Concrete (PCC) Mixture Designs
for O’Hare Modernization Program
Principal Investigators
Prof. Jeff Roesler
Prof. David Lange
PROJECT GOAL
Investigate cost-effective concrete properties and pavement
design features required to achieve long-term rigid
pavement performance at Chicago O’Hare International.
Acknowledgements
Principal Investigators
Prof. Jeff Roesler
Prof. David Lange
Research Students
Cristian Gaedicke
Victor Cervantes
Former OMP Research Students
Sal Villalobos – CTL, Inc. (Chicago area)
Civil engineer
Robert Rodden – American Concrete
Pavement Association (Chicago area)
Technical director
Zach Grasley – Texas A&M
Materials professor
Project Objectives
Develop concrete material constituents and
proportions for airfield concrete mixes
Strength
volume stability
fracture properties
Develop / improve models to predict concrete
material behavior
Crack width and shrinkage
Evaluate material properties and structural design
interactions
joint type & joint spacing (curling and load transfer)
Saw-cut timing
FY2005-06 Accomplishments
Tech Notes (TN) -
www.cee.uiuc.edu/research/ceat
TN2: PCC Mix Design
TN3: Fiber Reinforced Concrete for Airfield Rigid
Pavements
TN4: Feasibility of Shrinkage Reducing Admixtures for
Concrete Runway Pavements
TN11: Measurement of Water Content in Fresh
Concrete Using the Microwave Method
TN12: Guiding Principles for the Optimization of the
OMP PCC Mix Design
TN15: Evaluation, testing and comparison between
crushed manufactured sand and natural sand
TN16: Concrete Mix Design Specification Evaluation
TN17: PCC Mix Design Phase 1
FY2006 Accomplishments
Tech Notes (TN) -
www.cee.uiuc.edu/research/ceat
TN21: An Overview of Ultra-Thin Whitetopping
Technology
TN23: Effect of Large Maximum Size Coarse Aggregate
on Strength, Fracture and Shrinkage Properties of
Concrete
TN24: Concrete Saw-Cut Timing Model
TNXX: Recycled Concrete Aggregate Concrete (80%)
TNYY: Functionally Layered Concrete Pavements (70%)
TNZZ: Properties of concrete containing GGBFS
TNAA: Effects of Concrete Materials and Geometry on
Slab Curling (40%)
Presentation Overview
2006 Topics – TN & Brown Bag
Large-sized coarse aggregate mixtures
Slab Curling –theoretical analysis
Saw-cut timing model
Recycled Concrete Aggregate
P-501 Accomplishments
P-501 Remaining Items
Field Demo Project
Future Work
Phase II Mix Summary
Mixture ID
Coarse Aggregate Size (in)
Coarse Aggregate (lb/yd3)
Fine Aggregate (lb/yd3)
Water (lb/yd3)
Cement (lb/yd3)
Fly ash (lb/yd3)
Air (oz/yd3)
Slump (in.)
Air Content (%)
Unit Weight (lb/ft3)
Mixture ID
fsp28 (psi)
MOR28 (psi)
E28 (ksi)
688.38ST
0.75
1850
1103
262
588
100
12.7
7.5
6.5
145.1
688.38ST
570
802
3,752
688.38
1.5
1842
1083
261
588
100
19.4
6.25
8
141.8
688.38
454
639
3,438
571.44
1.5
1938
1140
251
571
0
16.1
2.25
6.5
146.2
571.44
524
794
3,958
555.44
1.5
1942
1142
244
455
100
15.6
8.0
3.7
150.2
Effect of larger-size
coarse aggregate on
strength
555.44
490
663
4,209
Larger-size coarse aggregate
Drying Shrinkage – Phase II
Total Shrinkage vs. Age
Shrinkage (microstrain)..
500
400
Effect of larger-size
coarse aggregate on
shrinkage
300
\
200
688.38 st
688.38
100
571.44
555.44
0
0
5
10
15
20
25
30
Concrete Age (days)
Mixture ID
sh3 (microstrain)
sh7 (microstrain)
sh14 (microstrain)
sh28 (microstrain)
688.38 st
688.38
571.44
555.44
48
193
292
417
118
233
338
405
139
250
320
380
52
158
273
335
Fracture Energy Results-Phase II
688.38 st
156
Mixture ID
GF (Nm)
688.38
166
3000
688.38st
688.38
555.44
Fv (N)
2000
1500
1000
500
0
0
0.5
1
CMOD(mm)
Age = 28-days
1.5
555.44
