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Full Depth Reclamationp

METROPOLITAN GOVERNMENT PAVEMENT ENGINEERS COUNCIL17TH ANNUAL GENERAL COUNCIL MEETING ANDCOMPREHENSIVE PAVEMENT INFORMATION SESSIONS

*Definition from Asphalt Recycling & Reclamation Association

Full Depth Reclamation* (FDR) Rehabilitation technique where full thickness of asphalt pavement & predetermined portion of underlying materials are uniformly pulverized & blended to an upgraded, homogenous base material

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Definitions

Stability - Ability of asphalt mixture to resist deformation from imposed loads;

Unbound, non stabilized material

resist deformation from imposed loads; dependent upon both internal friction (aggregate structure) & cohesion (binder)

Bound - Particle structure strengthened with a binding medium such as asphalt or cement

Stabilization - Mechanical, chemical or bituminous treatment designed to increase

Bound, stabilized material

bituminous treatment designed to increase material stability or otherwise improve engineering properties

DefinitionsMechanical stabilization - 1st step in reclamation; Mechanical stabilization - 1st step in reclamation; also used to describe FDR without addition of binder (Pulverization)

Chemical stabilization - FDR with chemical additive (Calcium or Magnesium Chloride, Lime, Fly Ash, Kiln Dust, Portland Cement, etc.)

Bituminous stabilization - FDR with asphalt emulsion, emulsified recycling agent, or foamed / expanded asphalt additive

Combination stabilization -Any 2 or more of above

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Project Analysis‐Design

• Needed for pavement design▫ Pavement design is necessary

• If not assessed▫ Weak areas or thicknesses variability won’t be▫ Weak areas or thicknesses variability won t be known until construction

1. Ideal Pavement & Material Assessment

• Springtime (preferred) structural l ti bevaluation by agency or 

consulting engineer ▫ Structure; layer evaluations▫ Drainage▫ Distresses▫ Road needs

Dynamic Cone Penetrometer (DCP)

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Ideal Pavement Assessment

• Soil borings▫ Sample top 6‐10 inch▫ Auger to 5 ft for layer 

thickness & identification & water table location

• Strength testing options identify weak areas & determine subgrade strength/modulus▫ Falling Weight Deflectometer (FWD)▫ California Bearing Ratio (CBR) or 

R V ltable location R‐Value▫ Dynamic Cone Penetrometer (DCP) ▫ Proof rolling (granular surfaces only)

Falling Weight Deflectometer - FWD

CBR device

R-ValueDetermination

(Hveem)

Typical costs

• Coring ‐ $1,000 to $1,500 (<2‐mile project)(<2 mile project)

• Soil / pavement borings ~$1,000 per mile• FWD w/ analysis ‐ $4,000 to $6,000• Sampling & sub grade testing ‐ $2,500  

(<2‐mile project)• DCP ‐ equipment costs $1 500DCP  equipment costs $1,500

Costs will vary depending on many factors, especially mobilization and traffic control

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Performance‐Related Specification Guidelines

Determine if appropriate early curing is occurring

Short Term Strength byCohesiometer ASTM D1560

Performance ParameterCriteria

Indirect Tensile Test (IDT)

Relative indicator of qualityStrain or deflection w/ applied

load for structural design

Resilient Modulus ASTM D4123

Resistance to moisture damage

Retained Strength ASTM D4867

g gCohesiometer ASTM D1560

Tests run on 150-mm SGC prepared specimens

Thermal cracking resistanceIndirect Tensile Test (IDT) AASHTO T 322

ReliabilityConstruction & QA/QC Requirements

Engineered Emulsion Technology

F l t d f • Formulated for: • Chemical break /Solvent less ▫ Earlier strength than conventional emulsions▫ Adhesion characteristics▫ Resistant to moisture damage▫ DispersionDispersion

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Engineered Emulsion Technology, cont.

• Formulated for:Hi h h lt t t• High asphalt content ▫ Good dispersion with higher film thickness

▫ Durable▫ Flexible

• Climate‐specific binderF l t d f h EEFDR• Formulated for each EEFDR project (SHRP)

Engineered Mix Design

• Virgin aggregate or RAP may be• Virgin aggregate or RAP may be needed▫ To increase depth of finished structural layer

▫ To improve gradationCleanliness (P200)Material qualityGradation

Add rock

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Equipment

Reclaimer

Reclaimer

• Typically used in FDR & GBS construction

• Typical properties:▫ Center mount cutter 

Generally up cuts

▫ Accurate emulsion addition

▫ 8‐ or 10‐ft wide▫ Emulsion added to enclosed mixing drum 

▫ Road is usually reclaimed a third at a time (24 ft wide, 8‐ft wide milling head)

