Forensic Analysis of a 22-Year Old 35% RAP Interstate Project Jo SiasDaniel Kelly Barry North Eastern States Materials Engineers Association Meeting October 23, 2013 1 1
Field Sections Paved in 1987 I-93 Travel & Shoulder 20,000 ADT 35% RAP Surface 35% RAP Binder I-89 Travel & Shoulder 36,000 ADT 0% RAP Surface 15% RAP Binder 19 mm max size AC-10 virgin binder Cores taken in 2010 2 2
Field Cores Cores cut for test specimens 1.5 thick specimens Surface layer Intermediate layer Testing IDT mode Dynamic Modulus Creep and Strength 6 diam ~1.5 Surface Course ~2.5 Intermediate Course 3 3
Air Voids Pavement Lane Layer Air Void I-93 Travel Surface 2.2% Intermed 5.1% Shoulder Surface 3.8% Intermed 5.0% I-89 Travel Surface 4.0% Intermed 2.6% Shoulder Surface 7.6% Intermed 5.1% 4 4
Binder Testing Extraction & Recovery by NHDOT AASHTO T-164 & T-170 Recover binder at 3 depths Top & middle from surface Except I89 Travel Lane Bottom from intermediate Testing DSR frequency sweep BBR DT Surface 0.5 Top 1.0 Middle 1.0 Bottom 5 5
Evaluate differences Project Objectives High RAP and low/no RAP sections Travel vs Shoulder Pavement layer Recovered binder and mixture testing 6 6
Binder Testing & Results 7 7
High Temperature Grade 88 82 High PG Grade, C 76 70 64 58 8 8
Low Temperature Grade Low PG Spec Temperature, C -16.0-22.0-28.0-34.0 S value m value 9 9
5.00 Difference between m-temp and S-temp m-temp minus S-temp, C 4.00 3.00 2.00 1.00 0.00-1.00-2.00 10 10
Top/Mid Temperature Ratio 1.00 Top/Mid Temperature Ratio 0.90 0.80 0.70 0.60 S value m value 0.50 I93 Sh I93 Tr I89 Sh I89 Tr 11 11
Critical Cracking Temperature -6 Critical Cracking Temperature, C -12-18 -24-30 -36 12 12
G* Master Curves G* (MPa) 1.0E+09 1.0E+08 1.0E+07 1.0E+06 1.0E+05 1.0E+04 1.0E+03 93T35t 93T35m 93T35b 93S35t 93S35m 93S35b 89T0t 89T15m* 89T15b 89S0t 89S15m 89S15b 1.0E+02 1.0E-06 1.0E-04 1.0E-02 1.0E+00 1.0E+02 1.0E+04 Reduced Frequency (Hz) 13 13
Travel Lane G* Ratios with Depth Ratio of G* Master Curves 5.0 0.5 1.00E-05 1.00E-03 1.00E-01 1.00E+01 1.00E+03 Reduced Frequency I-93 Top/Mid I-93 Mid/Bot I-93 Top/Bot I-89 Top/Mid I-89 Mid/Bot I-89 Top/Bot 14 14
Shoulder G* Ratios with Depth Ratio of G* 5.0 I-93 Top/Mid I-93 Mid/Bot I-93 Top/Bot I-89 Top/Mid I-89 Mid/Bot I-89 Top/Bot 0.5 1.00E-05 1.00E-03 1.00E-01 1.00E+01 1.00E+03 Reduced Frequency 15 15
RAP Level G* Ratios with Depth Ratio of G* Master Curves 5 I-93 Tr/ I-89 Tr Top I-93 Tr/ I-89 Tr Mid I-93 Tr/ I-89 Tr Bot I-93 Sh/I-89 Sh Top I-93 Sh/I-89 Sh Mid I-93 Sh/I-89 Sh Bot 0.5 1.00E-05 1.00E-03 1.00E-01 1.00E+01 1.00E+03 Reduced Frequency 16 16
Mixture Testing & Results 17 17
Dynamic Modulus Master Curves 8000 7000 6000 E* (MPa) 5000 4000 93 Tr Surf 2.2% AV 3000 93 Tr Int 5.1% AV 2000 93 Sh Surf 3.8% AV 1000 93 Sh Int 5.0% AV 0 89 Sh Surf 7.6% AV 1.E-02 1.E+00 1.E+02 1.E+04 1.E+06 1.E+08 Reduced Freq. (Hz) 18 18
Low Temperature Strength 500 Strength at -10C (psi) 400 300 200 100 0 I93 Tr Surf 2.2% AV I93 Tr Int 5.1% AV I93 Sh Surf 3.8% AV I93 Sh Int 5.0% AV I89 Sh Surf 7.6% AV 19 19
Mix Cracking Temperature 0 Cracking Temperature (C) -3-6 -9-12 I93 Tr Surf 2.2% AV I93 Tr Int 5.1% AV I93 Sh Surf 3.8% AV I93 Sh Int 5.0% AV I89 Sh Surf 7.6% AV 20 20
Summary and Conclusions 21 21
Summary of Binder Results High PG grades similar between high RAP and low/no RAP Shoulders stiffer than travel lanes (2 grades at top) Low PG grades & CCT Most m-controlled Shoulder stiffer than travel lanes -more with low/no RAP Impact of RAP observed in travel lanes, not as large of a difference in shoulder lanes Master Curves Larger differences with depth for low/no RAP Little impact of RAP at surface 22 22
Summary of Mixture Results Only one virgin mixture, air void differences RAP mixes decrease in stiffness and strength with depth Mixed results comparing travel and shoulder Virgin mix stiffest, lowest strength, warmest cracking temperature 23 23
Overall Conclusions Binder data indicates there is difference in how RAP mixtures and low/no RAP mixtures age More uniform properties between layers and lanes in high RAP pavements Differences between RAP and low/no RAP are smaller at the surface and in shoulder Implications in terms of how properties/performance change over life of pavement 24 24
Future Work Include test sections of wider range of RAP contents PG 58-28: 0%, 15%, 25% RAP PG 52-34: 25%, 30%, 40% RAP Evaluate initial mixture and binder performance Evaluate mixture and binder performance at regular time intervals throughout pavement service life 25 25
Kelly Barry Acknowledgements NHDOT for providing support for this work and conducting the binder extraction and recoveries and testing UNH asphalt research team members: Ashton Congalton, Dave Mensching, Sonja Pape 26 26
Infrastructure and Climate Network (ICNet) www.theicnet.org Webinar series CLIMATIC CHANGE IMPACTS ON FUTURE PAVEMENTPERFORMANCE AND MAINTENANCE COSTS Wednesday October 30, 2013 at 2pm EDT 27 27
5/7/2014 Questions? 28 28