Steel is widely used in bridge construction due to its high strength, versatility, and durability. Some key advantages of steel bridges include their speed of construction through prefabrication, ability to be modified or repaired, high strength-to-weight ratio which allows for shallow foundations and ease of transport, and sustainability through recycling. Major steel bridges from around the world demonstrate these advantages, such as the Millau Viaduct which used steel beams that were lighter and easier to construct than concrete would have been.

1. VERSATILE MATERIAL
Uses of steel in bridge construction

2. What is Steel
Steel:-
Steels are alloys of iron and other elements, primarily carbon
high tensile strengths and low costs.
Widely used in construction and other applications.

3. Uses of steel in bridge construction
Industrial importance on steel:
 More than 1.3 billion tons produced annually
 Mild steel replaced wrought iron
 Hardness, ductility, and tensile strength of the resulting steel is controlled
 Various grades defined by assorted standards organizations

4. Why we Uses steel in bridge construction??
The following are some of the advantages that steel can offer;
 Long steel
 High quality material
 Speed of construction
 Versatility
 Modification and repair
 Recycling
 Durability
 Aesthetics

5. Why we Uses steel in bridge construction??
Long steel
 As reinforcing bars and mesh in reinforced concrete
 Railroad tracks
 Structural steel in modern buildings and bridges
 Wires

7. Why we Uses steel in bridge construction??
High Strength to Weight Ratio
 strength to weight ratio of is particularly beneficial in poor
ground conditions
 Minimum self-weight is also an important factor in
transporting and handling components
 shallow construction depths overcome problems with
headroom and flood clearances, and minimize the length of
approach ramps
 For example………

8. The Newark Dyke
rail bridge
Comprises a 77m span
bowstring truss
 820 tones of S355 steel
The selection of steel was made
because of its high strength to
weight ratio,
The low self-weight also
minimized foundation works
adjacent to the existing rail line.
First UK steel bridge to be
designed for the next generation
of 225 Km/hr trains

9. Why we Uses steel in bridge construction??
Quality
 Steel is a high quality material
 grades,
 shapes
 sizes
 The testing regime carried out at the steel mills
properly
 Pre-fabrication in controlled shop conditions leads to
high quality work at minimum cost.
 cutting, drilling, welding, fit-up and painting is easily
permitted
Readily
available

10. Why we Uses steel in bridge construction??
Speed of Construction
The prefabrication of components
time on site in hostile environments is minimized.
The speed of steel bridge construction reduces the
durations of rail possessions and road closures,
public disruption to those networks are minimized
The light-weight nature of steel permits the
erection of large components
For example…..

11. The Hallen Bridge
A 500T truss bridge near
Bristol(England)
Carries a single-track
railway
Sections were shop-
fabricated and transported
to site where the bridge
was fully assembled off
line.
Transported into position
using multi-wheeled
Econofreight vehicles

13. Why we Uses steel in bridge construction??
Versatility
Steel suits a range of construction methods and
sequences.
Installation by cranes, launching, slide-in
techniques or transporters.
Steel gives the Contractor flexibility in terms of
erection sequence and programs.
Components can be sized to suit access
restrictions at the site

14. Why we Uses steel in bridge construction??
 Once erected the steel girders provide a platform for
subsequent operations.

15. Why we Uses steel in bridge construction??
Modification & Repair
 Steel bridges are adaptable
 And can readily be altered for a change in use
 They can be widened to accommodate extra lanes of traffic,
and strengthened to carry heavier traffic loads.
 Steel bridges can readily be repaired after accidental damage.
 A heat treatment technique, based on the theory of restrained
expansion, was proposed by a UK fabricator as a more
economic and less disruptive solution

16. Tamar suspension
bridge (Plymouth)
The needed widening and
strengthening due to increased
traffic loads and volumes
 The solution was to replace
the concrete deck with a new
lightweight steel one, and add
steel cantilever sections
 The result was that the
widened 5-lane bridge was only
25 tones heavier than the old 3-
lane structure, and was able to
accommodate 44 tone trucks

17. Why we Uses steel in bridge construction??
Recycling
 Steel is a ‘sustainable’ material. When a steel bridge reaches
the end of its useful life, the girders can be cut into
manageable sizes to facilitate demolition, and returned to
steelworks for recycling.

19. Why we Uses steel in bridge construction??
Durability
 Steel bridges now have a proven life span extending
to well over 100 years.
 The potential durability of steel may be summarized
in the following quote by a Mr. J. A . Waddell in
1921:
“The life of a metal bridge that is scientifically
designed, honestly and carefully built, and not seriously
overloaded, if properly maintained, is indefinitely long.”

20. Why we Uses steel in bridge construction??
Durability
 Steel has a predictable life, as the structural elements
are visible and accessible
 Signs of deterioration are readily apparent
 Corrosion is a surface effects are removed by
repainting the affected areas
 Alternative form of corrosion protection is the use of
weathering steel

21. Why we Uses steel in bridge construction??
Aesthetics
 Steel has broad architectural possibilities
 Could be sculptured to any shape or form
 The high surface quality of steel creates clean sharp lines and
allows attention to detail
 The painting of steelwork introduces color and contrast, and
repainting can change or refresh the appearance of the bridge
to appear as new one

22. Truss Bridge
(Incheon international airport)
This arch-truss bridge connects
incheon international airport to
seoul in korea (above), and has a
main span of 540m. Steel was
considered the only option for
such a high profile site.

24. Examples of steel bridges
MILLAW VIADUCT
 Location:- Millau-Creissels, France
 Total length:- 2460 m
 Longest span:- 342 m
 Concrete used:- about 127,000 cubic meter
 Steel used:- 19,000 tones of for the reinforced concrete
Required 5,000 tones steel of pre-stressed steel for the cables
and shrouds

25. lifetime of the bridge will be at least 120 years

26. Preference of steel for Millau viaduct
The advantages of the steel against the original concrete design are:
• light-weight and slenderness of the beam (36 t against 120 t)
• reduction of the depth of the beam to 4.2 m, meaning smaller wind
loads
• improved safety: less work at great height due to pre-assembly on
ground and incremental launching construction
• minimizing the number of stay cables and the size of foundations
• reduction in total costs – the over-riding advantage.
• Within two and a half years nearly 43 t of steel were fabricated for
the beam, the towers and the auxiliary piers.

27. Examples of steel bridges
Sydney harbour bridge:-
Made of steel the bridge contains 6 million
hand driven rivets
 The Bridge has huge hinges to absorb the
expansion caused by the hot Sydney sun. You
will see them on either side of the bridge at
the footings of the Pylons
 Six million hand driven rivets and 53,000
tonnes of steel were used in its construction

29. • Golden gate bridge
• Structural Steel Quantities
• Tons
• Kg
• Main Towers
• 44,400
• 40,280,000
• Suspended Structure
• 24,000
• 21,772,000
• Anchorages
• 4,400
• 3,991,000
• Approaches
• 10,200
• 9,250,000
• Total
• 83,000
• 75,293,000