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Construction Production Rates

• Typical production rates▫ Reclaimer rate (~30‐90 ft/min)▫ Daily production approximately 0.5 ‐ 0.75 centerline miles (reclaimer)

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Profiling ‐ Pre‐pulverization

• Pre‐pulverize, blade & lightly compact before reclamation

▫ Aids in material sizing 

▫ Corrects road profile if required

▫ Adjust for additional moisture to facilitate in mixing and compaction

▫ May not be required with some reclaimers

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EEFDR process

Compaction

CompactPadfoot roller

Blade to desired profile & remove pad marks

Final compaction ‐ pneumatic and/or steel rollers

• Cover with appropriate wearing surface after curing

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Pad foot Compactor

• Best for achieving compaction at bottom of layer• High amplitude/ low frequency• Back drag blade preferred• 28,000 lb ‐ 34,000 lb 

Motor Grader to Remove Pad MarksLevel Surface

Stephenson County, IL

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Finishing Rollers

Achieve surface compaction & final appearance

• Pneumatic roller▫ 20‐ton minimum▫ 90 psi tire pressure

Vibratory steel roller▫ 10‐ton minimum▫ low amplitude/ high frequency

Field Testing ‐ Quality Control

• Specific tests & testing frequency determined by agency & road requirements▫ Moisture content▫ Depth▫ Top sizeE l i t t▫ Emulsion content

▫ Compaction▫ Modified Proctor for target density

▫ Return to traffic

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Benefits,• Construction

‐ Immediate compaction

‐ Traffic return usually same day

‐ Overlay within 1‐2 weeks (or sooner)‐ Depends on weather & moisture

‐More uniform strength

‐ Increased structural capacity‐May reduce overlay thickness need

Benefits contd,

• Performance

‐ Flexible‐ Reduced moisture sensitivity‐ Resistance to cracking (fatigue)‐ Improved low temperature cracking‐ Same composite sectionp‐ 100% recyclable

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Structural Benefit

• The EEFDR process will increase the structural coefficient of the material

• The structural coefficient of EEFDR materials is dependent upon:▫ Amount of P200 (fines)▫ Angularity of existing material

Existing 2” Mill/Overlay2”Mill/Overlay

6” FDR

2” New HMA ( SN 88)3” HMA (SN .72)

6” Base (SN .72)

Total SN 1.44

2” New HMA (SN.88)

1” Old HMA (SN.24)

6” Base (SN.72)

Total SN 1.84

2 New HMA ( SN .88)

6” Full Depth (SN1.50)Reclamation

1” Base (SN.12)

Total SN 2.50

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Builds structure down into pavement

STA 0343‐027~US34 asphalt overlay, HMA, Full Depth Reclamation,

• Square yards (25,812) for the FDR section totaled 3.7 lane miles.

• (Included shoulders)• •$74,648.98 per lane mile for 8”• •$9,331.12 per inch/lane mile• •Square yard equals $10.60 per s yd. or $23.56 per ton (11,600 tons) 465 TL

• > Structural number = 2.00 for FDR

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18th Annual “Best in Colorado” Asphalt Pavement Awards Dinner & Program

BEST OVERALL QUALITY Innovative Technology (Asphalt Emulsion and Full Depth Reclamation and US Highway 160 East - Aztec CreekMP 11.5 – 17.97Contractor: Four Corners Materials Contractor: Four Corners Materials Construction Manager: SEMA ConstructionOwner: CDOT Region 5

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CDOT NH 1601‐061 US 160

• 310‐00610 Full Depth Reclam. of HMA 159,931 SY $2.75 $439,810.00

• 310‐00700 Asphalt Emulsion Full Depth 156,030 SY   $2.50 $390,075.00

• 411‐90040 Recycling Agent 517,637 GAL $1.75 $905,864.75 ($5.81 SY)

• $11.06 per s. yd.

