roadway design presentation
TRANSCRIPT
CITY OF SASKATOON GREEN STREET PROGRAM
Presented byDuane GuentherProject EngineerCity of Saskatoon
May, 2010
Acknowledgements COS Staff PSI Technologies Inc. University of Saskatchewan (SCETI)
Highlights
Background Design Issues Existing Conditions Solutions 2007 to 2009 Test Sections 2010 Test Sections Preliminary Findings Future Plans
Background
Asphalt Recycling History Asphalt Rubble
Stockpiled Landfilled
Asphalt Millings Stockpiled Added to new Hotmix
Background
Concrete Recycling History Concrete Rubble
Stockpiled Landfilled
Background
In Place Recycling Re-uses in place materials to rebuild the road
Typically includes some stabilization 31st Street Isabella Street Rylston Road Jasper Avenue Idylwyld Service Road Albert Avenue
Background
Rubble Processing Standard for many municipalities
Typically processed to a 3” minus gradation Used as a sub-base material Blends a variety of rubble materials Typically used primarily by own forces or sold to
contractors working on municipal projects.
Background
Other recycling applications Millings
Used as aggregate in hotmix Adds stiffness to mix Increases the variability
Can be used with rejuvinators in Cold Mix Stockpiles may need to be reprocessed to uniform
gradation
Background
Other recycling applications Crushed Concrete
Used as aggregate in new concrete Variability in cement content and other impurities Only for non-structural concrete
Background
Other recycling applications General Applications
Working platform in water & sewer trenches Bedding aggregate Surfacing aggregate
Lanes Temporary cut repairs
Low settlement fill where compaction is not easily attained
Design Issues Flexible System – City of Saskatoon
Dry CBR specification Granular systems
Structure determined by traffic level ESALS CBR Nomograph Road Classification
Design Issues Granular system does wet up over time
Fine content increases over time due to water pumping
412
607
397
548
377
502
420
613
409
553
389
508
428
619
421
561
403
514
432
625
431
567
411
522
0
250
500
750
Optimum MC (6.5%) Ambient Dry (3.7%) Optimum MC (6.6%) Ambient Dry (4.0%) Optimum MC (6.7%) Ambient Dry (3.2%)
Granular Base Base w/5% Subgrade Fines Base w/10% Subgrade Fines
Dyn
amic
Mod
ulus
(MP
a):
Med
ium
Str
ess S
tate
10 Hz 5 Hz 1 Hz 0.5 Hz
Design Issues Effect of Additional Fines
6.4%
8.8%
10.7%
0.0%
2.0%
4.0%
6.0%
8.0%
10.0%
12.0%
Granular Base Base w/5% Subgrade Fines Base w/10% Subgrade Fines
Wat
er In
take
(per
cent
)
Design Issues Effect of Additional Fines
250
199181
0
50
100
150
200
250
300
Granular Base Base w/5% Subgrade Fines Base w/10% Subgrade Fines
After Climatic Durability
Pea
k St
reng
th (
kPa)
Design Issues Flexible System – City of Saskatoon
Assumptions Free Draining – Always Dry Unchanging granular system
Existing Conditions Overall Site Conditions
Urban environment Watering
Existing Conditions Overall Site Conditions
Fixed Location Aggregate is becoming more scarce
Existing Conditions Overall Site Conditions
New Development locations Converted wetlands Poor quality subgrade
Chart Based on Subgrade CBR Value of 5.0 and Design Life of 15 YearsCLASSIFICATION LOCAL COLLECTOR INDUSTRIAL ARTERIAL FREEWAY
A B C
ADT <1,500 1,000 - 12,000 N/A 5,000 - 30,000 >30,000
TRUCK TRAFFIC 0.5% 2% N/A 5% 8%
WIDTH (M) 9 10 11 14 15 15 2/10.8 2/7.2 14.4 N/A
CROWN HEIGHT (MM) 130 145 160 190 200 200 Min. 2.5% Min. 2.5% 200 As per
project
HMA (MM) 40 45 50 75 80 80 110 100 90 design
and soils
BASE (MM) investigation.
