Multi-Parameter Study of Sulfate Attack in Bl d d C t M t ......Bonakdar, A., and Mobasher, B.,...
Transcript of Multi-Parameter Study of Sulfate Attack in Bl d d C t M t ......Bonakdar, A., and Mobasher, B.,...
2010 Concrete Sustainability Conference 1 © National Ready Mixed Concrete Association
Multi-Parameter Study of Sulfate Attack in Bl d d C t M t i lBlended Cement Materials
Aboozar Bonakdar , PhD CandidateBarzin Mobasher, PhD, PE, FACI
School of Sustainable Engineering and the Built EnvironmentDepartment of Civil, Environmental, and Sustainable Engineering
ARIZONA STATE UNIVERSITY
Concrete Sustainability Conference, April 13-15, 2010, Tempe, AZ
2010 Concrete Sustainability Conference 2 © National Ready Mixed Concrete Association
Cement & Concrete Technology:Temporal, Spatial, and Scientific Span
Disciplines
• Materials Science• Engineering• Chemistry• Mechanics • Computational Techniques• Manufacturing products and systems
Time
hydration Early age Long termService life
• Manufacturing products and systems• Sustainable development• Technical & non-technical labor poolnanometers to kilometers
(1x10-6 to 1x103 meters)
Space
Seconds to Centuries
(1 to 3x1010 Seconds)
y Early age Performance
2010 Concrete Sustainability Conference 3 © National Ready Mixed Concrete Association
Primary Incentives Research Theme
• Sustainability– Shrinking resources– Increasing demand– Globalization– Social justice & technology transfer
• Quality of life– Provide modern, energy efficient, and economical infrastructure for
societies with a growing middle class population
• Economical Development – Conservation of energy, time, resources, & cost– Value added products for infrastructure
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Outline
•Overview of Research Group activities
D bilit f t t i bilit i•Durability of concrete as a sustainability issue •Performance based specification, long term performance , economical materials selection, and life cycle cost• Models applicable to a host of transport related problems•Sulfate attack- case study
• Experimental program• Macroscopic expansion, what do ASTM results mean?• Microstructural studies
Transport properties• Transport properties• Mechanical properties
• Modeling• AssumptionsAssumptions• Parametric study and Verification
2010 Concrete Sustainability Conference 5 © National Ready Mixed Concrete Association
Concrete in Arizona- Pay Factors, Statistical Process Control
Source: ADOT Database for One ready mix supplier over a course of two years
10000
All concrete classes28 day strength
Over-strength LevelAt $100-$400 per cubic yard, $1.5-6 Billion industry in Arizona
8000
ngth
, psi
4000
6000
Del
iver
ed S
tren
o = 100 cubic yards
2000 4000 6000S ifi d f' i
2000
D
Specified f'c, psi
Laungrungrong, B., Mobasher, B., Montgomery, D., “Development of Rational Pay factors Based on Concrete Compressive strength Data, Arizona Department of Transportation,”, SPR 608, 2008.
B. Laungrungrong, B. Mobasher, D. C. Montgomery, and C. M. Borror, “Hybrid Control Charts for Active Control and Monitoring of Concrete Strength ” ASCE Journal of Materials Engineering Jan 2010
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Housing is a human rights issue
• Navajo Nation is 27,000 square miles in the states of AZ, NM, and UT, geographically is the largest Native American reservation in the U.S.
•The Navajo Nation has the highest poverty rate in the U.S. More than 56% of Navajos live below the poverty level
•Unemployment rate is 44 percent, median family income is $11,885, Per capita income is $6,217.
•The population has increased 3.5 times from the 50 000 people in 194050,000 people in 1940.
•Most homes do not have electricity, running water, or telephones.
