WRI Research Related to the Optimal Timing of Preventive Maintenance - PowerPoint PPT Presentation

WRI Research Related to the Optimal Timing of Preventive Maintenance for Addressing Environmental Aging Kickoff Meeting Fred Turner Western Research Institute MnROAD Research Facility July 23, 2008

Relevant Research Contracts � Fundamental Properties of Asphalts and Modified Asphalts III, Federal Highway Administration � Asphalt Surface Aging Prediction (ASAP) System, Research and Innovative Technology Administration • Asphalt Research Consortium, Federal Highway Administration (Aging element, F1c, being conducted by TAMU) 2

FPIII Aging Research • Study aging in laboratory and field conditions • Develop testing methods for analyzing aging • Compare results with the Global Aging System as implemented in the MEPDG 3

Techniques Developed • Micro extraction with FTIR analysis • Photoacoustic FTIR for surface analyses • Small scale DSR methodology for full range modulus and relaxation rheology (in progress) • Carbonyl index • Non-carbonyl FTIR-G* correlations • Spectral correlation software 4

5 Aging at the Arizona Validation Site

Arizona Validation Site Constructed Nov. 2001 2 – 63 mm lifts, 19-mm NMS dense graded Shoulder cored Nov. 2005 aggregate, 4.7% AC) Farrar, M. J., P. M. Harnsberger, K. P. Thomas, W. Wiser. Evaluation of Oxidation in Asphalt Pavement Test Sections after Four Years of Service. Proceedings of the International Conference on Perpetual Pavement, September, 2006, Columbus, Ohio. 6

Asphalt Hardening: Laboratory and Field Aging Relationship between carbonyl content and complex modulus of asphalts 1000 gel G*, kPa, 60°C, 10 rad/s sol 100 10 80°C, Dry 60°C, Dry 80°C, Moist 60°C, Moist AZ1-1 1 0.0 0.1 0.2 0.3 0.4 Carbonyl Content, Absorbance Units 7

Arizona Site Aging Profile Carbonyl Gradient AZ1-1 0.031 Carbonyl Index (A1700/A2900) 1 0.026 0.021 Linear relationship G* Gradient 0.016 3 Log G* vs. C=O 9 5 2 4 Hirsch 7 0.011 8 6 Model 0.006 0 10 20 30 40 50 60 E* Gradient Depth (mm) 8

Infrared Spectra From Each Layer AZ1-3b core Spectra normalized to CH 3 umbrella bending mode at 1376 cm -1 Carbonyl index Sulfoxide index Functional group Aromaticity index depth gradients Other indexes 9

10 G* gradient - Arizona validation site at year four Calibration curve

Carbonyl Index 1.6 0.20 1.4 0.16 1.2 A 2900 Absorbance Absorbance 1.0 0.12 A 1700 0.8 0.08 0.6 0.4 0.04 0.2 0.0 0.00 3100 3000 2900 2800 1800 1600 1400 1200 1000 800 600 -1 Wavenumber, cm -1 Wavenumber, cm A 1700 Carbonyl Index (CI) = A 2900 11

12 Carbonyl Index (8 asphalts)

ASAP Project • Develop and demonstrate ruggedized FTIR instrumentation, data acquisition system, and data processing procedures to predict and monitor the surface embrittlement of asphalt pavements caused by aging 13

Techniques Applied • Micro extraction with FTIR analysis • Photoacoustic FTIR for surface analyses • Carbonyl index • Non-carbonyl FTIR-G* correlations 14

Project Elements Laboratory (WRI) • Validate spectroscopy-rheology correlation • Find non-carbonyl relationship for airborne applications • Prepare samples for calibrating ruggedized FTIR system • Unaged, RTFO-aged, RTFO/PAV-aged, field samples • Develop procedures for handling real-world analyses: • Asphalt content < 100%, • Aggregate infrared absorption, contaminants • Carbonyl indexing • Aggregate and contaminant subtraction techniques 15

Project Elements Development of FTIR system (Innova, PLX, SimWright) • Design, construct, and test a vehicle-mounted ruggedized FTIR system • Demonstrate the technology in the field using a van- mounted, non-contact system • Determine the effective limits for low-altitude airborne deployment 16

Age-Related Change at Surface Az1-1 4-yr viscosity profile Observations and Assumptions • HMA pavements oxidize most 0 2e+5 4e+5 6e+5 8e+5 rapidly at their top surfaces. 0 • The oxidized binder at the surface has a much higher 1 stiffness than the bulk binder. • The surface stiffness or Depth, inches 2 complex modulus at lower ambient temperatures will approach the glassy modulus 3 of the binder (~ 10 9 Pa). • Pavement damage begins 4 under traffic load when the surface complex modulus of 5 the binder reaches some fraction of the glassy modulus 0 2e+5 4e+5 6e+5 8e+5 at current use temperature. 17 Binder Viscosity, P

Infrared Spectra Changes w/ Aging 1.4 WRI/FHWA AAB-1 neat 1.2 AAB-1 RTFO AAB-1 PAV 100°C 20hrs 1.0 AAB-1 PAV 80°C 480hrs Absorbance 0.8 1150 - 1250 cm -1 Region Solvent 0.6 Carbonyl 0.4 0.2 0.0 2000 1800 1600 1400 1200 1000 800 600 18 Wave Number, cm -1

