Lateral Drift

INTEGRATION OF RESEARCH AND
PRACTICE IN PRECAST CONCRETE
STRUCTURES IN THE UNITED STATES
Stephen Pessiki
Professor and Chairperson
Department of Civil and Environmental Engineering
Lehigh
g University
y
Bethlehem PA, USA
[email protected]
Sponsors & Contributors
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
National Science Foundation:
– PRESSS Phase 2B ((CMS
CMS--9393-07880)
– PRESSS Phase 2C ((CMS
CMS--9696-12165)
Precast/Prestressed
Precast/
Prestressed Concrete Institute
Pennsylvania Infrastructure Technology
Alliance
Blakeslee Prestress
Prestress,, Inc.
Inc
Blue Ridge Design, Inc.
Columbian Concrete Fibers
Dayton Richmond
Dywidag Systems International,
International Inc
Inc.
Florida Wire and Cable, Inc.
H. Wilden & Associates, Inc.
High Concrete Structures, Inc.
Koller Concrete,
Concrete Inc
Inc.
Metromont Materials Corporation
Morse Bros. Prestress Concrete Group
Nakaki and Bashaw
Bashaw,, Inc.
Th C
The
Consulting
lti E
Engineers
i
G
Group, IInc.
OUTLINE
• Current U.S. practice.
• Precast / Prestressed Concrete Institute (PCI).
• Current research needs in U.S. practice.
• Examples of industry / university research
partnerships.
TYPICAL FEATURES OF CURRENT PRACTICE
• Largest size / smallest number of pieces possible
• Pretensioned
• Long line casting beds
• Self
Self--consolidating concrete
• 24 hour fabrication cycle
• Up
Up--and
and--out field construction
DOUBLE TEE BEAMS
HOLLOW CORE PLANKS
Also commonly used with structural steel
framing, precast concrete walls, and light gage
steel stud walls
walls.
POCKETED SPANDRELS
COLUMNS
• post
post--tensioned
for handling
• up to 6 stories
in height
HORIZONTAL LIGHT WALLS
VERTICAL LIGHT WALLS
SPREAD WALLS
ARCHITECTURAL LOADLOAD-BEARING PANELS
ARCHITECTURAL LOADLOAD-BEARING PANELS
OUTLINE
• Current U.S. practice.
• Precast / Prestressed Concrete Institute (PCI).
• Current research needs in U.S. practice.
• Examples of industry / university research
partnerships.
Precast / Prestressed Concrete Institute (PCI)
• Headquarters in Chicago.
• Members are precast concrete producers, designers,
product / material suppliers, researchers.
• Members are competitors outside of PCI.
• Producer members pay dues as a percentage of sales.
• 9 % of dues applied
pp
to research and development.
p
• Committee structure organized in to technical and
marketing thrusts
thrusts.
Precast / Prestressed Concrete Institute (PCI)
4 Most Important Technical Documents:
1 Industry Design Handbook
1.
2. Standard Practice (interprets ACI 318 Code for Structural
Concrete)
3 Seismic
3.
S i i H
Handbook
db k
4. Fire Handbook
Research Program:
1. Market driven (protect existing markets, develop new
markets).
2. Research problem statements from technical committees.
3. Annual research funding
g competition.
p
4. Highly leveraged.
OUTLINE
• Current U.S. practice.
• Precast / Prestressed Concrete Institute (PCI).
• Current research needs in U.S. practice.
• Examples of industry / university research
partnerships.
RESEARCH NEEDS
• Seismic
• Fire
• Total Precast Buildings
RESEARCH NEEDS
• Seismic (overcome a perceived weakness)
• Fire (respond
(
to advances of other materials))
• Total Precast Buildings (develop new markets)
OUTLINE
• Current U.S. practice.
• Precast / Prestressed Concrete Institute (PCI).
• Current research needs in U.S. practice.
• Examples of industry / university research
partnerships.
RESEARCH EXAMPLES
• Seismic – Unbonded post
post--tensioned precast
concrete walls.