2010 Concrete Sustainability Conference 7 © National Ready Mixed Concrete Association
Aerated Fiber-Reinforced Concrete (AFRC)Block Manufacturing & Construction Methods
Demonstration Home in Town of Guadalupe, AZDesigned by ASU Stardust CenterDesigned by ASU Stardust Center
•Thermal Mass• Airtight, Whole wall coverage•reduce HVAC Equipment•Reduces energy consumption•Fire Resistant, 8” Bearing wall, 4 hour UL fire rating
2010 Concrete Sustainability Conference 8 © National Ready Mixed Concrete Association
Properties of AFRC
LVDT-1Actuator
-Energy efficient, Effective R-value, 3.4/in,Fire Pest resistant
LVDT-2
- Fire, Pest resistant- Durable, no autocalve- Acoustical insulation- Energy absorbing- Easy to use
2010 Concrete Sustainability Conference 9 © National Ready Mixed Concrete Association
Thermal Insulation of Concrete Homes
Thermal properties (200x200x20 mm plates)(200x200x20 mm plates)
50Experiment, Tout
Experiment, Tin
30
40
Tem
pera
ture
, 0 C
Simulation, Tin
Experimental and thermal simulation of insulation of concrete walls 0 10 20 30 40
Time, h
20
T
2010 Concrete Sustainability Conference 10 © National Ready Mixed Concrete Association
Durability of concrete
• Major concerns: • Life cycle cost• Premature failure and serviceability issues
• Design codes: • Durability- is a black box issue• Main criterion: compressive strength, W/C, empirical tests
P t ti t h i Wh t d t t lt ll ?• Proper testing techniques: What do test results really mean? • Key parameters affecting the durability: multi-scale and multi-variant•Transport mechanisms dominate major durability issues • Alkali silica reaction (ASR), sulfate attack, carbonation, leaching, frost resistance and corrosion•Damage by sulfate attack: building foundations, bridge, piers.
Before sulfate exposure
After sulfate exposure
2010 Concrete Sustainability Conference 11 © National Ready Mixed Concrete Association
External Sulfate attack
• Diffusion of sulfate ions into concrete and reaction with cement paste:• Dissolution of portlandite (CH) and decomposition of C-S-H phase • Formation of gypsum and/or ettringite crystals, vol. expansion
263 HSACHHSCAC →++
• Formation of ettringite: topochemical reaction: may cause expansion and cracking of the hardened cement
323623 263 HSACHHSCAC →++• Volume of reaction products >> volume of reactants • Need for better mechanics based models
• Blended cements improve sulfate resistance by reducing the porosity (diffusion) and lt i th h i l ti (l C A)altering the chemical reactions (less C3A)
2010 Concrete Sustainability Conference 12 © National Ready Mixed Concrete Association
Experimental program
• Hypothesis: • Can effect of different fly ash compositions be directly related to performance?• How do you measure performance?
•Type I/II portland cement + 7 different fly ashes (class F, C)•Tests: ASTM C 1012, XRD, microstructural studies (SEM/EDS), ionic diffusion (EDS, PIXE), micro-hardness, flexural response, fracture parameters
Cement F1 F2 F3 C1 C2 O
SiO2 21.62 62.93 58.72 56.48 52.16 37.2 41.1S O2 6 6 93 58 56 8 5 6 3
Al2O3 4.06 22.84 24.86 25.61 30.11 20.39 17.37
Fe2O3 3.54 4.01 4.94 3.01 2.71 5.32 3.45
CaO 63.90 2.57 4.56 3.22 8.93 25.91 19.8
M O 1 40 1 64 1 57 1 67 1 37 3 79 1 33MgO 1.40 1.64 1.57 1.67 1.37 3.79 1.33
SO3 2.81 0.14 0.21 0.38 0.51 1.93 10.12
Na2O 0.06 1.46 1.11 1.22 0.51 1.88 0.96
K2O 0.54 1.53 1.11 1.49 1.55 0.45 0.78
2010 Concrete Sustainability Conference 13 © National Ready Mixed Concrete Association
Properties of studied fly ashesSEM and XRD for fly ash particles
2010 Concrete Sustainability Conference 14 © National Ready Mixed Concrete Association
Expansion (ASTM C 1012)
Specimen size: 1x1x11 in (standard) vs. 0.4x0.4x4 in (modified)
0.1
0 06
0.08
, %
Standard SizePaste with 20% Fly ash
0.04
0.06
Expa
nsio
n,
ControlF1F2F3
0 100 200 300 400 500 6000
0.02 F3C1C2O
Exposure Time, Days
Hypothesis: can smaller specimens be used in order to measure the same material properties for modeling, what does 0.1% expansion mean?
