## 6 Results and Discussion
### The Impact of the BA Filler on the Results of Putting Resistance  
Table 11 shows the recorded average rut depths of both the sample with 50% bio-ash filler and of the control sample without a bio-ash filler. The results indicate that bio-ash BA improves the asphalt sample's resistance to rutting.  
During the rutting process, after every 2000 passes on the abscissa (x-axis), the depth of rutting in millimeters is recorded on the ordinate (y-axis), and a curve is drawn. Figure 4 shows the rutting curves (mean value of rutting) of the asphalt with BA and the asphalt without BA (the control sample). From Figure 5, it is evident that the rut depth RDair after 10,000 cycles (20,000 passes) is 2.7% higher for the asphalt sample without bio-ash BA as a filler. The asphalt with bio-ash is more resistant to the deformation of wheel tracks (rutting).  
An additional part of the research was conducted in order to confirm the influence of BA filler on rutting. The results were compared with the rutting parameters tested in the same laboratory on eight samples of asphalt concrete (AC 11 surf 50/70) with the classic mineral filler (of carbonate origin). Eight asphalt mixtures were selected according to the bulk density of the compacted asphalt specimen, which is comparable (within reproducibility) to the mixture with bio-ash. These eight samples were made as part of the preparation for the preliminary laboratory work for the mixed formulas of the asphalt mixtures, and they differ from each other in terms of the type of component materials and the composition and physical/mechanical properties of the mixture.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Number of Passes**} & **The Depth of the Rut for Asphal** & **The Depth of the Rut** \\  & **50\% BA** & **for Asphalt 100\%** \\  & **(mm)** & **Mineral Filler** \\ \hline
0 & 0.00 & 0.00 \\ \hline
2000 & 1.00 & 1.04 \\ \hline
4000 & 1.16 & 1.16 \\ \hline
6000 & 1.25 & 1.24 \\ \hline
8000 & 1.30 & 1.30 \\ \hline
10,000 & 1.36 & 1.37 \\  
Figure 5: Impact of asphalt type on rutting depth.  
Table 12 shows the results of the tested parameters for resistance to rutting: an asphalt sample with 50% BA filler and a sample with 100% mineral filler, and the median values of eight samples of the same type of asphalt mixture (AC 11 surf 50/70) with a classic mineral filler without BA.  
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**The Rutting Parameter** & **Asphal Sample 50\% BA** & **Asphal Sample 100\% Mineral Filler (1) & **Asphal Compared 8 Samples without BA** & **Max. Allowed Value [51]** \\ \hline  & (1) & (2) & (3) & \\ \hline Tracking speed WTSair (mm/1000 cycles) & 0.03 & 0.04 & 0.03 & 0.07 \\ \hline Relative (\%) rut depth PRDair at 10,000 cycles & 3.88 & 3.66 & 3.68 & 7.00 \\ \hline Rut depth RDair (mm) after 10,000 cycles & 1.50 & 1.54 & 1.36 & - \\ \hline \hline \end{tabular}  
Figures 6-8 show comparisons of rutting speed (WTSair), relative rutting depth (PRDair), and rutting depth (RDair) of  
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} (1) & an asphalt sample with 50% BA filler; (2) & an asphalt sample with 100% mineral filler; (3) & the median values of eight samples of the same type of asphalt mixture (AC 11 surf 50/70) using a classic mineral filler without BA.  
By using 50% BA filler in an asphalt mixture of type AC 11 surf 50/70, we achieved good resistance to the appearance of ruts.