The works concern the demolition and the following reconstruction of the existing deteriorated RC slab which supports the carriageway along 555m of the Mont Blanc tunnel (see pictures below).

Work Phases: A technical solution based on the use of prefabricated segments has been optimized in the executive design in order to meet a tight timescale which requires works carried out only nightly while the tunnel always in service during the day. During each night session the following recurrent phases will be undertaken:

1. To cut 10m of the existing slab into elements 2.5m wide and 8.6m long;
2. To load the cut items on trailers by the use of a gantry specially designed for the purpose;
3. To install the new prefabricated slab segments.