Pavement Performance

Florida Department of Transportation

Pavement Performance

Specifications

Research


• 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

Asphalt Pavement Facts


Statewide Pavement Performance

Section 334.046 of Florida Statutes: “Ensuring that 80% of the pavement on the SHS meets Department Standards”


Statewide Pavement Performance

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

22%

24%

26%

28%

CrackRideRut

% D

efi

cie

nt


Deficient Roadways


Asphalt Specifications UpdateJanuary 2013 – July 2014


• 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”



• 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




• Section 334 – Superpave Asphalt Concrete– Lowered minimum overbuild thickness for SP-12.5

to ½”

– Removed Ninitial requirements

Table 334-2Asphalt Binder Grade for Mixes Containing RAPPercent RAP Asphalt Binder Grade

0 - 15 PG 67-2216 - 30 PG 58-22

>30 PG 52-28



• 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



• 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


• 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

July 2013 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



• 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%



• 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



• 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.

July 2014 Workbook


Hot Topics & Research Notables

Florida Department of TransportationFlorida Department of Transportation

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.


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


• Traditionally FDOT has focused on milling and resurfacing

• Higher traffic volume roadways

• Goal: Get in, get out, stay out…

Pavement Preservation


Hot-In-Place Recycling Microsurfacing

Crack Sealing Fog Seal

FDOT LOOKING AT ALTERNATIVES…


• 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

HOT IN-PLACE RECYCLING


• 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

MICROSURFACING


• 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

Crack Sealing


• 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

Fog Sealing Test Sections


• US-98 Gulf County– Constructed 2012

• Ten Test Sections: 1. Control Section2. Micro-surfacing (Double course)3. 1/2” HMA overlays with 4.75 mm mix4. 3/4” HMA overlays with 4.75 mm mix5. 1” HMA overlay with 9.5 mm mix6. Hot-in-place recycling7. Bonded open graded friction course 8. Mill and resurface 1.0” with 9.5 mm mix9. Mill and resurface 1.5” with 12.5 mm mix10. Control section

Pavement Preservation Test Sections


Recycling Program


RAP Data

Conditions FY 10/11

FY 11/12

FY 12/13

FY13/14

Unrestricted (No Maximum Limit)

Average 25% 26% 25% 25%

Maximum 40% 38% 39% 41%

Restricted (Maximum 20%)

Average 17% 18% 16% 15%

Maximum 20% 20% 20% 20%


• National Hot Topic• FDOT pilot projects• 0.85 Binder Availability• Issues with the

unknown

RAS


NCAT: HIGH RAP VERSUS RAP/RAS

PG 76-22 (PMA) with

25% RAP

PG 76-22 (PMA) with

20% RAP & 5% RAS


• January 2012 specification

• Texture Meter• Pave-IR System

Pavement Segregation


Pave-IR Demo

• Oct. 2013 / Turnpike, Palm Beach

• Equipment: MOBA Pave-IR

• To detect Thermal Segregation


Bonded Friction Course

ConventionalTrackless

UltraFuse

eTac


• 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

• 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

Other Research


QUESTIONS/ COMMENTS?THANK YOU!

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Pavement Performance

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