Presentation1-Introduction to Masonry and Masonry Construction
Innovative Retrofit of Concrete and Masonry...
Transcript of Innovative Retrofit of Concrete and Masonry...
Innovative Retrofit of
Concrete and Masonry
Buildings Murat Saatcioglu, PhD., P.Eng.
Distinguished University Professor and
University Research Chair
Department of Civil Engineering
University of Ottawa
Ottawa CANADA
Seismic Retrofit Strategy?
Retrofit individual non-ductile elements for
improved strength and deformability
(jacketing, surface-bonded FRP etc.).
System level retrofit for structural bracing and
lateral drift control (bracing by added shear
walls, steel braces, active control,
supplementary damping devices etc.)
Lightly Loaded Square Bridge
Column (P = 0.15Po)
-800
-600
-400
-200
0
200
400
600
800
-8% -6% -4% -2% 0% 2% 4% 6% 8%
Drift Ratio
Mo
men
t, M
(kN
-m)
BR-SS-R
Short Square Column
L = 1500 mm
Continuous bars
3 CFRP plies (wrapping)
Axial Load = 1160 kN (15% P0)
h = 500 mm
M
PF
M=FL+P
L
BR-SS-R
Short Square Column
L = 1500 mm
Continuous bars
3 CFRP plies (wrapping)
P = 1160 kN (15% Po)
RS-5
-300
-250
-200
-150
-100
-50
0
50
100
150
200
250
300
-5.3 -4.0 -2.7 -1.3 0.0 1.3 2.7 4.0 5.3
Displacement Ductility (mD)
Mo
men
t (k
N.m
)-8 -6 -4 -2 0 2 4 6 8
Lateral Drift (%)
Heavily Loaded Square Building
Column (P = 0.35Po)
The Canadian Standards
Association CSA S806
“Design and Construction
of Building Structures with
Fibre-Reinforced
Polymers” has design
provisions.
FRP Design
-100-80 -60 -40 -20 0 20 40 60 80 100
Lateral Displacement (mm)
-600
-400
-200
0
200
400
600
-6 -4 -2 0 2 4 6
Drift (%)
BR-S1
M
PF
D
L
-6-6
12 # 25 Bars
#10 Hoops @ 300
mm
Shear Deficient Column
-100 -80 -60 -40 -20 0 20 40 60 80 100
Lateral Displacement (mm)
-600
-400
-200
0
200
400
600
-6 -4 -2 0 2 4 6
Drift (%)
Ext. Prestressed to 25% of ultimate with a spacing of 150 mm
BR-S2
M
PF
D
L
Retrofitted Shear Deficient Column
-120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120
Lateral Displacement, D (mm)
-600
-400
-200
0
200
400
600
Mo
me
nt,
M (
kN
·m)
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Drift (%)
BR-C6
FP
L
DM = FL + PD
L = 2000 mm
P = 15% Po
Confinement Deficient
Column
-120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120
Lateral Displacement, D (mm)
-600
-400
-200
0
200
400
600
Mo
me
nt,
M (
kN
·m)
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Drift (%)
BR-C7
FP
L
DM = FL + PD
L = 2000 mm
P = 15% Po
Retrofitted for Confinement
End of test(5% Drift)
-800
-600
-400
-200
0
200
400
600
800
-10% -8% -6% -4% -2% 0% 2% 4% 6% 8% 10%
Drift Ratio
Mo
men
t, M
(kN
·m)
Splice Deficient Column
-800
-600
-400
-200
0
200
400
600
800
-10% -8% -6% -4% -2% 0% 2% 4% 6% 8% 10%
Drift Ratio
Mo
men
t, M
(kN
·m)
After the test(10% Drift)
Retrofitted Splice-Deficient Column
Use of High Strength Packaging
Straps for Transverse Prestressing
Pneumatic Tensioner
Pneumatic Sealer
Seal
Use of High Strength Packaging
Straps for Transverse Prestressing
Precast concrete raiser units were manufactured
to complete square and rectangular sections to
circular and elliptical shapes,
Use of High
Strength
Packaging Straps
for Transverse
Prestressing
Flexure-dominant circular
column
Shear-dominant square
column
A large number of reinforced concrete frame
structures, with or without masonry infill
walls, are seismically deficient. They were
either designed prior to the enactment of
modern seismic codes, or built in areas
where code enforcement poses challenges.
Non-ductile R/C Frames
Retrofitted Frame with Infill Wall
Fiber anchor,
inserted into hole
in column with
epoxy
Strip width: 2 feet
-800
-600
-400
-200
0
200
400
600
800
-60 -40 -20 0 20 40 60
Force-Displacement Hysteretic Relationship
Retrofitted Specimen
(1%) (2%)
(-1%)(-2%)(-3%)
Force, kN
(3%)
Displacement, mm
(Drift)
Retrofitted
Unretrofitted
BL-2
-800
-600
-400
-200
0
200
400
600
800
-60 -40 -20 0 20 40 60
Force-Displacement Hysteretic Relationship Retrofitted Specimen
(1%) (2%)
(-1%)(-2%)(-3%)
Force, kN
(3%)Displacement, mm
(Drift)
Retrofitted
Unretrofitted
BL-3
Reference specimen, reflecting
as built conditions
Retrofitted specimen, diagonally
prestressed to 30% of ultimate on
both sides
Retrofitting by Diagonal
Prestressing
-800
-600
-400
-200
0
200
400
600
800
-80 -60 -40 -20 0 20 40 60 80
Force-Displacement Hysteretic
Relationship
BR-2
(-4%) (-2%) (-1%)
(1%) (2%) (3%) (4%)
(-3%)
Displacement, mm
(Drift)
Retrofitted
Unretrofitted
Retrofitting Walls with Steel
Strips
Reinforced Concrete Walls
Unreinforced Masonry Walls
Reinforced Masonry Walls
Stainless steel developed 60% elongation prior to
tensile rupture
URM Walls – FRP Retrofit with Ductile
Steel Sheet Anchors
URM Walls – FRP Retrofit with Ductile
Steel Sheet Anchors
Foundation concrete was cut
FRP anchors were
placed and epoxy
glued. They were
also bolted to
delay buckling