161
Effect of larger-size
coarse aggregate on fracture
properties
Load vs. CMOD curves for Wedge Splitting Samples
2500
571.44
N/A
2
P-501 Accomplishments
No fly ash replacement ratio
ASTM C157 <0.045% at 28-days*
MSA 1.5 inch*
Design strength 650 psi and specified
strength =620 psi
Min. cement content =535 lb/yd3
Min. w/cm 0.4 & max 0.45
P-501 Remaining Issues
Nominal vs. Maximum Size Aggregate
Combined Gradation
ASTM C1157 – blended cements
Performance spec
Air content
5.5% for 1.5inch MSA
Slag
ASTM C 1157
Combined Gradation
Sieve #
1.5"
1"
3/4"
1/2"
3/8"
#4
#8
#16
#30
#50
#100
Sieve size (mm)
40
25
20
12.5
10
5
2.5
1.25
0.630
0.315
0.160
Original aggregates
1" Aggregate
1.5" Aggregate FA
100
100
100
100
41
100
67
8
100
12
1
100
3
0
100
0
0
99
0
0
91
0
0
76
0
0
53
0
0
16
0
0
1
WF = Combined aggregate finer than No. 8 (%):
CF = coarse agg retained 3/8" / all retained No.8 (%)
OMP Combined gradations
1" + FA
1.5" + FA
100
100
100
63
79
42
45
38
39
37
37
37
34
34
28
28
20
20
6
6
0
0
34
92.0
34
94.8
Saw-Cut Timing and Depth
Process
Concrete Mix
• Aggregate size
• Cementitious content
Crack Propagates
Tensile strength of the slab at 12 hours
FRACTURE
PROPERTIES
Nominal strengthMPa)
1.00
0.80
688.38ST
0.60
0.40
0.20
0.00
0.00
Wedge Split Test
FEM Model
688.38
0.10
0.20
0.30
ao/d
0.40
Saw Cut Depth
Model
0.50
Summary of Notch Depth
Requirements
Saw Cut Depth (a0/d)
6
8
10
0.19
0.38
0.19
0.38
0.19
0.38
0.04
0.02
0.07
0.03
0.11
0.06
0.01
0.01
0.05
0.01
0.12
0.06
0.05
0.02
0.16
0.06
0.38
0.14
0.03
0.02
0.09
0.05
0.21
0.09
AGE(hrs)
Slab depth (m)
555.44
555.44st
688.38
688.38st
Saw Cut Depth vs Age
(Slab depth: 190 mm)
0.60
0.40
0.40
0.20
0.00
0.00
8
Age (hrs)
10
12
555.44
555.44st
688.38
688.38st
0.60
0.20
6
0.19
0.47
0.46
0.71
0.56
Saw Cut Depth vs Age
(Slab depth: 380 mm)
0.80
555.44
555.44st
688.38
688.38st
Saw Cut Depth.
Saw Cut Depth.
0.80
12
6
8 Age (hrs) 10
12
0.38
0.21
0.22
0.49
0.37
Recycled Concrete Aggregate (RCA)
Objectives
Determine the fracture properties of concrete
virgin and recycled coarse aggregate
w/ and w/o structural fibers
Effects of concrete drying shrinkage with
recycled coarse aggregate
Results – Virgin vs RCA
CMOD vs Load Curve Comparison
No FRC
3.5
Similar peak loads
3
Load (kN)
2.5
Virgin Agg.
2
Recycled Coarse Agg
1.5
Virgin GF is 1.6 times
larger than RCA GF
1
0.5
0
-0.5
0
0.2
0.4
0.6
0.8
1
CMOD (m m )
Beam 1
Beam 2
Ave.
E
(GPa)
27.19
24.74
25.96
KIc
(MPa m1/2)
1.06
1.18
1.12
CTODc
(mm)
0.0182
0.0195
0.0189
GF
Nm
63.16
82.81
72.98
Recycled Beam 1
Coarse Beam 2
Agg.
Ave.
30.12
25.84
27.98
1.13
1.06
1.09
0.0196
0.0186
0.0191
40.01
49.35
44.68
Virgin
Agg.
Results – Virgin FRC vs RCA FRC
CMOD vs Load Curve Comparison
FRC
Similar peak loads
3.5
Load (kN)
3
Virgin Agg.
2.5
Recycled Coarse Agg
Similar softening curves
2
1.5
1
0.5
Similar GF
0
0
0.5
1
1.5
2
2.5
3
3.5
4
CMOD (m m )
Virgin
Agg.
FRC
Beam 1
Beam 2
Ave.
E
(GPa)
26.81
25.25
26.03
RCA
FRC
Beam 1
Beam 2
Ave.
28.36
27.96
28.16
KIc
(MPa m1/2)
1.35
1.24
1.30
CTODc
(mm)
0.0262
0.0292
0.0277
GF
Nm
254.43
217.48
235.95
1.12
1.13
1.12
0.0193
0.0192
0.0192
278.48
164.62
221.55
RCA Shrinkage
TOTAL SHRINKAGE
75x75x285 mm specimen
Average Dry Shrinkage
(microstrain)
800
700
600
500
Virgin FRC
400
Virgin
300
RCA-FRC
200
RCA
100
0
0
10
20
30
Concrete Age (days)
40
50
60
Concrete Slab Behavior
Curling stresses
temperature
moisture
Joint Opening
Load transfer
Dowel vs. no dowel
Hygro-thermal Strain (1)
•
Quantify the drying shrinkage due to RH change
• Micro-mechanical model: modified Mackenzie’s
formula
 HT 
PS
3
1
1 