2010 Concrete Sustainability Conference 15 © National Ready Mixed Concrete Association
Expansion: modified vs. standard
paste mixture
1”x1”x11”0.24
mm
E i t l D t
.4”x.4”x4”0.16
pans
ion,
% . Experimental Data
Initial Linear FitFinal Linear Fit
1
1.8
Size effect consideration: SA/V0.08
Mod
ified
Exp
11
1R2 = 0.60
5.217.042.0
)/()/( tan ≈=
Modified
dardS
VSAVSA
0
Nor
mal
ized
M 1
Normallization Factor = 2.5
R2 = 0.86
Normalization Factor: 2.5
Bonakdar, A., and Mobasher, B., “Multi-Parameter Study of External Sulfate Attack in Blended Cement Materials ” Construction and Building Materials 24 (2010) 61–70 2009
0 0.03 0.06 0.09Standard Expansion, %
N
2010 Concrete Sustainability Conference 16 © National Ready Mixed Concrete Association
Expansion: mortar vs. paste
• Effect of aggregates is undeniable:0.5Experimental Data
standard ASTM size
- Creating ITZ in mortar - Increase of porosity due to ITZ- Higher rate of diffusion - Higher expansion values
0.3
0.4
sion
, %
Experimental DataOverall Exponential Fit
• Developing specifications for every combination of cement-fly ash-aggregate becomes improbable
0.2
orta
r Exp
ans
ln(Y) = 69.46 X - 5.90R2 = 0.52
• Need performance based specifications to address internal mechanisms
• How to address empirically based 0 0 03 0 06 0 09
0
0.1M
“effective transport parameters”?
Bonakdar & Mobasher, Journal of Construction and Building Materials, 2009
0 0.03 0.06 0.09Paste Expansion, %
2010 Concrete Sustainability Conference 17 © National Ready Mixed Concrete Association
Microstructural studies (SEM/EDS)
Specimen size: 0.4x0.4x0.4 in (used in expansion test)
Formation of ettringite crystals in pores
Bonakdar & Mobasher, Journal of Construction and Building Materials, 2009
2010 Concrete Sustainability Conference 18 © National Ready Mixed Concrete Association
Measurement of Other Properties
• Can we get extra information using the same specimens ?
1”1”
1/4”
• Microstructural studies-SEM EDS
or
SEM, EDS
• Transport properties-1D diffusion
2D diffusion
1x1x5”
- 2D diffusion
• Mechanical properties- Strength
Stiffness- Stiffness- Hardness
2010 Concrete Sustainability Conference 19 © National Ready Mixed Concrete Association
1-D diffusion using PIXE
12000
16000
20000
unts
1-4-1, w/c=0.7
Position 1Position 2Position 4Position 5Position 6
Si PIXE (Particle Induced X-ray Emission)
4000
8000
12000
Elem
ent C
o Position 6Position 7Position 8
S
AlNaK
Ca
CaTi
400
600
unt
Control (Experiment)Blended (Experiment)Error Function (Fitted)
Concentration of Sulfates (Mortar)0 1 2 3 4 5
Energy, KeV
0Ti
200
400
Sul
fur A
rea
Cou
Control: D = 2.4 x10-11
k = 4.4 x10-8
Blended: D = 1.6 x10-11
k = 2 2 x10 8
Specimen size: 2x2 in cylinders 0 10 20 30 40 50
Specimen Depth, mm.
