1、Standard Practice for Accepting Pavement Ride Quality When Measured Using Inertial Profiling Systems AASHTO Designation: R 54-141American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS 5a R 54-1 AASHTO Standard Practice fo
2、r Accepting Pavement Ride Quality When Measured Using Inertial Profiling Systems AASHTO Designation: R 54-1411. SCOPE 1.1. This practice provides guidance and example specification language intended for use by Owner-Agencies in the development of specific contract language when requiring the measure
3、ment and evaluation of ride quality and compliance using inertial profiling systems (IPS) and the International Roughness Index (IRI) as the quality measure. 1.2. If any part of this practice is in conflict with references made, such as ASTM or AASHTO Standards, this practice takes precedence for it
4、s purposes. 1.3. The values stated are in U.S. Customary units and are to be regarded as the standard. 1.4. This specification does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this specification to establish appropriate
5、safety and health practices and determine the applicability of regulatory limitations related to and prior to its use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 328, Inertial Profiler R 56, Certification of Inertial Profiling Systems R 57, Operating Inertial Profiling Systems 2.2. ASTM Standa
6、rds: E867, Standard Terminology Relating to Vehicle-Pavement Systems E1926, Standard Practice for Computing International Roughness Index of Roads from Longitudinal Profile Measurements 2.3. Other Document: Sayers, M. W. “On the Calculation of International Roughness Index from Longitudinal Road Pro
7、file.” Transportation Research Record 1501. Transportation Research Board, National Research Council, Washington, DC, 1995, pp. 112. 3. TERMINOLOGY 3.1. Definitions: 3.1.1. Inertial Profiling System (IPS)an inertial profiler that meets the requirements of M 328 when combined with an operator. 2016 b
8、y the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS 5a R 54-2 AASHTO 3.1.2. International Roughness Index (IRI)a statistic used to determine the amount of roughness in a measured longitudinal profile. The IRI
9、is computed from a single longitudinal profile using a quarter-car simulation at 50 mph (Sayers 1995). Computer programs to calculate the IRI from a longitudinal profile are referenced in ASTM E1926. 3.1.3. line lasera line laser obtains a series of data points along a line, which is typically perpe
10、ndicular to the travel direction, with the line typically being 4 in. long. A single, bridged elevation value is computed from this data. 3.1.4. localized roughnessany 25-ft segment of roadway that contributes disproportionately to the overall roughness index value. Areas of localized roughness are
11、identified using a report of continuous IRI with a base length of 25 ft. This yields the IRI of every possible 25-ft segment. Any segment for which the continuous report exceeds a threshold IRI value is considered a defective segment requiring correction. Note 1The threshold IRI value in inches per
12、mile should be determined by each Owner-Agency. A typical range of values for various highway types is shown in Table 1. Table 1Typical Threshold Values for Localized Roughness Roadway Type IRI (in./mile) Interstate 140 to 160 State primary 150 to 170 State secondary 160 to 190 3.1.5. longitudinal p
13、rofilethe vertical deviations of the pavement surface taken along a line in the direction of travel referenced to a horizontal datum. 3.1.6. report intervalthe longitudinal distance between the outputs of a profile index value. 3.1.7. roughness according to ASTM E867, the deviation of a surface from
14、 a true planar surface with characteristic dimensions that affects vehicle dynamics, ride quality, dynamic loads, and drainage. 3.1.8. Type A Roughness Measurementa test procedure to measure the longitudinal profile of a surface using an inertial profiler and to compute the profile index known as th
15、e International Roughness Index (IRI). 3.1.9. Type B Roughness Measurementa test procedure to measure surface profile deviations using a straightedge. 4. SIGNIFICANCE AND USE 4.1. This example provides specification language for measuring and accepting ride quality on newly constructed paving projec
