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.