2 Asphalt Pavement Facts FDOT: 5 million tons asphalt per yearApproximately $500 million300 construction projects96% of pavements in Florida are asphalt93% of pavements in US are asphaltIt’s 100% recyclable (RAP)Typical life-span in Florida is 17 years
3 Statewide Pavement Performance Section of Florida Statutes:“Ensuring that 80% of the pavement on the SHS meets Department Standards”
5 Deficient RoadwaysSome may think that we are getting better and better due to the fact that we are resurfacing more and more. This actually shows that not to be true. We are resurfacing about the same # lane miles per year (bar chart) and our # deficient lane miles is declining (line graph).With the new system of the resurfacing program being 25 years, and more of the work program being focused on capacity, the line may go up slightly; the bar graph will decrease.
6 Asphalt Specifications Update January 2013 – July 2014
7 January 2013 Workbook Section 300 – Prime and Tack Coats Approved NTSS-1hm (trackless tack) as prime coatTack all asphalt layers (clarification)
8 January 2013 WorkbookSection 320 – Hot Mix Asphalt – Plant Methods and EquipmentNo 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”
9 January 2013 WorkbookSection 330 – Hot Mix Asphalt - General Construction RequirementsEliminated mandatory requirement to perform QC rolling straightedge testing on friction course if final acceptance is by laser profilerCan only mill out high straightedge deficiencies. No milling of “two highs” to fix a low deficiency
10 Asphalt Binder Grade for Mixes Containing RAP January 2013 WorkbookSection 334 – Superpave Asphalt ConcreteLowered minimum overbuild thickness for SP-12.5 to ½”Removed Ninitial requirementsTable 334-2Asphalt Binder Grade for Mixes Containing RAPPercent RAPAsphalt Binder Grade0 - 15PG 67-22PG 58-22>30PG 52-28
11 January 2013 Workbook Section 334 – Superpave Asphalt Concrete No density testing if less than 50 tons of “density mix” in a sublotNo 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
12 January 2013 Workbook Section 916 – Bituminous Materials Elimination of RA viscosity graded binders. Now all binders are PG gradedRemoved RA-500, RA-750, RA-1000, RA-1500 and replaced with PG and PG 58-22No longer using PG for HMAEliminated net total of three bindersMaterials Memo issued to allow use on contracts let prior to January 2013
13 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 EngineerSection 320 – Hot Mix Asphalt – Plant Methods and EquipmentCover and tie down all loads of friction course
14 July 2013 WorkbookSection 330 – Hot Mix Asphalt - General Construction RequirementsMoved FC-5 temperature requirements from 337 to 330
15 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 layerPavement Composition Report changed to Pavement Coring Report
16 July 2013 Workbook Section 336 – Asphalt Rubber Binder Eliminated ARB-5 and ARB-12Section 916 – Bituminous MaterialsAddition of “PG (ARB)” to replace ARB-5 and ARB-12Requirements for “PG (ARB)”:Minimum 7% GTR. CertificationOptional polymer modification, if neededMust meet the requirements for PG 76-22Additional “separation” requirement to minimize settlement
17 July 2013 Workbook Section 916 – Bituminous Materials Previous PG with SBS polymer renamed to PG (PMA)PG (PMA) added to standard specificationImplementation of Multiple Stress Creep Recovery (MSCR) tests for modified binders onlyPolyphosphoric acid (PPA) may be used as a modifier not exceeding 1.25% by weight of asphalt binder
18 July 2013 Workbook Section 919 – Ground Tire Rubber Modified gradation requirements (only max particle size; 98% passing no. 30 sieve)Removed mandatory ambient grinding requirementChanged maximum Rubber Hydrocarbon Content from 55% to 60% to reflect modern day tires
19 January 2014 WorkbookSection 320 – Hot Mix Asphalt – Plant Methods and EquipmentAllows the first five loads of WMA to be produced at HMA temperature for purposes of heating the paver. Mix temperature not to exceed 330°FSection 330 – Hot Mix Asphalt - General Construction RequirementsDo not use diesel fuel or other petroleum based solvents contained in an open container for cleaning purposes on the paver
20 January 2014 Workbook Section 334 – Superpave Asphalt Concrete Removed coarse graded mixturesIncreased maximum lift thickness of fine graded SP-19.0 mix type from 3" to 3-1/2" because coarse graded mixtures were removedSection 337 – Asphalt Concrete Friction CoursesIncreased maximum possible design AC content for granite FC-5 mixtures from 7.0 to 7.5%
21 January 2014 Workbook Section 916 – Bituminous Materials Added a statement that excess PG (ARB) could be mixed with unmodified binder under the conditions outlined in the specification
22 July 2014 Workbook Section 300 - Prime and Tack Coats Removed cut-back prime coats and emulsion grades not being used any moreAdded two new trackless tack productsSection 320 – Hot Mix Asphalt – Plant Methods and EquipmentAdded 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
23 July 2014 Workbook Section 334 – Superpave Asphalt Concrete Added clarification for SP-19.0 mixtures: "Type SP 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.