0
k = 2.2 x10-8
2010 Concrete Sustainability Conference 20 © National Ready Mixed Concrete Association
2-D diffusion using EDS
Specimen size: 1x1x0.25 in (used in expansion test) 1”
1”1/4”1.6
1 2 3 4 5
5
4.8
6.4
25 mm
6.4
4
3
2
1.6
4.8
1
Sulfur Content, % (Interpolated Data)
0 8
0.9
11
12Calcium Content, % (Interpolated Data)
0 8
0.9
22
23
Diffusion of sulfur Leaching of calcium
Y, i
n
0.4
0.5
0.6
0.7
0.8
6
7
8
9
10
Y, i
n
0.4
0.5
0.6
0.7
0.8
18
19
20
21
Interpolated contour plots for diff t l t
X, in
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0.1
0.2
0.3
2
3
4
5
X, in
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0.1
0.2
0.3
16
17
18different elements
2010 Concrete Sustainability Conference 21 © National Ready Mixed Concrete Association
Mechanical properties
Control (no fly ash) Blended (30% class F fly ash)160
No 1: Control (Mortar)S/C=2.0, W/C=0.5, Curing=1 Month
160
No 2: Blended (Mortar)S/C=2.0, W/C=0.5, Curing=1 Month
Specimen size: 1x1x5 in80
120
l Loa
d, lb
f Before Exposure 3 Months Exposure12 Months Exposure
, , g
80
120
l Loa
d, lb
f Before Exposure 3 Months Exposure12 Months Exposure
, , g
Specimen size: 1x1x5 in(used in expansion test)
40
Flex
ural
40
Flex
ural
0 0.002 0.004 0.006
CMOD, in
00 0.002 0.004 0.006
CMOD, in
0
Ratio: Blended/Control MORElastic Flex.
StiffnessBefore exposure 0.81 1.04
3m exposure 0.85 0.7512m exposure 1.19 2.21
2010 Concrete Sustainability Conference 22 © National Ready Mixed Concrete Association
Modeling Steps
• Components of a diffusion reaction-micromechanics based damage model.
Tixier & Mobasher, ASCE, Materials Journal, 2002
2010 Concrete Sustainability Conference 23 © National Ready Mixed Concrete Association
Diffusion/Reaction Based Model
U Plane of symmetryU
Calcium Aluminates
U0 U0U0 U0
Sulfates,U
at t>0
at t=0
0 L0
ConcentrationProfile
0 L0
HSAC26H HS3C A C HSAC16H 2CSH HSACCH HSAC 14H HS3C AHC
323623
32362124
32362134
⇒++
⇒++
+⇒++
3236 HSACSqCA ⇒+ettringitesummarize
XX
Tixier & Mobasher, ASCE, Materials Journal, 2002
CA = C4AH13 (monosulfate and residual C3A combined)q = equivalent stoichiometric coefficient
323623
2010 Concrete Sustainability Conference 24 © National Ready Mixed Concrete Association
Transport properties
• Durability-related phenomena: one or more transport mechanisms: movement of water and chemicals in to or out of concrete
• Ionic diffusion: predominant transport mechanism in most cases• Ionic diffusion: predominant transport mechanism in most cases
• Sulfate attack: ionic diffusion + chemical reaction
)()( 2 txCtxC ∂∂ )(}),,(),,({),,(222
CtyxCtyxCtyxC ∂∂∂
Concentration Contour - with reaction
45
50
0.9
1
)(),(),(:1 20 CRx
txCDt
txCD +∂
∂=∂
∂− )(}),,(),,({),,(:2 220 CRy
tyxCx
tyxCDt
tyxCD +∂
∂+∂
∂=∂
∂−
80
90
100Concentration Profile - with reaction
without reactionwith reaction
1D Solution using error
Y-D
epth
, mm
20
25
30
35
40
0.4
0.5
0.6
0.7
0.8
40
50
60
70
80
C/C
0, %
with reaction
D=10-12 (m2/s)
using error function
X-Depth, mm
0 10 20 30 40 50
0
5
10
15
0
0.1
0.2
0.3
0 5 10 15 20 25 30 35 40 45 500
10
20
30
40
k=10-8 (1/s) 2D Solution using series
2010 Concrete Sustainability Conference 25 © National Ready Mixed Concrete Association
Volumetric Changes & Damage Evolution
• The result of reaction between sulfates and C3A is formation of delayed ettringite which has a lot more water molecules and consequent volume change.
