Shear Strengthening CA
Transcript of Shear Strengthening CA
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Solutions with Sika Systems
Shear StrengtheningSika CarboDur Composite Systems
v Long term tested and approved systems
v High strength composite systems
v Corrosion resistant
v Easy application
v No maintenance cost
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Sika CarboDur Composite Systems
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v Corrosion of steel reinforcementv Inadequate design of reinforcement
vSubject to corrosion
v High maintenance cost
v Increased weight/static loading
vLow material cost
v Offsite fabrication and
protection required
v High installation cost
Earthquake Column with shear failure
Insufficient Sof Reinforced Concr
Strengthening
Steel Shear Plates
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Shear Strengthening Alternatives
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v Increased permanent, live and traffic loadsv Change of the structural use
vDo not corrode
v No maintenance cost
vVery lightweight
vMedium material cost
v Easily cut/prepared on site
v Low installation cost
Increased load Beam with failure
Sika CarboShear L Plates SikaWrap Fabrics
ear Strengthe Structures due to
Alternatives
Sika CarboDur Composites
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Sika CarboDur Composite Systems
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Structural Requirements
When the working load is applied, the Sika CarboDur Composites absorb the tensile forcesproportionally with the steel reinforcement. An unused load-bearing reserve must be avail-able in the concrete compression zone of the existing structure. The Sikadur adhesive layeris fully capable of levelling out any stress peaks.
Sika CarboShear L
Composite Plate System
System Advantages
v Precise material properties
vWell defined anchoring
v Fully corrosion resistant
v High strengthvMinimum weight
v Range of dimensions optimum design
v Static loadingv Dynamic loadingv Crack bridgingv Creep preventionv Durability
Strengthening Sys
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Shear Strengthening Alternatives
SikaWrap
Composite Fabric System
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Environmental Influences
Corrosion resistance is an important factor in achieving durability. Sika CarboDurComposites also have high chemical resistance to the pollutants normally occurring onstructures. There is absolutely no risk of underrusting.
System Advantages
v Carbon, glass, aramid and hybrid fabrics available
v Uni- and/or bidirectional fabrics: 0, 0/90, +/45
vVery easy applicationv Ideal for strengthening non-uniform or not square cross sections
v Fully corrosion resistant
v TemperaturevMoisturev Frost Freeze/thaw cyclesv Corrosive chemicalsv Ultra-violet radiation
em Requirements
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Sika CarboDur Composite Systems:
SikaCarboShear L System
System Components
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Testing for Shear Strengthening
In 1998 the EMPA performed tests with Sika L-shapedCFRP plates. The objective was full scale testing of thesuitability of these plates for use in shear strengthening,as well as establishing a design proposal.
EMPA: Swiss Federal Laboratories for Materials Testingand Research, Dbendorf, Switzerland
Pretreatment of theCarboShear end withSikadur-30, 24 hoursbefore application in orderto shorten the anchoragelength.
Patent No. DE 19702246, 30 July 1998
EMPA Test Reports No. 169219E/1 and No. 169219E/2
Shear Strengthened T-beam
Beam T3 Strengthening with CarboShear L
Sikadur-30 Sikadur -41Adhesive Mortar
Compressive strength > 95 N/mm2
> 75 N/mm2
Bond strength on steel > 26 N/mm2
> 10 N/mm2
Bond strength on concrete > 4 N/mm2
> 4 N/mm2
(concrete failure) (concrete failure)
E-modulus 12800 N/mm2
9000 N/mm2
Sikadur Epoxy Adhesives and Mortars
F/4 F/4 F/4 F/4
350 13601360 520 2240 520 1360 350
6000
1770110 125
Sika CarboShear L CFRP Plates
Type Leg length (mm) Width (mm) Thickness (mm)
4/20/50 200 resp. 500 40 1.4
4/30/70 300 resp. 700 40 1.4
4/50/100 500 resp. 1000 40 1.4
Sika CarboShear L Plates
E-modulus (mean value) Tensile strength (minimum value)
120000 N/mm2
126 kN/40mm
380
500
120
375 375150
900
Sika CarboShear L
CFRP plate
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Technical Datas
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SikaWrapComposite Fabrics System
System Components
Testing for Shear Strengthening
In 1999 the EMPA performed tests with SikaWrap compositefabrics. The objective was full scale tests to confirm the suita-bility of these composite fabrics for use in shear strengthening,as well as to establish a design proposal. Two identical beamswere strengthened with SikaWrapHex-230C unidirectionalfabric and Sikadur-330 resin.
