Asfaltın karıştırma ve sıkıştırma sıcaklıklarının farklı viskozite modelleri ile incelenmesi

The determination of mixing and compaction temperatures through the ASTM (equiviscous) method has been defined as the standard method. The implementation of the Equiviscous method for the modified bitumen results in high temperatures, which may not be required during the construction of the asphalt mixtures. This study aims to investigate several alternative methods proposed in the literature named as high shear rate method (HSR), zero shear viscosity method (ZSV), steady shear flow method (SSF), and phase angle method. For this purpose, 50/70 and 160/220 penetration grades bitumen modified with elastomeric type – Styrene Butadiene Styrene (SBS) and Reactive Elastomeric Terpolymer – Elvaloy (RET) have used. The study also aims to measure the applicability of the proposed alternative methods for the warm mix asphalt involving organic and chemical additives. The results have shown that for the polymer modified bitumen, all suggested methods resulted in lower mixing and compaction temperatures compared to the Equiviscous method. While for the warm mix asphalt, the implementation of the SSF method only resulted in lesser temperatures compared to the Equiviscous method. Also, the asphalt mixture mechanical properties such as Marshall Mix design and Indirect Tensile Strength test (ITS) were measured based on the determined mixing and compaction temperatures through different methods. Finally, the economic impacts of the determined production temperatures for several models are evaluated by the estimation of energy consumption in terms of electricity and natural gas costs for the batch type asphalt plants. Besides, the possible environmental effects are estimated considering carbon dioxide emissions.