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October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 1/43
UW – Madison
Geological
Engineering
Geological Engineering Transportation Geotechnics Civil & Environmental Engineering
Behavior of Recycled Concrete Aggregate
as Unbound Road Base
Tuncer B. Edil
Recycled Materials Resource Center
Geological Engineering Program
University of Wisconsin-Madison
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 2/43
Objective of Pool Fund Project
• Characterize properties of recycled concrete aggregate
(and also recycled asphalt pavement) as unbound base
• Determine how RCA behaves in the field and how to
design pavements using these materials
• Both lab and field scale tests
• variability in material properties
•purity of materials
•control of material quality and best construction practices
•climatic effects and durability
•Environemntal suitability
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 3/43
Project TasksTask I Structural capacity, long-term stability, design properties
Task IA
Task IB
Task IC
Task ID
Literature Review
Relationship between Mr and Composition of RCA or RAP
Scaling and Equivalency: Specimen Tests to Field-Scale Conditions
Climate Effects
Task II Construction & Maintenance
Task IIA
Task IIB
Compaction Level and Assessment
Field Performance and Maintenance
Task III Materials Control
Task IV Leaching Characteristics
Task V Extended Monitoring
Task VI/VII Final Report & Dissemination
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 4/43
Recycled Materials
Recycled Concrete Aggregate (RCA)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 5/43
Objective of Today’s Presentation
o To characterize the engineering properties of RCA as unbound
road base without being treated or stabilized
o To assess the influence of
• compaction effort
• compaction moisture content
• freeze-thaw cycling
on the stiffness of RCA as unbound road base
o To determine the effect of varying RCA content on the
stiffness of natural aggregates used as unbound road base
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 6/43
LITERATURE SURVEY
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 7/43
Typical RCA Properties
Physical Properties
Specific Gravity2.2 to 2.5 (Coarse Particles)
2.0 to 2.3 (Fine Particles)
Absorption2% to 6% (Coarse Particles)
4% to 8% (Fine Particles)
Mechanical Properties
LA Abrasion Loss 20% to 45% (Coarse Particles)
Magnesium Sulfate Soundness Loss4% or Less (Coarse Particles)
Less than 9% (Fine Particles)
California Bearing Ratio (CBR) 94% to 148%
FHWA Report FHWA-RD-97-148
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 8/43
Gradation
Material
% Finer
Fine
(#200)
Coarse
(19.1 mm)
Conventional Crushed
Aggregate (MnDOT Class
5)
3 to 10% 90 to 100%
RAP1 to 8%
(Mean: 2.3%)
92 to 100%
(Mean: 95.0%)
RPM3 to 16 %
(Mean: 8.0%)
93 to 96%
(Mean: 95.8%)
RCA3 to 8%
(Mean: 5.1%)
50 to 100%
(Mean:82.4 %)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 9/43
UW – Madison
Geological
Engineering
Geological Engineering Transportation Geotechnics Civil & Environmental Engineering
RESULTS OF SURVEY BY RMRC 2009
The Usage, Storage and Testing of Recycled
Materials
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 10/43
Material Use and Storage
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 11/43
Which of the following recycled materials do you use
as a granular base course?
34 Total responses
• RAP: 18 (53%)*
• RCA: 30 (88%)*
• RPM: 17 (50%)*
* More than one response
possible
0
10
20
30
40
RAP RCA RPM
Number of Responses
Material
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 12/43
When are the recycled materials used?
Total response:
36 agencies
0
10
20
30
RAP RCA RPM
Used in place immediately
Stockpiled and used later
Both
Number of responses
Material
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 13/43
In a given year, how much of the recycled material do
you use?
Total response:
33 agencies
0
10
20
30
RAP RCA RPM
Less than 1,000 tons1,000 to 5,000 tons5,000 to 10,000 tons10,0000 to 25,000 tons25,000 to 50,000 tons50,000 to 75,000 tonsMore than 75,000 tons
Number of responses
Material
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 14/43
Are any of the following tests used in specifications for
the material?
Total response:
32 agencies
0
10
20
30
40
50
60
RAP RCA RPM
Grain size analysis: Wet sieve
and hydrometerLiquid limitPlastic limit and plasticity indexGrain size analysis: Dry sieve
Number of responses
Material
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 15/43
0
5
10
15
20
25
RAP RCA RPM
Aggregate abrasion valueGyratorySulfate soundnessTexas wet-millMicro devalL.A. abrasion
Number of responses
Material
Which of the following aggregate quality tests for
toughness do you perform on the material prior to
placement?
