1、Standard Practice for Continuous Thermal Profile of Asphalt Mixture Construction AASHTO Designation: PP 80-141American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-5c PP 80-1 AASHTO Standard Practice for Continuous Therm
2、al Profile of Asphalt Mixture Construction AASHTO Designation: PP 80-1411. SCOPE 1.1. This work shall consist of continuous thermal profiling of the asphalt mat temperature immediately behind the paver(s) during placement. 1.2. The equipment uses infrared temperature measurement technology to measur
3、e a longitudinal thermal profile across the pavement width directly behind the paver. This system includes a display that allows the operator in the field to view a pavement surface temperature contour plot and automatically stores and saves the data for later review. 1.3. This standard practice is
4、intended to be applied for construction quality control. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: None 2.2. ASTM Standards: None 3. TERMINOLOGY 3.1. Definitions: 3.1.1. contour plota graphic display of data using contour lines and/or color scales. These plots may display raw values or employ v
5、arying degrees of smoothing. 3.1.2. Distance Measuring Instrument (DMI)a sensor attached to a wheel on the paver to calculate distance and velocity. 3.1.3. Global Positioning System (GPS)a space-based satellite navigation system that provides location and time information, anywhere on or near the Ea
6、rth where there is an unobstructed line of sight to four or more GPS satellites. 3.1.4. indexmeasure or standard to quantify the uniformity of a hot- or warm-mix asphalt construction operation. 3.1.5. summary indicesthe combination of real-time indices plus the distribution of placement temperatures
7、 and the location and duration of paver stops exceeding 1 min. 3.1.6. sample intervalthe longitudinal distance between data thermal profiles. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5c PP 80-2
8、 AASHTO 3.1.7. thermal profilerthe combination of the equipment and host vehicle used to measure the thermal profile. Note 1The paving machine will typically serve as the host vehicle. 3.1.8. thermal profilea set of temperature measurements at discrete intervals across the mat. 4. GENERAL THERMAL PR
9、OFILE REQUIREMENTS 4.1. GeneralThe equipment shall function independently from the paving crew during normal paving operations. Note 2Initial data collection must be initiated by an operator. After initializing the equipment, no operator attendance shall be required for continuous data collection. 4
10、.1.1. The equipment shall be equipped with various sensor(s) and interface hardware that will measure, record, and display the thermal profile. The data shall be stored both internally and on a suitable high-density removable storage device during the test. If needed, the owner-agency may specify ad
11、ditionally to send the data to a remote database automatically. The thermal profile shall be taken within 3 m 10 ft of the trailing edge of the paver. The data must be stored internally at least every 5 min, and if a remote database is specified, then at least by the end of the days paving, the data
12、 will be uploaded automatically. 4.1.2. Distance traveled and velocity during collection of the thermal profile shall be measured using a DMI and/or GPS. The run-time software and postprocessing software shall be used to combine these measurements to develop a thermal-profile result with distance or
13、 stationing and GPS coordinates. 4.1.3. The equipment shall be capable of obtaining and storing profile measurement data at selected longitudinal distance intervals. The equipment shall be capable of a sample interval every 12 in. 305 mm or less at all paving speeds. 4.2. Maximum Sample SpacingMeasu
14、re the thermal profile with sensor(s) that provide temperature measurements that conform to the requirements in Table 1. Table 1Maximum Sample Spacing Location Interval Tolerance Lateral 305 mm 12.0 in. 25 mm 1 in. Longitudinal 152 mm 6 in. 12 mm 0.5 in. Note 3Longitudinal sample spacing may be incr
15、eased to 305 mm 12.0 in. if a single sensor (scanner) is used. 4.3. Calculating Temperature DifferentialThe temperature differential of each thermal profile shall be computed automatically in both real-time and postprocessing using the data collected and stored on either internal or external storage
16、 media. The temperature differential shall be calculated as follows, unless otherwise specified by the owner-agency: 4.3.1. The computer shall be capable of calculating the temperature differential based on a complete or filtered data set, whereby either the operator indicates which temperatures or
17、sensor(s) to ignore, or a supplier-supplied algorithm determines whether specific temperature or sensor data is valid or not. Any supplier-supplied filtering algorithm or operator ignored sensor(s) must be approved by the owner-agency prior to use. 2014 by the American Association of State Highway a
18、nd Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5c PP 80-3 AASHTO 4.4. The operational computer software shall provide all necessary functions for the operator to select and perform roadway testing as required. The test software shall activate the tes
19、ting using the data collection properties stored by the selected project. The position points of each measurement shall be automatically determined using the project property inputs, distance sensor, and/or GPS. The software shall detect abnormal conditions in the status of each sensor and report th
20、e condition to the operator. These results must be automatically transferred to removable media during testing for redundancy of data recording and, if required by the owner-agency, sent to a remote server. Data logged in result files shall be encrypted in a manner to prevent tampering or manipulati
