The consortium led by Bessac and including GTM Sud-Ouest TP GC and Soletanche Bachy—subsidiaries of VINCI Construction—for the Line B Connection (CLB) project of the Toulouse Metro has received a great distinction for the operation’s EXEGY®L+C3 very-low-carbon segments: the Gold Star of the Technical Innovation of the Year category of the 11th edition of the ITA Tunnelling Awards, organized by the International Tunnelling and Underground Space Association (ITA-AITES), and held on October 1st, 2025, at the Sava Centar in Belgrade, Serbia.
The jury awarded the site for its use of a very-low-carbon solution, EXEGY®L+C3, which incorporates metakaolin and limestone filler to replace 55% of clinker for the realization of the 2,850 precast tunnel lining segments of the project, the use of this formulation being unprecedented for this type of construction work. This innovation was carried out with both the support of PREGA, the precast factory having produced the segments, and of Tisséo, the project owner of the Line B Connection, which dared to innovate for their subway extension.
This innovation, presented by Bessac CLB Project Director Augustin Morando during the Technical Days of the French Tunnelling and Underground Space Association (AFTES) at Toulouse, was described by this panel of experts as a major breakthrough for the carbon footprint reduction of underground infrastructures, and as an object of pride for France making it shine on the international stage, and confirming its status as a world leader of underground construction.
EXEGY congratulates Bessac—which is celebrating in 2025 its 50-year anniversary—for this award, and thanks Tisséo, PREGA and all teams involved in the Line B Connection operation for their commitment to innovation, as well as their significant role in the central objective of concrete decarbonization established by VINCI Construction.