Total response:
21 agencies
Offered but not selected:
• Aggregate impact value
• Aggregate crushing value
• Durability mill
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 16/43
0
2
4
6
8
10
12
RAP RCA RPM
Magnesium sulfate soundnessAggregate durability indexSulfate soundness
Number of responses
Material
Which of the following aggregate quality tests for
durability do you perform on the material prior to
placement?
Total response:
12 agencies
Offered but not selected:
• Canadian freeze-thaw
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 17/43
Materials
RCA: 7
RAP: 7
RPM: 2
California
Minnesota
Colorado
Wisconsin Michigan
Texas
New Jersey
OhioRCA, RAP
RCA, RAP RCA, RAP
RCA, RAP
RCA, RAP, RPM
RCA, RPMRCA, RAP RAP
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 18/43
Representative Materials
Gradation RCA
Coarser Texas
Medium Michigan
Finer California
o Class 5 (Natural Aggregate)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 19/43
Gradation: RCAs and Class 5
0
10
20
30
40
50
60
70
80
90
100
0.010.1110100
Percent Finer (%)
Particle Size (mm)
RCA (TX)
RCA (MI)
RCA (CA)
Class 5 (MN)
RCA Lower Limit
(Literature)
RCA Upper Limit
(Literature)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 20/43
Test Method
o Resilient Modulus (Mr) Test
where σd = deviator stress, εr = recoverable elastic strain
Mr = σd /εr
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 21/43
Resilient Modulus
2
1
k
rkM θ= where θ = bulk stress
k1 and k2 = fitting parameters
Power
Function:
k2
k1
θ = σ1+2(σ3)=1
σ1
σ3σ3
log (bulk stress)
log (resilient modulus)
1
0
500
1000
1500
0 100 200 300 400 500 600 700
Resilient Modulus (MPa)
B u lk S tress (kPa)
SMr (θ=208 kPa)
Summary Resilient
Modulus (SRM)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 22/43
UW – Madison
Geological
Engineering
Geological Engineering Transportation Geotechnics Civil & Environmental Engineering
Freeze-Thaw Cycling
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 23/43
Freeze-Thaw Cycling
� Specimens
• Prepared in the same manner as resilient
modulus specimens
• Retained in the freezer for 24 hours
• Thawed at room temperature for 24 hours
� After the last cycle, specimens were extruded frozen
and thawed inside the resilient modulus cell
� Specimens were subjected to 5, 10, 20 cycles
TE1
Slide 23
TE1 Tuncer Edil, 10/1/2011
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 24/43
Temperature Records for RAPs and RCAs
-30
-20
-10
0
10
20
30
0 4 8 12 16 20 24
Freezing
Thawing
Temperature (Celsius)
Time (Hours)
-30
-20
-10
0
10
20
30
0 4 8 12 16 20 24
Freezing
Thawing
Temperature (Celsius)
Time (Hours)
RCARAP
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 25/43
0
100
200
300
400
500
600
700
Internal SRM (MPa)
RCA (TX)
RCA (MI)
RCA (CA)
0 5 10 20
Freeze and Thaw Cycles
Class 5 (MN)
RCAs: SRM vs F-T Cycles
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 26/43
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
SRMN/SRM0
RCA (TX)
RCA (MI)
RCA (CA)
0 5 10 20Freeze and Thaw Cycles
Class 5 (MN)
RCAs: Normalized SRM vs F-T Cycles
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 27/43
0.2
0.4
0.6
0.8
1
1.2
SRMN/SRM0
RAP (TX)
RAP (CA)
RAP (MN)
Class 5 (MN)
RAPs: Normalized SRM vs F-T Cycles
Coarser
Medium
Finer
0 5 10 20
Freeze and Thaw Cycles
AC=4%
AC=5%
AC=7%
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 28/43
Verification of RCA Behavior with Seismic
Modulus TestVP
Length, LDensity, ρ
Constrained ModulusP- Wave Velocity
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 29/43
RCAs: Constrained Modulus vs F-T Cycles
0
100
200
300
400
500
600
700
800
0 2 4 6 8 10 12
Constrained Modulus, (MPa)
Freeze Thaw Cycles
RCA (TX)
RCA (MI)
RCA (CA)
Class 5 (MN)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 30/43
UW – Madison
Geological
Engineering
Geological Engineering Transportation Geotechnics Civil & Environmental Engineering
Compaction Conditions
Effect of Density (Compaction Effort)
and Compaction Moisture on Modulus
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 31/43
18
19
20
21
22
2 4 6 8 10
Dry Unit Weight, (kN/m
3)
Water Content (%)
Density (Relative Compaction) Effect
95 % of MDU
OMC
90 % of MDU
85% of MDU
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 32/43
