PSI - Issue 25

Andronikos Loukidis et al. / Procedia Structural Integrity 25 (2020) 195–200

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A. Loukidis et al. / Structural Integrity Procedia 00 (2019) 000–000

3

100mm

`

25mm

AE

6mm

25mm

2.5mm

Fig. 1. Sketch of the centrally notched marble specimen labelled MARBLE. The position of the AE sensor is indicated by the green circle.

25mm

AE

50mm

100mm

25mm

Fig. 2. Sketch of the circular semi-ring marble specimen labelled CSR. The position of the selected AE sensor is indicated by the green circle.

50mm

AE

50mm

200mm

Fig. 3. The geometry the mortar cement specimen labelled CEM, along with the position of the AE sensor which is indicated by the circle.

3. Experimental protocol The specimens used in the present study were made of Dionysos marble and cement mortar. More specif ically, Dionysos marble was used to form a prismatic specimen of dimensions 25x25x100 mm 3 with a notch, of 2.5mm width and 6mm length, at its mid-span (Fig.1). The specimen was subjected to three-point bend ing under displacement-control mode at a rate of 0.01mm/min (Kourkoulis et al., 2018). Dionysos marble was also used to form a circular semi-ring specimen (CSR), based on the geometry proposed by Markides et al. (2018), with outer and inner diameter equal to 100mm and 50mm, respectively (Fig.2). The CSR specimen was subjected to uniaxial compression (with the aid of two grooves formed at the outer periph ery of the specimen) under displacement-control mode at a rate equal to 0.02mm/min. Finally, a cement mortar prismatic specimen (Fig.3) was prepared as it is described in Stergiopoulos et al. (2013b,a), with dimensions 50x50x200 mm 3 , which was subjected to three-point bending under displacement-control mode of 0.05mm/min. More than one acoustic R15 α sensor was properly attached on the marble specimens (prismatic with notch and CSR) not only to monitor the internal damage but also to detect the location of the origin of the