24 July 2014 Workbook Section 916 – Bituminous Materials Removed cut-backs, some emulsions, and added trackless tacksEmulsions now approved and monitored like binders. Added to the QPL.For PG (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.
26 NCAT Test Track20” 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 miles per driver per day. 6 days per week.3 year research cycle10 million ESALs applied over two years. (10.36 ESALs per pass)Forensics and reconstruction on 3rd year.Florida Department of Transportation
27 NCAT Test TrackFine vs. Coarse (PG 67-22)Continuation of 2000 cyclePG vs. PG 76-22Validation of SMO HVSValidation of Energy RatioBonded Friction CourseThick tack coatsPolymer vs. RubberHigh RAP vs. ShinglesFlorida Department of Transportation
28 Pavement Preservation Traditionally FDOT has focused on milling and resurfacingHigher traffic volume roadwaysGoal: Get in, get out, stay out…We technically do very little “traditional” pavement preservation. Mainly because of the high traffic levels. The public doesn’t understand why FDOT shuts down lanes, and works on a road (pavement preservation) and then five years later are out there again. Because of our good high quality subgrades and bases, our pavements generally function like perpetual pavements. Majority of the distress is within a few inches of the surface.
29 Hot-In-Place Recycling FDOT looking at alternatives…Hot-In-Place RecyclingMicrosurfacingWe’ve done a bunch of HIPR since 2001 (we did HIPR prior to that, but it was really outdated technology in the 70’s and early 80’s.) Some turned out well – SR-471 in Sumter County was reworked in 2002 and is 11+ years old; some didn’t - CR-315 in Putnam County was reworked in 2001 and failed within a few months.Crack SealingFog Seal
30 Hot in-Place Recycling 12 projects* constructed to date:11 as “Reworked Asphalt”1 as “Repaved Asphalt”Every district except for TurnpikeEarliest project* 2001Four projects completed in 2012* “Modern” EraWe’ve done a bunch of HIPR since 2001 (we did HIPR prior to that, but it was really outdated technology in the 70’s and early 80’s.) Some turned out well – SR-471 in Sumter County was reworked in 2002 and is 11+ years old; some didn’t - CR-315 in Putnam County was reworked in 2001 and failed within a few months.
31 Microsurfacing First FDOT microsurfacing project: US-319 Leon County2010Worked with several Contractors & Suppliers on specificationBased on ISSA requirementsISSA Type II mixture gradationSpread rate 20 – 26 lbs/sySingle courseRequired crack sealingWe did a micro-surfacing job on US-319 in Leon County in Cracks have all reflected up through the surface. We may have selected a job that was too cracked to begin with, plus it was only a single course.March 2014 project in Gainesville on NW 39th Avenue. It’ll be double course.
