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Pavement Performance. Specifications. Research. Asphalt Pavement Facts. FDOT: 5 million tons asphalt per year Approximately $500 million 300 construction projects 96% of pavements in Florida are asphalt 93% of pavements in US are asphalt It’s 100% recyclable (RAP)
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Pavement Performance Specifications Research
Asphalt Pavement Facts • FDOT: 5 million tons asphalt per year • Approximately $500 million • 300 construction projects • 96% of pavements in Florida are asphalt • 93% of pavements in US are asphalt • It’s 100% recyclable (RAP) • Typical life-span in Florida is 17 years
Statewide Pavement Performance Section 334.046 of Florida Statutes: “Ensuring that 80% of the pavement on the SHS meets Department Standards”
Asphalt Specifications Update January 2013 – July 2014
January 2013 Workbook • Section 300 – Prime and Tack Coats • Approved NTSS-1hm (trackless tack) as prime coat • Tack all asphalt layers (clarification)
January 2013 Workbook • Section 320 – Hot Mix Asphalt – Plant Methods and Equipment • No more viscosity testing of RAP every 5000 tons (Materials Memo 01-13) • Can use loaded aggregate trucks for scale checks. • Modified wording related to release agents; banning petroleum based products, not just “diesel fuel”
January 2013 Workbook • Section 330 – Hot Mix Asphalt - General Construction Requirements • Eliminated mandatory requirement to perform QC rolling straightedge testing on friction course if final acceptance is by laser profiler • Can only mill out high straightedge deficiencies. No milling of “two highs” to fix a low deficiency
January 2013 Workbook • Section 334 – Superpave Asphalt Concrete • Lowered minimum overbuild thickness for SP-12.5 to ½” • Removed Ninitialrequirements
January 2013 Workbook • Section 334 – Superpave Asphalt Concrete • No density testing if less than 50 tons of “density mix” in a sublot • No more pro-rating LOT pay factors by density required/no density required areas. Entire LOT gets pay factor unless entire LOT is no density required
January 2013 Workbook • Section 916 – Bituminous Materials • Elimination of RA viscosity graded binders. Now all binders are PG graded • Removed RA-500, RA-750, RA-1000, RA-1500 and replaced with PG 52-28 and PG 58-22 • No longer using PG 64-22 for HMA • Eliminated net total of three binders • Materials Memo 11-26 issued to allow use on contracts let prior to January 2013
July 2013 Workbook • Section 234 – Superpave Asphalt Base • Can substitute a SP-12.5 Traffic Level D or E mixture in lieu of a Type B-12.5 mixture, not to exceed 500 tons for a project, at no extra cost to the Department, in limited situations if approved by the Engineer • Section 320 – Hot Mix Asphalt – Plant Methods and Equipment • Cover and tie down all loads of friction course
July 2013 Workbook • Section 330 – Hot Mix Asphalt - General Construction Requirements • Moved FC-5 temperature requirements from 337 to 330
July 2013 Workbook • Section 334 – Superpave Asphalt Concrete • Variable thickness overbuild layers constructed using a Type SP-9.5 or SP-12.5 mixtures may be tapered to zero thickness provided a minimum of 1-1/2 inches of dense-graded mix is placed over the variable thickness overbuild layer • Pavement Composition Report changed to Pavement Coring Report
July 2013 Workbook • Section 336 – Asphalt Rubber Binder • Eliminated ARB-5 and ARB-12 • Section 916 – Bituminous Materials • Addition of “PG 76-22 (ARB)” to replace ARB-5 and ARB-12 • Requirements for “PG 76-22 (ARB)”: • Minimum 7% GTR. Certification • Optional polymer modification, if needed • Must meet the requirements for PG 76-22 • Additional “separation” requirement to minimize settlement
July 2013 Workbook • Section 916 – Bituminous Materials • Previous PG 76-22 with SBS polymer renamed to PG 76-22 (PMA) • PG 82-22 (PMA) added to standard specification • Implementation of Multiple Stress Creep Recovery (MSCR) tests for modified binders only • Polyphosphoric acid (PPA) may be used as a modifier not exceeding 1.25% by weight of asphalt binder
July 2013 Workbook • Section 919 – Ground Tire Rubber • Modified gradation requirements (only max particle size; 98% passing no. 30 sieve) • Removed mandatory ambient grinding requirement • Changed maximum Rubber Hydrocarbon Content from 55% to 60% to reflect modern day tires
January 2014 Workbook • Section 320 – Hot Mix Asphalt – Plant Methods and Equipment • Allows the first five loads of WMA to be produced at HMA temperature for purposes of heating the paver. Mix temperature not to exceed 330°F • Section 330 – Hot Mix Asphalt - General Construction Requirements • Do not use diesel fuel or other petroleum based solvents contained in an open container for cleaning purposes on the paver
January 2014 Workbook • Section 334 – Superpave Asphalt Concrete • Removed coarse graded mixtures • Increased maximum lift thickness of fine graded SP-19.0 mix type from 3" to 3-1/2" because coarse graded mixtures were removed • Section 337 – Asphalt Concrete Friction Courses • Increased maximum possible design AC content for granite FC-5 mixtures from 7.0 to 7.5%
January 2014 Workbook • Section 916 – Bituminous Materials • Added a statement that excess PG 76-22 (ARB) could be mixed with unmodified binder under the conditions outlined in the specification
July 2014 Workbook • Section 300 - Prime and Tack Coats • Removed cut-back prime coats and emulsion grades not being used any more • Added two new trackless tack products • Section 320 – Hot Mix Asphalt – Plant Methods and Equipment • Added language "For warm mix asphalt, the Contractor may produce the first five loads of the production day and at other times when approved by the Engineer, at a hot mix asphalt temperature not to exceed 330°F for purposes of heating the asphalt paver
July 2014 Workbook • Section 334 – Superpave Asphalt Concrete • Added clarification for SP-19.0 mixtures: "Type SP-19.0 - May not be used in the final (top) structural layer below FC-5 mixtures. Type SP-19.0 mixtures are permissible in the layer directly below FC-9.5 and FC-12.5 mixtures." • Set time limit of 60 days for how long a LOT can be left open.
