2019 basf trc_frc_uhpc

1. Opportunities in the Application development
with TRC Materials, Possibilities beyond Glass
and Carbon
Barzin Mobasher, PhD. PE., FACI
School of Sustainable Engineering and the Built Environment
Arizona State University
2019

2. Length
Scale
Time
Scale
Disciplines
Seconds to
Centuries
(1 to 3x1010
Seconds)
hydration Early age
Long term
Performance
Service life
• Materials Science
• Engineering
• Chemistry
• Mechanics
• Computational Techniques
• Manufacturing products and systems
• Sustainable development
• Technical & non-technical labor poolnanometers to kilometers
(1x10-8 to 1x103 meters)
Temporal, Spatial, and Scientific Span of Construction Products:

3. Globalization- American Model of Economic Development
• China and India have achieved fast economic growth rates by rapid
industrialization
• Over 40% of the 1.3 billion Chinese already live in cities with sky-rocketing
demand for energy and energy-intensive materials
• China has 50% of global cement production, 40% of global steel production,
15% of the global power generation. 80% of coal electric power generation

4. Global Warming, Mass Migrations, and Social Justice:
Alternative Construction Products

5. Global Warming is Global
Texas, Florida, Caribbean, Bangladesh,..
Hurricane Harvey,
2017
Hurricane Irma,
2017

6. FRC - Background
• high strength and ductile concrete has been made possible by advances in:
 particle packing, aggregate gradation , superplasticizers, rheology
 increased quality control
 Innovative fibers, testing and specification methods
 Chemical admixtures low water-to-cementing materials ratio.
• Ductility and crack width control that reduces liquid ingress, significantly
enhancing durability

7. Problem Statement
• How do we use the existing knowledge on concrete material
for better construction procedures and specifications for
implementing the concrete materials?
• How do we capture the economic benefits of FRC and TRC in
terms of speed of construction, reduced labor, better quality
concrete?
• Cost-effective specification procedures for use in cast in place,
precast, and shotcrete concrete applications.

8. Objectives
• Re-think existing procedures and standards
• Develop New mixtures, UHPC, TRC with locally available materials
• Develop Optimized Structural and material models based on realistic
performance criteria for strength, stiffness, crack width and durability.
• Focus Areas:
– Mechanical: strength, ductility, impact, repair,
– Durability: corrosion resistance, Permeability, Shrinkage and creep
resistance

9. Materials characteristics
• Ductility
• Toughening
• Improved tensile strength
• Increase level of energy absorption
• Fatigue life, impact/explosive loading
• Seismic resistance
• Steel work, labor, construction time.
• Corrosion damage
• Long-term repair and maintenance.
500 m
20 m
(c)
200 m
(d)
500 m

10. Accomplishments in Developing ACI Codes and
Guides Documents
• Criteria for fibers in structural applications
• Criteria for repair of existing structures and canals, shotcrete
• Development of performance based specifications
• Design opportunities:
– Ductility, durability, crack width, stiffness, cracked section modulus, Shear
– Hybrid approach of combining reinforcement and fibers for sustainability
– Minimum reinforcement requirements.
• Five major documents developed by the ACI 544-D committee in the past
four years
• ACI 544-9R Mechanical testing of FRC
• ACI 544-8R Tensile Design Properties from flexural tests, backcalcuation procedures
• ACI 544-4R Design
• ACI 544-6R Elevated slabs (2015)
• ACI 544-7R Tunnel lining

11. ACI related International Committee Reports
ACI 544.5R-10 “Physical Properties and Durability of Fiber-Reinforced Concrete,”
Report, ACI Committee, p. 31, (2010).
ACI 544.6R-15 Report on Design and Construction of Steel Fiber-Reinforced
Concrete Elevated Slabs (2015)
ACI 544.7R-16 Report on Design and Construction of Fiber-Reinforced Precast
Concrete Tunnel Segments (2016)
ACI 544.8R-16: Report on Indirect Method to Obtain Stress-Strain Response of
Fiber-Reinforced Concrete (FRC), ACI Committee 544 ACI 544.8R (2016)
ACI 544.9R-17: Report on Measuring Mechanical Properties of Hardened Fiber-
Reinforced Concrete, (2017)
https://www.concrete.org/Portals/0/Files/PDF/Previews/544.9R-17_preview.pdf
ACI 544.10R-17: Report on Measuring Properties of Fresh Fiber-Reinforced
Concrete, (2018)
ACI 544-4R ACI 544.4R-18: Report on Structural Design with Fiber-Reinforced
Concrete (2018)