• Fire
• Total
T t l Precast
P
t Buildings
B ildi
Base She
ear
Traditional Approach
Lateral Drift
Base She
ear
Traditional Approach
Lateral Drift
Base She
ear
Traditional Approach
Lateral Drift
Base She
ear
Traditional Approach
Lateral Drift
Base She
ear
Traditional Approach
Lateral Drift
Basse She
ear
Basse She
ear
New Approach
Approach–
– Nonlinear Elastic Systems
Lateral Drift
Lateral Drift
Unbonded PostPost-tensioned Walls
anchorage
g
wall panel
unbonded
PT steel
confining
reinforcement
horizontal
joint
foundation
Unbonded PostPost-tensioned Walls
Lateral Load Response
p
Base Shear
Δ
Hw
Vdec
d
decompression
i
Δ
Θ
Θ=
Hw
Lateral Drift
Θdec
Lateral Load Response
p
Base Shear
Vell
effective
linear limit
Vdec
d
decompression
i
Lateral Drift
Θdec Θell
Lateral Load Response
p
Base Shear
Vspl
spalling
Vell
effective
linear limit
Vdec
d
decompression
i
Lateral Drift
Θdec Θell Θspl
Lateral Load Response
p
Base Shear
Vllp
Vspl
PT bar yielding
spalling
Vell
effective
linear limit
Vdec
d
decompression
i
Lateral Drift
Θdec Θell Θspl
Θllp
Lateral Load Response
p
Vccc
Vllp
Vspl
Base Shear
PT bar yielding
spalling
Vell
confined
concrete
crushing
effective
linear limit
Vdec
d
decompression
i
Lateral Drift
Θdec Θell Θspl
Θllp
Θccc
Cyclic
y
Lateral Load Response
p
Base Shear
Lateral Drift
• Nonlinear due to gap opening
• Self-centering
Roof Drift Time History
drift
d ift (%)
4
2
0
-2
2
hollister
PGA=1g
-4
4
0
unbonded PT precast wall
conventional RC system
10
20
time (seconds)
30
unbonded
height
32ft--6in
32ft
23ft--9in
23ft
8ft--4in
8ft
unbonded
height
32ft--6in
32ft
23ft--9in
23ft
8ft--4in
8ft
Test Matrix
Loading
Ap
fpi/fpu
fci,p
Confinement
2
(ksi)
Type
(in. )
TW1 monotonic 7.50 0.553 1.19
spirals
TW2
cyclic
7.50 0.553 1.19
spirals
TW3
cyclic
7.50 0.553 1.19
hoops
TW4
cyclic
li
7 50 0.277
7.50
0 277 0.59
0 59
h
hoops
TW5
cyclic
3.75 0.553 0.59
hoops
Test
Wall
Confinement Ratio (%)
Volumetric
Area
7.39
7.39
1.75
1 75
1.75
1.75
Results - TW1
LLP
CCC
SPL
DEC
W
E
TW1 – SPL (spalling)
Θ = 0.61%
0 61%
TW1 – LLP
(PT yielding)
Θ = 1.35%
1.35%
TW1
Θ = 3.48%
3 48%
3.48
48%
TW1 - Failure
Θ = 3.57%
3.57%
Test Matrix
Loading
Ap
fpi/fpu
fci,p
Confinement
2
(ksi)
Type
(in. )
TW1 monotonic 7.50 0.553 1.19
spirals
TW2
cyclic
7.50 0.553 1.19
spirals
TW3
cyclic
7.50 0.553 1.19
hoops
TW4
cyclic
li
7 50 0.277
7.50
0 277 0.59
0 59
h
hoops
TW5
cyclic
3.75 0.553 0.59
hoops
Test
Wall
Confinement Ratio (%)
Volumetric
Area
7.39
7.39
1.75
1 75
1.75
1.75
monotonic vs
vs. cyclic loading
Results - TW1 and TW2
200
TW1 (monotonic)
TW2 (cyclic)
Base
e shear (k
kips)
150
100
50
0
50
-50
Θ = -2.83
2.83%
%
-100
150
-150
W
E
W
E
-200
-4
-3
-2
-1
0
1
Lateral drift (%)
2
3
4
TW5
Θ = 6.0
6.0%
% (1st cycle)
Ductility Factors
Θccc
Test
Wall
Θell
(%)
((%))
TW1
0.18
3.57
20
TW2
0.18
2.83
16
TW3
0.14
2.54
18
TW4
0.09
2.97
33
TW5
0.09
>6.0
67
μ
Tri--linear Model
Tri
Vccc
Vllp
Base Shear
LLP
Vell
CCC
ELL
Vdec
DEC
Lateral Drift
Θdec Θell
Θllp
Θccc
Fiber Model
constraint
rigid
g b-c
element
truss
element
fiber
element
frame
element
TW5 Results - Exp.
p vs. Models
200
Exp.
p
F.M.A.
C.F.E.
Base
e shear (k
kips)
150
100
50
0
50
-50
-100
150
-150
-200
-7
-6
-5
-4
-3
-2
-1 0
1 2
Lateral drift (%)
3
4
5
6
7
RESEARCH EXAMPLES
• Seismic
• Fire – Fire loads for precast parking
g structures
• Total Precast Buildings
PROTOTYPE PARKING STRUCTURE
• Non
Non--combustible structure
• Well
Well--controlled ventilation conditions (no glass breakage)
• Fuel loads fairly well defined
ANALYTICAL MODEL
CFD, FDS (NIST)
Plan View
.125m x .125m x .125m cells
ANALYTICAL MODEL
HEAT FLUX RECORD
HRR
R (kW)
10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
0
10
20
30
40
Time (min)
50
60
70
80
To
otal E (G
GJ)
HEAT FLUX RECORD
9
8
7
6
5
4
3
2
1
0
1975
1980
1985
1990
Production Year
1995
2000
HEAT FLUX RECORD
8000
Vehicle 1
Vehicle 2
7000
HRR ((kW)
6000
5000
4000
Vehicle 1
Vehicle 2
3000
2000
1000
0
0
10
20
30
40
50
60
Ti
Time
(min)
( i )
70
80
90
100
ANALYSIS VARIABLE – OPENING POSITION
Double
T
Tee
Beam
Center
Wall
Top
Opening
Bottom
Opening
Chimney
Opening
TEMPERATURE DISTRIBUTION
Top Opening
Heat flows freely to
opposite side of
garage.
