Shear Strengthening CA

7/28/2019 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

3

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

6

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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GFRP pads

Tensile force

Anchoragelength100 200 mm

GFRP pads

Basic Shear Plate Tests

8

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


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

9

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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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


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


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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


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

Documents

Shear Strengthening CA