IN SITU CONCRETE STRENGTH ASSESSMENT: PART I - THE USE OF MULTIPLE COMBINED NON DESTRUCTIVE TESTING

A series of nondestructive tests was performed with the purpose of investigating the mechanical properties of the concrete employed in civil buildings. A series of specimens were prepared to correlate the in situ concrete strengths obtained by multiple combined nondestructive methods with the cubical and cylindrical strength obtained by destructive methods. The multiple combined methods (SonReb methods + Windsor Pprobe tests) were used for the quality control and strength estimation of the concrete. In particular, a series of specimens by aggregates having various Mohs hardness and by aggregates with only a class of Mohs hardness was prepared. The comparison between nondestructive and destructive tests, conduced on cores from the specimens, were evidenced, as the use of Windsor methods is generally justifiable only if a reliable correlation for a particular type of concrete is developed and as both the SonReb and SonReb-Win methods give resistance values that are close to the actual ones.