14. Textile Reinforced Concrete
Sandwich layers
• Low cost equipment set up
• Uniform production
• high performance fabric-cement composites
• Tension, Compression, beam members
• High pressure pipes

15. Textile Reinforced Concrete
0 0.01 0.02 0.03 0.04
Strain, mm/mm
0
4
8
12
16
20
Stress,MPa
AR Glass Fabric
GFRC
Vf =5%
PE Fabric
E-Glass
Fabric
Mortar
ECC
500 m

16. Homogenization of Crack spacing –Mechanical interlock
0 10 20 30 40
Crack Spacing, mm
0
0.2
0.4
0.6
0.8
1
CumulativeDistributionFunction
Zone 1
= 0.015
Zone 2
.0273
Zone 3
 = 0.0387
AR-Glass Fabric
0 0.02 0.04 0.06
Strain, mm/mm
0
5
10
15
20
25
Stress,MPa
Zone 3
Zone 2
Zone 1
AR-Glass Fabric
AR Glass Bonded
Fabric
Polyethylene (PE)
Woven Fabric
Polypropylene (PP)
Knitted Fabric

17. Uniaxial Tensile Response large strain capacity and ductility
0 0.02 0.04 0.06
Strain, mm/mm
0
4
8
12
16
20
Stress,MPa
0
20
40
60
CrackSpacing,mm
Stress-Strain
Crack Spacing
Pultrusion
Peled, A. and Mobasher, B., (2005), “Pultruded Fabric-
Cement Composites,” ACI Materials Journal, Vol. 102 ,
No. 1, pp. 15-23.

19. Development of Polypropylene based Yarn/Fiber and
Textile technology (project sponsored by BASF Corp)
MAC 2200CB MF 40
Loading Rate (mm/min) 0.4 2.5
Gage Length (mm) 25 25
Effective Yarn Dia. (mm) 0.82 0.89
Tensile Strength (MPa) 311 (+/-38) 492 (+/-65)
Elastic Modulus (MPa) 4499 (+/-351) 1601 (+/-117)
Toughness (MPa) 34 (+/-12) MPa 5058 (+/-1748)
2) Microfiber – MF 40
Fibrillated multi filament micro-fiber
500 filaments of 40 microns per yarn
1) Macro-synthetic fiber – MAC 2200CB
Chemically enhanced macro-fiber

20. Fiber Pullout Test - Experimental setup
Load Cell
Pullout
Specimen

21. Effect of Fiber Embedded Length
Macro PP vs. Steel
Pullout energy as the area
enclosed by load slip response.
maximum for embedded length of
25 mm for all fiber types
Maximum pullout force for MAC is
similar for embedded length 20
and 25 mm. But about 40 % less
at 10 mm.

22. Development of Woven 2-D PP-Textiles
(BASF Construction Products Division)
 The objective is to develop low cost PP based fibers for the development of next
Generation Textile Reinforced Concrete.
 multifilament textiles developed with Partners:
Textile Institute, RWTH Aachen University, Germany
Plain and tricot weave knit patterns with 50% open-closed structure

23. Development of Pultrusion Process – TRC
 Computer controlled pultrusion process for Textile Reinforced Concrete (TRC)
 Different geometrical cross-sections: rectangular plates, angle, channel sections,
 Components: Treatment baths, pressure cylinders, tractor pull clamping, specimen mold, press, Pneumatic pistons,
solenoid valves, Lab view Interface , Simple set up, with low cost equipment, uniform production

