## 4 Test Results
### Cluster Analysis
This value is almost twice as high as the minimum criterion set forth in [18]. Such a high stiffness modulus and low sensitivity to loading time have also been observed by other researchers [8]. However, their observations do not confirm excessive cracking in pavements due to high stiffness of incorporated MCAS. Group 3 attained comparable dynamic modulus results to those in Group 1. Their equivalence indicates that this parameter (stiffness modulus) cannot be the only criterion when considering suitability of recyclable MCAS mixes with waste materials. The lowest results were obtained in Group 2 composed of mix specimens with dusts and large proportion of recycled aggregates, probably because of inadequate foamed bitumen-dust amount ratio. Group 2 included the specimens with dolomite and basalt dusts made independently in time, which excludes systematic errors in dosing. The average level of stiffness modulus in Group 2 was EUR = 6866 MPa. Note that this group contained also the specimens with recycled dolomite aggregate (RA) whose quality could have influenced the grouping process [7]. The phase angle (\(\delta\)) results complemented the analysis (Figure 4b). Note that although Group 1 and Group 3 were similar in terms of stiffness, their rheological character \begin{table}
\begin{tabular}{c c c} \hline
**Group 1** & **Group 2** & **Group 3** \\ \hline B/P5/A1.2 & B/P5/A2.4 & B/P5/A3.6 \\ B/P12.5/A1.2 & B/P12.5/A2.4 & B/P12.5/A3.6 \\ B/P20/A1.2 & B/P20/A2.4 & B/P20/A3.6 \\ D/P5/A1.2 & D/P5/A2.4 & D/P5/A3.6 \\ D/P12.5/A1.2 & D/P12.5/A2.4 & D/P12.5/A3.6 \\ D/P20/A1.2 & D/P20/A2.4 & D/P20/A3.6 \\ RAP50/SG50 & RA20/VA80 & RAP60/VA40 \\ RAP40/VA60 & RA80/VA20 & RAP80/VA20 \\ RC80/VA20 & RAP20/VA80 & RC40/VA60 \\  & RAP50/VA50 & \\  & RC20/VA80 & \\  & RC60/VA40 & \\ \hline \end{tabular}
\end{table} 
Table 4: List of recycled mixtures after preliminary classification in clusters (groups). at 40 \({}^{\circ}\)C was different. In Group 3, the phase angle was almost twice that of Group 1. Probably the viscous effect of Group 3 was due to the presence of specimens containing high amounts of bitumen and RAP material used in the composition of recycled MCAS mixtures. As a result, mixtures in Group 3 were different from Group 1 mixes by having an increased reserve of flexibility also at low temperatures. The effect of hydraulic binders, including binder blends, on the rheological character of the recycled mixtures was observed in [41] 4.0. Another group of parameters whose levels were diversified with respect to clusters were the characteristics related to climatic factors (TSR and WRW + 2M) and indirect tensile strength (ITS) at 25 \({}^{\circ}\)C. The grouping results are illustrated in Figure 5.  
The results of moisture resistance for the MCAS recycled mixtures (TSR and WRW+2M) (Figure 5a) were convergent with each other and showed the similarity of the overall results in Group 1 and Group 2. In Group 3, the average TSR value was high, TSR > 90%. This demonstrates the increased  
Figure 4: Grouping of the mixes based on: (**a**) dynamic modulus (E) at 5 \({}^{\circ}\)C; (**b**) phase angle (\(\delta\)) at 40 \({}^{\circ}\)C.  
Figure 5: Grouping by: (**a**) moisture resistance (TSR and WRW+2M); (**b**) indirect tensile strength at 25 \({}^{\circ}\)C (ITS). resistance to moisture-induced damage of the specimens in Group 3. It should be noted that Group 3 comprised the specimens with a large amount of bitumen. As with the ITS (Figure 5b) and TSR results, the highest levels were recorded in Group 3. The large group of MCAS results in Group 3 was within the MCE requirements range. Thus, the recycled mixtures in Group 3 had the highest cohesion and improved moisture resistance. In contrast, Group 2 represented mixtures with an acceptable moisture resistance level but with the lowest average level of the ITS parameter was relative to MCE. Evaluation of the results in Group 2 indicates a likelihood that ITS > 500 kPa and TSR < 50. This may be a sign of low cohesion of some of the mixes in Group 2, as mentioned in [7; 29].