# The Influence of Steel, Glass and Basalt Fibres on Selected Parameters of Construction Mortars
## 3 Results
The addition of steel fibres in an amount of up to 1% increases compressive strength by approx. 33% compared to the material without fibres. The results obtained indicate that, in economic terms, the maximum steel fibre content in terms of compressive strength is 1%. Statistical calculations of compressive strength gain were performed using StatisticaStatSoft 13.00 software for an assumed significance level of \(\alpha\) = 0.05. When comparing measurable variables with a normal distribution and homogeneous variance within groups, the ANOVA test was used, while [PERSON]'s F-test was applied if the variance was not homogeneous. In addition, for dependent variables with a normal distribution, the ANOVA test for repeated measures was used. A detailed assessment of differences between groups was performed using [PERSON]'s post hoc multiple comparisons test. Correlation analysis was calculated using [PERSON]'s correlation coefficient. The calculated analysis (Tables 6 and 7) showed a significantly statistical relationship for the SW, SZ, ST and SB samples after 7 days (\(p\) < 0.001). In addition, there were differences ([PERSON]'s post hoc test) between SW and SZ (\(p\) < 0.001); SW and ST (\(p\) = 0.023); SW and SB (\(p\) = 0.029); SZ and ST (\(p\) = 0.013); and SZ and SB (\(p\) = 0.010) (Table 6). The highest compressive strength was found in the SW mortar (17.37 \(\pm\) 0.90), while the lowest was found in the SZ mortar (14.46 \(\pm\) 0.52). The fcm values for the SW, SZ, ST and SB specimens were the same for experiments conducted after 28 days (\(p\) = 0.149) and after 56 days (\(p\) = 0.370). In summary, the compressive strengths of the above mortars (SW; SZ; ST and SB) tested after 28 and 56 days are not significantly different from each other. There are significant statistical differences between compressive strength for the SW (\(p\) < 0.001); SZ (\(p\) < 0.001); ST (\(p\) < 0.001); and SB (\(p\) < 0.001) series after 7, 28 and 56 days (Table 8). \begin{table}
\begin{tabular}{c c c c c c} \hline  & **SW** & **SZ** & **ST** & **SB** & **Analysis of Variance** \\ \hline  & \(\bar{x}\pm\mathbf{s}\) & \(\bar{x}\pm\mathbf{s}\) & \(\bar{x}\pm\mathbf{s}\) & \(\bar{x}\pm\mathbf{s}\) & F & \(p\) \\ \hline
7 days & 17.37 \(\pm\) 0.90 & 14.46 \(\pm\) 0.52 & 15.97 \(\pm\) 0.82 & 16.03 \(\pm\) 0.76 & 14.65 & \textless{}0.001 \\
28 days & 37.23 \(\pm\) 1.68 & 35.93 \(\pm\) 1.46 & 35.81 \(\pm\) 1.76 & 37.49 \(\pm\) 1.05 & 1.98 & 0.149 \\
56 days & 41.36 \(\pm\) 3.31 & 41.06 \(\pm\) 2.17 & 39.65 \(\pm\) 1.04 & 39.45 \(\pm\) 1.94 & 1.11 & 0.370 \\ \hline \end{tabular}
\end{table} 
Table 6: Statistical analysis with ANOVA test. \begin{table}
\begin{tabular}{c c c c c} \hline  & **SW** & **SZ** & **ST** & **SB** \\ \hline  & \(\bar{x}\pm\mathbf{s}\) & \(\bar{x}\pm\mathbf{s}\) & \(\bar{x}\pm\mathbf{s}\) & F & \(p\) \\ \hline SW & 17.37 \(\pm\) 0.90 & 37.23 \(\pm\) 1.68 & 41.36 \(\pm\) 3.31 & 151.08 & \textless{}0.001 \\ SZ & 14.46 \(\pm\) 0.52 & 35.93 \(\pm\) 1.46 & 41.06 \(\pm\) 2.17 & 370.25 & \textless{}0.001 \\ ST & 15.97 \(\pm\) 0.82 & 35.81 \(\pm\) 1.76 & 39.65 \(\pm\) 1.04 & 635.83 & \textless{}0.001 \\ SB & 16.03 \(\pm\) 0.76 & 37.49 \(\pm\) 1.05 & 39.45 \(\pm\) 1.94 & 460.73 & \textless{}0.001 \\ \hline \end{tabular}
\end{table} 
Table 8: Statistical analysis with repeated measurements ANOVA test. Using [PERSON]'s test, we obtained differences between the compressive strength for the SW series between 7 and 28 days (\(p<0.001\)); 7 and 56 days (\(p<0.001\)); and 28 and 56 days (\(p=0.046\)). The SZ series' strength varied between 7 and 28 days (\(p<0.001\)); 7 and 56 days (\(p<0.001\)); and 28 and 56 days (\(p=0.002\)). The ST series' strength varied between 7 and 28 days (\(p<0.001\)); 7 and 56 days (\(p<0.001\)); and 28 and 56 days (\(p=0.001\)). The SB fibre type varied between 7 and 28 days (\(p<0.001\)) and 7 and 56 days (\(p<0.001\)).