32 Crack Sealing Five Crack Seal Test Decks were placed in March 2012 Leon, Baker, Sumter, DeSoto, and Miami-Dade CountiesSeveral materials and construction techniques evaluatedPerformance will be monitored for three to five yearsWe did a number of crack sealing projects around the state in We’re monitoring them to see if they are effective. Typically cracks are sealed to keep water out of the base, and since our cracking is generally top down, we’re not sure that it’ll do much good. But we’ll see if it slows the crack growth.Crack seal test decks were constructed at five locations statewide:SR 61, Leon CountySR 121, Baker CountySR 471, Sumter CountySR 72, Desoto CountySR 997, Miami-Dade CountyEach test deck is 1.25 miles in length and consists of only one lane.The test decks are divided into five 1/4-mile segments. From south to north (or west to east) the five segments are the same at each location:Segment 1: Routing and sealing with asphalt rubber binderSegment 2: Crack filling with asphalt rubber binderSegment 3: Control (no work)Segment 4: Routing and sealing with polymer modified binderSegment 5: Crack filling with polymer modified binderConstruction occurred at all five locations in March 2013.Monitoring of each location will occur annually for a period of 3-5 years.Initial project selection criteria included roadway segments that had a 2012 crack rating between 7.0 and 8.0, a ride rating of 7.2 or better, and a rut rating of 9 or 10. Only dense graded friction courses were considered.Friction measurements were taken within 1-3 months of construction at all five locations. In comparison with the previously recorded friction measurement for each roadway segment, the average reading for the five sections were: +3.6, -0.6, +1.4, +2.6, and -4.6. I haven’t discussed the ramifications of these measurements with anyone, and I would hesitate to make any generalizations, but I do not see any discernable pattern with the data, and they all appear to be relatively close to the baseline measurements.Crack, ride, and rut measurements were taken for each segment (25 total) about three months prior to construction and about 2-3 months after construction. A comparison of the before and after measurements for the 20 segments that received treatment follows:Average IRI for each segment increased by 5.1 after construction. Over half of that increase came from four specific segments found in the first two jobs that were constructed. It appears from the data (and it appeared to me in the field) that once the guy working the wand became comfortable with the process and what I was looking for, that we got a much smoother product. The average IRI increase for segments found in the final three jobs was only 2.6.Average Ride Number (RN) for each segment decreased by 0.14 after construction. This would correspond with an average decrease in ride rating of 0.28. However, looking only at the final three jobs, the average RN for each segment decreased by only 0.07, which corresponds with an average decrease in ride rating of 0.15.Average rut rating was not affected by the installation of crack sealing.The final crack rating did not change for 18 of the 20 segments. However, an improvement in crack rating would not be expected immediately for roads with generally light crack severity. An improvement in crack rating would be evidenced over time, by comparison to the control section, which we would expect to deteriorate to moderate or severe cracking, while the test sections might be expected to maintain their “light cracking” status for a longer period of time.
33 Fog Sealing Test Sections Placed in 2013US-27 & US-17 Polk CountyPlaced on OGFCAttempt to reduce raveling & top-down crackingAge: 4 years oldGood conditionMultiple Test SectionsMultiple ProductsWe’re looking at fog sealing (at an early age) to see if it’ll extend the life of the pavement by either preventing raveling or top down cracking. The problem with fog sealing is the fairly dramatic loss of friction on the surface. It gets better in a few days/weeks but it’s a pretty high risk. Friction numbers can go down anywhere from 2 points down to 15 points (i.e., 40 to a 25), depending on the production.
34 Pavement Preservation Test Sections US-98 Gulf CountyConstructed 2012Ten Test Sections:Control SectionMicro-surfacing (Double course)1/2” HMA overlays with 4.75 mm mix3/4” HMA overlays with 4.75 mm mix1” HMA overlay with 9.5 mm mixHot-in-place recyclingBonded open graded friction courseMill and resurface 1.0” with 9.5 mm mixMill and resurface 1.5” with 12.5 mm mixControl sectionWe did a controlled experiment on US-98 in Gulf County. Construction was in Dec 2012 – Tried a number of things. Each section was 0.1 mile long. One Year PCS survey is coming up – they had equipment issues in December. This project will help guide FDOT’s direction on preservation.
41 Bonded Friction Course ConventionalTracklessUltraFuseeTacFlorida Department of Transportation
42 Other Research Binder Rejuvenators Optimization of FC-5 characteristicsField test method to detect Polymer and/or GTRPerformance Specification for Tack – Bond StrengthFC-5 image analysis for determination of optimum binder contentUnderstanding mechanisms of OGFC ravelingNew Flow Number (FN) Test: iRLPDHydrated Lime StudyVolumetric refinementAlternative technique(s) to mitigate reflective crackingRAP with Dense-graded FCEvaluation of FL mixes for crack resistance using Overlay Tester