## 5 Discussion of Results  
Regarding the flexural test, a total of eight panels were tested, some of them were damaged by previous ballistic tests and cast both in the laboratory and in an industrial unit. The behavior of the slabs under flexural loading showed a reasonable ductility of the material. Undamaged slabs reach a first peak-load in the range of 4.7 kN to 6.7 kN with a corresponding deflection ranging from 2.3 mm to 4 mm; while the maximum peak-load lies between 5.2 kN and 9.5 kN with a deflection ranging from 9 mm to 24.7 mm. Damaged panels do not present a first-peak during the application of the force and the curve trend is different from the undamaged panels, so it is only possible to evaluate the maximum force that ranges from 4.2 kN to 6.8 kN with a deflection ranging from 10.7 mm to 21 mm. The casting environment does not have any significant effect on the load resistance. The investigation of the fracture energy is differentiated between undamaged and damaged slabs. In the undamaged specimens, the fracture energy concerns the dissipation in both a strain-hardening region just before the peak-load and a strain-softening region. The specimens show the fracture energy values ranging from 32 J to 175 J in the strain-hardening region, while in the strain-softening region, the value is much bigger and lies between 80 J and 164 J. The total energy dissipated by the flexural fracture is in the range of 148 J to 290 J or from 9 kJ/m\({}^{2}\) to 17 kJ/m\({}^{2}\) if the cracking area is considered. In the damaged specimens, the fracture energy also concerns dissipation in both regions but there is no recognizable peak-load in the curve, i.e., the differentiation between the two regions is given by the max-load reached by the specimen. The slabs show the fracture energy ranging from 31 J to 110 J in the strain-hardening region, while in the strain-softening region, the fracture energy ranges from 65 J to 75 J. The total energy dissipated by the flexural fracture ranges from 99 J to 175 J or from 8 kJ/m\({}^{2}\) to 22 kJ/m\({}^{2}\) if the cracking area is considered. The smallest value belongs to a single slab cast in the industrial unit, but the number of the specimens considered is not so significant as to allow a correct evaluation of the difference of behavior according to the different casting environment. Figure 20: Ballistics loading of the tetragon house (on the left) and the post-test picture showing surface erosion from individual hits on the proximal face of the UHPFRCC plates (on the right). The flexural strength is studied as the stress experienced within the material just before the failure and it is derived assuming a linear stress distribution. Its value lies between 10 MPa and 19 MPa for undamaged slabs, and between 8 MPa and 13 MPa for damaged ones. Lastly, the fracture toughness is analyzed using two different methodologies, i.e., the ASTM 1018 Standard Test Method [30] and the JSCE Standard SF-4 Method [32]. According to the first, toughness characterization is considered only for the undamaged slabs since it is based on the measurement of the first crack. Instead, by the second, it is possible to evaluate the flexural toughness for damaged specimens too. Toughness indexes for each slab, in the beginning, are pretty similar for all the slabs tested; then, as expected, the scatter gets bigger. Residual strength in the material is rationally decreasing. The casting environment does not seem to have significant effects on the toughness characterization. Regarding the shear test, a total of three slabs were tested on the left and right side, so six shear tests were performed. All the specimens were undamaged and cast both in the laboratory and in an industrial unit. A difference of behavior between the left and the right side of the same slab can be noted and is probably due to a different distribution of the fibres inside the specimen body.