Lcr Thesis Presentation Final

SWANSON School of Engineering

CONCRETE MIXTURE PROPERTIES AFFECTING
THE
AGGREGATE INTERLOCK MECHANISM OF
JOINTS AND CRACKS
FOR RIGID PAVEMENT SYSTEMS

LUIS CARLOS RAMIREZ
Advisor : Dr. Julie Vandenbossche

Masters Thesis Defense
November 19, 2010

OUTLINE
INTRODUCTION

MOTIVATION

APPROACH

RESEARCH OBJECTIVES

METHODOLOGY

EXECUTION

RESULTS AND ANALYSIS

CONCLUSIONS

FUTURE WORK
Masters Thesis Defense 11/19/2010

INTRODUCTION
Pavement Performance
Faulting Punchouts

Corner Breaks Transverse Cracking


INTRODUCTION

Load Transfer Efficiency (LTE) of Cracks and Joints
(LTE)

L= 1 U= 0

L= 1 U= 1

U
LTE = x100%
L

INTRODUCTION
Aggregate Interlock Mechanism

PCC Slab

Base

LTEjoint=LTEbase+LTEAGG

20%-40%

AGG= Joint Spring Stiffness


INTRODUCTION
Factors Affecting the Aggregate Interlock Mechanism
Crack Surface Texture

Crack width
CA Top CA Matrix CA CA
Size Hardness Strength Gradation Angularity


MOTIVATION

Damage accumulation

σ+δ= f( AGG/kl)
AGG/kl)

M-E Design AGG = f( LTE)

LTE = f( Surface texture)
texture)

Surf. texture = f( PCC Material properties)


APPROACH

Surface Texture
Concrete Vandenbossche (1999)
(1999)
Mixture
Properties

Ioannides
LTE et.al (1990) AGG/
AGG/kl


RESEARCH OBJECTIVES

1. Establish a relationship between PCC properties and LTE.
LTE.

2. Establish a relationship between PCC properties and AGG.
AGG.

3. Investigate the effect of PCC properties on fracture
parameters.

4. Determine influence of fracture parameters on the
aggregate interlock.


METHODOLOGY

Select Cast
Identify
Data Points Specimens
Data Gaps
to Include & Testing
Data
Calculate
Selection
Results
Previous
from Tests
Studies
Data

Analyzed
Statistical Analysis of Development
Combined
Data Fitting Results of Models
Data


Full Factorial Design Matrix
LA Category CA Top Size (in) w/c ratio Category Existent
Low strength
0.75 Medium strength
High strength
Low strength
Low resistance to abrasion 1.5 Medium strength
EXECUTION

High strength
Low strength
2.5 Medium strength
High strength
Low strength
High strength
Low strength
Medium resistance to abrasion 1.5 Medium strength
High strength
Low strength
2.5 Medium strength
High strength
Low strength
High strength
Low strength
High resistance to abrasion 1.5 Medium strength
High strength
Low strength
2.5 Medium strength
High strength

EXECUTION
Concrete Mixtures Properties
Concrete Mix
LS_0.75_17_0.4 LS_0.75_17_0.45 SL_1.25_34_0.4 SL_0.75_34_0.4 SL_0.75_34_0.45
ID
Aggregate
Type
Limestone Limestone Slag Slag Slag
Top
Aggregate 0.75 0.75 1.25 0.75 0.75
Size (in)
Coarse
Aggregate
Volumetric
44
Proportion (%)
Water-to-
Cement Ratio
0.4 0.45 0.4 0.4 0.45

LA Value (%) 17 34

Absorption 0.5 4.78
Capacity, (%)
Bulk Specific 2.71 2.35
Gravity

CA Gradation AASHTO No. 57


EXECUTION
Testing Program
Day 1 Day 28

Fracture Energy Fracture Energy
Test RILEM TPM Test RILEM TPM
1990 1990
(4 specimens per (4 specimens per
mixture) mixture) Volumetric
Surface Texture
VST Test
(35 Fractured
Flexural Strength Faces)
Test ASTM C78
(3 specimens per
mixture)


INTRODUCTION
Volumetric Surface Texture Test (VST)

Vandenbossche (1999)


0.2365 in3/in2 VSTR Results 0.1289 in3/in2


VSTR Model
VSTR=0.3689+0.5004*TS-24.5162*(1/LA)-0.0540*w/c+0.2049*TS2-

2.2665*TS*w/c+61.5434*(w/c/LA)
Response Surface Method (RSM)
VSTR =Volumetric Surface Texture Ratio (in3/in2)

R2=0.91 Adjusted R2=0.86 TS = Aggregate Top Size(in)
LA = LA Abrasion (%)
w/c =w/c ratio

Source p-value Terms p-value
0.600
Regression 0.0000 Constant 0.000

Predicted VSTR (in³/in²)
0.500

Linear 0.0010 TS 0.002 0.400

0.300
Square 0.0010 1/LA 0.000 0.200

0.100
Interaction 0.0000 w/c 0.001
0.000
0.0000 0.1000 0.2000 0.3000 0.4000 0.5000 0.6000
TS2 0.000
Measured VSTR (in³/in²)
TS*w/c 0.000

w/c/LA 0.005


VSTR f(CA Top Size, CA LA) w/c ratio =0.45

0.60000
0.50000-0.60000
0.50000
0.40000-0.50000
VSTR (in3/in2)

