Hybrid Masonry Seismic Structural
Systems:
Material Characterization
Alejandro
Zepeda,
Texas A&M
University, alejandro_zepeda@neo.tamu.edu
REU Site: University of Illinois at Urbana Champaign
PI: Dr. Daniel Abrams, d
-
abrams@illinois.edu
Mentor:
Timothy A.
Gregor
, gregor2@illinois.edu
•
Hybrid Masonry is
a new
structural design for earthquake
-
resistant buildings proposed by
David Biggs at the 10
th
North
American Masonry conference.
•
Hybrid Masonry is a structural
system that incorporate a
reinforced masonry panel within
a steel frame.
•
There are three
types of Hybrid
Masonry: Type
I, Type II, Type III
•
In Type
I hybrid
masonry, steel
plates ( connector plates/ fuse
plate) will connect the masonry
panel to the steel frame.
•
In Type II and Type III, headed
studs will be welded to the steel
beam in order to transfer shear
forces to the masonry panel.
Additionally, vertical
compressive forces will be
transferred to the masonry panel
since the gap between the
masonry panel and the beam is
removed from Type II and III.
•
Hybrid masonry was designed
for low to mid rise buildings.
Several buildings in the eastern
United States have been built
using this new concept.
•
University of Illinois at Urbana
-
Champaign: Exploratory
studies and large Scale Testing
•
University of Hawaii at
Manoa
: Connector plate/ fuses
plate
t
esting
•
Rice University: Simulation Models
•
Ryan
-
Biggs Associates: Outreach and Education
What is Hybrid Masonry
Research Team
Material Testing
Further Information
Testing Outcomes
Future Usage
Literature Cited
Acknowledgements
I would like to thank Dr. Abrams for inviting me to UIUC, Tim
Gregor
for guiding my research, Greg
Pluta
for being a great
NEES site host,
Weslee
Walton for keeping me organized. I
would also like to acknowledge the NSF for founding our
research through the George E. Brown Jr. Network for
Earthquake
E
ngineering Simulation.
•
Material testing is an integral part of any research.
•
Data from material testing will be used to verify material
properties and define computer models.
•
Material testing was performed on all the construction
materials that make up a reinforced masonry wall:
c
oncrete
masonry unit, masonry prism, grout, and reinforcement bar.
•
All test were performed in accordance with ASTM
specifications.
•
Data processing, curing, and analysis followed the test.
•
The test results were then compared with ASTM findings.
•
All data collected from Material Testing was archived and
uploaded to the nees.org project page for future use.
•
Data summary tables, load versus displacement plots, and
stress versus strain plots were created for prism and
reinforcement test. Summary tables were created for grout
and block testing.
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4
.
1
Hybrid Masonry Detail (credit: IMI)
Grout
Sample
Cross
Sectional
Area (in
2
)
Peak
Compressi
ve Force
(
lbs
)
Stress
(psi)
1
9.375
55,588
5,929.38
2
9.1875
46,927
5,107.70
3
9.1875
50,980
5,548.84
Concrete
Masonry
Block
Sample
Cross
Sectional
Area (in
2
)
Peak
Compressi
ve Force
(
lbs
)
Stress
(psi)
1
34.9
151,040
4,328
2
34.8
155,000
4,450
3
34.8
142500
4,091
Masonry
Prism
Sample
(Grouted)
Cross Sectional
Area
(in
2
)
Peak Compressive
Force (
lbs
)
Stress (psi)
1
58.8
228,959
3,891
2
58.8
291,145
4,947
3
58.8
292612
4,972
Masonry
Prism
Sample
(Un
-
Grouted)
Cross Sectional
Area
(in
2
)
Peak Compressive
Force (
lbs
)
Stress (psi)
1
34.8
107,000
3,072
2
34.8
91,091
2,615
3
34.8
137,749
3,955
Reinforcement
Bar #4
External Sensor
(Extensometer)
600 Kip MTS uniaxial servo
-
controlled
hydraulic frame
Masonry Prism
External Sensor
(Extensometer)
For more information on hybrid masonry, please visit
the
Hybrid Masonry Seismic Structural Systems
project page at
nees.org, or please contact Dr. Abrams (PI)
at
d
-
abrams@illinois.edu
.
