Recycled Asphalt Shingles Floridas Perspective James A Musselman

Recycled Asphalt Shingles Florida’s Perspective James A. Musselman, P. E. State Bituminous Materials Engineer Florida Department of Transportation

Hot Mix Asphalt (HMA) Recycling • Started in 1977: – Contractor, FDOT, FHWA initiative – Multiple pilot projects – Good short-term performance • 1980: Recycled HMA specifications developed as a standard practice

Some Historical Data on RAP • FDOT usage since 1980: – 150 million tons HMA – 33 million tons RAP • Resource savings: – 31. 7 million tons aggregate – 1. 7 million tons asphalt binder • 2012/2013: – RAP in 85% of all HMA – Average RAP content: 25% • Good performance history with RAP – Transportation Research Record 2294

Recycled Tire Rubber • 1988 Legislation – Florida Statute 336. 044 – Contracted research – Multiple pilot projects • 1994: Asphalt rubber specifications adopted • Used in friction courses and interlayers • FDOT usage since 1994: – Over 70, 000 tons of GTR – Over 7 million tires • Improved performance over unmodified asphalt

SR-16 Bradford County With ARB Without ARB

FDOT is very progressive in adopting new technologies… …but is very cautious with respect to RAS. Here’s why….

Pavement Performance • Pavements are in very good condition – < 8% of system is deficient • Cracking biggest pavement distress • Typically top-down cracking • Concerned with stiff and brittle materials

Statewide Pavement Condition 28% 26% 24% Crack 22% Ride % Deficient 20% Rut 18% 16% 14% 12% 10% 8% 6% 4% 2% 0% 95 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 012 013 014 1 2 2 1 1 1 2 2 2 2 19 Year

Concerns with RAS • Binder stiffness – Extremely high viscosity • RAS ~ >10 million poises (PG 125+) • New pavements ~ 15, 000 poises (PG 70) – Will it increase cracking potential? • Will a stiff base lessen the risk? • Binder availability – How much of it is really viable asphalt? • High P-200 contents • Mix design considerations – AASHTO methods are lacking • Long term performance data

Other issues • RAP surplus in Florida – Increased RAS usage = decreased RAP usage • Stockpiling methods? – With RAP? Sand? Alone? – Impact of moisture – Impact of variable RAS feeds • Manufactured waste versus tear-offs – Deleterious materials

Future? • May become an environmental/political reality – Florida has hurricanes; hurricanes damage roofs • FDOT sponsored 2012 NCAT test track sections – PG 76 -22, 20% RAP, 5% RAS – PG 76 -22, 25% RAP control • Upcoming projects with RAS test sections: – – Manufactured Waste or Tear-Offs 100% Passing the No. 4 sieve. Max 3 - 5% (by weight) or max 40 – 50 % binder replacement PG 52 -28 binder • AASHTO guidance

Thank You! Comments / Questions?