HVS International Alliance FDOT Updatehvsia.com/uploads/cms/documents/exco/FDOT_Update_SMO.pdfEGT1. 12” Limerock + Subgrade Mixture. Not to Scale ` ` Subgrade: 1.5” SP-12.5 PG67-22

TRANSPORTATIONFlorida Department of

HVS International AllianceFDOT Update

James GreeneAugust 2014

Florida Department of Transportation

2013-2014 Research Cycle

• Recently completed research– Impact of wide-base tires on pavement

damage– Fiber reinforced polymer bridge deck– Structural benefit of a prime coat– PG 76-22 asphalt rubber binder

• Ongoing research– 4.75 mm mixture as a preservation treatment


Impact of Wide-Base Tires

• TPF-5(197), The Impact of Wide-Base Tires on Pavement – A National Study

• Objective: Quantify the impact of WBT on pavement damage utilizing advanced theoretical modeling and validate results using full-scale testing

• Scope:– University of Illinois, Principal Investigator– Contact stress measurements, CSIR– Instrumented pavement sections

FDOT, UC-Davis, Ohio University– Modeling effort

University of IllinoisDelft University of Technology


Test Pit Instrumentation

1.5 in SP12.5 (PG 67-22)

10 inch limerock base (100 LBR)

12 in limerock + A-3 (40 LBR)

1.5 in SP12.5 (PG 67-22)

A-3

Longitudinal & Transverse Surface Gauge (Offset from Tire)

Longitudinal & Transverse Embedded Gauges(Below Tire Center)

Pressure Cell(Below Tire Center)


Test Track Instrumentation

1.5 in SP12.5 (PG 76-22)

10 inch limerock base (100 LBR)

12 in limerock + A-3 (40 LBR)

1.5 in SP12.5 (PG 67-22)

A-3

Longitudinal & Transverse Surface Gauge (Offset from Tire)

Longitudinal & Transverse Embedded Gauges(Below Tire Center)

Pressure Cell(Below Tire Center)

1.0 in 4.75 mm (PG 76-22)


Test Matrix

Tire Type Inflation Pressure (psi) Tire Loading (kips)

NGWB and Dual 80 6 8 10 14 18

NGWB and Dual 100 6 8 10 14 18

NGWB and Dual 110 6 8 10 14 18

NGWB and Dual 125 6 8 10 14 18

Dual Only 60/110 6 8 10 14 18

Dual Only 80/110 6 8 10 14 18

Tests at 25⁰C, 40⁰C, and 55⁰C Testing completed…Final report should be published in 2015

180 Combinations


FRP Bridge Deck• Objective: Investigate alternative to open grid steel decks

– Must have a solid riding surface, weigh less than 25 lb/ft2, have a low profile (5 in depth), and low noise

• Background: Florida has the largest inventory of movable bridges in the US, most of which use open grid steel decks– High noise & vibration levels, costly maintenance


FRP Bridge Deck

18 kips


FRP Bridge Deck

• Applied more than 300,000 passes

• Significant system deflection (> 0.5 inches) in center of deck

• Surface cracks initiated after < 5000 passes

• No catastrophic failures of joints or panels

• Discussing testing of new design


Structural Benefit of Prime Coat

• Objective: Investigate structural benefit of prime coat

• Scope: Construct and instrument three sections with different base surface preparations: – Standard prime coat

(RC-70)– Trackless tack coat– No surface preparation

Prime Coat RC-70 (0.1 gal/sy)

Trackless Tack as Prime(0.4 gal/sy)


Instrumentation (Plan View)

` ` ` ` ` ` Wheel Path

Edge of Wheel Path

12” 12” 12” 12” 12”24”24”

ELG3 ETG3 ELG2 ETG2 ELG1 ETG1

` ` ` ` ` `

3”

` ` ` ` ` `

3”

` ` ` ` ` `

3”

` ` ` ` ` `

3”

PG-AS1PG-AS2

Surface Strain Gauges

SLG3-3 STG3-3

Not to Scale

SLG2-3 STG2-3 SLG1-3 STG1-3

SLG3-12 STG3-12 SLG2-12 STG2-12 SLG1-12 STG1-12


Instrumentation (Elevation View)

` ` ` ` ` `

10.5” Limerock Base

12” 12” 12” 12” 12”24”24”

EGL3 EGT3 EGL2 EGT2 EGL1 EGT1PG-AS1PG-AS2

12” Limerock + Subgrade Mixture

Not to Scale

``

Subgrade

1.5” SP-12.5 PG67-221.5” SP-12.5 PG67-22

PG-BS2`

PG-BS1`

` ` ` ` ` `


Longitudinal Strain at AC Bottom


Surface Strain


Vertical Stress


Structural Benefit of Prime Coat

• Strain and stress increase significantly when prime coat is not used at higher temperatures


PG 76-22 (ARB)