Bottom Opening
Heat trapped on
one side
id off
garage.
GAS TEMPERATURE
Temperature
Location
Temp.
T
(deg. C)e (C)
Tempe
erature
1200.00
1000.00
Bottom Opening
Top Opening
800 00
800.00
Bottom Opening
600.00
400.00
200.00
T Opening
Top
O
i
0.00
0.00
500.00
1000.00
1500.00
2000.00
Time (sec)
2500.00
Time (sec)
(
)
3000.00
3500.00
4000.00
PRESTRESSING STEEL TEMPERATURE
160
Bottom Opening
140
Steel
Temperature
L
Location
ti
Temp (deg.. C)
Tem
mperatu
ure (C)
120
100
80
Analysis 2
Analysis 1
Top Opening
60
40
20
0
0
1000
2000
3000
4000
5000
Ti
Time
(sec)
(
)
Time (sec)
6000
7000
8000
ANALYSIS VARIABLE – MULTIPLE VEHICLE FIRE
TEMPERATURE DISTRIBUTION
SUMMARY OF RESULTS
2000
1860 MPa
1800
1600
1580 MPa
15%
1400
(MP
Pa)
Stre
essStress
(MPa
)
93 deg. C (Analysis 3)
1200
Maximum
strength
reduction @ 214
degrees C
94 deg. C (Analysis 4)
1000
120 deg. C (Analysis 7)
129 deg. C (Analysis 5)
800
136 deg. C (Analysis 6)
600
142 deg. C (Analyses 1 and 4)
400
149 deg. C (Analysis 8)
214 deg. C (Analysis 9)
200
Ambient temp. = 20 deg. C
0
0
0.005
0.01
0.015
0.02
Strain
0.025
Strain (mm/mm)
0.03
0.035
0.04
RESEARCH EXAMPLES
• Seismic
• Fire
• Total Precast Buildings – Three wythe
sandwich
d i h wall
ll panels.
l
Precast Prestressed Concrete
Sandwich Wall Panels
Typical TwoTwo-wythe Sandwich Wall Panels
1 0 ft
1.0
1 0 ft
1.0
2.5 ft
40 ft
2.5 ft
3-2-3
3-2-3
12 ft
3-2-3
12 ft
12 ft
Two-wythe Panel
Three-wythe Panel
Temperature Distribution - Two
Two--wythe panel
x = 24 in.
T∞ = 125 °F
a
b
c
ed
T∞ = 25 °F
a
b
c
de
120 °F
140
120
a-a
100
Temp.
80
(°F) 60
40
b-b
c-c
d-d
20
0
ee
e-e
0
24
48
72
96
120 144
20 °F
Temperature Distribution - Three
Three--wythe Panel
x = 24 in.
T∞ = 125 °F
ab
c
d
ef
g
T∞ = 25 °F
ba
c
d
fe
g
120 °F
140
120
100
Temp. 80
(°F) 60
40
20
0
a-a
b-b
c-c
d-d
e-e
f-f
g-g
g
g
0
24
48
72
96
120 144
20 °F
Summary of Results
9
A
8
B
D
Three wythe panels
Three-wythe
7
F
G
H
I
J
K
L
M
6
R value
R-value
(hr⋅ft2⋅°F/Btu)5
4
3
2
Two-wythe panels
1
0
0
01
0.1
02
0.2
03
0.3
04
0.4
solid area / panel area (ft2/ft2)
Lateral Load Tests
• 6’- 8” × 35’ span
p (2/3
(
scale))
• Two cross sections
Panel 1
Panel 2
• Uniform load over span
Displacement transducer
Test Set-up
Reaction beam
Air bladder
Test panel
Vertical links
(load cell)
Load vs. Lateral Deflection for Panel 1
16000
L/4 and 3L/4 spans
14000
Tottal load (lb s.)
12000
10000
L/2 span
8000
6000
4000
2000
0
0.0
2.0
4.0
Deflection (in.)
6.0
8.0
SUMMARY
• Current U.S. practice.
• Precast / Prestressed Concrete Institute (PCI).
• Current research needs in U.S. practice.
• Examples of industry / university research
partnerships.
INTEGRATION OF RESEARCH AND
PRACTICE IN PRECAST CONCRETE
STRUCTURES IN THE UNITED STATES
Stephen Pessiki
Professor and Chairperson
Department of Civil and Environmental Engineering
Lehigh
g University
y
Bethlehem PA, USA
[email protected]