## 3 Results
### Conformation of Bituminous Mixtures and Tests
The bitumen emulsion and residual bitumen percentages are shown in Table 9.  
Once the optimum bitumen emulsion percentages were defined for each family of bituminous mixtures, several test samples of each family were manufactured with the grading defined in Figure 1 and the percentage of binder determined in Table 9. These Marshall type test samples were manufactured and cured according to the procedure described in the methodology. The test samples from each family were physically and mechanically characterized, showing the results for the tests detailed in the methodology shown in Table 10.  
As can be seen, the density of the bituminous mixtures conformed with ohmic filler (AOFO) is higher than that of the other bituminous mixtures, but very similar to the bituminous mixtures conformed with limestone filler (AOFC). This is due to the fact that the density of the ophite filler is higher than that of the other aggregates and that the percentage of filler in the mixture is very small, so that the mixture with limestone filler obtains similar results. In turn, the bituminous mixture conformed with biomass bottom \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Test** & **Standard** & **AOFC** & **AOFO** & **AOFA** \\ \hline Bitumen emulsion, \% & - & 7 & 7 & 8.5 \\ Bitumen, \% & - & 4.2 & 4.2 & 5.1 \\ Maximum density, kg/m\({}^{3}\) & UNE-EN 12697-5 [54] & 2640 \(\pm\) 65 & 2641 \(\pm\) 65 & 2625 \(\pm\) 62 \\ Bulk density, kg/m\({}^{3}\) & UNE-EN 12697-6 [55] & 2461 \(\pm\) 88 & 2460 \(\pm\) 87 & 2453 \(\pm\) 87 \\ Void content, \% & UNE-EN 12697-8 [56] & 6.77 \(\pm\) 0.25 & 6.87 \(\pm\) 0.24 & 6.57 \(\pm\) 0.23 \\ Particle loss, \% & UNE-EN 12697-7 [57] & 83 \(\pm\) 3 & 89 \(\pm\) 3 & 93 \(\pm\) 4 \\ Particle loss with immersion, \% & NLT-362/92 [58] & 76 \(\pm\) 2 & 80 \(\pm\) 3 & 86 \(\pm\) 3 \\ Marshall Resistance, N & UNE-EN 12697-34 [59] & 7671 \(\pm\) 274 & 8598 \(\pm\) 280 & 10,325 \(\pm\) 368 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Physical and mechanical tests of the different families of specimens made with the three fillers, AOFC, AOFO, and AOFA. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Family** & **\% Emulsion on Aggregate** & **\% Bitumen on Aggregate** \\ \hline AOFC & 7 & 4.2 \\ AOFO & 7 & 4.2 \\ AOFA & 8.5 & 5.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Optimum percentage of emulsion and residual bitumen for AOFC, AOFO, and AOFA bituminous mixes. Figure 7: Coating test of bituminous mixtures conformed with ophite coarse and fine aggregate and ophite filler AOFC. (**a**) 6.5% residual bitumen, (**b**) 7% residual bitumen, (**c**) 7.5% residual bitumen. ash filler (AOFA) has a lower maximum density than the other two types of mixtures, due to the lower density of the ashes and the higher percentage of binder. The bulk density of the bituminous mixtures is the density taking into account the air voids in the mixture. In this case, the three bituminous mixtures obtain very similar results, highlighting the lower density of the mixture conformed with biomass bottom ash (AOFA). This density reflects that the compatibility of the bituminous mixtures is similar, so it will directly influence the voids content of the bituminous mixture. Consequently, the void content of the three families of bituminous mixtures is similar, since the variations in the results obtained are minimal. This fact reflects that the incorporation of a higher percentage of emulsion in the mixture with biomass bottom ash filler (AOFA), as well as its lower density, does not negatively influence the production of a more closed bituminous mixture. Therefore, it can be stated that with these conditions, the AOFA bituminous mixture manages to obtain physical properties similar to traditional bituminous mixtures, since the void content is the most important physical property to be taken into account. This fact derives from the fact that the percentage of voids in the mix influences drainage, pavement friction, and even noise absorption.