QUESTIONS AND SOLUTIONS
Random sampling - ANSWER Are random numbers generated usually by a VT for
cores to be extracted from the roadway
How often should you calibrate a Straight edge - ANSWER Calibrate at the start of
each working period
Using the manual straight edge you find what kind of spot to place the rolling
straightedge? - ANSWER Locate a flat area with the manual straightedge and place the
rolling straightedge next to the manual straightedge and the gauge should read 0
The 3/16 and the 3/8 shims go under which wheels during calibration - ANSWER The
outside wheels to measure the low and the center to measure the high. Gauge should
read 3/16 on the 3/16 shim and vice versa for the 3/8 shims. Make sure the center
wheel moves up and down freely.
Calibration materials for Straightedge - ANSWER Rolling Straightedge
Manual Straightedge
Manual Measurement (ruler)
x4 3/16 shims 5mm thick
x4 3/8 shims 10mm thick
When to perform final straightedge - ANSWER After an entire lane has been paved
When to perform final straightedge - ANSWER Pavement should be an ambient
temperature
You cannot use the straightedge until it has been properly - ANSWER calibrated
When performing the straightedge procedure - ANSWER Maintain proper traffic
management and safety
Cross slopes can be either done - ANSWER Manually or with a smart level
When using a manual cross slope you first - ANSWER Place a simple level on
pavement
After placing the simple level on the pavement then you - ANSWER Raise the down
end of the level until it is level (bubble center)
, After the simple level is lifted until it is level you measure what - ANSWER The length
of the simple level and the height between the (previously down) end of the level to the
pavement
Formula to calculate the manual cross slope - ANSWER Calculate the slope using the
formula
( h / l ) x 100 = slope %
Requirements for the rolling Straightedge - ANSWER Must have a read out gauge, kept
clean and in working order, low and high reading, and marks to the nearest 1/16 (1mm)
Rolling Straightedge pulled at - ANSWER 3 to 5mph or less
Deficiencies pointed out with rolling straightedge you should first - ANSWER Mark the
pavement at the center wheel where the needle initially shows a deficiency and where is
ends. Also record location and measurements of deficiency.
Core sampling is used for - ANSWER testing density
and permeability
Core sampling equipment - ANSWER Concrete saw
Diamond bit core drill
Size of core depends on test
Ice chest (Optional)
Ice (Optional)
Asphalt to patch hole
During core sampling the barrel should always be - ANSWER perpendicular to
pavement
Core sampling patching - ANSWER Fill hole with patch mix, if in lifts tamp each lift
Storing cores - ANSWER Store in ice chest with bagged ice on top or put in an air
conditioned cab
Best stored upright in a cool place
DO NOT THROW INTO PICKUP
Determine Bulk Specific gravity on sampled cores - ANSWER Trim to correct lift
Weigh dry sample if dry otherwise
Place in water (77+-2) for 4+-1 minute
Then roll within five seconds to achieve SSD weight
Then dry to a constant weight with fan or core dryer
Bulk Specific Gravity formula - ANSWER dry / SSD - water weight = BSG