## 5 Conclusions  
1. Cyclic freezing and thawing decreases the relaxing ability of all the considered bitumens (both the neat bitumen and the modified bitumens). For example, the authors observed that after 50 cycles of FT, all binders satisfied the Superpave specification requirement at \(-24\), \(-30\), and \(-36\) degrees by having m-value greater than 0.3. The Elvay polymer modified binder was the only exception as its m-value at \(-30\) and \(-36\) fell below the 0.3 limit.  
2. Stiffness S of all the considered bitumens is essentially increased with the temperature decrease and the increase of FT cycles number. For example, the stiffness of the neat bitumen, the bitumens with polymers Butonal and Titan+SBS has increased after 50 cycles of FT and at the temperature of \(-24\)\({}^{\circ}\)C for 66.4%, 54.9%, and 55.8% respectively, and stiffness increase for the bitumens with polymers Butonal and Kraton at the temperature of \(-36\)\({}^{\circ}\)C was 87.0% and 88.8% respectively. The following binders have been found out as the most resistant to cyclic FT: at the temperature of -24\({}^{\circ}\)C--bitumen with SBS polymer (stiffness increase after 25 and 50 cycles for 3.1% and 15.9% respectively); at the temperature of -30\({}^{\circ}\)C--bitumen with Calprene polymer (19.6% and 27.6% respectively); at the temperature of -36\({}^{\circ}\)C--bitumen with polymers Calprene, SBS, Zydex+ SBS and Titan+SBS (from 14.7% to 34.6%).  
Thus, when selecting a suitable bituminous binder taking into account the climatic conditions it is necessary to consider both FT cycles number and the characteristic low temperature.  
3. Practically all asphalt concretes (both with the use of the neat bitumen and the modified bitumens) at all the considered temperatures after 50 cycles of FT tensile strength is decreased. The strength is decreased by 48% for specific types of asphalt concretes.  
Modification with polymers increases essentially the asphalt concrete strength both in the initial condition and after FT, especially at the considerably low temperatures (\(-20\)\({}^{\circ}\)C, \(-30\)\({}^{\circ}\)C). For example, addition of polymer Elvay increases the strength of the asphalt concrete for 50.6% at the temperature of \(-20\)\({}^{\circ}\)C in the initial condition (before CFT). And the addition of polymer Calprene increases strength of the asphalt concrete for 46.6% at the temperature of -30\({}^{\circ}\)C after 50 cycles of FT.  
4. Cyclic FT decreases essentially the ability of the asphalt concrete with rutting resistance: In the original binder the rut depth increased after 50 cycles almost three times (269.7%) after 10,000 wheel passes. Modification with polymers gives a large positive effect: all types of stone mastic asphalt concretes modified with polymers after 50 cycles of FT have shown the rutting resistance more than the relevant asphalt concretes in the initial condition (before FT).  
[PERSON], [PERSON], [PERSON] and [PERSON] conceived and designed the experiments; [PERSON], [PERSON], [PERSON] and [PERSON] performed the experiments; [PERSON], [PERSON], [PERSON] and [PERSON] analysed the data; [PERSON], [PERSON], [PERSON] and [PERSON] contributed reagents/materials/analysis tools; [PERSON], [PERSON], [PERSON] and [PERSON] wrote the paper.  
Figure 21: Rut depth on the samples of stone mastic asphalt concretes after 10,000 wheel passes.  
**Funding:** This research was funded by the Road Committee of the Ministry for Investments and Development of the Republic of Kazakhstan (Agreement No. 36 dated July 21, 2016).  
**Acknowledgments:** This research is supported by the Road Committee of the Ministry for Investments and Development of the Republic of Kazakhstan (Agreement No. 36 dated July 21, 2016).  
**Conflicts of Interest:** The authors declare no conflict of interest.