Home ArrowCase Studies Arrow Chillon Viaducts, Switzerland

Chillon Viaducts, Switzerland

Chillon Viaducts, Switzerland

Case Study Description

The Chillon viaducts are located in Switzerland, over the east end of Lake Geneva, south east of Montreux. It comprises two parallel 1.4 mile long prestressed concrete box girder bridges, bearing the east and westbound lanes of the Swiss A9 highway. Built in the 1960s, it was one of the largest works in prestressed concrete for many years, so it was of great historic value to the area. Originally designed to sustain an estimated volume of 10,000 vehicles per day, it is currently being used by 50,000 vehicles daily.

The Problem

The bridge was scheduled for deck rehabilitation but an inspection of the viaducts revealed that they were significantly damaged and deemed structurally deficient. In various places the concrete’s reinforcing bars had been corroded and the concrete itself was betraying signs of Alkali Silica Reaction (ASR). On closer inspection, following hydrodemolition tests, Alkali-Aggregate Reactions (AAR) were also detected, which meant the mechanical properties of the concrete were compromised. If repairs were not undertaken, it is likely the structure would have needed totally rebuilding.

The Requirements

With an ever increasing number of vehicles using the bridge, a solution was required to increase the shear, bending and fatigue resistance of the deck slab. The structure also needed any damage caused by ASR and AAR to be reversed, as well as waterproofing to prevent future damage and a significant improvement of its structural properties.

Our Solution

A thin steelbar-reinforced Ultra High Performance Fiber Reinforced Cement-based Composite (UHPFRC or UHPC) overlay was selected as the best and most cost-effective solution to meet the complex needs of the structure. The material has extraordinary strengthening and waterproofing qualities and, with the right skills and machinery, it is possible to place it extremely quickly, meaning that the roadway could be closed for the least amount of time possible, minimizing disruption and costs.


Case Study Info

2014 – 2015

  • Length:
    2 x 2.2 km (1.4 mi)
  • Width:
    2 x 12 m (40 ft)
  • Area of UHPC poured:
    53,000 m² (570,500 sq ft of Ductal®)
  • Thickness:
    45 mm (1.75 in)
  • Increase in traffic:
    + 10% in 3 years, over 50,000 vehicles per day
  • Permitted vehicle weight increase:
    from 24 to 40 metric tons (26.5 to 44 tons)


WALO International Ltd.
Heimstrasse 1
8953 Dietikon

+41 44 444 31 11

Contact us

View our WALO locations

WALO Chillon Viaduct UHPC Paver
WALO Chillon Viaduct UHPC Paver 1
WALO Chillon Viaduct UHPC Plant
Impressum schliessen

Responsibility is the official website of WALO US Holdings Inc.


WALO US Holdings Inc.
433 Broadway, Suite 604
New York, NY 10013
Tel. +1 (212) 691-4537


Concept / Design / Implementation

WALO – ABSURD – Gestalter


View disclaimer

WALO IT-ServiceDesk

Phone +41 848 000 118
Monday – Friday 06:30 – 12:00 AM / 01:00 – 05:30 PM


Download Quick Support