PSI - Issue 78

Antonella D’Alessandro et al. / Procedia Structural Integrity 78 (2026) 1887–1894

1892

c)

0 0,02 0,04 0,06 0,08 0,1

10 20 30 40 50 60 70

Crack initiation

FCR (%)

-10 0

Strain (mm/mm)

0

400

800

1200

Time (s)

Fig. 4. Time-domain response of FCR as a function of strain for specimens with 0.4% CCMF: (a) paste printed in the longitudinal direction; (b) paste printed in the transverse direction; and (c) mortar printed in the longitudinal direction.

Stress correlation was assessed using Equation 8. The cement paste sample exhibited the highest stress at failure, reaching 8.448 MPa. A value of 4.607 MPa was recorded for the mortar sample printed in the same (longitudinal) direction. In contrast, the cement paste sample with a transverse printing path reached only 3.429 MPa. This reduction is attributed to the internal orientation of the CCMF, with greater mechanical strength observed when fibers were oriented perpendicular to the loading direction (longitudinal path), compared to parallel alignment (transverse path), and the compactness of the materials due to the different contact among the layers. a) b)

10 20 30 40 50 60 70

0 2 4 6 8 10

10 20 30 40 50 60 70

0 2 4 6 8 10

FCR (%) Stress (MPa)

FCR (%)

FCR (%)

Stress (MPa)

Stress (MPa)

-10 0

-10 0

0 500 1000 1500 2000 2500

0 500 1000 1500 2000 2500 3000

Time (s)

Time (s)

c)

10 20 30 40 50 60 70

0 2 4 6 8 10

FCR (%)

Stress (MPa)

-10 0

0

400

800

1200

Time (s)

Fig. 5. Time-domain response of FCR as a function of stress for specimens with 0.4% CCMF: (a) paste printed in the longitudinal direction; (b) paste printed in the transverse direction; and (c) mortar printed in the longitudinal direction.