# Enhanced Performance of Concrete Dispersedly Reinforced with Sisal Fibers
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{
\begin{tabular}{c} **Concrete** \\ **Characteristics** \\ \end{tabular} } & \multicolumn{3}{c}{**Change in \% (\(\Delta\)) with the Content of Dispersed Reinforcement with Sisal Fibers, \% of the Mass of Cement**} \\ \cline{2-7}  & **0** & **0.25** & **0.50** & **0.75** & **1.00** & **1.25** & **1.50** \\ \hline \(R_{b,cub}\), MPa & 0 & +5.8 & +10.0 & +14.3 & +21.9 & +8.8 & +0.6 \\ \hline \(R_{b}\), MPa & 0 & +6.0 & +13.0 & +21.1 & +26.9 & +11.6 & +1.7 \\ \hline \(R_{btb}\), MPa & 0 & +10.9 & +14.5 & +21.8 & +32.7 & +18.2 & +5.4 \\ \hline \(R_{bt}\), MPa & 0 & +8.8 & +11.8 & +14.7 & +29.4 & +14.7 & +2.9 \\ \hline \(\varepsilon_{bk}\), mm/m \(\times\) 10\({}^{-3}\) & 0 & +5.8 & +10.1 & +19.3 & +24.6 & +16.9 & +4.8 \\ \hline \(\varepsilon_{bk}\), mm/m \(\times\) 10\({}^{-4}\) & 0 & +9.6 & +24.8 & +32.0 & +42.4 & +21.6 & +2.4 \\ \hline \(E_{b}\) = \(E_{bt}\), GPa & 0 & +2.7 & +7.9 & +11.9 & +14.9 & +7.0 & +0.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Influence of the percentage of reinforcement with sisal fibers on the strength and deformation characteristics of samples from normal weight concrete. Figure 11: Results of experimental studies of the modulus of elasticity \(E\) of concrete samples in the form of prisms with various percentages of reinforcement with sisal fibers. An analysis of the results of experimental studies of the strength characteristics of samples with dispersed reinforcement with sisal fibers, as well as an analysis of graphical dependencies and data on the effect of the percentage of fiber reinforcement on concrete characteristics (Figures 5-8 and Table 4), show that dispersed fiber reinforcement with sisal fiber has a significant effect on the strength characteristics of concrete. It has been established that the optimal fiber content is 1% by weight of cement. Such a percentage of fiber reinforcement allows achieving maximum strength characteristics of fiber-reinforced concrete. The value of the compressive strength in this case was 59.5 MPa, the axial compressive strength was 43.9 MPa, the tensile strength in bending was 7.3 MPa and the axial tensile strength was 4.4 MPa. It is noted that fiber reinforcement with sisal fibers increases the strength characteristics of concrete even at lower percentages of reinforcement (0.25%, 0.5% and 0.75%); however, compositions with a fiber reinforcement percentage of more than 1.25% showed a decrease in strength indicators up to values close to those of ordinary concrete. Dispersed reinforcement with sisal fibers with a dosage of 0.25% to 1.5% provides an increase in the deformation characteristics of concrete. The highest values of ultimate strains under axial compression and tension were observed in concretes reinforced with sisal fiber in an amount of 1% of the mass of cement, and their values are 2.58 mm/m \(\times\) 10\({}^{-3}\) and 1.78 mm/m \(\times\) 10\({}^{-4}\). In general, the trend of change in deformation properties is similar to the nature of change in strength characteristics. The maximum value of the modulus of elasticity of concrete, 37.8 GPa, was observed for samples reinforced with 1% fiber. The stress-strain curves constructed based on the results of experimental studies under compression \"\(\varepsilon_  
Analyzing the obtained deformation curves of concrete with dispersed fiber reinforcement with sisal fibers, it can be concluded that dispersed reinforcement with sisal fibers significantly affects the concrete deformation curves. The peak of the stress-strain curves of concretes with a fiber reinforcement content of 0.25-1.25% by weight of cement shifts up and to the right relative to the diagram of ordinary concrete, and the peak of the deformation curve of concretes with a content of sisal fibers of 1.5% approximately coincides with the peak of the diagram of ordinary concrete, being only slightly above and to the right.