0
100
200
300
400
500
600
700
800
RAP (TX)
RAP (CA)
RAP (MN)
95 90 85
InternalSRM (MPa)
Compaction Effort (%)
RCA (TX)
RCA (MI)
RCA (CA)
Class 5 (MN)
Effect of Relative Compaction on Modulus
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 33/43
RCA
Class 5
0
100
200
300
400
500
600
700
800
RAP
Summary Effect of Relative Compaction on
Modulus
Compaction Effort (%)95 90 85
Internal SRM (MPa)
RAP 37%
decrease
RCA 41%
decrease
Natural Aggr
47%
decrease
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 34/43
18
19
20
21
22
2 4 6 8 10
Dry W
eight, (kN/m
3)
Water Content (%)
Compaction Moisture Effect
95 % of Modified Proctor
-2% +2%
OMC
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 35/43
PSDs of RAPs and RCAs Used in Moisture
Effects Testing
Particle Size (mm)
Percent Finer (%)
Particle Size (mm)
Percent Finer (%)
0
10
20
30
40
50
60
70
80
90
100
0.010.1110100
RCA (OH)
RCA (CO)
RCA Lower
Bound
(Literature)
RCA
Upper
Bound
(Literature)
Medium
Finer
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 36/43
RCA (CO)
RCA (OH)
100
200
300
400
500
600
700
800RAP (TX)
RAP (OH)
- 2% OMC + 2%
InternalSRM (MPa)
Effect of Compaction Moisture on Modulus
Coarser
Finer
Finer
Medium
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 37/43
RCA (CO)
RCA (OH)
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
RAP (TX)
RAP (OH)
- 2% OMC + 2%
SRMwc/SRMOMC
Effect of Compaction Moisture on Normalized
SRM
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 38/43
RCA (CO)
RCA (OH)
29%
decrease
7 %
decrease
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6 RAP (TX)
RAP (OH)
- 2% OMC + 2%
SRMwc/SRMOMC
Summary of Compaction Moisture Effect on
Normalized Modulus
RCA 28 %
increase
RAP 17 %
increase
boz59
Slide 38
boz59 bu grafiklerin font sizelarini buyutmeye calis ve arial kullandinsa her yerde arial kullan ki consistency olsunbozyurt, 8/2/2011
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 39/43
RAP (OH)-Before
100
200
300
400
500
600
700
800
4 6 8 10 12
RAP (TX)-Before
RAP (OH)-After
RAP (TX)-After
Moisture Content Before and After Test
Coarser
Finer
Internal SRM (MPa)
Water Content (%)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 40/43
RCA (OH)-Before
RCA (OH)-After
RCA (CO)-After
100
200
300
400
500
600
4 6 8 10 12 14 16
RCA (CO)-Before
Water Content (%)
RCA: Effect of Compaction Moisture on
Modulus
Finer
Medium
Internal SRM (MPa)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 41/43
UW – Madison
Geological
Engineering
Geological Engineering Transportation Geotechnics Civil & Environmental Engineering
Effect of RAP or RCA Content on
Stiffness of Natural Aggregate Blends
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 42/43
Materials Selected for Blends
RCA Natural
Aggregate
Minnesota Minnesota
(Class 5)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 43/43
PSD of RCA (MN) and Class 5 Used in Blends
0
10
20
30
40
50
60
70
80
90
100
0.010.1110100
Percent Finer (%)
Particle Size (mm)
Class 5 (MN)
RCA (MN)
RCA Lower Bound
(Literature)
RCA Upper Bound
(Literature)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 44/43
Compaction Curve: RCA (MN) Blend
18
19
20
21
22
0 2 4 6 8 10 12 14 16
Dry Weight, (kN/m
3)
Water Content (%)
Class 5 (MN)
Blend (50-50)
RCA (MN)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 45/43
100
200
300
400
500
600
700
800
RAP (CA)
RAP (CO)
0 50 100
InternalSRM (MPa)
RAP or RCA (%)
RCA (MN)
SRM vs
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 46/43
0.5
1
1.5
2
RAP (CA)
RAP (CO)
0 50 100
SRM Blend/SRM Class 5
RAP or RCA (%)
RCA (MN)
Results
RCA 30%
increase
RAP 68%
increase
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 47/43
Quantitative Assessment of
Environmental and Economic Benefits
of Using Recycled Construction
Materials in Highway Construction
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 48/43
Schematic of Two Pavement Designs:
Reference-Conventional Materials vs. Alternative-Recycled Materials
Alternative
(Recycled materials)
Reference
(Conventional materials)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 49/43
Life Cycle Analysis (LCA)
Environ-
mental
Metric
Conventional Materials Recycled Materials
Differ-
enceMaterial
Productio
n
Transpor-
tation
