Bridge and deck construction

Our portfolio of methods

1/ In situ construction

  • Incremental launching
  • Cast-in-place cantilever
  • Construction on scaffolding

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2/ Precast segmental erection

  • Balanced cantilever erection with launching gantry / lifting frames / cranes
  • Span by span erection with launching gantry / on falsework
  • Precast girder erection
  • Full span precast method

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3/ Heavy lifting and handling of structures

  • Heavy lifting: strand lifting, precision jacking
  • Sliding techniques: autoripage, autofonçage, airpad sliding, lateral sliding
  • Rotation systems
  • Special formwork

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  • 1946
    First development and use by Freyssinet of industrialized methods for bridge erection, for the Luzancy bridge
  • 320+
    Number of cable-stayed bridges where Freyssinet has been involved
  • 70+
    Number of bridges built in situ by Freyssinet
  • 50+
    Number of precast bridge decks erected by Freyssinet

Why choose Freyssinet

TMCLK, Hong Kong_Lifting frame

Hundreds of bridge and deck construction projects around the world for over 70 years, small to large-scale.

Applicable to:


  • Choice of construction method
  • Optimization of superstructure design and construction method
  • Design & supply of equipment and temporary structures
  • Erection of the superstructure, equipment operation, concrete casting, prestressing
  • Finishing work, including installation of structural fittings
  • Maintenance and repair services

Proven ability to propose and implement alternative designs and methods to achieve the best possible value at the lowest life cycle cost.

Under the leadership of our Major Project Department for the largest and most complex projects, our specialist supervising teams are able to manage safely the construction project within budget and on time, taking into account all technical and environmental factors.

Bridge and deck construction

A global approach to bridge construction

Our references

In situ deck construction

Incremental launching

The principle is to progressively build the bridge deck behind one of the abutments.

Segments of comparable length are concreted in a formwork or assembled in an assembly area. Then, each segment is match-cast against the previous one and prestressed to the section of the deck already built. As segments are added and slided over special bearings, the increasing length of bridge deck is repeatedly pushed / pulled out of the formwork or assembly area, over the abutment onto the piers, to reach its final position. Provision of a launching nose stressed against the first deck segment will reduce the big bending moments in the deck during launching.
  • Erection rate
    one segment every 7 or 8 days
  • Quality of segment fabrication
    with a sheltered casting yard
  • Limited investment in special equipment
    (launching nose, jacking system,
    launch bearings, side guides)
Incremental launching specifications
Type of structure…
  • Concrete box girder bridges
  • Composite steel concrete bridges
  • Steel bridges
  • Cable-stayed bridges
Best suited…
  • Bridges with constant radius of curvature and cross-sectional shape
  • Structures with high piers or where cranes, scaffolding or ground formwork cannot be used.
Bridge length…
  • Over 250m
Deck span for PT concrete decks…
  • 30m to 65m
Deck span for composite / steel decks…
  • 35m up to 150m
Launching force…
  • One strand jack suitable to over 600t.

Incremental launching sketch

Incremental launching sketch

Cast-in-place cantilever with form travellers

The method consists in building the deck by successive segments, in symmetry on both sides of the pier, by making the built part support the weight of the next segment and of the mobile casting equipment. The deck construction does not have to be linear; it can be sequenced to follow pier construction.

This method is ideally suited: to cross high gaps and avoid ground constraints for bridges whose length does not require prefabrication, or with different cross sections or casting lengths
  • High erection rate
    one pair of segments every 3 to 7 days
  • Long-span bridges
    with access constraints
  • Limited investment

Our references in deck construction

Precast segmental deck erection

Balanced cantilever erection
with launching gantry

The prefabricated segments are transported by truck or barge to the erection site. They are then installed symmetrically on either side of the supports using gantry cranes or floating cranes, mobile handling equipment fixed to the deck and launching girders. This construction method is adapted to long structures (deck span from 30m to 60m) with multiple spans; it combines the advantages of cantilever construction together with segment prefabrication.
  • High erection rate
    1 or 2 pairs of segments per shift
  • Minimal disruption to existing
    roads, traffic and services
  • Clear access to several work fronts

Balanced cantilever erection
with lifting frame

Following installation and commissioning, our lifting frames can operate independently, providing both lifting and self-launching mechanisms. While the gantry crane is used for medium and large projects, this method is suitable for smaller, long span structures (30m to 170m). It is particularly versatile and applies both to precast segmental decks and cable-stayed decks (either precast, composite, or steel) regardless of span range and segment weight. The equipment can be reused for other projects.
  • High erection rate
    up to 2 pairs of segments per shift
  • Craneless method applicable
    both to precast segmental decks
    and cable-stayed decks
  • System adapted to large segments

Span by span erection with launching gantry

This method consists of assembling a complete span as it moves forward. The span is made of segments that are hung on a launching gantry and are assembled by pre-stressing while the span is placed on the piers.

The technique is applicable to prestressed concrete bridges, continuous spans, multiple spans not exceeding 50m, and spans with steeply curved alignment, regardless of the longitudinal and plane profiles of the structure.
  • Most economic and fastest method
    for multi-span viaducts
    High erection rates
    2 to 4 spans per shift
  • Strict geometry controls
    of segments on precast area
  • Smaller crew size required
    compared to balanced cantilever construction
  • Precast segmental bridge

Precast girder erection

The method is based on the use of launching beams, beam launchers or lifting frames capable of receiving prefabricated beams (I-, U- or T-beams) behind, below or parallel to the erection system. Strand and winch lifting systems are used, ensuring precise placement of the precast elements, with several degrees of alignment possible and at an efficient rate.
  • Fast erection rate, 1 span per shift
  • Simple method
    which can be done by a small team
  • Minimised geometry control
  • Precast segmental bridge

Our references in deck construction

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