Experimental tests have been carried out to evaluate the crushing and the fracture energies absorbed by concrete specimens during compression and flexural failure. In the former case, concrete cylindrical specimens having a different slenderness have been considered. In order to…
Experimental tests have been carried out to evaluate the crushing and the fracture energies absorbed by concrete specimens during compression and flexural failure. In the former case, concrete cylindrical specimens having a different slenderness have been considered. In order to obtain the complete load vs. displacement response, the tests have been controlled by the circumferential strain measured with a linked chain placed around the cylinder at mid-height. The absorbed energy per surface unit is computed from the overlapping constitutive law. As far as the fracture energy is concerned, three-point bending tests have been carried out according to RILEM recommendations. The loading process has been displacement-controlled, and the fracture energy computed as the area beneath the load vs. mid-span deflection curve. Furthermore, all the tests have been monitored by the Acoustic Emission (AE) technique. In particular, the evolution of the most representative AE parameters has been analyzed, in order to better understand the cracking pattern evolution during the test. The waves frequency and the rise angle are used to discriminate the prevailing cracking mode from pure opening or sliding. The cumulated number of AE events and their amplitude are used to compute the signal energy.