Ultra-high performance concrete (UHPC) is characterised by impressive strength and durability. Thin layers of UHPC are used increasingly to strengthen and protect existing ordinary concrete (OC) structures, with the purpose of improving their performance and increasing their service life.

Experimental studies have been carried out at HEIA-FR to assess the evolution of the bond between UHPC and OC in the very first hours after UHPC casting, and to identify non-destructive testing techniques (NDT) for early-age detection of interface defects.