Grading asphalt binders with the, multiple stress creep recovery test, AASHTO TP 70 and MP 19

Grading Asphalt Binders with the Multiple Stress Creep Recovery Test AASHTO TP-70 and MP-19 “The Future is Coming” Karl Zipf DelDOT February 2014 WARNING Brief History of the Test • DTFH61-08-H-0003 – Cooperative Agreement between the FHWA and the Asphalt Institute • John A D’Angelo (FHWA) • Asphalt Binder ETG • Member Companies of the Asphalt Institute – Technical Advisory Committee • The present test methods for asphalt binder grading not adequately characterize rutting or polymermodified asphalts (PMA) • The current PG System (AASHTO M-320) is blind to modification and requires PG plus tests such as Elastic Recovery to characterize PMA binders • The PG system was supposed to reduce rutting but over the past decade and a half it has not The New Asphalt Binder Test • Uses the DSR which labs already have • Runs the sample 10 times Load and relax MSCR Test Data • The test gives two values which are the basis of the standards, TP-70 and MP-19 • Jnr – Nonrecoverable creep compliance for 10 cycles at a creep stress of 3.2 kPa • % Average Recovery at a creep stress of 3.2 kPa The New Asphalt Binder Test What’s in a Name • SHRP (Sharp) – Strategic Highway Research Program • ISTEA (Ice Tea) – Intermodal Surface Transportation Equality Act • TWG (Twig) – Technical Working Group • MSCR (???) – Multiple Stress Creep Recovery “MASCAR” • Sounds like NASCAR Looks Familiar • USDA Plant Hardiness Zone Map Northeast States LTPP High, Low and USDA M-320 & MSCR Nomenclature • Right now it now it looks like the PG System • The BIG change is that everything is based on the LOCAL high temperature environment • Our environment is 64C and our standard grade, like the PG system is PG 64-22 • Other grades, PG 70, and PG 76 will be tested at 64C as PG 64(something), based on the Jnr • Binder name becomes state/region dependent MSCR and Low Temperature • The low temperature tests and nomenclature will not change with MSCR • It still uses the BBR results • The mid temperature criteria, the mm DSR test, will have 6000 kPa as a cutoff for the stiffer grades, since for DelDOT the test temp will be 25C MP-19 Grades at 64C • • • • • • • • • Jnr = 2.0 – 4.0 = PG 64S-22 “Standard” = PG 64-22 Jnr = 1.0 – 2.0 = PG 64H-22 “Heavy” = PG 70-22 Jnr = 0.5 – 1.0 = PG 64V-22 “Very Heavy” = PG 76-22 Jnr = 0.25 – 0.5 = PG 64E-22 “Extreme” = PG 76-22 Note MP-19 uses “High” & “Heavy” interchangeably Standard “S” = traffic < 10 million ESALs, > 70 km/h Heavy “H” = traffic 10-30 million ESALs, 20-70 km/h Very Heavy “V” = traffic > 30 million ESALs, < 20km/h Extreme “E” > 30 million ESALs, < 20km/h, toll plazas Polymer Curve & DelDOT Data Where the New Grades Fall at 64C When Will DelDOT See MP-19? • The FHWA is pushing the MSCR test ASAP • The Asphalt Institute is pushing the MSCR test • The NEAUPG (Northeast Asphalt User-Producer Group) is reviewing a limited regional implementation for maybe 2014 • NEAUPG will be polymer curve in 2014, and nonPMA in a future year • SEAUPG will consider it in 2015, central USA later, and west coast probably not at all • National implementation date is unknown DelDOT M-320 vs MP-19 Grades • • • • • • • PG 58-28 = PG 58S-28, Jnr 2.0 – 4.5 58C PG 64-22 = PG 64S-22, Jnr 2.0 - 4.5 64C PG 64-28 = PG 64S-28, Jnr 2.0 – 4.5 64C PG 70-22 = PG 64H-22, Jnr 1.0 – 2.0 64C No Grade = PG 64V-22, Jnr 0.5 – 1.0 64C For 2014 ? PG 76-22 = PG 64E-22, Jnr < 0.5 64C and meet polymer elasticity curve DelDOT and PG 76-22 as MSCR 64V 64E NEAUPG & PMA • From Maine to Maryland there will probably be two standard grades, PG 58S & PG 64S • NYDOT will switch over all grades around Sept 2014 to MP-19 MSCR and RAP • Like the PG System, M-320 the MSCR spec, MP-19 is based on 100% virgin binders • RAP is stiff, Jnr 0.1 - 0.2, but not elastic so will fail the polymer curve • RAP affects the low temperature properties, and these rules have not changed, and it is the low temperature where one sees failure August 2014 • The MSCR Test AASHTO TP-70 will be a full standard AASHTO T-350 • The MSCR Binder Grading AASHTO MP-19 will be a full standard, AASHTO M-322 The End (Not really There will probably be more next year.) Questions? Implementing a New Standard ... times Load and relax MSCR Test Data • The test gives two values which are the basis of the standards, TP- 70 and MP- 19 • Jnr – Nonrecoverable creep compliance for 10 cycles at a creep stress of... sees failure August 2014 • The MSCR Test AASHTO TP- 70 will be a full standard AASHTO T-350 • The MSCR Binder Grading AASHTO MP- 19 will be a full standard, AASHTO M-322  ... (???) – Multiple Stress Creep Recovery “MASCAR” • Sounds like NASCAR “Massacre” • Like in the Boston Massacre “Mascara” • Both asphalt and mascara are black “Muskrat” • Multiple Stress Creep Recovery