M ( / l ) ( / 3)
32623 263 HSACHHSCAC →++
Mi (g/mole) ρi(g/cm3) ai
C3A 270 3.04 3
Gypsum 138 2.32 1
Ettringite 710 1.75 3
∑∑ ±==Δi i
ii
ii
MaVVρ.
r)
Da
Stress-Strain CurveDegraded SlopeDamage Functionft
reactedreacted SVV .Δ=Δ
reactedVt Δ== )(εε ensi
le S
tress
(σr
amage Function
E' = E0 (1- ω) E'
E
specimenVV V
t)(εε
Tixier & Mobasher, ASCE, Materials Journal, 2002T il St i ( )
Te (ω)
'E' decreasing nq
dxx ])(1.[)( 0 −=σσ
u(x)
d
2010 Concrete Sustainability Conference 26 © National Ready Mixed Concrete Association
Parametric study
Effect of reaction term(on the concentration)
Effect of diffusion term(on the stiffness and expansion)
20000
25000
MPa
Modulus of Elasticity
0.08
0.1
Expansion
D1=10-12 D2=10-13 D3=10-140.6
0.8
1
/U0
0 5 10 15 20 25
without reaction (k=0)
D = 5x10-13 m2/s
10000
15000
of E
last
icity
, M0 04
0.06
Expansion,
w/c = 0.4E0/E1 = 75%k = 10-7
D1 10 2 3
'D' decreasing0
0.2
0.4U/
1 month
12 months
0 8
1
5000
10000M
odul
us
0.02
0.04 %k = 10
D1=10-12 D2=10-13 D3=10-14
0.2
0.4
0.6
0.8
U/U
0 with reaction (k=10-7)
D = 5x10-13 m2/s
12 months
0 100 200 300 400
Exposure Time, Days
0 00 5 10 15 20 25
X, mm
01 month
2010 Concrete Sustainability Conference 27 © National Ready Mixed Concrete Association
Parametric study
Effect of W/C ratio(on the expansion values)
Effect of C3A content(on the expansion values)
0.3
0.4
W/C = 0.8 (Experiment)W/C = 0.8 (Model)W/C = 0.6 (Experiment)W/C = 0.6 (Model)W/C = 0.45 (Experiment)W/C = 0 45 (Model)
Ouyang et al. Data(1988)
0.3
0.4
C3A = 8.8% (Experiment)C3A = 8.8% (Model)C3A = 7.0% (Experiment)C3A = 7.0% (Model)
Ouyang et al. Data(1988)
0.2
xpan
sion
, %
W/C = 0.45 (Model)
S/C = 4E0/E1 = 80%α = 75% W/C = 0.6
W/C = 0.8D = 7.5x10-12
k = 4.0x10-7
0.2
0 3
pans
ion,
%
C3A = 4.3% (Experiment)C3A = 4.3%(Model)
D = 5x10-12
k = 1-1.5x10-7
W/C = 0.6S/C 0
C3A = 8.8%
0.1
Ex α 5%
C3A = 5%ft = 1.7-2.0 MPa
W/C = 0.45D = 5x10-12
k = 2 5x10-7
D = 6x10-12
k = 3.0x10-7
0.1
ExS/C = 4.0α = 80%ft = 2 MPa
7.0%
0 40 80 120
Exposure Time, %
0k = 2.5x10-7
0 100 200 300
Exposure Time, %
04.3%
2010 Concrete Sustainability Conference 28 © National Ready Mixed Concrete Association
Model Verification
Prediction of modulus of elasticity Prediction of expansion
40
50
Pa
Ferraris et al. Data(2006)
0.25
0.3Ferraris et al. Data(2006)
S/C = 2.75W/C = 0.485C3A = 5%
30
40
f Ela
stic
ity, G
P
SF:D = 1x10-13
k = 1x10-7
0.15
0.2
ansi
on, %
ControlD = 2x10-12
k = 2.5x10-7
FA_F(Class F flyash):D = 7x10-13
k = 1.5x10-7
10
20
Mod
ulus
o
Control (Experiment)Control (Model)SF (Experiment)SF (Model)
ControlD = 2x10-12
k = 2.5x10-7
w/c = 0.485C3A = 5% 0.05
0.1Exp
a
Control (Experiment)Control (Model)FA_F (Experiment)FA_F (Model)SF (Experiment)SF (Model)SF (Silica fume):
D = 1x10-13
k = 1x10-7
0 100 200 300 400 500
Exposure Time, Days
00 100 200 300 400 500
Exposure Time, %
0
2010 Concrete Sustainability Conference 29 © National Ready Mixed Concrete Association
