## 4 Discussion
### Short Beams
In order to carry out the analysis, the model in Figure 7 was selected, which is composed of two inclined concrete rods and a steel (BRF beams) or mixed steel and concrete (BHR and BHM beams) strap. Table 9 shows the results obtained from the analysis carried out. The second column shows the average value of the breaking load in the beams tested as obtained through experiments (\(P_{max}\)). The third column shows the mechanical capacity of the fabrics (\(U_{f}\)). This was obtained by multiplying the force that the fabric is capable of developing per unit of length (Table 3) by the length of fabric being used as a strap, which was taken to be 200 mm for the underside of the beam (100 mm) and 50 mm for each side. The fourth column shows the mechanical capacity of the beams under tensile stress (\(U_{th}\)), obtained as the sum of the mechanical capacities of the frame and of the HR or HM fiber. For the mechanical capacity of the frame, the data associated with the working capacity in elastic state were used: 23.8 kN or 35.6 kN at fracture. In the rows related to \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Beam** & \(P_{max}\) **(kN)** & \(U_{f}\) **(kN)** & \(U_{th}\) **(kN)** & \(P_{th}\) **(kN)** & \(U^{\prime}_{th}\) **(kN)** & \(P^{\prime}_{th}\) **(kN)** \\ \hline BRF & 46.0 & 0 & 23.8/35.6 & 36.6/54.8 & 29.9 & 46.0 \\ BHR & 114.0 & 160.4 & 184.2/196.0 & 283.2/301.3 & 190.3 & 292.6 \\ BHM & 110.8 & 145.6 & 169.4/181.2 & 261.0/279.3 & 175.5 & 270.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Results of analysis via the rods and straps method. Figure 7: Rods and straps model used for the analysis. the beams reinforced with fibers, the mechanical capacity values obtained are indicated as the sum of the capacity of the steel in elastic state plus the fiber and the sum of the capacity in elastic state plus the fiber. The fifth column sets out the theoretical maximum test load (\(P_{th}\)) obtained by using the mechanical capacities from the previous table. Once again, two values are provided, based on the mechanical capacity of the steel considered. The sixth column details the average mechanical capacities for each type of beam when the value of 29.9 kN (\(U^{\prime}_{th}\)) was used as the mechanical capacity of the steel. This value was calculated analytically using the rods and straps model and using the value obtained through experiments as the breaking load. The value of 29.9 kN exceeds the mechanical capacity of steel in elastic state but does not reach the capacity upon fracture, which indicates that the steel has plastified when the beam fractures. The mechanical capacities of the reinforced beams under tensile stress were obtained using this value. The values contained in the last column refer to the theoretical maximum test load obtained when the mechanical value of the steel that was really deployed was used in the calculations (\(P^{\prime}_{th}\)). This value was obtained in the model using the real load obtained in the test. It can be seen how both the values for \(P_{th}\), using the theoretical mechanical capacity of frames and fibers, and the values for \(P^{\prime}_{th}\), using the mechanical capacity developed by the frame plus the theoretical mechanical capacities for the fibers, are very similar, since the load capacity for both types of fabric is also very similar. Furthermore, both values are much higher than the test loads, practically tripling them, which indicates that the performance capacity of these fabrics is very low in terms of heavy-duty performance. The difference between the maximum experiment load values reached by the reinforced beams (\(P_{max}\) BH) and by the unreinforced beams (\(P_{max}\) BR) provides an estimate of the value of the test load withstood by the fiber fabrics (\(P_{f}\)).