24. Test setups for plate, angle and channel sections under
compression and tension
Continuous versus 2D
Reinforcement -Tensile

25. Effect of curing age and dosage, MF series
 MF 40 at dosages of 1.0 and
2.5% tested after 7 and 28
days of moist curing (73 F,
90% RH)
 First crack and ultimate
strength (UTS) increased
marginally with longer
hydration periods
 Toughness increased
considerably due to fiber
content

26. Effect of Fiber Volume Fraction on Tensile
Response of MAC
 Improvement in strength and toughness
with increase in volume fraction.
 First cracking strength increases by
30% and post-crack (tangent) modulus
increases by over 107%.
 The ultimate tensile strength (UTS) and
toughness increases by a factor of 2 at
4% dosage
 Strengthening mechanisms - distributed
parallel cracking, crack bridging and
deflection, fiber pullout, fiber failure.

27. Effect of Fiber Dosage on Tensile Response
 MF 40 vs. MAC – Significantly higher improvement in strength and toughness
with increase in volume fraction from 1.0 – 2.5%
 Possible mechanisms, better bond with the matrix due to matrix penetration
between the filaments.

28. Continuous Fiber versus 2D Textile Reinforcement,
Comparison with Carbon Textiles

29. Micro Toughening Mechanism
1
2
3
Crac k Deflec tion
Debonding
Fric tional SlidingFibers and fiber-matrix interface prevents complete
localized failure in the matrix place through a series of
distributed cracks transverse to the direction of the load.
Distributed cracks enable deflection of matrix cracks
through fiber-matrix debonding and frictional
sliding of the fibers under tension

30. Toughening Mechanisms – MAC
Fiber bridging across loading directionDistributed cracks across loading direction

31. Automated pultrusion system, full
scale structural shapes composed
of TRC laminates can be
manufactured efficiently and
effectively.
Pultrusion Process Schematic Diagram
Light gage steel sections
Structural Shapes: Development, Analysis, and Implementation
using Design Approach

32. Pultruded Full Size TRC Structural Shapes
Cross section of pultruded shapes with TRC laminates

33. TRC Structural Sections
• Full-scale structural sections were manufactured using the pultrusion system and an ARG
textile dosage of 1%
• Angles of 19x75x75 cm2 by 1.22 m were tested in tension with six 8 mm bolts in three rows of
two bolts per leg (UTS of 2.7 MPa)
• Preliminary channels were tested in tension and attached in the web only

34. Efficiency of Structural Shapes
• Angle sections exhibited multiple parallel cracking, a 51% strength reduction
from fixed-fixed testing, and a 40% reduction from fixed-bolt testing

35. DIC based analysis of Static and High Speed Testing

36. Strain Map of Tension Stiffening
Short fiber vs. continuous fiber systems
σ =
0.8 MPa
σ =
2.9 MPa
σ =
4.1 MPa
σ =
4.3 MPa
σ =
2.6 MPa
3.1
MPa
6.1
MPa
16.7 MPa 19.5 MPa 21.6
MPa
Yao, Y., Silva, F. A., Butler, M., Mechtcherine, V., & Mobasher, B. (2015). Tension stiffening in textile-reinforced concrete under
high speed tensile loads. Cement and Concrete Composites, 64, 49-61.

37. Quantification of DIC strain
 A: Localization Zone – Fiber debonding
 B: Shear Lag Zone – Shear lag bonding stress distribution
 C: Uniform Zone – Fiber and matrix are perfectly bonded
DIC strain versus time histories at different zoneIdentification and label of each zone
Rambo, D. A. S., Yao, Y., et al. (2017). Experimental investigation and modelling of the temperature effects on the tensile
behavior of textile reinforced refractory concretes. Cem. Concr. Compos. 75, 51-61.

38. Crack Width Measurement
 Non-contact measurement
 Quasi-static to high speed
 Single crack and multiple cracks
Displacement Field
Displacement
Distribution Along
Specimen
Stress-Crack Width
Relationship
Rambo, D. A. S., Yao, Y., et al. (2017). Experimental investigation and modelling of the temperature effects on the tensile
behavior of textile reinforced refractory concretes. Cem. Concr. Compos. 75, 51-61.