16、ts using an IPS and the IRI quality measure. If an Owner-Agency elects to use some other ride quality index, the fundamental methodology described herein remains valid, but not the individual settings. Note 2The IPS should be verified on the same pavement surface type and texture as that being measu
17、red. When profiling pavements with rough macrotexture, a height sensor with a large footprint is needed. A line laser that utilizes a bridging algorithm is an example of a sensor with a large footprint. The consequence of not using a large footprint sensor may be an upward bias in the IRI as measure
18、d by an IPS with a single-point (dot) laser. An IPS with a single-point laser can also collect inaccurate data on longitudinally tined, longitudinally grooved, or diamond ground pavements. A line laser that utilizes a bridging algorithm is recommended for such pavements. 2016 by the American Associa
19、tion of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS 5a R 54-3 AASHTO 5. EQUIPMENT AND OPERATOR 5.1. Provide an approved 10-ft straightedge. 5.2. Provide an inertial profiler meeting all requirements and specifications found in M 32
20、8 and currently certified in accordance with R 56. Operate the equipment in accordance with R 57. 5.3. Provide the Owner-Agency a copy of the equipment certification. Display a current decal on the equipment indicating the expiration date of certification. Note 3An equipment certification or decal w
21、ould be required only if the Owner-Agency had a certification program that issued them, or where it recognizes another agencys certification program in which certifications, decals, or both are issued. 5.4. Provide a qualified profiler operator. Provide the Owner-Agency a copy of the operators quali
22、fications or current certification. 6. WORK METHODS 6.1. Quality Control (QC) Testing (nondirected)Perform QC tests on a daily basis throughout the duration of the project. Use an approved straightedge, inertial profiler, profilograph, or any other appropriate means. 6.2. Quality Control Testing (di
23、rected)Use Type A Roughness Measurement. Use Type B Roughness Measurement only when Type A Roughness Measurement cannot be used or when specified by the Owner-Agency. Measure the finished surface of the completed project or at the completion of a major stage of construction as approved by the Owner-
24、Agency. Coordinate with and receive authorization from the Owner-Agency before starting testing. Obtain roughness measurements within 7 days after receiving authorization and submit results to the Owner-Agency within 24 h of data collection. 6.2.1. Operate the profiler in accordance with R 57 and pr
25、ovide the Owner-Agency the results of the Daily Measurement Control on a daily basis. The Owner-Agency may require QC testing be performed at off-peak times for traffic flow. Operate the inertial profiler in a manner that does not unduly disrupt traffic flow as determined by the Owner-Agency. Use an
26、 approved traffic control plan. Traffic control for QC and verification testing by the Owner-Agency is at the expense of the contractor. Provide all profile measurements to the Owner-Agency in electronic data files of the format specified in R 57. 6.3. Verification TestingWithin 10 working days afte
27、r the contractors QC testing under Section 6.2 is completed, the Owner-Agency may perform verification testing using an inertial profiler meeting the requirements of R 56. If the verification testing produces an IRI obtained over the same section of roadway that differs from that obtained using the
28、contractors profiler by more than the percentages shown in Table 2, then the Owner-Agency and contractor shall attempt to resolve the differences to their mutual satisfaction. 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violat
29、ion of applicable law.TS 5a R 54-4 AASHTO Table 2Typical Allowable IRI Differences Mean of Agency and Contractors IRI (in./mile) Max Allowable DifferenceaLess than 50 8.5% of mean IRI 50 to 150 6.0% of mean IRI Greater than 150 7.0% of mean IRI a Actual values should be set by the Owner-Agency. 6.3.
