Surface Mix Experience and PerformanceCity of Edmonton

Hugh Donovan, P.Eng.Hugh Donovan, P.Eng.

Construction Services EngineerConstruction Services Engineer

Transportation Department Transportation Department

City of EdmontonCity of Edmonton

2006 CUPGA MeetingCharlottown, P.E.I.

CITY OF EDMONTON ROADWAY 2007-2011 CONSTRUCTION BUDGET

0 20 40 60 80 100 120 140Dollars (X 000,000)

2007

2008

2009

2010

2011

Year

2007 - 2011 CPP Funded Projects

Growth Rehabilitation

Estimated Aggregate Reserves:

• 1978 aggregate reserves 6,980 Million tonnes;

2,235 Million tonnes of Gravel4,745 Million tonnes of Sand

• Gravel Sized Materials; 1,036 Million tonnes of Concrete

Aggregate1,199 Million tonnes of Asphalt Aggregate

• Sand Sized Materials;2,241 Million tonnes of Dune Sand200 Million tonnes potential Street Sand2,304 Million tonnes Other sand materials

•Only 95 Million tonnes of Aggregate both Sand and Gravel had actually been confirmed in 1978

1978

2006•By the end of the 2006 construction season it has been estimated that we will have used an additional 432 Million tonnes of sand and gravel in the Edmonton region;

•By 2026 given current growth we estimate that we will have used an additional 500 to 650 Million tonnes of sand and gravel in the Edmonton region

Cumulative Aggregate Usage 1978-2006

020406080

100120140160180200220240

Year

To

nn

es

(M

illio

n's

)

Concrete Gravel Sand

1978 - 2026 Cumulative Aggregate Usage - Predicted

050

100150200250300350400450500

Year

Tonn

es (M

illio

n's)

Gravel Concrete Sand

2006

Aggregate Supply Issues:

•Current Aggregate Sources:

Are of poorer quality; Have smaller rock fraction

maximum size; More costly to process; Secondary processing to

remove deleterious materials;

Further aggregate haul distances

Aggregate Supply Issues:•Pit Logistics:

In 1978 aggregate materials came from pits located along the North Saskatchewan River in close proximity of the City (<10km);

In 2006 aggregate materials are coming from pits located well outside the City such as Wabamum, Villenuve, Onoway, Camrose, Smoky Lake and Ponoka. These pit can be as far away as 60-135km;

In 2005 and 2006 our premium aggregates is coming from as far away as Whitcourt, Nordeg and Rocky Mountain House some 220 to 270 km from Edmonton

In 2005 we had a cement shortage, resulting delays in project completions;

Also in 2005 the Independent truckers went on strike – Net result was an increase in trucking costs, increase in project costs and delays in project completion;

In 2006 we had an Asphalt Cement shortage, resulting in project delays;

Manpower issues, with the hot construction market in Alberta it is becoming much more difficult to attract workers;

Other Issues

GENERAL ROAD STRUCTURES IN EDMONTONGENERAL ROAD STRUCTURES IN EDMONTON

150 - 300mm150 - 300mm

Granular Base Granular Base

oror

Soil Cement Soil Cement BaseBase

100-150 mm100-150 mm Hot MixHot MixAsphaltAsphalt

50 - 250mm50 - 250mmHot MixHot MixAsphaltAsphalt

200-200-300mm300mmHot MixHot MixAsphalt Asphalt

ororOil MixOil Mix

Deep Strength Deep Strength Asphalt Asphalt

ororOil MixOil Mix

( 10% of Network)( 10% of Network)

Granular/Granular/Soil CementSoil Cement

(63% of Network)(63% of Network)

CompositeCompositePavementPavement

( 27% of Network( 27% of Network))

150-200mm150-200mmPortland Portland CementCement

ConcreteConcrete

Historical Overview of Asphalt Mixes  Surface Mix

Arterials and Collectors (High Volume

Roadways)

Surface Mix Arterials and

Collectors (Low Volume Roadways)

Surface Mix Residential and Lanes

Base Mix (High Volume

Roadways)

Base Mix (Low Volume Roadways)

           

1980-1990 Type l 75 Blow Marshall 12.5mm

Type l 75 Blow

Marshall 12.5mm

Type ll 50 Blow

Marshall 12.5mm

Type lll 75 Blow

Marshall 25mm

Type lll 75 Blow

Marshall 25mm

1990-1991 Type HS 75 Blow

Marshall 20mm

Type LS 75 Blow

Marshall 20mm

Type RS 50 Blow

Marshall 12.5mm

Type HB 75 Blow

Marshall 25mm

Type LB 75 Blow

Marshall 25mm

1991-1993 Type ACS 75 Blow

Marshall 20mm

Type ACS 75 Blow

Marshall 20mm

Type ACR

50 Blow Marshall

12.5mm

Type ACB 75 Blow

Marshall 25mm

Type ACB 75 Blow

Marshall 25mm

1993-1999 Type ACS 75 Blow

Marshall 20mm

Type ACO 75 Blow

Marshall 12.5mm

Type ACR

50 Blow Marshall

12.5mm

Type ACB 75 Blow

Marshall 25mm

Type ACB 75 Blow

Marshall 25mm

1999-Present

Type ACO 75 Blow

Marshall 12.5mm

Type ACO 75 Blow

Marshall 12.5mm

Type ACR

50 Blow Marshall

12.5mm

Type ACB 75 Blow

Marshall 25mm

Type ACB 75 Blow

Marshall 25mm

Specialty Mix Initiatives:

