar is from coal
Does viscosity increase or decrease as the temperature increases? - CORRECT
ANSWER Viscosity decreases (inverse relationship)
What effect does the rate of loading have on an asphalt pavement? - CORRECT
ANSWER High Temp + low rate = viscous
Low Temp or high rate = elastic
What statistical approach is used in selecting a binder and what are its benefits? - CORRECT
ANSWER A reliability bell curve is plotted to determine the reliability of temperature
ranges for a given region
What is the effective asphalt content? - CORRECT ANSWER Effective asphalt content
is the asphalt not absorbed by the aggregate
,What tests are used to analyze pavement deformation potential of an asphalt binder? -
CORRECT ANSWER Rotational Viscometer
Dynamic Shear Rheometer
Bending Beam Rheometer
Rolling Thin Film Oven
Pressure Aging Vessel
What does the rotational viscometer test help determine? - CORRECT
ANSWER Mixing and compaction temperature
What does the dynamic shear rheometer test help determine? - CORRECT
ANSWER Rutting and pavement deformation
What does the bending beam rheometer test help determine? - CORRECT
ANSWER Low temperature thermal cracking
What does the rolling thin film oven test determine? - CORRECT ANSWER Short
term aging (during mixing, compacting, placement)
What does the pressure aging vessel test determine? - CORRECT ANSWER long term
(10 year) aging
What are the different tests to use on an asphalt mix? - CORRECT ANSWER Rutting
(Hamburg wheel test, French wheel tracking test, asphalt pavement analyzer)
Fatigure (Bending beam rheometer)
Thermal cracking (semi-circular bending test, disc shaped compact tension test, DCT,
TSRST)
What device measures the creep potential of an asphalt binder? - CORRECT
ANSWER Bending beam rheometer
, What are the components of the dynamic modulus? - CORRECT ANSWER Apply a
repeated load at varying frequencies to a test specimen over a relatively short period of time
and measure the specimen's recoverable strain and permanent deformation. Some dynamic
modulus tests are also able to measure the lag between the peak applied stress and the peak
resultant strain, which provides insight into a material's viscous properties. Test results
correlate reasonably well with in-service pavement rutting measurements but the test is
somewhat involved and difficult to run.
How are air voids determined? Be specific about the tests and corresponding properties. -
CORRECT ANSWER Air voids are determined using the bulk and max specific
gravities of the mix, determined by obtaining weights of dry, saturated surface dry, and
submerged, and for max, taking a loose sample, and removing air voids (rice).
Phase diagram for HMA - CORRECT ANSWER Air
Effective asphalt
Absorbed asphalt
Aggregate
What does asphalt primarily consist of chemically? - CORRECT ANSWER 80% by
weight of carbon;
around 10% hydrogen;
up to 6% sulfur;
small amounts of oxygen and nitrogen;
trace amounts of metals such as iron, nickel, and vanadium.
What does a chart of binder susceptability look like? - CORRECT
ANSWER Rotational viscometer graph
Temperature (x-axis)
Log[viscosity] (y-axis)
inversely correlated
