Description
The action of moderate and high temperatures produces the degradation of main physical and mechanical properties of Ordinary Portland Cement (OPC) composites. As an example, from an application point of view and at a structural level, the case of concrete radiation shielding containers in nuclear facilities can be mentioned, which can be severely affected by thermal cracking. In this work, the results of Acoustic Emission (AE) monitoring of mortar prismatic specimens under three-point bending tests are analyzed. Samples are firstly submitted to a heating treatment in an electrical furnace, with maximum target temperatures ranging between 100 to 600 ºC. After the heating process, the prisms were cooled down and finally, mechanically tested, i.e. under residual conditions. The AE signals were continuously recorded during each bending test and its characteristics at different loading stages were explored, scrutinizing variations in AE parameters, such as event rise time, amplitude and energy. Additionally, average frequency (AF) and RA value parameters were employed to assess fracture modes aiming to highlight situations where tension or shear/mixed modes predominate through the test. A comparative analysis of the AE characteristics during loading path and progressive damage is presented.
