A　procedure　to　determine　the　shear　strength　characteristic　value　(Vrck)　is　presented　and　applied　to　two　existing　RC　beams　extracted　from　an　old　structure　built　in　Italy　in　the　early　1900s.　Several　nondestructive　tests　(NDT)　and　destructive　tests　(DT)　were　performed,　and　the　experimental　outcomes　show　a　great　variability　of　the　compressive　strength　in　the　same　beam.　For　this　reason,　Vrck　values　were　calculated　for　each　beam,　assuming　different　knowledge　levels　about　the　concrete　compressive　strength.　The　procedure　results　are　compared　to　those　obtained　by　applying　a　traditional　Bayesian　updating　procedure,　where　the　updating　basic　variables　(represented　by　the　concrete　strength)　was　determined　by　using　indirect　measures　of　strength　as　a　prior　information.　©　2018　Czech　Technical　University　in　Prague.　All　rights　reserved.