The Corrosion of the Bridge

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THE CORROSION OF THE BRIDGEHafidz Husni Saepudin – 3334080234

Metallurgical Department

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OUTLINE

Preface

Material Specification

Corrosion Form

Preventions

Conclusions

References

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PREFACE

Corrosion?? Bridge

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TYPES OF THE BRIDGE

Wood bridge

Steel bridge

Concrete bridge

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MATERIAL SPECIFICATION

Metallic material used is medium-carbon steel

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COMPOSITION

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CONCRETE BRIDGE COMPONENTS

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CORROSION FORM

GALVANIC CORROSION

FILIFORM CORROSION

UNIFORM CORROSION

CREVICE CORROSION

STRESS CORROSION CRACKING

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GALVANIC CORROSION

GALVANIC CORROSIONCorrosion Potential Survey on Bridge Column

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FILIFORM CORROSION

(barrier of steel bridge)UNIFORM CORROSION (deck of steel bridge)

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CREVICE CORROSION

Edge of front truss member with crevice corrosion

Steel bridge

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Crevice corrosion has severely bent the top, the sides and the bottom of the box members. and overstressed the rivets.

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STRESS CORROSION CRACKING

A common form of crevice failure occurs due to stress corrosion cracking.

where a crack or cracks develop from the base of the crevice where the stress concentration is greatest.

The Silver Bridge upon completion in 1928

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This was the root cause of the fall of the Silver Bridge in 1967 in West Virginia

where a single critical crack only about 3 mm long suddenly grew and fractured a tie bar joint

The collapsed Silver Bridge, as seen from the Ohio side

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WEATHERING STEEL CORROSION

Bridge with Ice in Water Bridge on Sea Water

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CASE : STEEL REBAR REINFORCEMENT CORROSION

Reinforcement : reinforcing steel (baja tulangan)

Common steel grade 32 is used (yield strengths 32 ksi)

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MINNEAPOLIS BRIDGE COLLAPSE

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 MECHANISMS

Carbonation and chloride ions equal a lot of corrosion.

The carbonation and chloride ions diffuse through the concrete

The pH is lower by the presence of the chloride ions.

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PREVENTION AND PROTECTION

1) Dense impermeable concrete

2) Adequate reinforcement cover

3)  Rich cement factor

4)  Salt-free aggregates

5)  Minimum chloride content in mixing water when it is built (Bridge on Sea Water)

6) Proper type of cement mix

7)  Consolidation of cement around steel reinforcement

8) Adequate curing (complete hydration)

9)  Organic coatings10) Allow no galvanic

coupling by using other metals (i.e. copper & aluminum) in the reinforcement.

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MATERIAL SELECTION

Steels of the ASTM A709, grade 50, type, which have yield strengths in the (50-ksi)

Mechanical Properties A709 Gr 50:Tensile: 58 min ksiYield: 50 ksi minElongation: 16% min in 8” 19% min in 2”

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CONCLUSIONS

HSLA Steel Plate A709, grade 50 remain good materials to choose for the bridge.

Weathering Steel Corrosion is a hazard which can be avoided by prevention and protection

Protection by Organic coatings and Allow no galvanic coupling by using other metals.

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REFERENCES

Lawrence J. Korb, Rockwell. 1987. ASM Handbook volume 13 of the 9th edition. ASM International Handbook Committee.

http://corrosion-doctors.org/Bridges/Steel.htm

http://www.corrosionclinic.com/corrosion_news.htm

http://www.nrc-cnrc.gc.ca/eng/ibp/irc/ctus/ctus-n73.html

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Thank You