Effect of short-and long-term ageing on the rheological properties of modified binders

Since the bituminous binders obtained from petroleum refineries are insufficient to meet the increasing stresses on highways, additives have been used recently in order to improve the properties of bitumen and thus bituminous hot mixes. For this purpose, the most commonly used additives are styrene-butadienestyrene and styrene-ethylene-butadiene-styrene polymer group materials. In addition, waste rubber obtained from old vehicle tires is another material frequently used for this purpose. Bituminous binders are mixed during preparation and aging occurs during the service life of the mixture. Within the scope of this thesis, styrene – butadiene – styrene (SBS), styrene – ethylene – butadiene – styrene (SEBS) and ground tire (CR) in 3 different ratios (3%, 4% and 5% by bitumen weight) B 160/220 class the effects on the properties of modified bitumen by adding it to the bitumen were investigated. Penetration into püre, modified, short- and long- term aged binders. Viscosity, dynamic shear rheometer (DSR), beam bending rheometer,softening point, rotational viscosity tests were applied. As a result of the studies, the penetration values decreased regularly as the additives. From the results obtained, it was determined that the most effective additive in all three ratios was SEBS, and additive with the least effectiveness in the selected ratios was CR. With the use of aaditives, the softening point values of the binders increased, thus their consistency at high temperatures increased. At both 165 ℃ and 135 ℃, the highest viscosity value is seen in SEBS added binders, while the lowest viscosity values are observed in CR added binders. The most reduction in phase angle values of binders occurs in binders containing 5% SEBS. The least reduction occurred in the pure binder. The additive that reduces the phase angle value the most among the additives is the SEBS additive. Among binders containing additives, binders containing SEBS additive have the highest complex shear modulus value, while binders containing CR additive have the lowest shear modulus value. Keywords: Bitumen, Modification, Styrene-Butadien-Styrene, Styrene-Ethylene-Butadiene-Styrene, Tire Waste