K
K
s 

where
P : pore fluid pressure
  RH 3 
S : saturation factor, S  1  0.751  
 
  0.98  
K , K s : bulk modulus for the porous body
and solid phase
Hygro-thermal Strain (2)
•
Kelvin-Laplace equation
ln( RH ) RT
p
'
where
R : universal gas constant;
T : temperatu re in Kelvin degree;
 ': molar volu me of water
Slab-base friction
f
L: joint spacing
Expansion caused by friction (after K.P. George)
f 
    L2
4E
Joint opening ()
  L         
T
HT
curl
f
when     0, i.e. contraction,  "" taken;
T
HT
otherwise, "-" taken.
Field Validation
•
Field data: three concrete slabs were cast on
06/22/06 at ATREL
• Slab size: 15’x12’x10’’, BAM
• Temp., RH measured @ surface, 1’’,3’’,5’’,7’’
and 9’’ at 15-min. interval
• Two LVDTs installed in each joint to measure
joint opening
Joint Opening Measurement
Two week joint opening
0.12
D
C
A
6/30
7/2
0.1
JOINT-OPENING (in)
B
A
B
C
D
0.08
0.06
0.04
0.02
0
-0.02
6/22
6/24
6/26
6/28
DATE
7/4
7/6
7/8
Two month joint opening
0.14
D
B
C
A
A
B
C
D
0.12
JOINT-OPENING (in)
0.1
0.08
0.06
0.04
0.02
0
-0.02
6/12
6/22
7/2
7/12
7/22
8/1
DATE
8/11
8/21
8/31
9/10
9/20
Shrinkage (mm/mm)…….
Concrete Free Shrinkage
SHRINKAGE 688.38 ST MIX
800
Total shrinkage - Lab Mix
Total shrinkage - Field Mix
Autogrenous shrinkage - Field Mix
600
400
200
0
0
4
8
12
16
20
24
28
Age (days)
Material inputs
•
•
•
•
•
•
•
•
Setting temp. T= 50°C (122°F)
=5.75 x 10-6/ °F (10.35 x 10-6/ °C)
K=2.12 x 106 psi
Ks=3.77 x 106 psi
E=4.03 x 106 psi
Unit weight =149 pcf
Friction coeff. = 2.5
Data set: 0:08a.m. on 07/01/06 –12:38p.m. on
07/13/06 at 15-min. interval
Predicted joint opening(1)
Predicted joint opening(2)
Future Work
Concrete Pavement / Material
Interaction
Hygro-thermal effects on slab behavior
Curling & joint opening (slab sizes)
Dowel
Construction practices (curing, temp, mix components)
 Early & long age
Material effects (e.g.)
Combined gradation*
Slag
High early strength/stiffness
FRC
Surface Energy Balance
Solar radiation
Wind
Convection
Reflected radiation
PCC slab
Conduction
BAM
ASB
Subgrade
Conduction
N-layer Heat Transfer Model
B.C.s
r
Layer 1
Layer 2
h1 , 1 , 1 , T1
h2 , 2 ,  2 , T2
Governing PDE
T
  T 1 T  T  Q
 