30、1. If the differences cannot be resolved, then referee testing will be conducted. The Owner-Agency will conduct the referee testing and the results will be final and will be used to establish pay adjustments. Referee testing will be conducted using an inertial profiler that recently has been certifi
31、ed in accordance with R 56. The certification should not be more than 90 days old unless both parties agree otherwise. 6.3.2. If the testing confirms the Owner-Agency profiler and fails to confirm the contractors profiler, then the contractors profiler shall be taken out of service until it has been
32、 recertified in accordance with R 56. A similar requirement will apply if the testing confirms the contractor equipment but fails to confirm the Owner-Agency. If the referee testing fails to confirmeither the Owner-Agency or contractor equipmentthen both profilers shall be removed from service until
33、 recertified. 6.4. Evaluation of ProfilesThe contractor shall evaluate profiles for acceptance, incentive payments, disincentive payments, or corrective action using the current version of ProVAL and provide the results to the Owner-Agency within 24 h of completing testing under Section 6.2. If the
34、profile data files are created using an export option in the manufacturers software where filter settings can be specified, use the filter settings that were used to create data files for certification. Analyze the entire profile. Exclude any areas specifically identified in the contract. Exclude fr
35、om the analysis for localized roughness the first 12.5 ft after the start of the paving operations and last 12.5 ft prior to the end of the paving operation. Also exclude the first 12.5 ft on either side of bridge structures, manhole covers, utility covers, and approach slabs. Determine pay adjustme
36、nts in accordance with Sections 6.4.3 and 6.4.4. The Owner-Agency will verify the analysis. Note 4The Profile Viewer and Analysis (ProVAL) software program developed for the Federal Highway Administration, which can be used to import, display, and analyze the characteristics of pavement profiles fro
37、m many different sources, is available at . 6.4.1. Type A Roughness MeasurementThe Owner-Agency may use the QC test results obtained under Section 6.2 to determine pay adjustments for ride quality provided it is able to verify the contractors profile data. Areas excluded from measurement under Type
38、A Roughness Measurement shall be measured in accordance with Section 6.4.2. 6.4.2. Type B Roughness MeasurementTypically used where an IPS cannot be effectively operated. There are no pay adjustments when Type B Roughness Measurement is used. In a manner approved by the Owner-Agency, correct surface
39、 areas that have more than 1/4-in. variation between any two contacts on the straightedge. There is no payment for correcting deficient areas. Following correction, retest the area to verify compliance. 6.4.3. Pay Adjustment ScheduleThe pay adjustment factors from Table 3 will be used in conjunction
40、 with the histogram printout from ProVALs Smoothness Assurance Module, based on a report of continuous IRI with a base length of 528 ft, to compute a final pay factor (incentive or disincentive). The final pay factor (PF), computed to three decimals, is equal to the sum of the products of the indivi
41、dual pay adjustment factors shown in Table 3 times ProVALs corresponding histogram percentages divided by 100. In addition to the final pay factor determined from Table 3, disincentives for localized roughness may apply as described in Section 6.4.4. 2016 by the American Association of State Highway
42、 and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS 5a R 54-5 AASHTO Table 3Pay Adjustment Factors and Computation of Final Pay Factor IRI Range, in./milea(1) Pay Adjustment Factors (2) Percent of Pavement within IRI Range Taken from ProVALs Smoothness
43、 Assurance Module (SAM) (3) Pay Adjustment (4) #.0 0.# #.# or #.# #.# or #.# #.1 #.0 0.# #.# or #.# #.# or #.# #.1 #.0 0.# #.# or #.# #.# or #.# #.1 #.0 0.# #.# or #.# #.# or #.# #.1 #.0 1.00 #.# or #.# #.# or #.# #.1 #.0 1.# #.# or #.# #.# or #.# #.1 #.0 1.# #.# or #.# #.# or #.# #.1 #.0 1.# #.# or
44、 #.# #.# or #.# #.0 0.# #.# or #.# #.# or #.# #.1 #.0 0.# #.# or #.# #.# or #.# #.1 #.0 0.# #.# or #.# #.# or #.# #.1 #.0 0.# #.# or #.# #.# or #.# #.0 1.00 #.# or #.# #.# or #.# Final % disincentive = (100 sum) = #.# or #.# aThe number of steps in the table as well as the IRI ranges and pay adjustm
45、ent factors should be set by the Owner-Agency. Note 6A different set of pay adjustment factors may be used for different project requirements. This pay adjustment table is just one style of many possible pay tables and was designed to utilize quality assurance features within ProVAL. For this table
46、the final percent disincentive is determined by taking the values in column (2) and multiplying them by column (3). The results are shown in column (4). The results in column (4) are then summed and subtracted from 100 to obtain the final percent disincentive. 2016 by the American Association of Sta
47、te Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS 5a R 54-6 AASHTO 6.4.5. Deficiencies and Corrective WorkAll corrective work will be at the contractors expense. 6.4.5.1. A defective segment is any area of localized roughness as determined
48、in Section 6.4.4. 6.4.5.2. Propose a plan and methodology to correct deficiencies and receive approval from the Owner-Agency before beginning any corrective work. This must be done with the purpose of correcting the minimum area needed to decrease the roughness to acceptable limits. ProVALs Smoothne
49、ss Assurance Module is an example of a computer program that can be used to assist in developing a plan. 6.4.5.3. The Owner-Agency will determine the final disposition of defective segments, which may include corrective actions, assessment of a penalty, or some combination thereof. 6.4.5.4. After making corrections, reprofile the corrected pavement section to verify that the corrections have produce