Since the mid 1970’s, the City of Edmonton has been involved with trials utilizing a variety of Hot Mix Asphalt specialty mixes:

Asphadur (1980 & 1981);

Sulphur-Modified Asphalt (1981);

Polymer Modified Binders (1986 – Present);

Stone Mastic Asphalt [SMA] (2000-Present);

Asphalt Rubber (1976, 2002-Present);

Superpave (1999, 2001-2002);

Polymer Modified Binder UsageYear Project Location Material

     

1986 170 Street, North of Yellowhead Trail to 137 AvenueImperial Oil Engineered Bitumen

1987 Terwillegar Drive Southbound, North of 23 Avenue Novophalt

1994 Whitemud Drive, 53 Avenue to Rainbow Valley BridgeImperial Oil Engineered Bitumen

1996 McKenzie Ravine Bridge Deck Husky "Black Max"

1997 Jasper Avenue, 106 to 107 Street Over Corona Station Husky "Black Max"

1998 Winterburn Overpass at Yellowhead Trail Husky PMA Bridge Mastic

1999 Beverly Bridge - East bound Husky PMA Bridge Mastic

1999 97 Avenue, 107 Street to James McDonald Bridge Husky "Black Max"

2000 23 Avenue & Calgary Trail - SMA Moose Jaw PMA PG 76-28

2001 3 Intersections, Calgary Trail/Gateway Blvd. - Superpave Husky "Black Max"

2002 97 Street, Southbound 127 to 135 Avenues -SMA Husky PMA PG 76-28

2003 3 Intersections - SMA Husky PMA PG 76-28

2004 Yellowhead Tr, 89 to 107 Street - SMA Husky PMA PG 70-28

2005 Yellowhead Tr, 121 to 124 Street - SMA Husky PMA PG 76-28

2005 Whitemud Drive, 34 to 50 Street - SMA Husky PMA PG 70-28

2006 Yellowhead Tr, 50 to 17 Street & 170 to 149 Streets - SMA Husky PMA PG 70-28

1999 - 2006

All new and Rehabilitated Bridge Decks Husky PMA Bridge Mastic

SMA, Stone Mastic Asphalt•SMA 16mm, 50 Blow Marshall Surface Mix

(Overlay and Surface Mix on Higher Traffic Volume Roadways)

Year Projects Tonnes of Mix

Depths (mm)

Binder Used

         

2000 2 1,500 50 - 90 80-100 & PG 76-28

2002 1 1,000 100 PG 76-28

2003 3 3,100 50 - 100 PG 76-28

2004 1 7,000 50 - 75 PG 70-28

2005 2 13,000 50 PG 76-28 & PG 70-28

2006 2 30,000 45 - 100 PG 70-28

Advantages/Disadvantages

•Disadvantages of SMA: Aggregate costs, bringing in high quality

aggregate from Whitecourt, Nordeg and Rocky Mountain House;

Higher Binder costs with the use of the polymer modified binders;

•Advantages of SMA: SMA provides durable, and rut resistant

wearing course; Mix surface texture characteristics are such

that noise generated by traffic is lower than dense graded mixes (measured at 4 decibels quieter);

Can be placed and compacted with conventional paving and rolling equipment;

May provide reduced reflective cracking from underlying cracked pavements due to the flexible mastic.

Yellowhead Trail East of 50 Street (2006)

66 Street & Yellowhead Trail (2004)

YHT - 66 Street SMA Performance - Outer WheelpathSMA Placed in October 2004

0

1

2

3

4

5

6

7

8

9

10

0 100 200 300 400 500 600 700 800

Days since Placed

Ru

t D

ep

th (

mm

)

.

.