Model Verification
Prediction of expansion (current study)
0.1 5E-007
Effect of D and k in modeling
0.08
%
Control (Experiment)Control (Model)30% Flyash (Experiment)30% Flyash (Model)
Control: D 8x10 13
4E-007
3 /(m
ole.
s)
Ouyang Data (OPC)Sahamaran Data (OPC)Current Study (OPC)Ferraris Data (Blended)Sahamaran Data (Blended)Current Study (Blended)
0.04
0.06
Exp
ansi
on, %
30% Class F: D=4x10-13
E0/E1 = 0.5
Control: D=8x10-13
E0/E1 = 0.45
2E-007
3E-007
f Rea
ctio
n, m
3 Current Study (Blended)
Zone 1: Fly ash BlendedZone 2: OPC
0
0.02
Current Study: Expansion of Pastes
W/C = 0.4α = 70%k = 1x10-7
ft = 2 MPa1E-007
Rat
e of
Zone 1 Zone 2
0 100 200 300 400 500 600Exposure Time, Days
01E-014 1E-013 1E-012 1E-011
Coeffidient of Diffusion, m2/s
2010 Concrete Sustainability Conference 30 © National Ready Mixed Concrete Association
Conclusions
• Effect of various fly ashes on the sulfate resistance of concrete was studied using traditional and developed test methods .
• ASTM C1012 test method using 1x1x11 inch specimens can take up to 12 months for results. Using modeling, smaller size specimens accelerates the reactions and provides results in much shorter titimes.
• Supplementary tests were performed in order to obtain the diffusivity (D) and reactivity (k) of sulfate ions in 1-D and 2-D cases using characterization techniques.
• Flexural tests were performed on exposed samples which showed quantitative measurements of the damage evolution from sulfate q gattack.
2010 Concrete Sustainability Conference 31 © National Ready Mixed Concrete Association
Conclusions
• A predictive model is presented based on cement chemistry, concrete physics and solid mechanics.
• Key factors in modeling are: C3A content and reactivity, internal porosity and ionic diffusivity.
• Input parameters are compatible with experimental data.
• Effects of degradation, specimen size, curing duration, and material ingredients can be verified using the modelingredients can be verified using the model.
• SULFATE2 computer program can be downloaded on the link to the web site is as follows: http://ciks cbt nist gov/~bentz/phpct/cmml htmlhttp://ciks.cbt.nist.gov/~bentz/phpct/cmml.html
2010 Concrete Sustainability Conference 32 © National Ready Mixed Concrete Association
Acknowledgement
• Work Conducted under support from ADOT Project SRR-633 Economical Concrete Design, (Christ Dimitroplos,633 Economical Concrete Design, (Christ Dimitroplos, Program manager). Support of Salt River Materials Group, SRMG, (Jeff Hearne) for the experimental portions of the project is greatly appreciated. p j g y pp
2010 Concrete Sustainability Conference 33 © National Ready Mixed Concrete Association
ASR Reaction Products
Control: swelling gels fly ash Blended: safer gels
Bonakdar, Mobasher, Dey, Roy (2010), ACI Materials Journal, V. 107, No.