• Objective: Validate newly developed PG 76-22 (ARB) specification

• Background: Florida has extensively used ARB in the past 25 years. New specification applies performance requirements to ARB.– 1988, Florida Legislature directed research and expansion

of waste materials in highway construction– 1994, ARB specifications (ARB-5 and ARB-12)– Issues with settlement– 2011, FDOT/Industry task team to improve ARB

performance and specification


Experiment Design

BinderProducer

BinderType

ModifierMixture

IDA PG 76-22 (PMA) SBS PG 76-22 (PMA)A ARB-5 5% GTR ARB-5A PG 76-22 (ARB) Min 7% GTR and SBS (Lower % GTR) Hybrid A-LA PG 76-22 (ARB) Min 7% GTR and SBS (Higher % GTR) Hybrid A-HB PG 76-22 (ARB) Min 7% GTR and SBS Hybrid BC PG 76-22 (ARB) Min 7% GTR GTR C


Specification Binder Tests

TestTest Temp.,

°CHybrid

A-LHybrid

A-HHybrid

BGTR

CSpecification Requirement

Original Binder

Separation Test, Softening Point Difference, °F

N/A 11 17 6 26 Max. 15°F

Flash Point, COC N/A 500+ 500+ 500+ 500+ Min 450°FRotational Viscosity 135 2.21 3.10 1.73 2.51 Max 3 Pa•s1

DSR, G*/sin δ, @ 10 rad/s(with 2.00 mm gap)

76 1.28 1.31 1.41 2.35 Min 1.0 kPa

Phase Angle 76 68.0 68.6 73.0 74.4 Max. 75 degreesRTFO Residue

RTFOT, % Mass Change 163 -0.118 -0.158 -0.160 -0.226 Max ±1.000%MSCR(with 2.00 mm gap)

67% Recovery, 3.2 kPa-1 68.94 49.70 55.52 35.71 %R3.2 ≥ 29.37(Jnr3.2)-0.2633

Jnr, 3.2 kPa-1 0.322 0.559 0.297 0.357“V” grade =

Max 1.0 kPa-1

Jnr, % Difference 17.93 54.52 24.30 21.92 Max 75%PAV Residue

DSR, G* sin δ, @ 10 rad/s 26.5 1580 1110 3190 3200 Max 5000 kPaBBR Creep Stiffness, S

-12110 70 153 168 Max 300 MPa

BBR Creep Stiffness, m-value 0.358 0.385 0.300 0.299 Min 0.3001 FDOT allows binders with values higher than 3 Pa∙s to be used with caution and only after consulting with the suppler as to any special handling procedures, including pumping capabilities.


Mixture Tests (Laboratory)

Mixture ID

AMPT Properties Fracture Properties at 10 °C

Dynamic Modulus, ksi (1 Hz, 20 °C)

Flow Number

Fracture Energy (KJ/m3)

CreepRate

(1/psi·sec)

Energy Ratio

Control 699 72 2.8 2.8E-09 4.2

ARB-5 573 60 5.4 6.8E-09 4.5

Hybrid A-L 421 97 5.0 9.5E-09 2.6

Hybrid A-H1 271 63 7.2 2.0E-08 2.5

Hybrid B 696 423 4.7 3.1E-09 6.6

GTR C2 657 382 2.7 2.3E-09 5.0

Note 1 – failed separation test and rotational viscosityNote 2 – failed separation test, MSCR % recovery, and BBR creep compliance


HVS Performance


PG 76-22 (ARB) Summary

• All mixtures showed good rutting performance. Rutting resistance of PG 76-22 (ARB) mixtures was found to be comparable to that of mixture with a standard PG 76-22 (PMA).

• All mixtures exhibited a good range of ER values, which indicated good cracking resistance.

• The Hybrid A-H and GTR C binders failed to meet the separation test requirements, indicating that there is likely an optimum range of GTR and SBS proportions that provide some stability to the resulting binder.

• Adoption of a performance graded ARB specification replaces two ARBs (ARB-5 and ARB-12) with one (PG 76-22 (ARB)), which simplifies binder storage during HMA production.


4.75 mm Preservation Treatment

• Thin overlay as preservation treatment

• Overbuild course• Reflection crack

mitigation layer

1.5-inch SP-12.5 w/ PG 67-22

10.5-inch limerock base

12-inch granular subbase

4.75-mm mixture w/ PG 67-22

1.5-inch SP-12.5 w/ PG 76-22

4.75-mm w/ PG 67-22

1.5-inch SP-12.5 w/ PG 67-22

10.5-inch limerock base

12-inch granular subbase

1.5-inch SP-12.5 w/ PG 76-224.75-mm mixture w/ PG 76-22

4.75-mm w/ PG 76-22

4.75-mm thickness ranges from ½ to 1 inch

Testing should be completed

by end of 2014


2015 - 2016 Research Cycle

• Potential projects– Asphalt segregation– Submerged roadway– Rapid flexible pavement rehab– PG 76-22 HP evaluation– Refine APAS aging protocol– Thicker FC-5 using PG 76-22 and PG 82-22– 9.5 mm NMAS lift thickness restrictions– HMA density limits– Fatigue cracking reinforcement treatments– Special select soil option for concrete pavements– Bonding of HMA layers– US 301 concrete test road instrumentation validation– Bridge deck alternatives to open grid steel

Documents

HVS International Alliance FDOT Updatehvsia.com/uploads/cms/documents/exco/FDOT_Update_SMO.pdfEGT1. 12” Limerock + Subgrade Mixture. Not to Scale ` ` Subgrade: 1.5” SP-12.5 PG67-22