21、on. 4.5. The software shall also display in real time the thermal profile contour plot, total distance, location in terms of station and/or GPS coordinates, paver speed, time, and sensor status. The software shall automatically determine the temperature differential of each thermal profile and allow
22、 the operator access to review the summary indices while maintaining continuous thermal profile data collection. Automated thermal profile testing shall continue until the operator selects to stop data acquisition. Upon stopping data acquisition, the software shall provide a module to input the corr
23、ect ending distance or station should a distance sensor calibration error exist. When used, the software will employ a distance correction and normalize the data to the inputted true distance. 4.6. CalibrationThe equipment shall have built-in provisions to facilitate the calibration and verification
24、 of each infrared temperature sensor(s) signal, DMI, and GPS. These sensor(s) shall be calibrated at intervals not to exceed 12 months in conjunction with a calibration protocol. These recurrent calibrations shall ensure the accuracy of the data. 5. HARDWARE 5.1. General RequirementsThe thermal prof
25、iler shall meet the requirements in Table 2. Table 2Sensor Requirements Sensor Limits Tolerance Infrared Temperature Range 0 to 250C 32 to 480F 1C 1.8F Infrared Temperature Repeatability 0.75 percent of reading or 0.75C 1.4F, whichever is greater GPS Accuracy Within 1.2 m 4 ft in the X and Y directi
26、ons DMI Encoder Accuracy 0.025 5.2. The thermal profiler shall support both English and SI units for distance data incrementing or decrementing mode from a selected starting point and relate the longitudinal distance to any test point. Optionally, the equipment may also report in station format. 5.3
27、. The thermal profiler shall provide real-time and postprocessing software capable of developing and analyzing thermal profiles for the entire project. 5.4. Power consumption of all installed equipment shall not exceed the capacity of the equipment providing operating power. Complete discharge of th
28、is system shall not impact the vehicles regular electrical system. 5.5. Equipment is not allowed to be placed so it impedes the influence area under the thermal sensor(s) or restricting the accuracy and functionality of the GPS or DMI. 6. DATA FILE FORMAT 6.1. The output data shall be formatted so e
29、ach files header conforms to Table 3 and each interval of thermal profile data is formatted as indicated in Table 4. The data shall be saved on the internal 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable la
30、w.TS-5c PP 80-4 AASHTO computer continuously and at least once every 5 min to the external memory device or remote server. Table 3Data Header Description Example Data Section Title Highway 77 Machine Manufacture ABC Company Machine Model Temp Bar Number of Temperature Sensor Readings 10 Lateral Dist
31、ance between Temperature Readings, mm in. 305 12 Distance between Temperature Sensors and Mat, mm in. 914 36 Longitudinal Distance between Thermal Profiles, mm in. 305 12 Table 4Data Blocks Data Field Name Example Data Date Stamp, YYYYMMDD 20130607 Time Stamp, HHMMSS.S (military format) 090504.0 (9
32、hr 5 min 4.0 s) Longitude, decimal degrees, with at least 8 significant digits 94.85920403 Latitude, decimal degrees, with at least 8 significant digits 45.22777335 Distance, m ft 0.3 1 Direction heading, degree angle, clockwise from the north 45 Speed, m/min ft/min 9.1 30 Surface temperature sensor
33、 reading/Location 1, C Fa143 290 Surface temperature sensor reading/Location N, C Fa149 300 aTemperature sensors/locations are numbered from 1 to N, left to right, in the direction of paving. Note 4 The variables defined in the table above are given only as examples. Specific variables and their def
34、initions may differ among agencies. 7. CALIBRATION 7.1. Infrared Temperature SensorBefore each project, compare the thermal output from the infrared temperature sensor(s) to a NIST traceable temperature sensor when measuring a material of a known temperature. If the temperature is outside the limits
35、 or not working as specified in Table 2, then replace the sensor(s). 7.2. GPS SystemBefore each project, the GPS output shall be compared to a survey grade rover coordinate over a static point. The comparison is considered acceptable if the X and Y distance between the GPS system and survey rover ar
36、e within the limits in Table 2. The thermal profiler shall not be used if the difference is outside the limits. 7.3. DMI SystemIf the system uses a DMI, the operational computer software shall allow the operator to perform a distance sensor calibration and use the calculated factor to perform the op
37、erational distance measurements. Make sure the DMI is fully functional before beginning each project. 8. PROFILER ACCURACY 8.1. Thermal Profile PrecisionCurrently, no precision information exists for this test method. 8.2. Thermal Profile BiasCurrently, no bias information exists for this test metho
38、d. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5c PP 80-5 AASHTO 9. REFERENCES 9.1. Miller, S. R., Doree, A. G., ter Huerne, H. L., and Sluer, B. W. Paving the Way Forward: A Case Study in Innovat
39、ion and Process Control. Presented at Fourth Annual Eurasphalt and Eurobitume Congress, May 2123, 2008, Copenhagen, Denmark. 9.2. Read, S. Construction Related Temperature Differential Damage in Asphalt Concrete Pavements. University of Washington, Seattle, WA, 1996. 9.3. Sebesta, S., Saarenketo, T.