July 2014 Workbook • Section 916 – Bituminous Materials • Removed cut-backs, some emulsions, and added trackless tacks • Emulsions now approved and monitored like binders. Added to the QPL. • For PG 76-22 (ARB), provide a certification statement on the product evaluation application and in the Quality Control Program that a minimum of 7.0% GTR is used in the formulation of the binder.
NCAT Test Track • 20” of asphalt base insures all failures are in the top 4” asphalt structural layers. • One truck = six fully loaded 18-wheelers (152,000 lbs.) • Five trucks are operational at one time. ≈ 45 mph. • Load 5 AM to 11 PM. Two shifts per day. 340 miles per driver per day. 6 days per week. • 3 year research cycle • 10 million ESALs applied over two years. (10.36 ESALs per pass) • Forensics and reconstruction on 3rd year. Florida Department of Transportation
NCAT Test Track • 2000-2003 • Fine vs. Coarse (PG 67-22) • 2003-2006 • Continuation of 2000 cycle • PG 76-22 vs. PG 76-22 • Validation of SMO HVS • 2006-2009 • Validation of Energy Ratio • 2009-2012 • Bonded Friction Course • 2012-2015 • Thick tack coats • Polymer vs. Rubber • High RAP vs. Shingles Florida Department of Transportation
Pavement Preservation • Traditionally FDOT has focused on milling and resurfacing • Higher traffic volume roadways • Goal: Get in, get out, stay out…
FDOT looking at alternatives… Hot-In-Place Recycling Microsurfacing Fog Seal Crack Sealing
Hot in-Place Recycling • 12 projects* constructed to date: • 11 as “Reworked Asphalt” • 1 as “Repaved Asphalt” • Every district except for Turnpike • Earliest project*2001 • Four projects completed in 2012 * “Modern” Era
Microsurfacing • First FDOT microsurfacing project: • US-319 Leon County • 2010 • Worked with several Contractors & Suppliers on specification • Based on ISSA requirements • ISSA Type II mixture gradation • Spread rate 20 – 26 lbs/sy • Single course • Required crack sealing
Crack Sealing • Five Crack Seal Test Decks were placed in March 2012 • Leon, Baker, Sumter, DeSoto, and Miami-Dade Counties • Several materials and construction techniques evaluated • Performance will be monitored for three to five years
Fog Sealing Test Sections • Placed in 2013 • US-27 & US-17 Polk County • Placed on OGFC • Attempt to reduce raveling & top-down cracking • Age: 4 years old • Good condition • Multiple Test Sections • Multiple Products
Pavement Preservation Test Sections • US-98 Gulf County • Constructed 2012 • Ten Test Sections: • Control Section • Micro-surfacing (Double course) • 1/2” HMA overlays with 4.75 mm mix • 3/4” HMA overlays with 4.75 mm mix • 1” HMA overlay with 9.5 mm mix • Hot-in-place recycling • Bonded open graded friction course • Mill and resurface 1.0” with 9.5 mm mix • Mill and resurface 1.5” with 12.5 mm mix • Control section
RAS • National Hot Topic • FDOT pilot projects • 0.85 Binder Availability • Issues with the unknown
NCAT: High RAP versus RAP/RAS PG 76-22 (PMA) with 25% RAP PG 76-22 (PMA) with 20% RAP & 5% RAS
Pavement Segregation • January 2012 specification • Texture Meter • Pave-IR System
Pave-IR Demo • Oct. 2013 / Turnpike, Palm Beach • Equipment: MOBA Pave-IR • To detect Thermal Segregation
Bonded Friction Course Conventional Trackless UltraFuse eTac Florida Department of Transportation
Other Research • Binder Rejuvenators • Optimization of FC-5 characteristics • Field test method to detect Polymer and/or GTR • Performance Specification for Tack – Bond Strength • FC-5 image analysis for determination of optimum binder content • Understanding mechanisms of OGFC raveling • New Flow Number (FN) Test: iRLPD • Hydrated Lime Study • Volumetric refinement • Alternative technique(s) to mitigate reflective cracking • RAP with Dense-graded FC • Evaluation of FL mixes for crack resistance using Overlay Tester