Technical Report Documentation Page 1. Report No. FHWA/TX-06/5-4577-01-1
2. Government Accession No.
3. Recipient's Catalog No.
4. Title and Subtitle PILOT IMPLEMENTATION OF PAVE-IR FOR DETECTING SEGREGATION IN HOT-MIX ASPHALT CONSTRUCTION
5. Report Date September 2005 Resubmitted: February 2006
6. Performing Organization Code
7. Author(s) Stephen Sebesta, Tom Scullion, Wenting Liu, and Gerry Harrison
8. Performing Organization Report No. Report 5-4577-01-1 10. Work Unit No. (TRAIS)
9. Performing Organization Name and Address Texas Transportation Institute The Texas A&M University System College Station, Texas 77843-3135
11. Contract or Grant No. Project 5-4577-01 13. Type of Report and Period Covered Technical Report: September 2003-August 2004
12. Sponsoring Agency Name and Address Texas Department of Transportation Research and Technology Implementation Office P. O. Box 5080 Austin, Texas 78763-5080
14. Sponsoring Agency Code
15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. Project Title: Further Development of NDT Devices to Identify Segregation in HMAC URL: http://tti.tamu.edu/documents/5-4577-01-1.pdf 16. Abstract Past research projects illustrated temperature differentials greater than 25 F on hot-mix asphalt (HMA) construction projects indicate potential segregation problems in the mat. Through the years infrared cameras have been used to collect thermal data on newly placed HMA projects. Texas Transportation Institute (TTI) researchers refined infrared methods for detecting segregation on paving projects by developing an infrared temperature bar and accompanying data collection and processing software package. As a combined system, called Pave-IR, TTIs system allows for much simpler data collection and analysis procedures as compared to using infrared cameras. This report documents pilot efforts to implement Pave-IR into Texas Department of Transportation operations, including the current equipment development and example data from Pave-IR. 17. Key Words Segregation, Hot Mix Asphalt, Infrared Imaging, Quality Control
18. Distribution Statement No restrictions. This document is available to the public through NTIS: National Technical Information Service Springfield, Virginia 22161 http://www.ntis.gov
19. Security Classif.(of this report) Unclassified
20. Security Classif.(of this page) Unclassified
21. No. of Pages 26
22. Price
Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
http://tti.tamu.edu/documents/5-4577-01-1.pdfhttp://www.ntis.gov
PILOT IMPLEMENTATION OF PAVE-IR FOR DETECTING SEGREGATION IN HOT-MIX ASPHALT CONSTRUCTION
by
Stephen Sebesta Associate Transportation Researcher
Texas Transportation Institute
Tom Scullion, P.E. Research Engineer
Texas Transportation Institute
Wenting Liu, P.E. Associate Research Scientist
Texas Transportation Institute
and
Gerry Harrison Research Technician
Texas Transportation Institute
Report 5-4577-01-1 Project 5-4577-01
Project Title: Further Development of NDT Devices to Identify Segregation in HMAC
Performed in cooperation with the Texas Department of Transportation
and the Federal Highway Administration
September 2005 Resubmitted: February 2006
TEXAS TRANSPORTATION INSTITUTE The Texas A&M University System College Station, Texas 77843-3135
v
DISCLAIMER
The contents of this report reflect the views of the authors, who are responsible for the
facts and the accuracy of the data presented herein. The contents do not necessarily reflect the
official views or policies of the Texas Department of Transportation or the Federal Highway
Administration. This report does not constitute a standard, specification, or regulation. The
engineer in charge was Tom Scullion, P.E. (Texas, # 62683).
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ACKNOWLEDGMENTS
This project was made possible by the Texas Department of Transportation and the
Federal Highway Administration. Special thanks must be extended to Magdy Mikhail, P.E., for
serving as the project director, and Craig Clark, P.E., for serving as the program coordinator.
vii
TABLE OF CONTENTS
Page List of Figures .............................................................................................................................. viii
List of Tables ................................................................................................................................. ix
Executive Summary ........................................................................................................................1
Chapter 1. The Current Pave-IR System.........................................................................................3
Background..................................................................................................................................3
Overview of the Current Pave-IR System ...................................................................................4
Closer Details of Pave-IR System Components ..........................................................................5
Chapter 2. Example Field Use of Pave-IR......................................................................................9
Background of Field Surveys.......................................................................................................9
Results from Type D HMA in Paris District ...............................................................................9
Chapter 3. Recommendations .......................................................................................................13
References ....................................................................................................................................15
viii
LIST OF FIGURES
Figure Page 1.1. Concept Infrared Temperature Bar (4) ................................................................................3
1.2. TTIs Current Pave-IR System Collecting Project Data......................................................5
1.3. Infrared Sensor Installed in Blackbody for Calibration (a)
and Pave-IR Calibration in Progress (b) ..............................................................................6
1.4. Master Control Box for Pave-IR..........................................................................................7
1.5. Sensor Side and Internal Sides of Temperature Bar ............................................................8
2.1. Example Thermal Profile from Initial Paving Operation on US 82 ..................................10
2.2. Example Thermal Profile from Modified Paving Operation on US 82 .............................10
2.3. Histogram of Measured Mat Placement Temperatures from Initial
Paving Operation on US 82 ...............................................................................................11
2.4. Histogram of Measured Mat Placement Temperatures from
Modified Paving Operation on US 82 ...............................................................................11
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LIST OF TABLES
Table Page 1.1. Key Pave-IR Hardware Specifications ................................................................................4
1
EXECUTIVE SUMMARY This report documents the current Pave-IR system developed by the Texas Transportation Institute (TTI) for pilot implementation into operations of the Texas Department of Transportation (TxDOT). TTI currently has three operable units of Pave-IR, which consists of a transverse bar with 10 infrared sensors immediately behind the paver, and the Pave-IR software package, which collects and displays the thermal profile in real time as the paving train progresses. In addition to real-time data display, Pave-IR can display in real time whether the paving temperatures fall within user-defined limits, and during paving Pave-IR can provide a histogram of temperatures every 100 ft. (30.5 m). Post-processing functions in Pave-IR currently consist of data playback and review, spot temperature display, and creation of a histogram of the placement temperatures for the entire data file. Together Pave-IR hardware and software provide a system that is rugged, easy to service and maintain, simple to set up and operate, and useful for providing a large amount of near full-coverage data for evaluating hot-mix asphalt (HMA) paving projects during placement. In many instances Pave-IR surveys have revealed significant thermal variations in HMA paving projects which likely would not have been detected without Pave-IR. Pave-IR surveys can not only be used to evaluate a project for thermal segregation, but should also be performed after implementation of corrective action on the project to ensure the effectiveness of changes made to the placement process.
3
CHAPTER 1
THE CURRENT PAVE-IR SYSTEM BACKGROUND
In 1996 Read revolutionized how industry viewed segregation when he used an infrared camera to determine that temperature differentials in HMA appeared related to segregation (1). With Reads discovery, the concept of segregation types including the