39. Evolution of Crack Spacing in TRC
σ = 3.5 MPa σ = 4.7 MPa σ = 5.5 MPa σ = 11.5 MPa
I II III IV
1.75
2.00
1.50
0.00
yy, %
1.25
1.00
0.75
0.50
0.25
 Multiple cracking in tension
 Tension stiffening
 Development of parallel cracks
 Indication of toughening mechanisms
 Corresponding to the characteristic length in
numerical modelling
Rambo, D. A. S., Yao, Y., et al. (2017). Experimental investigation and modelling of the temperature effects on the tensile
behavior of textile reinforced refractory concretes. Cem. Concr. Compos. 75, 51-61.

40. Videos of AR-Glass Fabric and Composites
AR-Glass CompositeAR-Glass Fabric

41. Videos of PE Fabric and PE Composite
PE Composite with Silica FumePE Fabric

42. Carbon Fiber Bundle and Carbon Composite
Carbon Composite (plain cement)Carbon Fiber Bundle

43. New Product Development
• Sandwich composite systems with TRC and light-weight aerated concrete core
• Structural sections with TRC
Aerated concrete
core
Textile reinforced
cement skin layer
Dey, V., Zani, G., Colombo, M., Di Prisco, M., Mobasher, B., “Flexural Impact Response of Textile-Reinforced Aerated
Concrete Sandwich Panels”, Journal of Materials and Design, 2015, doi: 10.1016/j.matdes.2015.07.004

44. Tunnel Lining
• Fiber-reinforced concrete can be used in tunnel lining segments.
• Macro steel fibers and macro synthetic fibers are mainly used for this type of application.
• Using fibers can reduce or even eliminate the steel rebar reinforcement which results in
faster and cheaper production.
M. Moccichino et al., 2010 world
tunnel conference, Italy
BEKAERT

45. Test Setup
• 3 point bend flexure test
• Instrumentation to measure the
deflection, strains, cracking initiation
and propagation
LVDT
Strain Gage
Top view
Demo video

46. Large Frame Testing setup

47. Test Results
Tunnel lining with load
https://www.youtube.com/watch?v=7d9d2UgC9no&feature=youtu.be

48. Crack appears
DIC Analysis of PP12_N1
Crack grows
Crack formedFinal state
Video 3.Tunnel_Lining_Segment_Flexure
https://www.youtube.com/watch?v=Sou6uagg0zE

51. Comparison of Steel (50 lbs/yd3) and PP fibers
(12 lbs/yd3)
• Load deflection response of both the
specimens is compared.
• Both specimen crack around 25-26 kips load
• ST50 has higher post crack strength.

52. Structural Design with FRC Materials: testing,
modeling, analysis and Design
Shotcrete applicationsPrecast panels
Design with Strain
Softening materials

53. Analysis of Precast Wall Panels
• Assume continuous wall, pin connection at the
bottom and free at the top
• Lateral water pressure in ultimate and
serviceability limit states

54. Residual strength Effect
0 0.03 0.06 0.09 0.12 0.15
CMOD, inch
0
500
1000
1500
2000
2500
3000
Load,lbf
36 hrs - Sample 1
36 hrs - Sample 2
16 hrs - Sample 1
16 hrs - Sample 2
8 hrs - Sample 1
8 hrs - Sample 2
Three Point Bending Test Result
Mix 1
10-12 lbs/yd3 of macro fibers

55. Stress distribution for a cracked material with Strain-Softening
FRC
0 0.01 0.02 0.03 0.04 0.05
Deflection, in
0
200
400
600
800
1000
FlexuralLoad,lb
Experiment
Present Model
L-056 : 9.5 lb/yd3 FibraShield
sample 1
age: 14 days
0 400 800 1200 1600
Stress (psi)
-2
-1
0
1
2
SpecimenDepth,(in)
ARS Method, LE material
ASU Method, Elastic Softening
Stress Distribution
Softening Zone
L056-01