Infrared Spectra Changes w/ Depth 3.0 Pavement Depth WRI/ FHWA 2.5 Surface 0.1" 2.0 Absorbance 0.5" 1.5 1" 1.0 0.5 0.0 2000 1800 1600 1400 1200 1000 800 600 -1 Wave Number, cm 19

G* Correlations With Carbonyl Content For AAB-1 1.E+08 AAB-1 9.54E+00x y = 1.12E+06e 2 = 9.24E-01 R 1.E+07 Shear Modulus, G*, at 10 rad/s 1.E+06 1.63E+01x y = 2.88E+03e 2 = 9.70E-01 R 25°C unaged 1.E+05 25°C RTFO 25°C PAV at 60°C 25°C PAV at 80°C 1.E+04 25°C PAV at 100° 60°C unaged 60°C RTFO 1.E+03 60°C PAV at 60°C 60°C PAV at 80°C 60°C PAV at 100°C 1.E+02 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 -1 ), au Carbonyl Content (1700 cm 20

Analysis of Infrared Spectra for Correlating Regions 1.0 AAM-1 R-Squared for Asphalt AAM-1 Correlation 0.8 0.6 0.4 0.2 Log(G*) at 60°C, 10 Rad/s 0.0 2000 1800 1600 1400 1200 1000 800 600 21 Wave Number

Comparison of Absorbances for Laboratory Sample AAM-1 0.60 AAM-1 0.55 IR Absorbance at 1212 cm -1 0.50 0.45 y = 0.3539x + 0.2358 R 2 = 0.9662 0.40 0.35 0.30 0.25 0 0.1 0.2 0.3 0.4 0.5 0.6 IR Absorbance at 1703 cm -1 22

Relationship Between Absorbance at 1212 cm -1 and G* 6.0 AAM-1 5.5 5.0 y = 9.3037x + 1.153 R 2 = 0.9629 4.5 Log G* 4.0 3.5 3.0 2.5 2.0 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 23 Absorbance at 1212cm-1

G* Correlation Using Absorbance at 1212 cm -1 1000000 y = 0.9974x R 2 = 0.997 100000 G*, fit 10000 Four asphalts, ten aging conditions 1000 100 100 1000 10000 100000 1000000 24 G*, measured 60°C, 10rad/s

PA spectra changes on oxidation of AAD-1 7.42 (a) Blue: Unaged. Green: RTFO only. 7.0 Black: RTFO/PAV 20hours. Brown: RTFO/PAV 144 hours. 6.5 Pink: RTFO/PAV 240 hours. Red: RTFO/PAV 480 hours. 6.0 OPD velocity 0.5 cm/sec, 512 co-added scans, gain (4). 5.5 5.0 ) 4.5 its n u y a 4.0 itr b r (a ity 3.5 s n te n I 3.0 A P 2.5 2.0 1.5 1.0 0.5 0.03 4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600.0 cm-1 25

Photoacoustic spectra – Arizona surface samples from AZ1-3b 512 co-added scans Small (approx. 4 mm wide) samples removed from the surface AZ1-3b core 26

27 PA Spectra of Aggregates

What is Needed? • Validation sites for evaluating concepts and instrumentation • Multiple asphalt sources and grades • Multiple surface treatments • Save original materials • Periodic distress surveys and coring • High-resolution age profiling in cores 28

WRI Contribution • Age profiling in cores using micro extraction, photoacoustic techniques • Field analyses with ASAP System • Other specialized testing? 29

G* Correlations With Carbonyl Content For AAC-1 1.E+08 AAC-1 1.E+07 Shear Modulus, G*, at 10 rad/s 7.92E+00x y = 4.42E+05e 2 = 9.62E-01 1.E+06 R 1.E+05 1.14E+01x y = 6.65E+02e 2 = 9.58E-01 R 1.E+04 25°C unaged 25°C RTFO 25°C PAV at 60°C 25°C PAV at 80°C 1.E+03 25°C PAV at 100°C 60°C unaged 60°C RTFO 60°C PAV at 60°C 60°C PAV at 80°C 60°C PAV at 100°C 1.E+02 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 -1 ), au Carbonyl Content (1700 cm 31

G* Correlations With Carbonyl Content For AAD-1 1.E+08 AAD-1 1.69E+01x y = 4.22E+05e 2 = 9.23E-01 R 1.E+07 Shear Modulus, G*, at 10 rad/s 2.48E+01x 1.E+06 y = 1.64E+03e 2 = 9.74E-01 R 1.E+05 25°C unaged 25°C RTFO 25°C PAV at 60°C 1.E+04 25°C PAV at 80°C 25°C PAV at 100°C 60°C unaged 60°C RTFO 1.E+03 60°C PAV at 60°C 60°C PAV at 80°C 60°C PAV at 100°C 1.E+02 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Carbonyl Content (1700 cm -1 ), au 32

G* Correlations With Carbonyl Content For AAM-1 1.E+08 AAM-1 5.07E+00x y = 1.60E+06e 2 = 9.46E-01 R 1.E+07 Shear Modulus, G*, at 10 rad/s 1.E+06 1.02E+01x y = 3.92E+03e 2 = 9.72E-01 R 1.E+05 25°C unaged 25°C RTFO 1.E+04 25°C PAV at 60°C 25°C PAV at 80°C 25°C PAV at 100°C 60°C unaged 1.E+03 60°C RTFO 60°C PAV at 60°C 60°C PAV at 80°C 60°C PAV at 100°C 1.E+02 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Carbonyl Content (1700 cm -1 ), au 33

Wave Number, cm -1