Comparisons (Phase 1) $2,783,010 @ $39.40 

Description Units Unit Bid Project

Price Quantity TotalAggregate Base Course (Class 2) TON $13 30,620 $398,068 Aggregate Base Course (Class 6) TON $21 7,857 $165,017

Full Depth Reclamation of HMAReclamation of HMA Pavement (0-8") SY $2.80 70,639 197,013HMA (Grading SX) (75) TON $54 25,380 $1,370,521 Asphalt Cement Performance Grade (PG 64-22) TON $460 1,390 $638,781 Emulsified Asphalt (Slow-Setting) GAL $5 2,722 $13,611

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Comparisons (Phase 2) $5,846,396 @ $37.58 

Description Units Unit Bid Project

Price Quantity TotalAggregate Base Course (Class 3) TON $16 58,795 $712,402 Aggregate Base Course (Class 6) TON $19 47,571 $585,323 Full Depth Reclamation of HMA (8-12") SY $2.75 159,931 $427,828 Asphalt Emulsion Full Depth Reclamation SY $2.50 156,030 $388,935 Hot Mi AsphaltHot Mix Asphalt (Grading SX) (75) TON $47.50 34,228 $1,686,461 Asphalt Cement Performance Grade (PG 64-22) TON $480 2,304 $1,135,348 Emulsified Asphalt (CSS-1H) GAL $4 7,848 $39,200

City of Las Vegas - MLK Case Study Resource Usage

Reconstruction Option 

Milling  36,749 Tons  1400 Tons / Day 26 Days Excavation  62,578 CY 1400 CY / Day  45 Days Type 2 road base  96,941 Tons  1400 Tons / Day 69 Days Hot Mix Asphalt  42,874 Tons  2500 Tons / Day 17 Days

Reconstruction Option  157 Days 

FDR Option 

Milling  36,749 Tons  1400 Tons /Day  26 Days Excavation  19,712 CY 1400 CY /Day  14 Days Type 2 road base  11,405 Tons  1400 Tons /Day  8 DaysPre‐pulverize material  25,031 CY 1400 CY /Day  18 DaysFDR material 25 031 CY 1400 Cy /Day 18 DaysFDR material  25,031 CY  1400 Cy /Day  18 Days Hot Mix Asphalt  36,749 Tons  2500 Tons /Day  15 Days 

FDROption  99 Days 

• 85,536 tons of additional Type 2 would have been needed using the traditional reconstruction method

• Using the FDR method saved more than 6,800 truck trips

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MLK Bid tab

$13.65 per square yard8’ to 10” AEFDR

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MLK

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• They total $170,909.94 divided by 15,450 square yards come out to $11.06 per square yard. 

•• 15,450 square yards equals 2.19 lane miles which comes out to $78,041.07 per lane mile (7,040 square yards per lane mile).

•

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HMA @ SN .44 Per Inch(Costs Per S. Yd.)

HMA $$$ per ton SN 1.00 SN 1.50 SN 2.00

$50.00 $6.32 $9.49 $12.66

$75.00 $9.48 $14.23 $18.98

$100.00 $12.64 $18.98 $25.31

$125.00 $15.80 $23.72 $31.64Note:SN 1.00 = 2.25” overlay thicknessSN 1.50 = 3.50” overlay thicknessSN 2.00 = 4.50” overlay thickness

MEPDG ConsiderationsMEPDG Considerations

Future Design GuideFuture Design Guide

Material Properties:• Level 1 – measured▫ Dynamic Modulus E* input is criticalis critical

• Level 2 – estimated• Level 3 ‐ defaults

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φ/ωσosinωt

Compressive Dynamic Modulus Compressive Dynamic Modulus (|E(|E*|) *|)

• Asphalt Mixture PerformanceTester (AMPT)

•Input into the new pavement design

Time, t

εosin(ωt-φ)

σ, εσ0 ε0

p p gguide (MEPDG)

•AASHTO TP-62•Modulus – Rate of change of stresswith strain (4°C, 20°C, & PG High)

0

0|*|εσ

=E itωφ =

FDR Dynamic Modulus ResultsFDR Dynamic Modulus Results

100,000 A:75% RAPA:25%RAP

Emulsion FDR Mixtures

1,000

10,000

Dyn

amic

Mod

ulus

, M

A:25% RAPB:75% RAPB:25% RAPB:25%RAP;1%cA:25%RAP;1%c19 mm HMA

100

1,000

1.E-05 1.E-03 1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

Reduced Frequency (Hz)

D

FDR “stiffer” than HMA at low frequency or warm temperatures

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CIR Dynamic Modulus ResultsCIR Dynamic Modulus Results10,000,000

19 mm AC (PG 64-22)

10,000

100,000

1,000,000

Dyn

amic

Mod

ulus

, E* (

p

MEPDG - CIR

MEPDG - FDR

12.5 mm AC (PG 64-22)

1,000

,

1.0E-05 1.0E-04 1.0E-03 1.0E-02 1.0E-01 1.0E+00 1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07

Reduced Frequency (Hz)

16 Kansas Projects

MEPDG Default values are low

Questions ???