t
r r z  c
 r
where
 : thermal diffusivit y (m / hr)
2
i
2
i
i
2
i
i
h
2
p
Layer n
n ,  n , Tn
2
i
2
Q : heat of hydration (J/m / hr)
 : concrete density (kg/m )
c : specific heat capacity (J/kg/C)
h
Z
3
p
QUESTIONS
www.cee.uiuc.edu\research\ceat
Thanks!
Curling Questions
How does shrinkage effect slab size?
What are the combined effect of
moisture/temperature profile?
What is the role concrete creep?
How do other concrete materials behave –
FRC & SRA?
Slab Curling
 (t , z ) 
Effects of materials
and slab geometry on
moisture and
temperature curling
C (t ) E (t ) ( z ) C (t ) E (t ) T (t , z )   HT (t , z )   CR (t , z ) 

2(1  v)
2(1  v)
 tot   T   HT   CR
 HT ( z ) Total 
  RH ( z )  3  
RT ( z )  1
1 

1

0
.
75

   ln( RH ( z ))
1  


v w  3k 3k 0  
  0.98   
 CR  0.5   HT
Vapor
Diffusion
 HT L NL ( z )   HT ( z )
Total
h/2
  RH ( z )  3  
1
RT ( z )  1
1 
 
   ln( RH ( z ))dz
 
 1  0.751  
h h / 2 v w  3k 3k 0  
0
.
98
  
 

Pc

Stress




Time
after Grasley (2006) & Rodden (2006)
Field vs Lab
95
Surface - 1
90
Surface - 2
-7.5
-6
1/2" - 1
85
-4.5
1/2" - 2
80
Location in Slab (in)
Internal RH (%)
100
1"
75
5"
7"
70
11" - 1
65
14" - 1
55
14" - 2
0.6
0.7
0.8
0.9
1
1.1
0
Actual RH
1.5
Second Order
3
4.5
11" -2
60
-3
-1.5
6
7.5
RH (%)
50
8
9
10
11
12
13
14
Elapsed Time (days)
Lab
15
100
Field
95
Internal RH (%)
90
0"
85
1/2"
80
1"
75
3"
70
7"
11"
65
14"
60
55
50
0
5
10
15
Elapsed Time (days)
20
25
30
Ground Granulated Blast Furnace Slag
GGBFS
Introduction
By product of the steel industry
Produced in blast furnaces
Highly cementitious
Hydrates similarly to Portland cement
Production
Iron blast furnace
slag is quenched…
it is then ground to a fine
power
Pros and Cons
Pros
Improves workability
Lower water demand
Higher paste volume
Higher strength potential
Using 120 grade
Longer setting time
Decreased permeability
Performs well in freeze
thaw tests
Reduces the effects of ASR
Cons
Reduced heat of hydration*
More susceptible to drying
shrinkage
Slower strength gain*
Slag Activity Index
Higher grade GGBFS can be used in larger
percentages
Improves early and ultimate performance
ASTM C989