INTELLIGENT COMPACTION FOR HMA

Transcription

1 South Carolina APA Spring 2010 Asphalt Conference INTELLIGENT COMPACTION FOR HMA February 23, 2010 Robert D. Horan, PE Regional Engineer Asphalt Institute

2 Black Hills, South Dakota

3 AsphaltMagazine.com Asphalt Magazine, which celebrated its 60 th year of publication in 2009.

4 We ve Come a Long Ways! Buffalo Springfield Steam Roller

5 Importance of Compaction We ve known it for a long time "THE IMPORTANCE OF COMPACTION in highway construction has long been recognized. Recent laboratory and field investigation have repeatedly emphasized the value of thorough consolidation in both the base and surfacing courses. Thorough compaction in known to produce the following desirable results: 1. It increases interlocking of the aggregate particles, which is the primary factor in developing a high degree of stability. 2. It retards the entrance of moisture, thus preventing excessive loss of stability under adverse service conditions. 3. It reduces the flow of air and water through bituminous mixtures and is therefore an effective means of lessening damage from weathering and film stripping." Reference -- "Public Roads, May 1939, authors J.T. Pauls and J.F. Goode" 1-5

6 Why Intelligent Compaction? Why Do We Need IC? Proper in-place density is vital for good performance Conventional compaction equipment and procedures have shortcomings and too often produce poor results Intelligent compaction technology appears to offer a better way

7 Shortcomings in Compaction Process Limited On The Fly Feedback Over or Under-Compaction Can Occur

8 Shortcomings in Compaction QC/QA Limited Number of Locations After Compaction is Complete

9 What is Intelligent Compaction?

10 What is Intelligent Compaction?

11 What is Intelligent Compaction? An Innovation in Compaction Control and Acceptance

12 What is Intelligent Compaction? Vibratory Single Drum Soil Roller Vibratory Tandem Drum Asphalt Roller

13 What is Intelligent Compaction? IC Roller Requirements Roller Measurement Value (RMV) GPS-Based documentation system Color-coded display (on-board) Surface temperature measurement system Optional: automatic feedback system

14 IC Pooled Fund (ICPF) ND MN WI NY PA KS IN VA MD 2008 TX MS GA ICPF States / Year

15 Key Questions to Answer Are the IC compaction results improved over conventional compaction? Is the IC compaction more efficient than conventional compaction? Does the IC measurement values correlate well with properties measured using other independent testing?

16 Tandem Drum IC Roller Suppliers Ammann/Case Volvo Dynapac Bomag America Caterpillar Sakai America

17 Available Tandem Drum IC Rollers Bomag Sakai

18 Mat Surface Temperature Measurement Infrared Thermal Gauge

19 Surface Temp vs Internal Temp

20 Color-Coded On Board Display-Sakai

21 Color-Coded On Board Display-Bomag

22 TB 01A Intermediate HMA Layer Georgia ICPF Project Roller pass Sakai CCV Surface temperature ( o C) Sakai IC roller

23 Global Positioning System (GPS) GPS Base Station GPS Radio & Receiver GPS Rover Real Time Kinematic (RTK) GPS Precision

24 How Does GPS Work? High Precision RTK GPS used on projects GPS base station at fixed location GPS receiver and radio on mobile IC rollers Both base and rollers get GPS location Roller receives radio signal of base location/ compares to its location/ corrects roller location Typical nominal accuracy of 1 cm ± horizontally and 2 cm ± vertically Real Time Kinematic (RTK)

25 In Situ Test Devices / Methods LWD-a NG NNG PSPA

26 Major Finding # 1: Improving Roller Patterns

27 Shortcomings of Compaction Process Roller Passes Shoulder (Supported) Paving Direction Courtesy Sakai America Longitudinal Joint

28 Improved Rolling Patterns Before After Indiana ICPF Project Sakai IC roller

29 Major Finding # 2: Mapping Underlying Layers Prior to Placing Surfacing

30 Mapping of underling layers Minnesota ICPF Project Mapping of the subgrade / agg. base layer

31 Mapping of HMA layers Minnesota ICPF Project Compaction/mapping of HMA base course layer

32 MN ICPF Project Reflection of hard spots on the HMA layer HMA Map HMA non-wearing course layer map a = 0.6 mm, f = 3000 vpm Subbase Map Class 5 aggregate subbase layer map, a = 0.6 mm, f = 2500 vpm CCV HMA (a = 0.6 mm, f = 3000) y = 2.45 ln(x) R 2 = CCV Subbase (a = 0.6 mm, f = 2500) CCV Subbase (a = 0.3 mm, f = 3000) C Reflection of hard spots on the HMA layer Reflection of soft spots on the HMA layer CCV Subbase (a = 0.3 mm, f = 3000) Sakai IC roller 5 0 y = 0.27x R 2 = CCV Subbase (a = 0.6 mm, f =

33 Test bed 02 Mapping Bomag Evib Bomag Sakai Sakai CCV Mapping Milled HMA MD ICPF Project

34 Correlations of RMV vs Density Still analyzing data from 2009 ICPF projects Results to date indicate many variables that can adversely affect correlation Mat temperature (min. 220º F?) Mat temperature variations Underlying material support / variability Accuracy / calibration of density gauges

35 What s Next? Demo and Open House Kansas ICPF Open House

36 What s Next? Roller Operator Training

37 What s Next? New / Improved IC Technology Caterpillar Remote Wireless Capabilities

38 Data format Data collection Data storage Data processing Issues with IC Data Develop independent software tool Efficient Accurate Fast What s Next? Management

39 What is Planned for 2010 ICPF? Four projects in VA, PA, ND and WI Two soils and two HMA HMA - concrete rubblization / HMA overlay HMA FDR with WMA overlay Field Projects complete (12 states) ICPF Complete!

40 Benefits of IC for HMA Improve density.better performance Improve efficiency.cost savings Increase information better QC/QA Overall Benefit: Improved Pavement Performance!

41 Where to find more IC info

42 Intelligent Compaction The Future of Compaction Technology?

43 IC for HMA Questions?