Con-
struction
Material
Production
Transpor-
tation
Con-
structio
n
CO2 (Mg) 3630 323 111 3028 163 54 -20%
Energy (GJ) 66,680 4318 1476 58,023 2187 723 -16%
RCRA
Hazardous
Waste (Mg)
629 31 9 611 16 4 -6%
Water (L) 17,185 735 144 15,637 372 70 -11%
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 50/43
Life Cycle Cost Analysis (LCCA)
Categories Reference Alternative Saving
Agency Cost ($) 9,044,570 7,107,230 1,937,340 (21%)
User Cost ($) 10,570 8,380 2,190 (21%)
Total ($) 9,055,140 7,115,610 1,939,530 (21%)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 51/43
Conclusions Extrapolated to a Nationwide Scale
Point of
ImpactQuantity Equivalent to
Energy (PJ) 368
• Annual energy use for 3.67 million householders
(EIA 2005 survey)
• 68% of annual wind power generation in 2008
(EIA 2009)
Water
(million L)63
• 1.4 million persons daily water use for shower
(43.9 L/capita)
CO2e
(million
Mg)
26• Equivalent to the removal of 5 million passenger
cars per year from roadways
LCCA
(billion $)62
•Average annual salary for 1.5 million Americans
($39,500/yr)
* Based on an assumption of 150,000 km annual road construction (Carpenter et al 2007)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 52/43
Environmental Concerns
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 53/43
PVF
0 5 10 15 20 25 30 35 40 45
Eh
50
100
150
200
250
300
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Eh of RCA from five sites
PVF
0 5 10 15 20 25 30 35 40 45
EC(m
s/cm
)
0
1
2
3
4
5
6
7
8
9
10
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
EC of RCA from 5 sites
PVF
0 5 10 15 20 25 30 35 40 45
pH
7
8
9
10
11
12
13
14
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
pH of RCA from five sites
pH of RCA Column test(From 7-7-2010 to 9-16-2010)
The five kinds RCA are respectively: California RCA, Colorado RCA, Michigan RCA,
Minnesota RCA and Texas RCA
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 54/43
PVF
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Concentration(ppb )
1
10
100
1000
10000
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Al-Aluminium
MDL
Calibration range
Note: Compared with the lowest MCL
MCL(CO & TX) 50 ppb
PVF
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Concentration(ppb )
0.01
0.1
1
10
100
1000
10000
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Ba-Barium
MDL
MCL (CA) 1000ppb
Calibration range
PVF
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Concentration(ppb )
0.01
0.1
1
10
100
1000
10000
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Fe-Iron
MDL
MCL (USEPA) 300ppb
PVF
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Concentration(ppb )
0.1
1
10
100
1000
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Cr-Chorumlum
MDL
MCL(CA) 50ppb
Elements MCL At lease once: Al, As*, Ba, Cr, Fe, Pb, Sb*, Se, Sr, Tl,
Take the 23 elements into consideration Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn,
Mo, Ni, Pb, Sb, Se, Sn, Sr, Ti, Tl, V, and Zn(From 7-7-2010 to 8-18-2010)
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 55/43
PVF
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Concentration(ppb )
0.01
0.1
1
10
100
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Pb-Palladium
MDL
Far below MDL
MCL(MI) 15ppb
Note: ICP analysis slighty negative
PVF
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Concentration(ppb )
0.1
1
10
100
1000
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Se-Selenium
MCL (MN) 30ppb
MDL
PVF
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Concentration(ppb )
0.1
1
10
100
1000
10000
CA RCA
CO RCA
MI RCA
MN RCA
TX RCA
Sr-Strontium
MDL
Calibration range
MCL(USEPA) 4ppb
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 56/43
Conclusions
o Freeze-thaw cycling reduces the SRM of RAP and natural
aggregate.
• The modulus loss of RAP over 20 cycles is comparable to that of
natural aggregate (i.e., 28% vs 21%).
• RAP with finer gradation experienced more modulus loss mostly
in the first 5 cycles.
o RCA consistently displayed an unusual trend with freeze-
thaw cycling first modulus decreasing up to 5 cycles
followed with increasing up to 20 cycles
October 4, 2011 Unbound Recycled Material Jim Tinjum, PhD, PE
University of Wisconsin-Madison Slide 57/43
Questions?