Hybrid Masonry Seismic Structural Systems:

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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.
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