TPF-5(230) Evaluation of Plant-Produced High- Percentage RAP Mixtures in the Northeast

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1 TPF-5(230) Evaluation of Plant-Produced High- Percentage RAP Mixtures in the Northeast Dr. Jo Sias Daniel Northeast Asphalt User/Producer Group Steering Committee Meeting April 6,

2 Research Team University of New Hampshire Dr. Jo Sias Daniel, PE (Project PI) University of Massachusetts Dartmouth Dr. Walaa Mogawer, PE Rutgers University Dr. Tom Bennert, PE NC State University Dr. Y. Richard Kim, PE

3 Pooled Fund Participants New Hampshire (NHDOT) - Lead Agency Maryland (MDOT) New Jersey (NJDOT) New York (NYSDOT) Pennsylvania (PennDOT) Rhode Island (RIDOT) Virginia (VDOT) Federal Highway Administration (FHWA) 3

4 Project Objectives Evaluate the performance of plant-produced RAP mixtures in terms of low temperature and fatigue cracking Impact of plant production variables on material properties (temps, silo storage time) Produce better performing mixtures while also using higher RAP contents 4

5 Testing Virgin & Recovered Binder PG grade & critical cracking temperature Rheology using DSR Mixture Dynamic Modulus Moisture: Hamburg & TSR Low Temperature Creep & Strength, TSRST Fatigue AMPT S-VECD TX Overlay Tester Beam Flexure 5

6 Mixtures Phase I (2010): 18 mixtures, 3 plants: NH, NY, VT, up to 40% RAP, different virgin PG grades Phase II (2011): 10 additional mixtures from NH and VA Phase III (2013): Controlled laboratory study with 20% & 40% RAP, two binder grades, range of binder contents Silo Storage Study Task (2014): virgin & 25% RAP mixture sampled at multiple storage times up to 10 hours 6

7 Phase I: NH PMPC Dynamic Modulus (psi) 10,000,000 1,000, ,000 10,000 RAP % Temperatures ( o F) Silo Storage Agg. Heating Mix Discharge Time (hrs) PG % PG % PG % PG %??? Pike NH % RAP - Plant Compacted Pike NH % RAP - Plant Compacted Pike NH % RAP - Plant Compacted Pike NH % RAP - Plant Compacted 1, E E E E E E E E+07 Loading Frequency (Hz) 7

8 Phase I: NY PG PMPC 8

9 NY 30% RAP Comparison 9

10 NY 40% RAP Comparison 10

11 Impact of Reheating: E* 11

12 Impact of Reheating: E* Ratio Low (4.4C) E* Ratio (Reheated & Compacted/Plant QC Lab Compacted) Pike - VT (52) Pike - VT (64) Call - NY (64) Pike - NH (64) Pike - VT (52) Pike - VT (64) Call - NY (64) Pike - NH (64) Pike - VT (52) Pike - VT (64) Call - NY (64) Pike - NH (64) Pike - VT (52) Medium (20C) High (30 or 35C) Pike - VT (64) Call - NY (64) Pike - NH (64) Virgin 20% RAP 30% RAP 40% RAP

13 Plant vs Lab, Reheat and Field 13

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16 Silo Storage Study Task Early phases indicated likely impact of silo storage time on measured properties Targeted study to evaluate storage time Materials Virgin mixture PG 64-22,12.5 mm NMAS 0, 2.5, 5, 7.5 hours 25% RAP mixture PG 64-28,12.5 mm NMAS 0, 2.5, 5, 7.5, 10 hours End of season high production temperature Source: 16

17 Binder: Glover-Rowe Parameter 17

18 Binder: Glover-Rowe Parameter 18

19 Dynamic Modulus Master Curves 19

20 Lab- versus Plant-Compacted Dynamic Modulus RAP Comparison 0 hr 2.5 hr 5 hr 7.5 hr 10 hr % of LC to PC Dynamic Modulus Temperature (Celsius) and Frequency (Hz) 20

21 Fatigue: G R -N f Better fatigue resistance Virgin mix only G R : Fatigue failure criterion; characterizes damage accumulation N f : Number of cycles to failure 21

22 LVECD Pavement Life Evaluation Uses Dynamic modulus & S-VECD fatigue results Pavement structure: Asphalt layer: 100 mm (thin), 300 mm (thick) Aggregate base: 200 mm, 350 MPa Subgrade: 100 MPa 22

23 LVECD Pavement Life Evaluation 23

24 Summary of Observations Dropping PG grade not effective in all cases Virgin binder grade, RAP stiffness, and binder source important Plant conditions have impact on measured properties Temperature, storage time Specimen fabrication technique matters Reheating, Lab vs field Current laboratory protocols don t always capture what happens in the plant Need to use engineering judgement 24

25 Questions? Inside the RAP drum FM Conway Plant near London 25