Factors affecting mechanical strength of concrete cores: an investigation concerning public buildings located in Toscana

ABSTRACT: Mechanical characterization of materials is a key moment in the process of evaluating the structural capacity of existing buildings. In the case of RC buildings, a method widely used to estimate concrete strength is based on compression tests on samples obtained by coring. However, it is known that the strength values obtained from these tests are conditioned by several factors mainly related to the extraction modes, to the concrete quality and to the core size. For this reason many studies have been developed to obtain a reliable prediction of the in-situ concrete strength of RC existing buildings. In this work, different formulations have been analysed, aimed at evaluating the in-situ concrete strength starting from values obtained by laboratory tests performed on cores extracted from the investigated buildings. In particular, some of the most important code standards together with some scientific works considered as basic for this topic, have been considered. These formulations have been applied to a large sample of concrete cores belonging to public RC buildings located in Toscana.