56. Shotcrete Applications
ASTM C1550-Round Panel 3P-support specimen

57. Round Panel Continuous Support Specimens

58. Modeling of Failure Mechanisms
Oberseite - ULS Mittellast
S
N
West Ost
Unterseite
S
N
WestOst
Durchgezogen: bis 200 kN
gestrichelt: bis Brucklast

59. Analysis, Design and Installation of precast water
tank panels
• Load Case1:
– Self weight + Water pressure
– Moment in short span controls
 Load Case2:
– 1.4 Self weight +
1.7 Earth pressure +
1.7 Uniform pressure due to surcharge
– Moment in short span direction SM1

61. Typical Embedded Track Section
Current Design approach
consumes significant time FRC design increases ductility
and saves time and cost.

62. Full size Slab testing

63. Various stages of cracking

64. Particle Packing Based
Design of Ultra-High
Performance Concrete

65. Materials for UHPC Paste Design
Materials selected
 OPC – ASTM C150 cement
 Alumina sources – Slag,
Metakaolin (pozzolanic as well
as react with carbonates
present in the system)
 Limestone – 3.0 micron and
1.5 micron. Fine limestone
helps with dense packing of
microstructure.
 Fly Ash – pozzolanic,
spherical particles aid with
workability.
 Micro-silica – pozzolanic,
extremely fine particles to
improve particle packing

66. Mix Designs
K10 M10 M20 F20 F30 S20 S30
F10K10 F20K10 S10K10 S20K10 F10M10 F20M10 S10M10 S20M10
F20L10a F20L10b F25L5a F25L5c S20L10a S20L10b S25L5a S25L5b
F17.5K7.5
L5b
F17.5K7.5
L5c
F17.5M7.
5L5b
F17.5M7.
5L5c
S17.5K7.5
L5b
S17.5K7.5
L5c
S17.5M7.
5L5b
S17.5M7.
5L5c
*F20 L10b = 20% Fly Ash and 10% Limestone
• 33 mixes selected for study
• Cement replacement level up to 30% by mass, individual or hybrid
• Water-to-binder ratio of 0.24
• High-range water reducer content of 1.25% solids content by mass of
binder.
F – Fly Ash
M - MicroSilica
S - Slag
K - Metakaolin
L - Limestone
La, Lb (3.0 and 1.5
m)

67. Microstructural Packing
• 3D RVEs generated using a stochastic particle packing model with spherical
particles.
• Digitized microstructures are used to obtain key parameters influencing the
hydration

68. Rheology of Pastes

69. Selection Criteria
Model 1
Model 2
Microstructure Packing Criteria Rheology Criteria
Microstructure Packing Criteria Rheology Criteria

70. Mixtures Selected
• Only ternary and quaternary mixtures are considered in view of their better
packing, with limestone included only in the quaternary mixtures.
• A total cement replacement level of 30% is used to ensure sustainable UHP
binders.

71. Mix Designs for Detailed Study

72. Aggregate Classes Used
• 5 different aggregate classes were used corresponding to sizes - #4, #8,
#10, coarse sand with a d50 = 0.6 mm, fine sand with a d50 = 0.2 mm
• Steel fibers – d = 0.6 mm, l = 13 mm.
Mechanical Splitter used to obtain uniform gradation of particles
72

73. Compressible Packing Model
• Calculates the random virtual packing density based
on the particle size distributions of the constituents.
• Uses a compaction index ‘K’ to account for the
compaction process and evaluates the actual packing
density, Φ.
• It is assumed that mixtures are composed of several
components of equal-density particles. Particles may
not be spherical particles.

