Transcript Innovative Application of Damage Tolerant FRC Material for New Construction and Retrofit of Structures in Regions of High Seismic Risk  Principal Investigators: James.

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
Components of the Project
 Development of a HPFRCC Mix for field
applications (Naaman, Parra-Montesinos)
 Biaxial Tests of HPFRCC Specimens (ElTawil, 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)
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, ElTawil)
 EOT Programs at UM and Stanford (All PIs
with special project from Finholt)
Development of Self-Consolidating HighPerformance 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)
Material and Mix Proportion
Matrix
Steel Fiber
Fine Aggregate
Cement, Pozzolan (FA)
φ= 0.5mm ; 0.38mm
l = 30 mm
Aspect ratio = 80
Hooked Fiber
Coarse Aggregate
Diameter < 3/8 in
Example: proportions by weight of cement Vf=1.5%
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
Flowability Test Results
High Strength hooked fiber Vf = 1.5%
Flowability Test Results
Compression Testing
(High Strength hooked fiber Vf = 1.5%)
Tension Testing
(High Strength hooked fiber Vf = 1.5)
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.
Specimen
Loading
Brush
Cyclic Load
2
f’c
Compression-Compression
Quadrant
(Symmetry)
1
Tension-Tension
Quadrant
f’c
Loading Paths
1.5% Spectra Fibers
70
C-C
60
50
Strain
0.3C - C
40
Uniaxial
30
20
10
0
0
0.005
0.01
0.015
Stress (MPa)
0.02
0.025
Isolated HPFRCC Coupling Beam
Tests at UM
HPFRCC Test Specimen
Projected Test Program Details
Specimen CB–1
 Precast beam to be embedded 1” into wall with
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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: 11 fc
Diagonals expected to carry 25% of shear demand
Construction of Composite Beam
Cracking Pattern and Failure Mode
SP-1 vs. SP-4 at 1.5% Drift
SP-1
SP-4
Shear Stress vs. Beam Drift Response
SP-1 vs. SP-4
10
8
Shear Stress (MPa)
6
4
2
0
-2
-4
SP-1
SP-4
-6
-8
-10
-6
-4
-2
0
Drift(%)
2
4
6
Testing of Coupled Shear Walls at
MUST-SIM Facility
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
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
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
Infill Panel
P
Connections
P
2
Retrofit Goals:
 Protect frame from brittle
fracture as per FEMA 355D
 Limit yielding of frame
Experiments
Single Panel Tests
Double Panel Tests
@ U. Michigan
Summer ‘06
@ U. Michigan
Winter ‘07
Pseudo-dynamic Testing
of Infilled Frames
@ NEES-Berkeley
Fall ‘08
Current Progress on Hybrid Simulation
Coupled Wall System:
Computational substructure
OpenSees
v2
v2
u1
Hybrid
Simulation:
Axial loads to be considered
because moment capacity of the
coupled wall is greatly affected
by the axial load
u2
2
1
Experimental substructure
Mixed displacement/load control

V1
1

v2
u1
2
u2
EOT Components
 Summer appointments in research groups at
UM and Stanford (various programs)
 Educational outreach to colleges/universities
specializing in undergraduate education
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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
Thank you
Projected Test Program Details
Numerical Simulation of Hybrid Testing
(displacement control)
 A two-story building with linear behavior
 1940 El Centro earthquake record (PGA=0.348g)
Matlab Environment:
Experimental substructure: Beam element
Computational substructure: Rectangular element
Computational
substructure
Experimental
substructure
M2=22.19
(kN sec2/m)
u2
Computational
substructure
M1=44.38
(kN sec2/m)
u1
Experimental
substructure
Numerical Simulation of Hybrid Testing
(displacement control)
~ ~B
Mai 1  C vi 1  K di 1  Ri 1 (di 1 )  Fi 1
N
N
d i
 vi
Fi 1
 ai
~
d i 1
~ ~
Ri 1 (diB1 )
~ ~B
Ri 1 (di 1 )
Computational
substructure
Experimental
substructure
Numerical Simulation of Hybrid Testing
(displacement control)
u2
Computational
substructure
u1
Experimental
substructure
Displacement of the first floor
0.2
0.15
0.1
Displacement(m)
0.05
0
-0.05
-0.1
-0.15
-0.2
0
10
20
30
Time(sec)
40
50
60