CE990 Graduate Seminar Presentations

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The presentation materials shown in this file were prepared by graduate

engineering students for educational purposes within the Department of Civil and

Geological Engineering at the University of Saskatchewan. The quality and

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Presented by

Diana Podborochynski, M.Sc. Candidate

Department of Civil and Geological Engineering Graduate Seminar (CE 990)

Friday,  February 3, 2012

Characterization of Reclaimed Asphalt Concrete Pavement for Saskatoon Road 

Construction

Acknowledgments

Saskatchewan Centre of Excellence in Transportation and Infrastructure

Ministry of Highways and Infrastructure

City of Saskatoon

Advisory Committee

Introduction Sustained growth in the City of SaskatoonIncreased demand for new construction

Increased demand for rehabilitation & reconstruction

Challenges facing Saskatoon:Road conditions: truck loads, materials, climate

Costs ↑, Budgets staying the same

Aggregate sources

Public

Environmental ResponsibilityBeing Green

Infrastructure Sustainability

Introduction & Background

City of Saskatoon has seen an increase in HMAC rubble.

Stockpiled in the city yard instead of being landfilled.

How could the City of Saskatoon use HMAC rubble materials in road rehabilitation? 

Background

Stockpiled asphalt concrete rubble

Stockpiled Portland cement concrete rubbleImpact Crusher

Processing MaterialStockpile

Background

GW OGBC Rock

Background

Asphalt recycling is not a new concept.

Limitations to using reclaimed asphalt pavement (RAP) in Saskatoon include:•Empirical specifications are obsolete.

•No material specification for RAP structures.

•Limited research in Saskatchewan.

Need a scientific based mechanistic material characterization of Saskatoon’s reclaimed asphalt pavement.

Research Goal/Objectives Research Goal

•To validate the use of crushed RAP rubble materials as a structural base layer in COS pavement structures.

•100% RAP base layer

Research Objectives1.To evaluate the laboratory mechanistic constitutive relations of GW and OGBC RAP including varying amounts of cementitious and emulsion stabilization systems.

2.To determine the engineering feasibility of using crushed RAP rubble materials in urban road rehabilitation as an engineered base course layer.

Methodology

Project Element 1: Background and Literature Review

Project Element 2: Materials Sampling

GW OGBC

Methodology

Laboratory Testing

Construction                         Post Construction       HWD Testing

Results ‐ Gradations

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.01 0.1 1 10

Perc

ent F

iner

Tha

n

Sieve Size (mm)City of Saskatoon Base 2009 GW RAP Sample 1 2009 GW RAP Sample 22009 GW RAP Sample 3 2009 GW RAP Sample 4 2009 GW RAP Sample 5

Results ‐ Gradations

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.01 0.1 1 10

Perc

ent F

iner

Tha

n

Sieve Size (mm)City of Saskatoon Base 2009 OGBC RAP Sample 1 2009 OGBC RAP Sample 22009 OGBC RAP Sample 3 2009 OGBC RAP Sample 4 2009 OGBC RAP Sample 5

Results – Loss on Ignition3.

46% 4.21

%

3.66

%

3.60

%

3.45

%

5.52

%

4.85

% 5.56

%

5.46

%

5.29

%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 1 Sample 2 Sample 3 Sample 4 Sample 5

2009 GW RAP 2009 OGBC RAP

Los

s on

Igni

tion

(per

cent

)

1271

Sam

ple F

aile

d

2037

1363

1313

533

1501

99312

29

Sam

ple F

aile

d

2185

1509

1369

Sam

ple F

aile

d

1472

893

1245

Sam

ple F

aile

d

2377

1681

1336

Sam

ple F

aile

d

1537

900

1169

Sam

ple F

aile

d

2113

1492

1229

642

1410

93011

53

Sam

ple F

aile

d

2003

1594

1325

Sam

ple F

aile

d

1327

905

0

500

1000

1500

2000

2500

3000

MC VacSat MC VacSat MC VacSat MC VacSat

Unstabilized 2% Cement 2% SS-1 1% Cement - 1% SS-1

Dyn

amic

Mod

ulus

(MPa

)

2009 GW RAP, High Stress State, 10 Hz

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5

Results ‐ Strengthening

Results – Summary

Crushed RAP rubble materials met COS base aggregate specification.

Unstabilized RAP specimens did not survive vacuum saturation

Cement and/or emulsion stabilization improved the performance of the RAP materials.•RAP specimens treated with 2% cement showed the most improvement in stiffness post MC and post VacSat.

•RAP specimens with 1% cem‐1% SS‐1 also showed improvement.

Field Test Sections

2 field test sections in City of Saskatoon•Marquis Drive, eastbound in front of Costco

•8th Street, Boychuk Drive westbound 500 m Typical cross section

•Marquis Drive – RAP bas layer was emulsion stabilized

•8th Street – RAP base layer was cement & emulsion stabilized

Reclaimed PCCDrainage RockExcavated Subgrade

RAP

Non-Woven Geotextile Fabric

Weeping Tile

Woven Geofabric and Geogrid

Cem/EmulsionStabilized RAP

HMAC surfacing

Field Test Sections•Concrete Plant •COS Aggregate Yard•Sub-division construction

•540 m section•3 lanes, westbound only 8th Street Test Section

Start ofMarquis Drive

Thatcher Avenue

(km 0.000)

End ofMarquis Drive

IdylwyldDrive

(km 0.425)Costco Entrance

(km 0.175) Marquis Drive Test Section

Field Test Sections

8th Street Marquis DrivePre Construction

Field Test Sections

Milling HMAC Surface(Stockpiled)

Placement of Woven Geofabric, Geogrid and Weeping Tile

Construction

Field Test Sections

Placement of Stockpiled and CrushedGW RAP Materials

Mixing SS-1 Emulsion in RAP Base Layer

Construction

Field Test Sections

Finished Compacted RAP Base Layer Finished HMAC SurfaceConstruction

Field Test Sections

8th Street Marquis DrivePost Construction

Field Test Sections1.

85

0.55

0.55

1.77

0.52

0.51

0.93

0.73

0.48

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

Pre 2009 Post 2009 Post 2010 Pre 2009 Post 2009 Post 2010 Pre 2009 Post 2009 Post 2010

West End (km 0.000 to km 0.175) East End (km 0.175 to km 0.425)

Marquis Drive 8th Street East (km 0.000 to km 0.540)

Ave

rage

Pea

k Su

rfac

e Def

lect

ion

(mm

)

Mean Peak Surface Deflections at Primary Legal Load Weight Limits

Cost Comparison

$-

$20,000

$40,000

$60,000

$80,000

$100,000

$120,000

$140,000

$160,000

$180,000

$200,000

8th Street

Marquis Drive

$41,580

$119,070

$16,363$46,856

$83,160

$158,760

$32,725$62,475

Tota

l Cos

t Ran

ge

RAP Base MaterialVirgin Granular Base Material

$10/tonne

$10/tonne

$30/tonne

$30/tonne

$20/tonne

$20/tonne

$40/tonne

$40/tonne

Cost Estimate of Acquiring and Hauling Aggregate Material in 2009 (LCC not calculated)

Conclusion

Using crushed RAP material as a base layer in urban road construction is feasible•Alternative to using virgin granular base aggregates

City of Saskatoon “Green Street” test sections constructed in 2009 and 2010•On‐going monitoring of test sections using non‐destructive testing measures.

•Good performance to date.

Presented by

Diana Podborochynski, M.Sc. Candidate

Department of Civil and Geological Engineering Graduate Seminar (CE 990)

Friday,  February 3, 2012

Thank You!