## 4 Results and Discussion
### Mechanical Properties
#### 4.1.2 Static Bending Strength  
In Figure 10, a relation is presented of \(\sigma_{\text{max}}\) and the corresponding elongation (L at \(\sigma_{\text{max}}\)) in the bending strength test for the composites EP and VE reinforced with basalt powder (BP), basalt fibre (BF) and basalt textile (BT) for measurements at 25 \({}^{\circ}\)C.  
Figure 10: Relation of \(\sigma_{\text{max}}\) and corresponding elongation (L at \(\sigma_{\text{max}}\)) in bending strength test for composites EP and VE reinforced with basalt powder (BP), basalt fibre (BF) and basalt textile (BT) for measurements at 25 \({}^{\circ}\)C.  
The results indicate, as in Section 4.1.1, that at room temperature reinforcing with basalt powder has a negative effect on the resistance to static bending. Meanwhile, basalt textile provided the resins with the highest \(\sigma_{\text{max}}\) value among all the samples that had been reinforced. Both unfortunate and surprising, the result of the reference sample was not outperformed. The amount of fillers (more than 10%) might have been too high and led to a reduction in strength properties since they did not propagate the stresses acting upon them and merely constituted foreign inclusions. The best properties were observed for the materials containing basalt textile. In this case, there were no considerable differences between the epoxy and vinylester resins. Nevertheless, samples VE/BT and EP/BT did not exhibit the greatest elongation degree at \(\sigma_{\text{max}}\). The \(\sigma_{\text{max}}\) results at 25 \({}^{\circ}\)C are in line with literature reports for materials strengthened with chopped fibre and powder fillers [16; 17; 18; 19; 20]. In theoretical considerations described in the literature, the worst strength properties have been seen for composites containing chopped or ground fibre and fibre mats providing the reinforced plastics with both spatial and in-plane isotropy [21; 22; 23; 24; 25]. Similarly to the analysis presented for the vinylester compositions at room temperature, decreasing the sample temperature to below 0 \({}^{\circ}\)C allowed us not only to preserve the strength properties of the textile-reinforced compositions, but also to slightly improve them, while the error bar values were at a comparable level (Figure 11). Thus, using two in-plane orthotropic textile layers made it possible to preserve the mechanical properties under relatively rigorous measurement conditions. Such an effect was not observed in the case of the powder (BP) or chopped fibre (BF) fillings. This study proved that as far as epoxy resins are concerned the properties of the composites are determined mainly by the filling, and in the case of the vinylester resins, the opposite, by the matrix constituting the dominant composition part. Figure 11: Relation between \(\sigma_{\text{max}}\) and corresponding elongation (L at \(\sigma_{\text{max}}\)) in bending strength test for composites EP and VE reinforced with basalt powder (BP), basalt fibre (BF) and basalt textile (BT) for measurements at \(-20\)\({}^{\circ}\)C.  
Raising the ambient temperature to 80 \({}^{\circ}\)C during a static bending test trial gave the materials highly elastic properties, with entropic elasticity becoming a dominant feature. Such an elasticity type is associated with much greater deformations exceeding even 100%. The curves showing the relation between the stress and deformation of the material had a non-linear character. The dominant role was mainly played by effects connected to entropic elasticity and viscoelasticity. The strength results (Figure 12) from the bending tests of epoxy samples (EP) and vinylester samples (VE) at a higher temperature were different. Clearly, the filler type affected the mechanical properties of the epoxy resins, whereas it did not lead to any substantial changes in the case of the vinylester compositions.