performance of cfrp under real fire

8/13/2019 Performance of CFRP Under Real Fire

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The Performance of CFRP Strengthening During a Real Fire

Tim Stratford

Jian-fei ChenMartin Gillie

The University of Edinburgh

The Performance ofCFRP Strengthening

During a Real Fire


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BackgroundCarbon fibre reinforced polymer

(CFRP) strengthening


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Background

Example applications of Carbon Fibre ReinforcedPolymer (CFRP) strengthening systems


4/48The Performance of CFRP Strengthening During a Real Fire

Background

Concrete substrate

Bonding adhesive

Carbon fibre

(preformed plate or wet lay-up)

Finish (coating resin etc)

Tg

= 65 - 100C



Background

Preformed CFRP plate

Tg of resin 250C (?)

Bonding adhesive

Tg 65 to 100C (?)



Concrete Society Technical Report 55:

Fire protection.

Regulations may require the application of an

over-coat layer, which has been tested on the

fully-cured composite system

Unless a rigorous analysis is undertaken it is

sensible to neglect the strengthening from FRPin fire situations.

Background



Background



Structural alterations

FRP carrying permanent load, and must carry load during fire

Background

Fire protection?



Background

Dalmarnock compartment fire tests

Unique opportunity to assess CFRP

Strengthening in a Real Fire



Installation of

Strengthening



I t ll ti


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InstallationWINDOW

FRP plate 11180

1360

1560

1940

2190

2420

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

Intumescent

Intumescent

Unprotected

Unprotected

Gypsum Board

Gypsum Board

x

y

I t ll ti


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Installation

PLATES NSM

Intumescent

Un

protected

Gyproc

In

tumescent

U

nprotected

G

yproc

I t ll ti FRP Pl t


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Installation FRP Plates

I t ll ti FRP Pl t


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Medium Modulus (MM) CFRP plate, 100x1.2mm.

2-part ambient cure epoxy adhesive.



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Installation NSM FRP


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Near-surface mounted FRP strengthening:

bonded into a groove cut into the concrete soffit

Industry perception: better fire performance.




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Gypsum board

2 layers of 12mm board+ intumescent sealer

(Designed system)


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Experimental Setup

Strain gauges, Thermocouples

WINDOWy

Experimental Setup


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1180

7Pt 7Mt

5Pt*

4Pt

3Pt

6Pt

5Mt

6Mt

4Mt

3Mt

2Pt 2Mt

1360

1560

1940

2190

2420

x

7Nt

6Nt*

4Nt

4Qt*

4Rt

3Nt

5Nt

2Nt

FRP plate 1

FRP NSM 1

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

Experimental Setup

Thermocouples

in FRP bondline

WINDOWy

Experimental Setup


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FRP plate 11180

750 750

7P 7M

5P

4P

3P

6P

5M

6M

4M

3M

2P 2M

1360

1560

1940

2190

2420

FRP NSM 1

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

x

7N

(Dead Gauge)

4N

3N

5N

2N

Experimental Setup

Strain gauges on FRP

plates (bonded side)


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Other instrumentation:

-gauges on top of slab

-gauges on top of slab

-gauges againstadjoining wall

Thermocouples throughslab depth

Thermocouples within

compartment (gas phase)


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Results

Results


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Results


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Gas-phase temperatures

0

100

200

300

400

500

600

700

800

900

1000

0 5 10 15 20

Time (mins)

Temperatu

re(C)

TC-12-2

TC-14-2

TC-17-2

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

Results


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ResultsUnprotected FRP Plate


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Fibres on floor (resin burnt off)

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

ResultsIntumescent + FRP Plate


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Mostly debonded.Resin mostly burnt off.

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

ResultsGypsum board + FRP Plate


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Gypsum board intact.Plate and adhesive visually sound.

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

ResultsUnprotected NSM FRP


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Bonding adhesive burnt awayfrom beneath and to sides,

leaving fibre in FRP exposed.

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

ResultsIntumescent + NSM FRP


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Intumescent layer intact;FRP and adhesive in place.

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

ResultsGypsum board + NSM FRP


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Gypsum board sound.FRP and adhesive visually sound.

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

Results


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FRP Plates Bondline Temperatures

0

50

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60

Time (mins)

Temperat

ure(C)

Unprotected

Intumescent

Gypsum Board

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

Results


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WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3

NSM FRP Bondline Temperatures

0

50

100

150

200

250

300

350

0 10 20 30 40 50 60

Time (mins)

Temperat

ure(C)

Unprotected

Intumescent

Gypsum Board

Results


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NSM FRP Bondline Temperatures

0

50

100

150

200

250

300

350

0 10 20 30 40 50 60

Time (mins)

Temperature(C)

Unprotected

Intumescent

Gypsum Board

FRP Plates Bondline Temperatures

0

50

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60

Time (mins)

Tempera

ture(C)

Unprotected

Intumescent

Gypsum Board

Temperatures >> Tg in all tests.


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Results


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NSM Plates - Central Strain Gauge Readings

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0 10 20 30 40 50 60

Time (min)

Strain(strain)

Unprotected

Intumescent

Gypsum Board

WINDOW

FRP plate 1

FRP NSM

FRP plate 2

FRP NSM 2

FRP plate 3

FRP NSM 3


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Results


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NSM Plates - Central Strain Gauge Readings

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0 10 20 30 40 50 60

Time (min)

Strain(strain)

Unprotected

Intumescent

Gypsum Board

NSM Plates - End Strain Gauge Readings

-500

0

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60

Time (min)

Strain(strain)

Unprotected

Intumescent

Gypsum Board

Strains indication of catastrophic failureNB: - Corrected for temperature effects using T.C. data.

- All strains are the result of thermal effects: no applied load.


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Ongoing work and

Conclusions

Ongoing Work


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Further analysis of complete strain and

thermal dataset

Characterisation of properties of materials used

Modelling of composite strengthened slab

(thermal strains in concrete)

Thermal analysis

Conclusions


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During a real fire, the glass transition temperature

of the adhesive is exceeded.

Gypsum board can be used to insulate the FRP,

but further research is required before it can

be reliably designed

The integrity of NSM strengthening is superior

to plate FRP strengthening during a fire.

Acknowledgements


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Concrete Repairs Ltd

BASF Construction

performance of cfrp under real fire

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