Innovative Application of Damage Tolerant FRC Material for New Construction and Retrofit of Structures in Regions of High Seismic Risk

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Innovative Application of Damage Tolerant FRC
Material for New Construction and Retrofit of
Structures in Regions of High Seismic Risk

• Principal Investigators
• James Wight, Univ. of Michigan
• Sarah Billington, Univ. of Stanford
• Sherif El-Tawil, Univ. of Michigan
• Gustavo Parra-Montesinos, Univ. of Michigan
• Associated Investigators
• Antoine Naaman, Univ. of Michigan
• Tom Finholt, Univ. of Michigan
• James LaFave, Univ. of Illinois at U-C
• Sponsored by NSF

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Components of the Project

• Development of a HPFRCC Mix for field
  applications (Naaman, Parra-Montesinos)
• Biaxial Tests of HPFRCC Specimens (El-Tawil,
  Parra-Montesinos, LaFave)
• Testing of Isolated HPFRCC Coupling Beams at UM
  (Wight, Parra-Montesinos)
• Testing of Isolated HPFRCC Infill Panels at UM
  (Billington, Olsen, Wight)

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Components of the Project

• FE Modeling of HPFRCC Specimens and Refinement of
  PSD Testing Protocol (El-Tawil, Billington,
  Olsen)
• Testing of Coupled Wall Assemblies at UIUC
  (Wight, Parra-Montesinos, El-Tawil, LaFave)
• Testing of Frames Infilled with HPFRCC Panels at
  UC-Berkeley (Billington, Olsen, El-Tawil)
• EOT Programs at UM and Stanford (All PIs with
  special project from Finholt)

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Development of Self-Consolidating
High-Performance Fiber Reinforced Concrete

• FRC Fiber Reinforced Concrete
• HPFRCC High Performance Fiber Reinforced
  Cementitious Composite (exhibits tensile strain
  hardening)
• SCC Self-Consolidating Concrete (a highly
  workable concrete that can flow through densely
  reinforced elements under its own weight to fill
  voids without segregation or excessive bleeding
  and without the need for vibration)

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Material and Mix Proportion
Steel Fiber
Matrix
Coarse Aggregate
f 0.5mm 0.38mm l 30 mm Aspect ratio
80 Hooked Fiber
Fine Aggregate Cement, Pozzolan (FA)
Diameter lt 3/8 in
Example proportions by weight of cement Vf1.5
Cement Type 3 Fly Ash Sand Coarse Aggregates Water SP VMA Steel Fibers
1 0.5 1.7 1 0.6 0.003 0.0095 0.244
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Flowability Test Results

• High Strength hooked fiber Vf 1.5

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Flowability Test Results
gt600mm
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Compression Testing

• (High Strength hooked fiber Vf 1.5)

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Tension Testing

• (High Strength hooked fiber Vf 1.5)

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Panel Tests of HPFRCC at UIUC
Size of specimen 5.5 in. x 5.5 in. x 1.4
in. Four independent loading actuators In-plane
and out-of-plane displacements at the front panel
are captured by the Krypton non-contact system
whereas out-of-plane displacements at the back
are measured by LVDT.
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1.5 Spectra Fibers
C - C
0.3C - C
Uniaxial
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Isolated HPFRCC Coupling Beam Tests at UM
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HPFRCC Test Specimen
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Projected Test Program Details

• Specimen CB1
• Precast beam to be embedded 1 into wall with
  sufficient development of beam reinforcement
  extended into shear wall boundary region.
• Minimal shear keys provided to prevent sliding
  shear failure at interface
• Coupling beam maximum expected moment 2500 k-in
• Max expected shear
• Diagonals expected to carry 25 of shear demand

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Construction of Composite Beam
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Cracking Pattern and Failure Mode
SP-1 vs. SP-4 at 1.5 Drift
SP-1
SP-4
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Shear Stress vs. Beam Drift Response SP-1 vs.
SP-4
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Testing of Coupled Shear Walls at MUST-SIM
Facility
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Ductile HPFRCC Infill Panels for Seismic Retrofit
for Steel Moment Frames
HPFRCC Infill Panels
Existing Steel Frame
Steel Plate
Pretensioned Bolts
Bent Steel Plate
Nelson Stud in concrete deck
Steel Beam
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Panel Design Analysis
Nonlinear Finite Element Analysis using DIANA
Studying variations in panel shape, thickness and
reinforcement layout
Principle Tensile Strain Contours
Hysteretic results used in larger-scale fiber
element analyses
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Panel Design Analysis
Fiber Element Analysis using OpenSees
Conducting pushover and time-history analyses to
evaluate capacity and demand in frames with
various infills and infill arrangements
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Experiments
Single Panel Tests _at_ U. Michigan Summer 06
Double Panel Tests _at_ U. Michigan Winter 07
Pseudo-dynamic Testing of Infilled Frames _at_
NEES-Berkeley Fall 08
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Current Progress on Hybrid Simulation
Coupled Wall System

• Computational substructure

OpenSees
Axial loads to be considered because moment
capacity of the coupled wall is greatly affected
by the axial load
v2
v2
u1
u2
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Hybrid Simulation

• Experimental substructure

Mixed displacement/load control
v2
V1
u2
u1
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EOT Components

• Summer appointments in research groups at UM and
  Stanford (various programs)
• Educational outreach to colleges/universities
  specializing in undergraduate education
• Contacts established at Lawrence Tech Univ. (near
  Detroit) and Calvin College (near Grand Rapids)
• Earthquake Engineering component to be added to
  undergrad strength of materials course or
  structures course
• Pilot program planned at UM in Fall 2006 as part
  of structural analysis course

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Thank you
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Projected Test Program Details
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Numerical Simulation of Hybrid Testing
(displacement control)

• A two-story building with linear behavior
• 1940 El Centro earthquake record (PGA0.348g)

Matlab Environment
M222.19 (kN sec2/m)
M144.38 (kN sec2/m)
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Numerical Simulation of Hybrid Testing
(displacement control)
Computational substructure
Experimental substructure
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Numerical Simulation of Hybrid Testing
(displacement control)