WBL Lane 1 WBL Lane 2 WBL Lane 3

EBL Lane 1 EBL Lane 2 EBL Lane 3

Rutting Performance

Asphalt RubberAsphalt rubber mix is a gap graded 12.5mm, 75 blow Marshall surface asphalt mix containing 18% crumb rubber particles and 82% AC 80-100

 Projects Tonnes of

MixDepths (mm)

       

1976 1 1,500 50

2002 1 2,300 50 & 100

2003 4 12,750 50 - 100

2004 6 20,575 50 - 100

2005 2 15,600 50

2006 5 10,750 50 - 75

Advantages/Disadvantages

•Disadvantages of Asphalt Rubber: Aggregate costs, aggregate processing is

similar to an SMA mix resulting in additional processing;

Higher Binder costs due to the increase quantity of binder required in the mix and blending equipment;

Cost of Crumb rubber component; Surface of mix requires a solution of lime water

to be applied prior to trafficking

•Advantages of Asphalt Rubber: Asphalt Rubber provides a textured and rut

resistant wearing course; Surface texture characteristics are such that

noise generated by traffic is lower than dense graded mixes 4-8 decibel reduction depending on the roadway;

Can be placed and compacted with conventional paving and rolling equipment;

Stony Plain Road (2003)

50 Street South of 13 Avenue (2003)

153 Avenue East of 66 Street (2006)

SuperpaveOur Superpave mix is a 12.5mm Superpave Course surface asphalt mix with a PG 58-34 binder with a design traffic loading of <3X106

ESAL's.

 

Projects Tonnes of Mix

Depths (mm)

Binder

         

1999 1 8,500 50 PG 58-34

2001 4 (Intersections)

2,500 50-75 PMA1 (Husky)

2002 1 8,000 50 PG 58-34

Advantages/Disadvantages

•Disadvantages of Superpave: Aggregate costs, additional aggregate

processing results in additional costs; Additional mix costs due to PG testing of

Binder; Some difficulty in placement of mix due to

mix tenderness

•Advantages of Superpave: Mix is designed for anticipated traffic

loadings; Longer pavement life, with less fatigue and

thermal cracking, Can be placed and compacted with

conventional paving and rolling equipment;

Winterburn Interchange on Yellowhead Trail (2002)

Other Initiatives

Full Depth Reclamation using Foamed Asphalt

Infrared Thermography Studies

Use of Ground Penetrating Radar for structural evaluation of roadway structures

Full Depth Reclamation Utilizing Foamed Asphalt

 

Projects Area (m2)

Depths (mm)

Approximate Mix Components

         

2001 3 39,000 200-250 2.5% Asphalt 1.5% Cement

2002 9 119,500 175-300 2 - 2.5% Asphalt 0.5 - 1.5% Cement

2003 13 140,000 175-250 2 - 2.5% Asphalt 0.5 - 1.5% Cement

2004 12 plus 2 Neighbourhoods

155,000 125-250 2 - 3% Asphalt 0.5 - 1.0% Cement

2005 9 plus 3 Neighbourhoods

427,000 125-250 2 - 3% Asphalt 0.5 - 1.0% Cement

2006 7 plus 5 Neighbourhoods

395,000 125-250 2 - 3% Asphalt 0.5 - 1.0% Cement

Advantages of Full Depth Reclamation with Foamed Asphalt Reuse of the material in the existing Reuse of the material in the existing

pavement pavement generally better quality materials generally better quality materials than are than are currently available.currently available.

Derive maximum benefit of existing Derive maximum benefit of existing pavement pavement structure as a stabilized base structure as a stabilized base course materialcourse material

Simultaneous addition of “make-up Simultaneous addition of “make-up (granular)” (granular)” material and/or stabilizing material and/or stabilizing agent(s)agent(s)

Speed of construction - one or two pass Speed of construction - one or two pass operation vs. a multi-pass operation vs. a multi-pass

operationoperation

Accommodation of traffic - roadway is Accommodation of traffic - roadway is never never closed to trafficclosed to traffic

Economics ($) 30 to 50% savingEconomics ($) 30 to 50% saving

150 Avenue East of 94 Street (2001)

12/10/2006 12/10/2006

Ellerslie Road ~ 50 Street (2003)

12/10/2006

150 Avenue Deflection Performance150 Avenue, 87 Street to 94 Street

0.00.30.50.81.01.31.51.82.02.32.52.83.03.33.5

0+00

0

0+04

0

0+09

0

0+14

0

0+19

0

0+24

0

0+29

0

0+34

0

0+39

0

0+44

0

0+49

0

0+54

0

0+59

0

0+64

0

0+69

0

0+74

0

0+79

0

0+84

0

Station

Def

lect

ion

(m

ils)

Pre - 2001 Post - 2001 Aug -02 May-05 May -06

Infrared Thermography

cold spots = thermal segregation results in poor performance

From 1999 Washington State / U of W Study

00.51

1.52

2.53

3.54

4.55

5.56

6.57

7.5

0 10 20 30 40 50

Temperature Difference (C)

Chan

ge in

Air

Voids

(%)

Ground Penetrating Radar

Asphalt on Soil Cement Base

Asphalt on Concrete on

Granular Base

Asphalt on Soil Cement Base

Where Do We Go From Here?

Trial project utilizing warm asphalt technology;

Cold-in-Place Recycling of existing road structures;

Study on our current Hot-Mix Asphalt mixes with respect to the incorporation of RAP