2010 Concrete Sustainability Conference 34 © National Ready Mixed Concrete Association
Chemical Composition vs. Expansion
0.2
0.25
14 Days28 Days0.2
0.2514 Days28 Days
0.1
0.15
xpan
sion
, % Y = 0.094 (Ceq/Seq) - 0.129R2 = 85%
0.1
0.15
xpan
sion
, %
Y = 0 114 (C /S ) - 0 077
0
0.05
Ex
Y = 0.081 (Ceq/Seq) - 0.139R2 = 89%
0
0.05
Ex
Y = 0.099 (Ceq/Seq) - 0.096R2 = 81%
Y = 0.114 (Ceq/Seq) - 0.077
R2 = 75%
eqsimplified
eq
C CaO( )S SiO Al O
=+2 2 3 )37605890(01
)700.0595.0905.0(0.6)( 322
OFeOAlSiOSOOKONaCaO
SC
MLeq
+++++=
1 1.5 2 2.5 3 3.5 4Total Ceq/Seq Ratio (ML)
01 1.5 2 2.5 3 3.5 4
Total Ceq/Seq Ratio
0
eqS SiO Al O+2 2 3
• One can use this fitted equation to estimate the optimum Ceq/Seq ratio for a required expansionlimitNote: ML formula includes molar equivalents and reaction factors (Malvar and Lenke , 2006)
)376.0589.0(0.1 32322 OFeOAlSiOSeq ++
Bonakdar, Mobasher, Dey, Roy (2010), ACI Materials Journal, V. 107, No.
2010 Concrete Sustainability Conference 35 © National Ready Mixed Concrete Association
Effect of Fiber-Reinforcement
Flexural properties on 150x150x450 mm prisms
time =0 minCOD=0.0 mmfR=0.00 MPa
time =3 minCOD=0.9 mmfR=0.24 MPa
time =6 minCOD=3.6 mmfR=0.28 MPa
time =12 minCOD=9.2 mmfR=0.25 MPa
time =24 minCOD=18 mmfR=0.13 MPa
2010 Concrete Sustainability Conference 36 © National Ready Mixed Concrete Association
Full-Scale Testing of AFRC
Shear wall test results
Note: Фs.Vn: factored shear capacity, Vu: un-factored shear capacity, Фs.Vu: factored service loadload
60
80
Shear Wall Test (2.4x2.4x0.2 m setup)
60
80
Shear Wall Test (2.4x2.4x0.2 m setup)
φs.Vn = 68.7 kN
40
She
ar L
oad,
kN
40
She
ar L
oad,
kN
φs.Vu = 34.3 kN
Vu = 54.9 kN
0 1 2 3 40
20
S
0 4 8 12 160
20
S
0 1 2 3 4
LVDT-1, mm0 4 8 12 16
LVDT-1, mm
magnified
2010 Concrete Sustainability Conference 37 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 38 © National Ready Mixed Concrete Association
AAC vs. AFRC
AAC (plain, autoclaved) AFRC (fiber-reinforced, non-autoclaved)
600
f
Flexural Response for AFRC Beams (6x6x18 in)
600
f
Flexural Response for AAC Beams (6x6x18 in)
200
400
exur
al L
oad,
lbf
AFRC - Samples 1-4
200
400
exur
al L
oad,
lbf
AAC - Samples 1-4
0
200Fle
Average σR = 77 psi
0
200Fle
Average σR = 93 psi
0 0.05 0.1 0.15 0.2 0.25 0.3
CMOD, in
00 0.004 0.008 0.012 0.016 0.02
CMOD, in
0
Note the difference between scales on X-axis