Exam Questions and Answers WITH
EXPLANATION A GRADE GUARANTEE
PASS
Proper weight of mix for gyratory compactor - Answer- Around 4500 - 5000g.
Determined through the mix design process to achieve the height of 115 +/- 5mm
Required amount of mix for Gmm (rice) samples? - Answer- 2000-2200g total or 1000-
1100 grams individually for two flasks
Required amount of mix for ignition samples? - Answer- Depends on the mix. SP & FC
5, 9.5, 12.5 are 1500g. SP 19 is 2000g
Asphalt burns off at what temp - Answer- 538°C (1000°F)
The furnace must be capable of what temperature - Answer- 650°C (1200°F)
Flasks should be calibrated at what temperature and how often? - Answer- 77 +/ 2°F of
water and once a month or >0.4 grams of dry weight
How many parts of wetting agent to water - Answer- 1ml wetting agent to 1000ml water
The vacuum applied to flasks for GMM - Answer- 30 +/- 2mm
Vacuum pressure for GMM must be reached within - Answer- 2 minutes
The Orbital Shaker must oscillate at - Answer- 270 +/- 10 rpms
The vacuum and oscillating test for GMM then continues for how long when it reaches
target pressure - Answer- 15 +/- 2minutes
Gyratory compaction angle is - Answer- an internal angle of 1.16 +/- .02 degrees
Ram pressure for gyratory compaction is - Answer- 600 +/- 18 kpA perpendicular to the
axis
RPM the gyratory compactor operates at - Answer- 30 +/- .5 gyrations a minute
, Gyratory (GMB) and Rice (GMM) samples must be conditioned at what temp and for
how long - Answer- compaction temp +/- 9 for 1 hour +/- 5minutes and mix should be
within +/-20° of compaction temp
The mold and base plate for the gyratory compactor should be in the oven for how long
- Answer- 30 to 60 minutes
Target specific height for pills - Answer- 115.0mm +/- 5mm
How do you determine aggregate is dry? - Answer- Weigh the material every 15
minutes when it has lost less than 0.5 grams is it considered dry
Bulk specific gravity (pill) water weight is determined after - Answer- 4 +/- 1 minute
When the pill is removed from the water it should be blotted and weighed in what time
and how - Answer- 5 seconds with a top and bot flip and then a roll roll
The towel should be damp
Formula for GMB (BSG) - Answer- Dry ÷ (SSD - Water Weight)
Round to 3 decimal places
Calculating air voids - Answer- (Gmm - Gmb ÷ Gmm) × 100
For Asphalt Binders PG stands for what? - Answer- Performance Graded
What do the numbers mean for an asphalt binder? ex: PG 67-22 - Answer- 67 is the
average 7 day high temp in Celsius and 22 is the negative low temp in Celsius
ATPB stands for and is used in what? - Answer- Asphalt Treatsd Permeable Base
Used under concrete for drainage
Friction Courses are required on what jobs based on AADT and Design Speed -
Answer- AADT > 3000
Design Speed > 35 mph
A PMA asphalt binder stands for what? - Answer- Polymer Modified Asphalt
An ARB asphalt binder stands for what? - Answer- Asphalt Rubber Binder
Subgrade requires an LBR of what? - Answer- 40
When do you sample tack? - Answer- During unloading when it reaches 1/3 of the load
What do you do first before sampling tack or binder? - Answer- Discard the first gallon
to clear the line