Min. CBR 60 110 125 125 150 150 150 150 150 150
SUBBASE (MM)
Min. CBR 25 100 100 150 225 225 350 300 300 300
SUBGRADE (MM) 150 150 150 300 300 300 300 300 300
Existing Conditions Overall Site Conditions
Solutions Material Separation
Geotextiles Allow water to pass through No material transfer
Solutions Additional Stress Distribution
Geotextiles Bridging Additional resistance to tension
Solutions Drainage Structures
Geotextiles Water collection Drainage Pipe
Drainage Rock Gap graded Moisture break
Solutions Geotextiles
Add $3 to $10 per square meter to construction Drainage aggregate
Can add $10-$15 to cost if not included in regular structure
Structural Drainage Layer With Virgin Aggregate, adds $10 - $15
Use Recycled Aggregate instead to maintain low cost
Solutions Drainage Layer Design
Green Street Test Sections Objectives
Develop Standard for Processing Asphalt and Concrete Rubble Protocols for receiving rubble material Determine what is the optimum gradation (s) available Encourage optimal use of the processed material
Green Street Test Sections Objectives
Develop Standard for Processing Asphalt and Concrete Rubble
0.01 0.1 1 10 100
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
City of Saskatoon Crushed Rock Granular Base Type 1 PCC
Type 2 PCC Type 3 PCC Type 4 PCC
Sieve Size (mm)
Per
cent
Fin
er T
han
Green Street Test Sections Objectives
Develop Methodology for constructing roads with recycled materials Compaction methods for the various materials Matching Material characteristics with location in road
structure Possible addition of cement / emulsion for increased
material characteristics
Green Street Test Sections Objectives
Develop Design Method for roadways that meets needs of urban environment. Drainage capability Material Characteristics determine placement location Design based on critical state failure rather than ESAL’s
Esals vs CBR Nomographs were designed for thick pavement structures
Green Street Test Sections
Green Street Test Sections Material Characterization
100
267
8
90
32
198
0
50
100
150
200
250
300
Conve-ntional
'09 19mm(GW)
'09 19mm(OGBC)
'09 19mm (GW) '09 25mm(OGBC)
Cold In-Place
Granular Base Crushed PCC Crushed RAP In-Place Recycled
Con
duct
ivit
y (µ
S/cm
)
357
637
267
147
357417
0
100
200
300
400
500
600
700
Conve-ntional
'09 19mm(GW)
'09 19mm(OGBC)
'09 19mm (GW) '09 25mm(OGBC)
Cold In-Place
Granular Base Crushed PCC Crushed RAP In-Place Recycled
Wat
er I
ntak
e (m
L)
Green Street Test Sections Material Characterization
Green Street Test Sections Material Characterization
47
9 63
1
94
2
15
46
15
09
20
25
99
0
48
0 64
7 92
4
15
11
13
93
17
99
94
1
48
8 64
5 91
2
15
43
118
6
13
66
85
3
49
1 65
4 93
3
16
00
112
5
12
35
81
5
0
500
1000
1500
2000
2500
Conve-ntional
'09 9mm (Fines) '09 19mm (GW) '09 19mm(OGBC)
'09 19mm (GW) '09 25mm(OGBC)
Cold In-Place
Granular Base Crushed PCC Crushed RAP In-Place Recycled
Dyn
amic
Mod
ulus
(MP
a):
Low
Str
ess S
tate
10 Hz 5 Hz 1 Hz 0.5 Hz
29
5 40
2 60
9 72
7
114
0
16
86
75
5
Sa
mpl
e F
ail
ed
41
3 55
9 72
7
10
49
14
82
71
2
Sa
mpl
e F
ail
ed
40
5 59
0 74
0 88
5 110
0
62
2
Sa
mpl
e F
ail
ed
40
7 59
9 74
7
82
8 97
6
58
8
0
500
1000
1500
2000
2500
Conve-ntional
'09 9mm (Fines) '09 19mm (GW) '09 19mm(OGBC)
'09 19mm (GW) '09 25mm(OGBC)
Cold In-Place
Granular Base Crushed PCC Crushed RAP In-Place Recycled
Dyn
amic
Mod
ulus
(MP
a):
Hig
h St
ress
Sta
te
10 Hz 5 Hz 1 Hz 0.5 Hz
Green Street Test Sections Marquis Drive – Rotomix existing surface
Green Street Test Sections Marquis Drive – Remove Rotomixed
surface & stockpile on site
Green Street Test Sections Marquis Drive – Excavate and remove
subgrade
Green Street Test Sections Marquis Drive – place drain pipe
Green Street Test Sections Marquis Drive – first layer of geotextiles
Green Street Test Sections Marquis Drive – crushed concrete drainage
layer
Green Street Test Sections Marquis Drive – geotextile separation layer
