WAQTC: Asphalt 2 Questions with
Correct Answers
What are the two primary ingredients in asphalt mixtures? - ANSWERSAggregate &
asphalt binder
HMA - ANSWERSHot Mix Asphalt
WMA - ANSWERSWarm Mix Asphalt
3 Types of Asphalt Mixtures? - ANSWERSDense-graded
Open-graded
Gap-graded
What's included in the total volume of an asphalt mix? - ANSWERSEntrapped air voids
Moisture
Effective & absorbed binder
Mineral aggregate
Air Voids (Va) - ANSWERSTotal volume of small air pockets between coated aggregate
SMA - ANSWERSStone matrix asphalt
Cutback Asphalt - ANSWERSBinder that's been modified by blending w/a chemical
solvent
Gmm - ANSWERSTheoretical maximum specific gravity
Gmb - ANSWERSMeasured bulk specific gravity
Gsb - ANSWERSOven-dry bulk specific gravity of aggregate
Gsa - ANSWERSApparent specific gravity of aggregate
Gse - ANSWERSEffective specific gravity
Gb - ANSWERSSpecific gravity of the asphalt binder
Containers used for sampling - ANSWERSCardboard boxes, metal cans, stainless steel
bowls, or other agency approved containers
, Specs for sampling plate - ANSWERSThick metal, minimum 8 gauge, wire attached to
corner long enough to reach from the center of the paver to the farthest auger
extension. Min one 0.25 in. hole in the corner of the plate
What is a Mechanical Sampling Device - ANSWERSPermanently attached device that
allows sampling receptacle to pass through the entire stream of material or diverts
material into the container by manual, hydraulic, or pneumatic operation
Release agent - ANSWERSNon-stick product that prevents mix from sticking to the
apparatus (no solvents or petroleum based products)
How do you determine sample size - ANSWERSDepends on test methods specified.
Check agency requirement for size required.
Explain the procedure for attached sampling devices - ANSWERS-Coat or pre-heat it
-Pass container through twice, once in each direction perpendicularly w/out overfilling
-Transfer to sample container w/out loss
-Repeat until sample size is obtained
-Combine to form full sample
Explain the procedure for sampling from conveyor belts - ANSWERS-avoid the
beginning or end
-stop the belt
-place sampling template through the mix on the belt
-remove mix from inside the template, including all fines and place in container
-repeat, obtaining equal sized increments until sample size is obtained
-combine
Explain the procedure for sampling from haul units - ANSWERS-visually divide into 4
equal quadrants
-identify one sampling location
-remove approx. 1 ft from the top to avoid surface segregation
-collect sample
Explain the procedure for sampling from a paver auger - ANSWERS-obtain sample from
the end of the auger using a square head shovel
-place shovel flat to be paved over
-allow stream of asphalt mix to cover shovel and lift vertically
-put in sample container
-repeat until sample size is obtained
-combine
Explain the procedure for sampling from a windrow - ANSWERS-visually divide into 3
equal sections
-remove approx. 1 ft from the top
-insert shovel, tilt back, and lift slowly
Correct Answers
What are the two primary ingredients in asphalt mixtures? - ANSWERSAggregate &
asphalt binder
HMA - ANSWERSHot Mix Asphalt
WMA - ANSWERSWarm Mix Asphalt
3 Types of Asphalt Mixtures? - ANSWERSDense-graded
Open-graded
Gap-graded
What's included in the total volume of an asphalt mix? - ANSWERSEntrapped air voids
Moisture
Effective & absorbed binder
Mineral aggregate
Air Voids (Va) - ANSWERSTotal volume of small air pockets between coated aggregate
SMA - ANSWERSStone matrix asphalt
Cutback Asphalt - ANSWERSBinder that's been modified by blending w/a chemical
solvent
Gmm - ANSWERSTheoretical maximum specific gravity
Gmb - ANSWERSMeasured bulk specific gravity
Gsb - ANSWERSOven-dry bulk specific gravity of aggregate
Gsa - ANSWERSApparent specific gravity of aggregate
Gse - ANSWERSEffective specific gravity
Gb - ANSWERSSpecific gravity of the asphalt binder
Containers used for sampling - ANSWERSCardboard boxes, metal cans, stainless steel
bowls, or other agency approved containers
, Specs for sampling plate - ANSWERSThick metal, minimum 8 gauge, wire attached to
corner long enough to reach from the center of the paver to the farthest auger
extension. Min one 0.25 in. hole in the corner of the plate
What is a Mechanical Sampling Device - ANSWERSPermanently attached device that
allows sampling receptacle to pass through the entire stream of material or diverts
material into the container by manual, hydraulic, or pneumatic operation
Release agent - ANSWERSNon-stick product that prevents mix from sticking to the
apparatus (no solvents or petroleum based products)
How do you determine sample size - ANSWERSDepends on test methods specified.
Check agency requirement for size required.
Explain the procedure for attached sampling devices - ANSWERS-Coat or pre-heat it
-Pass container through twice, once in each direction perpendicularly w/out overfilling
-Transfer to sample container w/out loss
-Repeat until sample size is obtained
-Combine to form full sample
Explain the procedure for sampling from conveyor belts - ANSWERS-avoid the
beginning or end
-stop the belt
-place sampling template through the mix on the belt
-remove mix from inside the template, including all fines and place in container
-repeat, obtaining equal sized increments until sample size is obtained
-combine
Explain the procedure for sampling from haul units - ANSWERS-visually divide into 4
equal quadrants
-identify one sampling location
-remove approx. 1 ft from the top to avoid surface segregation
-collect sample
Explain the procedure for sampling from a paver auger - ANSWERS-obtain sample from
the end of the auger using a square head shovel
-place shovel flat to be paved over
-allow stream of asphalt mix to cover shovel and lift vertically
-put in sample container
-repeat until sample size is obtained
-combine
Explain the procedure for sampling from a windrow - ANSWERS-visually divide into 3
equal sections
-remove approx. 1 ft from the top
-insert shovel, tilt back, and lift slowly
