## 3 Results and Discussion
### Deformation Diagrams of Concrete and Fiber-Reinforced Concrete  
Moreover, based on the results of experimental studies, calculations were made and diagrams of compression \"\(\varepsilon_{b}-\sigma_{b}\)\" and tension \"\(\varepsilon_{bt}-\sigma_{bt}\)\" were plotted. The following types of concrete state diagrams were used as calculated diagrams of concrete that determine the relationship between stresses and relative deformations: curvilinear, including those with a falling branch, piecewise-linear (two-line and three-line). Compression and tension diagrams differ significantly in their parameters: concrete tensile strength is an order of magnitude less than compression. To construct diagrams of concrete deformation, we applied the method of constructing curvilinear diagrams [52]. To build a diagram, it is necessary to create an array of points, which is the dependence of the individual stress level, calculated through the entire algorithm for constructing a diagram of concrete deformation, taking into account the ascending or descending branch. Within the framework of the model of short-term loading under axial compression and tension, the concrete deformation diagram is represented as  
\[\varepsilon_{b(bt)}=\frac{\sigma_{b(bt)}}{E\cdot p_{b(bt)}} \tag{18}\]  
where \(\sigma_{b(bt)}\) are stresses arising in concrete under load, \(\varepsilon_{b(bt)}\) are ultimate deformations of concrete, \(E\) is the modulus of elasticity, and \(v_{b}\) is the coefficient of change of the secant modulus. The multiplication \(E\cdot v_{b(bt)}\) forms the secant module required to construct a curvilinear diagram. For the ascending branch of the diagram, the coefficient of change of the secant modulus is:  
\[v_{b}=\overline{v_{b(bt)}}+(v_{0}-\overline{v_{b(bt)}})*\sqrt{1-\omega_{1}* \eta-\omega_{2}*\eta^{2}} \tag{19}\]  
where \(\eta=\sigma_{b(bt)}/\overline{b_{b(bt)}}\) stress level factor, \(v_{0}=1\) secant modulus factor at the beginning of the diagram, and \(\varepsilon_{b(bt)}\leq\overline{\varepsilon_{b(bt)}}\), \(\omega_{1}\), \(\omega_{2}\) are variables that determine the curvature of the diagram, depending on the limiting value of the secant modulus at the top of the diagram. For an ascending curve, the variables \(\omega_{1}\), \(\omega_{2}\) are determined by the formulas  
\[\omega_{1}=2-2.5\overline{\varepsilon_{b(bt)}};\;\omega_{2}=1-\omega_{1} \tag{20}\]  
The principle of constructing the descending branch has a slight difference, the coefficient of change of the secant modulus has the form  
\[v_{b}=\overline{v_{b(bt)}}-(v_{0}-\overline{v_{b(bt)}})*\sqrt{1-\omega_{1}* \eta*-*\eta^{2}} \tag{21}\]where \(v_{0}\) is the value of the secant modulus at the beginning of the diagram that differs from the value when constructing the ascending branch and is calculated by the formula  
\[v_{0}=2.05\cdot\overline{v_{b(bt)}}\;p\mathrm{P}I\;\varepsilon_{b(bt)}>\overline {\varepsilon_{b(bt)}} \tag{22}\]  
The variables \(\omega_{1}\), \(\omega_{2}\), which determine the curvature of the diagram for the descending branch, are determined by the formula  
\[\omega_{1}=1.95\cdot\overline{v_{b(bt)}}-0.138;\;\omega_{2}=1-\omega_{1} \tag{23}\]  
Table 10 shows the calculated coefficients for plotting compression \"\(\varepsilon_{b}-\sigma_{b}\)\" and tension \"\(\varepsilon_{bt}-\sigma_{bt}\)\". Figure 15 shows diagrams of compression \"\(\varepsilon_{b}-\sigma_{b}\)\" and tension \"\(\varepsilon_{bt}-\sigma_{bt}\)\" for concrete of the control composition and for fiber-reinforced concrete with the best strength and deformation characteristics. As a result of the study of the deformations of the control concrete compositions, the following was established: based on the obtained deformation diagrams, the peak of the diagram with displacement up and to the left is present in the deformation diagram of concrete with the volumetric content of steel fiber in the amount of 2% and basalt in the amount of 2%. The rest of the diagrams had a lower peak with a shift to the right.