PSI - Issue 47

Andrea Zanichelli et al. / Procedia Structural Integrity 47 (2023) 37–42 Zanichelli et al./ Structural Integrity Procedia 00 (2023) 000–000

40

4

100.0

80.0

60.0

40.0

20.0

0.0

COMPRESSIVE STRENGTH [MPa] PM GOM

SPECIMENS TYPE

Fig. 2. Mean value and standard deviation of the compressive strength, for both the PM and GOM specimens.

The mean value of the fracture toughness, computed for both PM and GOM specimens, is reported in Fig. 3 together with the corresponding standard deviation. It can be observed that a significant increase of the fracture toughness (equal to about 26% ) is achieved for the GOM specimens with respect to that for the PM ones.

0.0 1.2 FRACTURE TOUGHNESS [MPam 0.5 ] PM GOM 0.3 0.6 0.9

SPECIMENS TYPE

Fig. 3. Mean value and standard deviation of the fracture toughness, for both the PM and GOM specimens.

From the X-ray diffraction analysis, the following products are found for both examined powder types, that is (in abundance order): CH; AF t ; AF m ; C 3 S; C 2 S; and gypsum. Fig. 4 shows the microstructural images of both the PM sample (Fig. 4 (a)) and the GOM sample (Fig. 4 (b)). From Fig. 4 (a), quartz and Ca-rich phases can be observed, as from Fig. 4 (b); the difference consists in the shape of Ca rich silicate crystals, that are elongated with a size of few microns for the PM sample, whereas are more compacted with a micrometre size for the GOM sample.