## 4 Results and Discussion
### Mechanical Properties  
#### 4.1.1 Static Tensile Strength  
Figure 3 shows the relation between \(\sigma_{\text{max}}\) and the corresponding elongation at the maximum stress point (L at \(\sigma_{\text{max}}\)) for the epoxy (EP) and vinylester (VE) composites reinforced with basalt powder (BP), basalt fibre (BF) and basalt textile (BT) for measurements taken at 25 \({}^{\circ}\)C. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Base Polymer Type**} & \multicolumn{3}{c}{**Filler**} \\ \cline{2-5}  & **Basalt Powder** & **Basalt Fibre** & **Basalt Textile** & \\ \hline Vinylester resin & **VE/BP** & **VE/BF** & **VE/BT** & \\ \hline Epoxy resin & **EP/BP** & **EP/BF** & **EP/BT** & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Designations of composite samples used in Results and Discussion section. Figure 3: Relation between \(\sigma_{\text{max}}\) and corresponding elongation at maximum stress point (L at \(\sigma_{\text{max}}\)) for composites EP and VE reinforced with basalt powder (BP), basalt fibre (BF) and basalt textile (BT) based on the measurements taken at 25 \({}^{\circ}\)C.  
While stretching a polymeric material, even at room temperature, local temperature spikes by even 20 \({}^{\circ}\)C may occur due to some molecular processes of reorganisation and reorientation of the structure. An effect of that may be, for example, mechanical twinning of lattice crystals. The smaller the inclusion particles in the polymeric alloy, the higher the diversity of the samples turns out to be, since smaller particles have a tendency to lump into larger aggregates. Nevertheless, adding such fillers into the highly crystalline matrix results in a lower maximum stress point. It is concluded that despite keeping a constant ratio of unstretched chains to stretched chains in the test, limiting segment motions by introducing reinforcement during the so-called \"necking\" phenomenon not only reduces the elongation degree, but also flattens the maximum stresses. The maximum tensile force for the materials based on epoxy resin, as tested at a temperature of 25 \({}^{\circ}\)C, was 435 MPa in the case of the reference fittings (Figure 3). The lowest value was recorded for the modifications with basalt powder and fibre, which may be a consequence of weak adhesion of fibre to resin and hence cause easier tensile deformation. The maximum tensile force in the case of vinylester samples was 235 MPa for the composition modified with basalt fibre (BF). The modification of VE resin with textile did not lead to a drastic improvement of \(\sigma_{\text{max}}\). In this case, the least favourable addition was basalt powder which reduced the maximum tensile force by 45% in the EP matrix and by 38% in the VE matrix. The best tensile strength at 25 \({}^{\circ}\)C among the materials studied here was observed for the epoxy resin modified with basalt textile, yet the \(\sigma_{\text{max}}\) values of the reference materials (REF) had not been surpassed. As expected, the tensile deformation values at the \(\sigma_{\text{max}}\) point were decreasing (for both types of polymeric materials) with an increasing influence on the filling orientation in the matrix. Therefore, the greater the influence on the additive/filler orientation in some resin layer, the lesser the elongation of the composite material. Unfortunately, this trend was not reflected in the \(\sigma_{\text{max}}\) values. Resin compositions were also tested at temperatures \(-\)20 \({}^{\circ}\)C and 80 \({}^{\circ}\)C. The results of static tensile strength tests at \(-\)20 \({}^{\circ}\)C reveal that the maximum tensile force (290 MPa) was reached for composition EP/BP (Figure 4). It had been expected that at temperatures below 0 \({}^{\circ}\)C the mechanical strength would depend mostly on the strength of the reinforcement itself. Here, the physical and chemical properties of the polymeric matrix and its affinity to the reinforcement played the main role.