## 3 Results and Discussion
Figure 12: Slices and top view of the basalt fabric reinforced geopolymer composite after the impact test in longitudinal (**a1–c1**) and transverse (**a2–c2**) directions (the lines indicate where the other cross sections were taken). (**d1–d2**) The response from the damaged area. For the E-glass and the carbon fabrics, the delamination was visible, but the accompanying expansion in thickness was limited. The thickness of the basalt composite was more than double in the affected area. This behavior was attributed to the strong chemical interactions and the mineral exchange among the basalt fabrics and the geopolymer matrix [24]. Thus, strong chemical bonding transforms the composite-like cement structure, and above all, it weakens the fibers, showing the fragile behavior of the composite structure. The carbon fiber pull out around the impact zone was well explained by the concept of the laser scanner, and these observations match well with ours. The unidirectional carbon fibers in an epoxy matrix and the arrangement of the fibers in the laminar plane were studied using \(\upmu\)CT [16], highlighting different failure modes of the composite and internal damage [25; 26] that agreed with the fiber damage concept presented in this study. The central damage areas of the carbon, the E-glass, and the basalt fabric composites got larger in that order (Figure 13a-c). Fiber breakage and matrix cracks were observed in all cases [SEM micrographs of the damaged samples for E-glass (Figure S1) and basalt (Figure S2) fabric reinforced composites are reported as examples in the Supplementary Materials], however, for carbon composites, the area outside the range of 25 mm showed no change in appearance. The fiber damage within the central region was observed while the rest of the composite was intact with good adhesion of fibers within the matrix. The severely damaged area of the carbon geopolymer composite was 15 \(\pm\) 2 mm\({}^{2}\) (calculated from the picture of the damaged area at the impact side), but the damage stretched over a larger circumferential area. Figure 13: (**a**) The damage area of carbon, (**b**) E-glass, and (**c**) basalt reinforced composite. The green part represents the less affected area while the dark one represents the most affected area. This can be seen in Figure 5, where the affected zone was larger on the surface. The E-glass and the basalt composites showed only damage in the clearly distorted area with no effective changes in other parts of the composite. The pull out mechanism of the carbon fiber effectively impacted other parts of the composite, probably due to the inter shear stress mechanism [27]. The sliding mechanism of the E-glass fibers reduced the inter shear effect, while the basalt composite was penetrated suddenly, almost as if no fibers were present. The E-glass composites presented a severely damaged area in the range of 42 \(\pm\) 3 mm\({}^{2}\). The basalt reinforced composite had a severely damaged area of 97 \(\pm\) 5 mm\({}^{2}\). The area of damage is also represented in Figure 13, where the green part represents the non-affected area and the black one is the heavily distorted area. Not only was the affected area much larger for the basalt reinforced composites, but the shape of the impact was different as well. The non-spherical deformation was caused by the orientation of the textile fibers, which can also be seen in Figure 12c, where the deformation of the fiber bundles is very clear. The theoretical and experimental approach of woven fiber in the carbon composite at various axis of damage during dynamic loading was described in literature [28] and well matches with the damage behavior observed here, such as matrix cracking and fiber debonding on the composite. The overall fiber orientation and rupture through the composite from the edge towards the center is supported by the supplementary file Video S1. The parameters for the 3D image construction and some results were compared to the carbon, the E-glass, and the basalt reinforced geopolymer composites (Table 3).