Green Street Test Sections Marquis Drive – Rap & rotomixed surface
as new base
Green Street Test Sections Marquis Drive – SS-1 emulsion with
rotomixing on top 100mm
Green Street Test Sections Marquis Drive – compacted surface ready
for paving
Green Street Test Sections Marquis Drive – paving complete
Green Street Test Sections Heritage Crescent
Green Street Test Sections Attridge Drive
Green Street Test Sections Kenderdine Road
Green Street Test Sections 8th Street
Green Street Test Sections Test Section Structural Validation
1.101.50
0.95
1.49
#N/A
1.93
0.58 0.47 0.44 0.380.69
0.28
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
115th Street(Conv. Drainage
Rock)
Kenderdine Road 8th Street Field House Road ArlingtonBack Lane
Marquis DrivePeak
Sur
face
Def
lectio
n (m
m)
Pre Construction Post Construction
COS Target <0.75mm
1.63
2.21
1.42
2.40
#N/A
2.67
0.89 0.71 0.66 0.581.02
0.42
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
115th Street(Conv. Drainage
Rock)
Kenderdine Road 8th Street Field House Road ArlingtonBack Lane
Marquis DrivePeak
Surf
ace D
eflec
tion (
mm
)
Pre Construction Post Construction
COS Target <0.75mm
2010 Green Street Test Sections
Test Section Locations Kenderdine Road Phase 2 Wilkinson Crescent Adolf Way
Test Section Design Entire granular structure as processed concrete
Preliminary Findings Processing
Increased number of materials reduces overall fines produced
Able to produce a number of specialized materials Changes need to be made to material
specifications to allow these materials
Preliminary Findings Construction
Larger concrete aggregate is better received by field staff
Vibratory compaction not recommended for recycled concrete within drainage
Residents favour the use of recycled material Changes need to be made to material
specifications to allow these materials Typical testing parameters used locally are not
valid
Preliminary Findings Design
Testing data indicates good performance of recycled material
Different design procedure needed other than CBR / ESAL design
Capability to design for different materials is needed
Preliminary Findings Test Section Economic Validation
Typi
cal A
rteria
l Stru
ctur
e
Arteria
l with
Dra
inag
e Roc
k su
bstit
uted
for S
ub-B
ase
Arteria
l with
Cru
shed
Con
cret
e su
bstit
uted
for S
ub-b
ase
Typi
cal A
rteria
l Stru
ctur
e with
Non
-Stru
ctur
al S
ubdr
ain
$-
$1.00
$2.00
$3.00
$4.00
$1.98
$2.94 $2.34 $2.40
$3.95
$2.10 $1.67 $1.71
Roadway Material Cost
Cost/Year of Design LifeCost/Year of Actual Life
Cost
/ Square
Mete
r
Future Plans Specifications
Material specifications should be modified to allow for recycled material
Quality Control tests need to be changed In order for testing agencies to get apparatus to
do different tests the local demand has to be present
In order for municipalities to require new tests there needs to be a familiarity with the testing results
Future Plans Aggregate Use
Capability is there to have little demand for virgin aggregates in Public Works Maintenance operations Requires a change in mindset of personnel Requires a change in internal policy of
administration Determination the best use of Recycled
aggregates Industry is pushing for millings to be used in
Hotmix instead Poor understanding of material science within
municipal agencies
Future Plans Aggregate Use
Specification change could allow new development to include a drainage layer economically
Determination the best use of Recycled aggregates Industry is pushing for millings to be used in
Hotmix instead Poor understanding of material science within
municipal agencies therefore training required
Future Plans Design Standards
Design method required to meet the needs of urban traffic patterns Critical Load driven Related to material mechanical characteristics Measureable results post construction
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