0.40000 0.30000-0.40000
0.20000-0.30000
0.30000
0.10000-0.20000
0.20000 0.00000-0.10000

0.10000

0.00000
16
21
26
31
LA (%) 37 2.34
2.02
42 1.71
1.39 CA top size(%)
1.07
0.75



VSTR f(CA LA, w/c ratio) CA Top size = 1 in

0.35000
0.30000
VSTR (in3/in2)

0.25000 0.30000-0.35000
0.20000 0.25000-0.30000

0.15000 0.20000-0.25000
0.15000-0.20000
0.10000
0.10000-0.15000
0.05000
0.05000-0.10000
0.00000
0.38
0.40 0.00000-0.05000
0.43
w/c ratio 0.45
43
0.48 38
32
27 LA (%)
21
16


LTE Model
 VST 
LTE = 39.7 ⋅ log  + 5.6
 cw 
R2=0.95

Adjusted R2 =0.90

VST = VTSR ⋅ t eff
teff
Vandenbossche (1999)

[(0.3689 + 0.5004 ∗ TS − 24.5162 ∗ (1/ LA) − 0.0540 ∗ w / c + 0.2049 ∗ TS 2 −
LTE = 39.7 ⋅ log{

2.2665∗ TS ∗ w / c + 61.5434∗(w _ c / LA)]∗ 2.54 * teff
} + 5.6
cw
LTE= Load Transfer Efficiency (%)
VST=Volumetric Surface Texture (in3/in)
VSTR =Volumetric Surface Texture Ratio (in3/in2)
TS = Aggregate Top Size(in)
LA = LA Abrasion (%)
w/c =w/c ratio
Masters Thesis Defense 11/19/2010 teff= Slab Effective Thickness (cm)
cw= Crack Width (cm)

100

90 0.75 in

80

LTE (%)
1 in
70

60 1.5 in
50

40 2 in
0 20 40 60 80 100 120

LTE vs. Crack Width Crack width (mils)

100

Jensen & Hansen (2001) 90 Predicted 1in
Slab thickness =10 in
Limestone LA =34% , TS =1in
Gravel LA 22%, TS=2iin 80
Mesured 1 in
LTE (%)

70
Predicted 2 in
60

50 Measured 2 in
40
0 20 40 60 80 100 120
Masters Thesis Defense 11/19/2010 Crack width (mils)

AGG Model
100

90
...

80
 1 
−1.17786

70
 − 0.01 
Load Transfer Efficiency, %

60
AGG =  LTE  ⋅k⋅l
 0.012  
 
50

  
40
 
30

20 Crovetti (1994)
10

0 Ioannides et. al (1990)
0.01 0.1 1 10 100 1000
Nondimensional Stiffness, AGG/kl

[(0.3689 + 0.5004 ∗ TS − 24.5162 ∗ (1/ LA) − 0.0540 ∗ w / c + 0.2049 ∗ TS 2 −
LTE = 39.7 ⋅ log{
2.2665∗ TS ∗ w / c + 61.5434∗(w _ c / LA)]∗ 2.54 * teff
} + 5.6
cw
LTE= Load Transfer Efficiency (%)
VST=Volumetric Surface Texture (in3/in)
0.25 VSTR =Volumetric Surface Texture Ratio (in3/in2)
 Eh3  TS = Aggregate Top Size(in)
l=
 12 ⋅ (1− ν 2 )k 
 LA = LA Abrasion (%)
  w/c =w/c ratio
teff= Slab Effective Thickness (cm)
cw= Crack Width (cm)
k= Modulus of Subgrade Reaction (psi/in)
Masters Thesis Defense 11/19/2010 l = Radius of Relative Stiffness (in)


AGG f(LA, w/c ratio) k =200 psi
l= 30 in
cw=0.08 in
teff=11 in
CA top size= 1 in
7.00E+04

6.00E+04

5.00E+04
AGG (psi)

4.00E+04 6.00E+04-7.00E+04
5.00E+04-6.00E+04
3.00E+04
4.00E+04-5.00E+04
2.00E+04 3.00E+04-4.00E+04
1.00E+04 2.00E+04-3.00E+04
1.00E+04-2.00E+04
4.00E+01
0.38
0.40 4.00E+01-1.00E+04
0.42
w/c ratio 0.44
0.46
0.48 43 46
32 35 38 40
24 27 30 LA (%)
16 19 21


CONCLUSIONS

Development of VSTR model
VSTR = f (w/c, TS, LA).

Development of LTE model
LTE = f (w/c, TS, LA, cw, t)

Development of AGG model
AGG= f (w/c, TS, LA, cw, t, k, l)


FUTURE WORK
To expand and additional validation of VSTR model.

To incorporate AGG model into the MEPDG.

To investigate the effect of additional PCC properties on the
surface texture.

To investigate the relationship between concrete fracture
parameters and the aggregate interlock mechanism.


Thank you!

QUESTIONS?/COMMENTS?


Lcr Thesis Presentation Final

Recommended

Recommended

More Related Content

Viewers also liked

Viewers also liked (20)

Lcr Thesis Presentation Final