•
Number 4 rebar was tested using a 100 kip servo controlled
hydraulic frame.
•
Four 2
-
1/2’ specimens were tested for yield strength and
ultimate strength.
•
An external sensor was used to measure the displacement of
the specimen while an internal load cell recorded the
corresponding force.
•
Stress strain plots were formed to evaluate the properties of
the rebar.
•
T
hree
concrete
masonry
units
(CMUs
)
were
tested
for
compression
strength
.
•
An
axial
compression
force
was
applied
to
the
blocks
at
a
rate
of
8
-
19
psi
per
second
.
•
The
peak
compression
force
was
recorded
and
the
corresponding
stress
was
calculated
using
the
net
cross
-
sectional
area
.
The
results
were
recorded
in
table
format
.
•
The
Hilsdor
equations
can
be
used
to
estimate
the
value
of
the
compressive
strength
of
the
masonry
prisms
.
Hilsdorf
equation
•
Three
grout
samples
were
prepared
following
ASTM
C
476
mixing
specifications
and
prepared
using
ASTM
C
1019
specifications
.
•
After
28
days,
the
grout
samples
were
tested
in
a
similar
manner
as
the
CMUs
and
the
results
tabulated
.
•
Connector plate design and testing is being explored at The
University of Hawaii at
Manoa
.
•
Two types of plates are under investigations: strong
connector plates and energy dissipating plates.
•
The connector plates are exposed to cyclic loading until
failure occurs.
•
The Hysteretic curve shows the load versus deflection.
•
The results from material testing will be used to estimate
the flexural and shear strength of the reinforced masonry
panel and the overall behavior of the hybrid masonry
structural system.
•
The panel strength is necessary to develop and design the
connector plates and also to design the steel frame that will
incase the masonry panel.
•
Rice University who is working on the computer simulation
models will refer to the material testing data.
Abrams 2011: Abrams, D., “NSF
-
NEESR Research on Hybrid
Masonry Seismic Structural Systems,” Proceedings of the 11th
North American Masonry Conference, Minneapolis, Minnesota,
June 2011.
Biggs 2007: Biggs, D.T., “Hybrid Masonry Structures,”
Proceedings of 10th North American Masonry Conference, St.
Louis, Missouri, June 2007
.
Gregor
2011:
Gregor
, T.,
Fahnestock
, L.A., Abrams, D.,
“Experimental Evaluation of Seismic Performance for Hybrid
Masonry,” Proceedings of 11th North American Masonry
Conference, Minneapolis, Minnesota, June 2011
.
Johnson 2011: Johnson, G., Robertson, I.N., Goodnight, S.,
Ozaki
-
Train, R., “Behavior of Energy Dissipating Link
Connectors,” Proceedings of 11th North American Masonry
Conference, Minneapolis, Minnesota, June 2011.
•
Six masonry prisms, three grouted and three un
-
grouted,
were constructed and tested using ASTM C1314
specifications.
•
The prisms were tested with a
600 Kip MTS uniaxial servo
-
controlled hydraulic
frame.
•
A uniform axial compression force was applied to the prism
until failure occurred.
•
An external sensor measured the prism displacement while
the internal load cell measured the compressive force.
•
The data from the extensometer and load cell was used to
form load versus displacement and stress versus strain
plots.
•
The prism compressive strength was calculated from the
net cross
-
sectional area and the peak compressive force.
•
The grouted prism had greater values for compressive
strength which confirms previous grout and block
compressive strength data.
Concrete Testing
A
pparatus
Grout
Sample
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