40、, and Scullion, T. Using Both Infrared and High-Speed Ground Penetrating Radar for Uniformity Measurements on New HMA Layers. SHRP 2 Project R06(C) Final Report, SHRP 2, Washington, DC. (in publication). 9.4. Sebesta, S., and Scullion, T. “Application of Infrared Imaging and Ground-Penetrating Radar
41、 to Detect Segregation in Hot Mix Asphalt Overlays.” In Transportation Research Record: Journal of the Transportation Research Board, No. 1861, TRB, National Research Council, Washington, DC, 2003, pp. 3743. 9.5. Sebesta, S., and Scullion, T. “Infrared Imaging and Ground-Penetrating Radar as QC/QA T
42、ools for Hot Mix Paving in Texas.” In Asphalt Paving Technology 2007: Journal of the Association of Asphalt Paving Technologists, Vol. 76, Association of Asphalt Paving Technologists, Lino Lakes, MN, 2007. 9.6. Stroup-Gardiner, M., and Brown, E. R., NCHRP Report 441: Segregation in Hot Mix Asphalt P
43、avements. Transportation Research Board, National Research Council, Washington, DC, 2000. 9.7. Ulmgren, N. Temperature ScannerAn Instrument to Achieve a Homogenous Asphalt Pavement. Second Euroasphalt and Eurobitumen Congress, Barcelona, 2000, 6 pp. 9.8. Willoughby, K., Read, S., Mahoney, J. P., Mue
44、nch, S. T., Pierce, L. M., Thompson, T. R., Uhlmeyer, J. S., Moore, R., and Anderson, K. W. Construction Related Asphalt Concrete Pavement Temperature Differentials and the Corresponding Density Differentials. Report WA-RD 476.1, Washington Department of Transportation, Seattle, WA, July 2001. 9.9.
45、Results of the 2013 Survey of AASHTO Members on Upcoming and Potential SHRP2 Projects Available for Implementation, SHRP2, April 2013. http:/shrp2.transportation.org/Documents/AASHTO_Survey_Summary_SHRP2_Products.pdf APPENDIXES (Nonmandatory Information) X1. EXAMPLE ACCEPTANCE CRITERIA X1.1. The fol
46、lowing example acceptance criteria have been developed by the Texas Department of Transportation and the Minnesota Department of Transportation to assess the quality of the mat using this standard practice. Each owner-agency will need to develop their individual criteria. X2. TERMINOLOGY X2.1. moder
47、ate thermal segregation temperature differentials exceeding 5C 25F and not exceeding 11C 50F, unless otherwise defined by the owner-agency. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5c PP 80-6 A
48、ASHTO X2.2. real-time indicesthe number and percentage of thermal profiles with moderate and severe thermal segregation and each thermal profiles actual temperature differential. X2.3. severe thermal segregationtemperature differentials exceeding 11C 50F, unless otherwise defined by the owner-agency
49、. X2.4. temperature differentialthe difference between the statistical 98.5 percentile and the statistical 1 percentile within a thermal profile, unless otherwise specified by the owner-agency. X2.5. thermal profilethe geospatial makeup of hot- or warm-mix asphalt placement temperatures over a paving distance of 45.7 m 150 ft. X2.6. temperature differential = maximum temperature recordedminimum temperature recorded in the thermal profile. Note X1The minimu
