On the reliability of experimental data in the geomechanical characterization of dimension stones

In the last 40 years different procedures to estimate standard properties of dimension stones have been proposed by Italian and European technical committees as well as by international associations. The introduction of numerous and different standards, based on different sampling and testing conditions, has produced many practical consequences over the years, such as the doubtful reliability of results from the tests. This paper deals with this issue, analysing the differences between uniaxial compressive strength values of a Miocene limestone from the Central–Southern Apennines, Italy, calculated with four different standard procedures and evaluating the effects of loading rate, environmental conditions, specimen size and shape on the measured values. An additional finding of this study is a specific correlation between uniaxial compressive strength data and the size-corrected point load strength index. Although there are several studies asserting that point load test is an attractive alternative for indirect uniaxial compressive strength evaluation, there are many variables affecting this correlation, as shown by the high variability of results reported in the literature.