Mechanical characterization of concrete: the case of a school building located in Tuscany

Mechanical characterization of concrete is an important step in the knowledge process aimed at assessing RC existing buildings. In particular, concerning structural response of an existing building subject to severe actions, such as the seismic ones, it is important to accurately define the concrete constitutive law, including both the compressive and the tensile branch. Definition of these mechanical properties is usually achieved through laboratory tests, mostly involving cores drilled from the building under investigation. While the compression tests are easy to perform, execution of the tensile tests is more difficult to implement. In this case, indirect tests are usually performed, such as the bending test or the splitting test. The paper presented herein concerns results of both compression and tensile tests (splitting tests) carried out on cores belonging to structures (beams and columns) of a school building located in Tuscany. Each core was interested by both types of tests: the central part of the specimen was used for the direct compression test, while the remaining end portions, resulting from the core preparation, were used for the execution of the splitting test; in this way, specimens involved in tensile tests were about twice those employed for the compression tests. Finally, results provided by laboratory tests were subjected to a subsequent re-elaboration mainly concerning the tensile strength, in order to make a comparison with strength values provided by formulations present in the technical and scientific literature.