Presentation delivered at the CalAPA Spring Asphalt Pavement Conference April 9-10, 2014 in Ontario. Topic: New asphalt pavement smoothness specificaitons and measurement technology is discussed in depth.
4. Until recently, pavement smoothness was
measured using a California profilograph
and straightedge
The first profilograph was invented by
Francis Hveem and constructed in 1940 by
the Materials and Research Division of the
California Division of Highways.
5.
6. Profile Index
0.2 inch blanking band
0.0 inch (Zero) blanking band
Must Grinds
0.3 inches in 25 feet
7. Because its front and rear wheels are in contact with the pavement surface, the
profilograph cannot accurately measure the pavement profile.
13. Accelerometers are used in a wide variety of
equipment and personal electronics including
seismology equipment, car alarm systems, and
crash detection/air bag deployment sensors.
In profilers, they measure the movement of the
vehicle body
14. The laser height sensors measure the distance from
the reference plane to the pavement surface. They
operate around 16KHz. At 60 mph they can take about
15 readings per inch of vehicle travel.
15.
16.
17.
18. The site is located in the median of Interstate
80 at the Sacramento Regional Transit Light
Rail station (Watt/I-80) parking lot.
Two test sections (asphalt and concrete)
University of California Pavement Research
Center with the assistance of the Pavement
Program and METS will administer calibration
program
Calibration tests will be conducted 2 to 4 times
per year (March, May and July for 2014)
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21. Block Test
AASHTO R57-10, Section 5.3.2.3.1
This test will be conducted on a relatively flat and level area
It’s purpose is to check the height measurements from the
height sensor(s) of the test vehicle using blocks of known
heights (i.e. 0.5 inch, 1.0 inch, 2.0 inch).
Bounce Test
AASHTO R57-10, Section 5.3.2.3.2
It’s purpose is to ensures that the data from the height
sensor and accelerometer are legitimate and being properly
combined to compute the longitudinal elevation profile
Distance Measurement Index Test
AASHTO R56-10, Section 8.4
Tests accuracy of profilers distance measurement
instrument (DMI)
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22. Equipment Precision (Repeatability)
AASHTO R56-10, Section 8.3.1.2
Compare ten Inertial Profiler runs over same test
section against each other
Calculate repeatability agreement score
Score of 0.92 or greater is required
Equipment Accuracy (Reproducibility)
AASHTO R56-10, Section 8.3.1.4
Compare several inertial profiler runs over same test
section against a reference profiler
Calculate accuracy agreement score
Score of 0.90 or greater is required
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23. Failed tests (Equipment or Operator)
May re-test the following day (if site available)
Only one re-test per operator/equipment allowed
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24. International Roughness Index (IRI)
Computer Algorithm
Areas of Localized Roughness (aka “must grinds”)
Isolated areas of roughness
25. The International Roughness Index (IRI) is a
scale for roughness based on the simulated
response of a generic motor vehicle to the
roughness in a single wheel path of the
road surface.
IRI is used to define a characteristic of the
longitudinal profile of a traveled wheel
track.
26.
27.
28. Where B = 250 mm (9.8 in) for IRI
(represents tire contact with ground)
29.
30. 0.1 mile 0.1 mile
ETW
RWP = Right Wheel Path
LWP = Left Wheel Path
ETW
Direction of Travel
RWP
LWP
IRI = 58 in/mi
IRI = 64 in/mi
IRI = 60 in/mi
IRI = 62 in/mi
Direction of Travel
MRI = 60 in/mi MRI = 62 in/mi
32. AreasofLocalized Roughness
“Must Grinds” are now defined as “Areas of
Localized Roughness”
Areas of localized roughness uses a continuous IRI
for each wheel path with a 25 ft interval
Areas of localized roughness that exceed 120(160)
in/mile must be corrected regardless of the IRI
values of a 0.1 mile section
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34. AreasofLocalized Roughness
“Must Grinds” will now be called “Areas of
Localized Roughness”
Areas of localized roughness use a continuous IRI
for each wheel path with a 25 ft interval
Areas of localized roughness that exceed 120
in/mile must be corrected regardless of the IRI
values of a 0.1 mile section
35. Certification
Inertial Profiler must be certified within the last
12 months
Profiler Operator must be certified within the
last 12 months
Contractors must obtain certification from the
California Certification Site (no longer Texas
Transportation Institute)
36. Submittals
Within 5 business days before start of profiling or
changing profile or operator
Inertial Profiler certification
Operator certification
Manufacturer’s recommended calibration and
verification tests
Within 2 business days after profiling engineer
approved test section
Cross correlation test results
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37. Submittals
Provide data within 2 business days after each day
of profiling
Profile data must include:
Raw profile data for each lane (ppf extension)
ProVAL ride quality analysis report in IRI for both wheel paths
ProVAL ride quality analysis report in MRI for each lane
ProVAL smoothness assurance analysis report in IRI for both
wheel paths
GPS data
Manufacturer’s recommended calibration and verification results
AASHTO calibration and verification test results
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38. Submittals
Provide data within 2 business days after each day
of profiling
Profile data must include:
Raw profile data for each lane (ppf extension)
ProVAL ride quality analysis report in IRI for both wheel paths
ProVAL ride quality analysis report in MRI for each lane
ProVAL smoothness assurance analysis report in IRI for both
wheel paths
GPS data
Manufacturer’s recommended calibration and verification results
AASHTO calibration and verification test results
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39. Smoothness Measurement
Contractor to notify Engineer of start location by
station and start time at least 2 business days
before profiling
Begin and end station will be marked on pavement
shoulder before profiling
Following “leave out” areas will be recorded
Begin and end of all bridge approach slabs
Begin and end of all bridges
Begin and end of all culverts visible on the roadway
surface
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40. Smoothness Correction
For HMA, if the final surface does not comply with
the smoothness acceptance values the contractor
can do the following:
Grind the pavement to within specified tolerances
Remove and replace it
Place an overlay of HMA
For PCC, if the final surface does not comply with
the smoothness acceptance values the contractor
can do the following:
Grind the pavement to within specified tolerances
Remove and replace it 40
42. Collects data at a high rate of speed
(approx. 30 mph to 60 mph)
Collects data for both wheel paths
simultaneously
No traffic control
Safer
$$$$ Savings
No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride.Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer.Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents.Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride.Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer.Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents.Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
Background and smoke used to illustrate laser
Example of 4 inch wide line laser…Roline is a major manufacturer
SSP highlights
Any Questions?Thank you for coming today. We hope that the information presented was useful.