EMPA: Swiss Federal Laboratories for Materials Testingand Research, Dbendorf, Switzerland
F/4 F/4 F/4 F/4
350 13601360 520 2240 520 1360 350
6000
1770110 125
EMPA Test Report No. 200137/E/1
F/4 F/4 F/4 F/4
350 13601360 520 2240 520 1360 350
6000
1770110 125
EMPA Test Report No. 405552E
Beam T4 Fabric Applied Vertically
Beam T5 Fabric Applied with 45 Inclination
SikaWrap Fabrics
Carbon fiber fabrics Glass fiber fabrics
SikaWrapHex-230C/-103C SikaWrapHex-430G/-100G
Tensi le strength > 3500 N/mm2
> 2250 N/mm2
of fibers
Tensile modulus > 230000 N/mm2
> 70000 N/mm2
of fibers
Sikadur Epoxy Adhesives
Sikadur-330 Sikadur -300/-306
Flexural strength 3800 N/mm2
3120 N/mm2
Bond strength on concrete > 4 N/mm2
> 4 N/mm2
(concrete failure) (concrete failure)
For additional information see the Product Data Sheets
SikaWrapFabrics
380
500
120
375 375150
900
Sika Wrap fabric
Shear Strengthened T-beam
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Sika CarboDur Composite Systems:
GFRP pads
Tensile force
Anchoragelength100 200 mm
GFRP pads
Basic Shear Plate Tests
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Ready for test
After failure test
Anchorage ZoneTensile Test
Bend Zone Tensile Test
Load-bearing Capacity of
Sika CarboShear L Tests at the EMPA
Beam T3
Sika CarboShear L Plates
Bend zone length150 300 mm
Concretetest specimen
Tensile force
GFRP pads
Mid-span Deflection of the Beams st
0
100
200
!
"
#
600
0 20 40 60
Failureload
Ftotal
[kN]
Mid-span Deflection of the Beams st
EMPATestReportN
o.
405552E
EMPA Test Report No. 169219E/1
Concretetest specimen
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Performance Testing
SikaWrap Tests at the EMPA
Beam T4
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eams T3, T4 and T5
Ready for test
After failure test
Test Set-upfor the Moir Measurements
Ready for test
After failure test
Beam T5
SikaWrapFabrics
gthened with Sika CarboDur
80 100 120
Beam T3
Beam T4
Beam T5
gthened with Sika CarboDur
Deflection [mm]
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Sika CarboDur Composite Systems:
Preparation ofthe Concrete Substrate
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Sika CarboShear L Installation Procedure
v Pretreatment of the anchor zone of the Sika CarboShear LPlate with Sikadur-30, 24 hours before fixing.
v Blast cleaning or equivalent mechanical meansv Clean, oil and grease free surfacevVacuum the surface before resin applicationv Levelling with Sikadur mortars as necessaryv Smoothening the edge of the structure to fit the inner
radius of the L-shaped plates
Preparation of the
Sika CarboShear L Plate
Fixing Sequence
v The CarboShear L Plate on the second side isthen installed in exactly the same way as on the first side.
Bonded Bonded
Sika CarboShear L Plates
Inserting the Sika
CarboShear L Plateand carefully removing
the exuded excess resin.
Drilling holes withdiamonds coated
chain saw
Sika CarboShear L
Plate: completedinstallation
v When the anchor lengthis reached, the plate ispressed with a rubberroller against the substrate.
v The long leg of precutCarboShear L is slightlyinclined and pushed intothe boreholes prefilled withSikadur-30.
Drilling Holes in the Concrete Slab and Filling them Completely
with Sikadur
-30
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Installation and Application
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The SikaWrap Installation Procedure
v Trowel apply the Sikadur-330 resin with a notchedtrowel and control the thickness.
v Blast cleaning or equivalent mechanical meansv Clean, oil and grease free surfacevVacuum the surface before resin application
Preparation of theConcrete Substrate
Application of the Mixed
Sikadur-330 to the PreparedSubstrate
Careful Impregnation of the
SikaWrap
Fabric into the Sikadur
Resin with the Laminating Roller
Shear Strengthening of the
Reinforced Concrete BeamCompleted withSikaWrap Fabric andSikadur-330 Resin
SikaWrapFabrics
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Basis of
v Eurocode EC 2
v EMPA and EPFL Test Reports
vApprovals from SOCOTEC and ICBO
Sika CarboDur Composite Systems:
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Proceeding
Sika CarboShear L Design Proposal
vVservice Vconcrete + Vsteel stirrups + VCarboShear L
National Standards
2. Serviceability Limit State
AS = Cross section of one stirrupfS = Stress in steel stirrups, 0.8fyielding , acc. fib/ACI-440
LS= Strain in CarboShear LEL = Modulus of elasticity, CarboShear L Compatibility
LS = Steel, with max. 0.8fyieldAS fS
zs cotg +
ALLSEL zs cotg
v No sudden failure of the whole structure in case of
loss of Composite/CarboShear L contribution
vVd : Shear force design value
=Shear force at working level with DL=LL=1.0
vVRO : Shear resistance of unstrengthened section
Therefore Vd1
3. Unstrengthened Section
Sika CarboShear L Plates
vVd : Shear force design value = DLVDL + LLVLLDL, LL = Load factors, according to National Standards
vVR : Shear resistance of the concrete section
strengthened with CarboShear L
= Vconcrete + Vsteel stirrups + VCarboShear L
See EC2, or National Standards
v Structural safety is proven if:Vd