74. Compressible Packing Model - Equation
𝐾 =
𝑖=1
𝑛
𝑦𝑖 𝛽𝑖
1 𝛷 − 1 𝛾𝑖
This equation is solved to obtain the value of packing density Φ for a mixture of particles.
• n – Number of different sizes of aggregates present in the mixture
• 𝑦𝑖 - Volume fraction of aggregate size ‘i’ in the mixture
• K – compaction index.
– depends on the physical process used for compaction of aggregates. For example,
the value of K for vibration and compression is 9
• 𝛽𝑖 - packing density of aggregate size ‘i’.
– Evaluated experimentally using dry-rodded unit weight method
• 𝛾𝑖 - virtual packing density of a mixture when aggregate size ‘i’ is dominant.
– If we consider a perfect placing process where each particle is placed one by one
in its ideal location, the packing density reaches the virtual packing density.
74

75. Compressible Packing Model – Wall and Loosening Effect
𝛾𝑖 =
𝛽𝑖
1 − 𝑗=1
𝑖−1
1 − 𝛽𝑖 + 𝑏𝑖𝑗 𝛽𝑖 1 − 1 𝛽𝑗 𝑦𝑗 − 𝑗=𝑖+1
𝑛
1 − 𝑎𝑖𝑗 𝛽𝑖 𝛽𝑗 𝑦𝑗
𝑎𝑖𝑗 = 1 − 1 − 𝑑𝑗 𝑑𝑖
1.02
75
𝑎𝑖𝑗 - Loosening effect coefficient
– Reduction in packing density of large sized grains due to the
presence of smaller sized grains
𝑏𝑖𝑗 - Wall effect coefficient
Represents the reduction in packing density of smaller
grains due to the presence of a relatively larger
grain.
𝑏𝑖𝑗 = 1 − 1 − 𝑑𝑗 𝑑𝑖
1.50
Loosening
Effect
Wall Effect

76. Aggregates – Measured Packing Values
Aggregate Size #4 #8 #10 Concrete Sand Fine Sand
Packing Density 0.572 0.544 0.520 0.620 0.527
Average Diameter 0.25” 0.09” 0.08” 0.02” 0.009”
DRUW Method to
determine packing density
of aggregates

77. CPM - Results
• The Compressible packing model
was solved for about 900
aggregate combinations
• Maximum packing fraction of
0.696 was obtained
77

78. Compressible Packing Model (CPM)
Compressible
Packing Model
5 different aggregate
classes were used
corresponding to sizes -
#4, #8, #10, coarse
sand with a d50 = 0.6
mm, fine sand with a
d50 = 0.2 mm

79. Results from CPM
• Each combination of aggregates results in a unique value for packing
density
• Maximum packing fraction of 0.696 was obtained
Aggregate
Combination for
maximum packing
density

80. CPM – Cumulative Size Distribution of Aggregates
Aggregate Type #57 #68 #78 #89 φmax
Packing Density 0.600 0.612 0.613 0.655 0.696

81. UHPC Design Considerations
• Use the optimized paste proportions as determined using
microstructure and rheology model
• Water to binder ratio of 0.16 – 0.18 (w/w) depending on the
workability of the mixture.
• Superplasticizer content of 1.25% solids by weight of binder.
• Aggregate to binder ratio of 0.7 by mass.
• Optimized aggregate proportions from compressible packing model
• Steel fibers – 1% by volume of mixture, when added.

82. Implementation in a Large Mixer
82

83. Stress-Strain Response in Compression
Vf= 0%
Vf= 1%

84. Flexural Test Results

85. Cost Comparison

86. Conclusions
• New technologies and directions are clearly available in our future
progression in Construction industry.
• Use of materials science based and mechanics based approaches to
obtain better ways to characterize, model, analyze, and design.
• Better train, communicate, and follow through
– Design of Materials and Structures for novel construction.
• Address specifications, quality, and long term performance.
• Fiber Reinforced Concrete can be effectively used as a technology
enabler for our alternative energy generation, use and infrastructure
development

87. Shrinkage Induced Transverse Cracking
• Reduce load carrying capacity
• Accelerate deterioration
• Increase maintenance costs
• Reduce service life
• Plastic Shrinkage: Water evaporation at
early age
• Drying Shrinkage: Loss of excessive water
from hardened concrete

