2018 general frc_2018_12

1. Design Procedures for Fiber Reinforced
Concrete Applications in New and
Repair of hydraulic Structures
Barzin Mobasher, PhD. PE., FACI
School of Sustainable Engineering and the Built Environment
Arizona State University
2018

2. 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

3. 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 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.

4. Objectives
• Existing procedures and standards on proportioning FRC mixtures and the
fiber specific characteristics affecting the overall performance.
• Develop typical FRC mixtures with locally available materials
• Recommended Test methods and Specifications for qualification of
mixtures for various applications
• Optimize the Structural and material design procedures based on
performance criteria for strength, ductility, crack width and durability.
• Availability of specifications and testing guidelines for:
– Mechanical: strength, ductility, impact, repair, volume changes and
crack resistance
– Durability: corrosion resistance, resistance to chloride ion ingress and
freeze and thaw, shrinkage, curling, cracking.

5. Introduction
• Concerns for sustainable design of environmental structures is the main driver for
development of new materials and design methods.
• In consideration to traditional design methods, as the cost of raw materials, labor,
and energy have increased, many new alternative designs for fiber reinforced
concrete are increasingly become cost effective.
• Development of new guidelines for concrete materials to address higher strength,
ductility, and stiffness, as well as corrosion protection, serviceability and cracking
potential are addressed.
• Innovative fiber reinforced concrete materials when designed using fundamental
aspects of mechanics and materials science with specific focus on durability offer
efficient and sustainable structural systems.

6. Non-Traditional Water Conservation through Design and
Construction Techniques
• The Pima-Maricopa Irrigation Project is a tribal program operated through
an annual funding agreement with the U.S. Bureau of Reclamation.
• Since January 2010, P-MIP has constructed more than $350M in projects
that total 85.37 miles in length.
• This includes pipeline and open channel canal, with the latter going from a
34-foot bottom (2,000 cfs) down to a 2-foot bottom (15 cfs).

7. specifications and design guides for
sustainable construction systems
• New materials, testing procedures, and applications for fiber reinforced
concrete to address improved ductility-durability measures.
• Application areas include early age properties, shrinkage cracking, and
correlation of ductility with durability.
• Testing, analysis, and design guidelines to obtain material models that can
be directly integrated within structural analysis software. Integration of
material and structural design through the development of analytical
closed-form solutions for design and analysis of beams, slabs, canal lining,
retaining walls, pipes, and buried structures.
• Solutions for sustainable development of infrastructure systems using
blended cements, thermal energy considerations of concrete buildings,
blast, impact, and high ductility required designs such as vehicle impact.

8. Canal Lining

9. SouthSide Canal
• The Southside Canal Project is part of the Pima-Maricopa Irrigation Project that is
extremely important to agriculture in the area.
• Coffman Specialties was awarded $16 Million Canal Contract through the Pima-
Maricopa Irrigation Project (P-MIP)
• More than 145,000 square yards of concrete to line the 8’ deep, 32’ wide canal.
• The Community's ultimate goal is to design and construct a water delivery system
that will potentially include 2,400 miles of canal and pipeline.

10. Santan Canal
• The Santan Canal is part of the Gila River Indian Community's master plan
to deliver 173,000 acre feet of water to farmlands within the Community.
• Scope of the project includes earthwork to construct the canal prism,
concrete lining and thirty-five reinforced concrete structures. In addition,
Granite will construct a reservoir and excavate approximately 344,000
cubic yards of borrow needed to complete the work.
• Granite Construction Company was awarded a $22.0 million contract by
the Gila River Indian Community to construct the final phase of an 8.5-
mile Santan Canal located approximately 40 miles southeast of Phoenix.

11. 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

12. Tasks
• Criteria for fibers in structural applications
• Criteria for repair of existing structures and canals
• Criteria for fibers in 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
• 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

13. 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)

16. FRC Engineering Applications
Ductility, Durability, Sustainability
 The type and volume fraction of fibers affect the level of energy absorption
 increased energy absorption, fatigue life, impact/explosive loading conditions, and seismic
resistance
 Pavements/slabs,Precast components, Shotcrete

17. 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

18. 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

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

20. 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)

21. Excess rebar specified can be replaced using a
hybrid design approach in many applications
• 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.

22. Canal lining, WWF, or rebar replacement
Fiber Reinforced Concrete Mix
Photo Courtesy: Pima-Maricopa Irrigation
Project, Sacaton, Arizona
Traditional #5 rebar layout
Photo Courtesy: Rick Shelly, Pulice
Construction

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

24. 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

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

26. 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

27. 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

28. 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

29. 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

30. 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

31. 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

32. Consideration of 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

33. 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

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

35. Round panel tests for evaluation of SFRC
• Test setup
– displacement controlled, continuous
support, center point load
• Dimensions
– D, t= 1500, 150 mm
– stroke diameter = 150 mm
Vf = 80 kg/m3 Vf = 100 kg/m3

36. Round Panel Continuous Support Specimens

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

38. Plastic analysis approach
Distributed load on a simply supported square slab.
The work equations are derived as:
Where the resultant NR and rotation θ (from figure 9a)
are:
For the four segments with an NR acting at 1/3 of δmax :
θ θ
q
δmax
L
L/2
L/2
m
m
A A
δ
Yield Line
Square Slab
Simply Supported
int extW W
R( N ) ( M L )     
2
2 2 4
R
L L qL
N q ( ) ( )   
2 max
L

 
2
2
4 4
4 3
max max
L
qL
( ) ( ) ( M ) ( L ) ( )
 
     
2
24
ult
p
q L
M 

39. 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

40. Mechanics of Fiber and Textile Reinforced
Cement Composites
• CRC press, 2011
• E-mail: barzin@asu.edu
• http://enpub.fulton.asu.edu/cement/

41. 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