88. Joint failure
• Intended to control the cracks
• Presence of joints and corners aggravates
the potential cracking as well as long term
durability
• Joint edge chipping, uplift, and corner
flexural cracks
• Potentially induced due to curling of the slab
• Point load such as truck wheel

89. Use of fibers in joint-free slab
• Crack bridging
• Load transfer
• Distributed fine cracks
• Non-critical crack pattern

90. Hybrid Reinforcement
Alternatives:
1- Conventional Steel Bars
2- Fiber Reinforcement
3- Hybrid Design
Issues with conventional reinforcement
• Significant space, time & labor needed to assemble cages &
place reinforcing bars
• Spalling/Bursting cracks at segment joints/corners because
of no reinforcement at concrete cover
Advantages of fiber reinforcement
• Improved precast production efficiency
• Reduce spalling or bursting cracks of concrete cover at
vulnerable edges and corners
• Crack control, improved serviceability & durability
• High strength, ductility & robustness against unintentional
impact loads
Segments near portal of Alaskan Way Viaduct/SR99 (Dia. 17.5m)– Reinforcement Ratio > 120 kg/m3
(Largest TBM tunnel in the world which is heavily reinforced but large cracks are observable)

91. Excess rebar specified can be replaced using a
hybrid design approach
• Eliminate a substantial amount of reinforcing bars by using a highly flowable,
steel /polymeric fiber-reinforced concrete
• The fibers are introduced during the concrete mixing process.

92. Canal Lining

93. Canal lining, WWF, or rebar replacement

94. Safety, mobilization, and Cost savings due
to reduced section sizes

95. Shrinkage as a Volumetric Change
• Drying and plastic shrinkage
(due to water loss by evaporation)
• Autogenous/self-desiccation shrinkage
(due to cement hydration)
– Thermal shrinkage (due to decrease in temperature)
• Carbonation shrinkage
(reaction of hydrated cement w/carbon dioxide)
aggregates paste
Evaporation
cross-section of hydrating cement paste
low degree of
hydration
high degree of
hydration
Solid matter
(hydrates and anhydrous cement)
pore water
empty pore volume

96. Free shrinkage test for hardened
concrete
0 10 20 30
Time (Days)
0
500
1000
1500
2000
2500
3000
FreeShrinkageStrain(microstrain) Control (1)
Control (2)
ARG05 (1)
ARG05 (2)
ARG10 (1)
ARG10 (2)
w/c = 0.45
• Tests are performed
according to ASTM C157

97. 1D Shrinkage Cracking Ring Test AASHTO PP34-99
- Curing: 24 h under plastic sheets
- Relative humidity: 30% ± 1%
- Temperature: 40 ± 1°C
0 2 4 6 8 10 12 14
Drying Time, day
-100
-75
-50
-25
0
25
50
StraininSteel,microstrain
Strain Gage 1
Strain Gage 2
w/c=0.55,
curing time = 1 day
strain gage 2
strain
gage 1
0 2 4 6 8 10
Drying Time, day
-100
-75
-50
-25
0
25
50
StraininSteel,microstrains
Stage 3
Stage 2
Stage 1
Pre-peak region
(elastic loading)
Post-Peak
Cracking
Corresponding to
ultimate tensile strength
Expansion
equilibrium
A typical result of a strain gage
attached to steel ring

98. Image Analysis of 1D Restrained
Shrinkage Cracks
0 5 10 15 20 25 30
Time, Days
0
0.02
0.04
0.06
0.08
CrackWidth,in.
Control
ARG2.5
ARG5.0
ARG7.5

99. Effect of fiber addition on strain in the steel rings
0 2 4 6 8 10 12 14
Drying Time, day
-100
-75
-50
-25
0
25
50
StraininSteel,microstrain
Control
ARG2.5
ARG5.0
ARG7.5
w/c=0.55
curing time = 1 day
1. Extension of time to cracking
2. Post cracking ductility and strain distribution
Average crack width: 1.15 mm
Standard deviation: 0.0787 mm
Average crack width: 0.341 mm
Standard deviation: 0.048 mm