This study investigated the effects of polymer modified bitumen emulsion production methods on the microstructural properties of modified binders and the mechanical properties of cold recycled mixtures with a more emphasis on durability. Modified bitumen emulsions containing styrene butadiene rubber (SBR) produced using three methods, including soap pre-batching, post-blending and co-milling. Surface free energy (SFE) and atomic force microscopy (AFM) tests have been used to inquire into the fundamental and microstructure properties of samples. Indirect tensile strength and dynamic modulus tests were used to investigate the mechanical properties of cold recycled mixtures. Mechanical properties of mixtures were investigated in dry state, after saturation and placement in the freeze-thaw (F-T) cycles with and without deicing agents including calcium magnesium acetate (CMA) and calcium chloride (CaCl₂). Accordingly, the soap pre-batching method had the most suitable performance in terms of dynamic modulus at high temperatures and superior durability under F-T cycles. The samples made by soap pre-batching method showed the lowest surface roughness, maximum adhesion and the highest cohesive energy and surface free energy based on the results of AFM and SFE tests, which were effective in improving the mixture performance. Overall, the post-blending and co-milling methods can be rated as the second and third ranks in terms of both mechanical and nano-mechanical properties, respectively. Finally, in comparison with CaCl₂, CMA salt significantly reduced the destructive effects of F-T cycles on the mechanical properties of recycled mixture.

本研究调查了聚合物改性沥青乳液生产方法对改性粘合剂的微观结构特性和冷再生混合物机械性能的影响，更强调耐久性。使用三种方法生产的含有丁苯橡胶 (SBR) 的改性沥青乳液，包括皂类预配料、后共混和共磨。表面自由能 (SFE) 和原子力显微镜 (AFM) 测试已被用于研究样品的基本和微观结构特性。间接拉伸强度和动态模量测试用于研究冷再生混合物的机械性能。在干燥状态下研究混合物的机械性能，₂）。因此，皂预配料方法在高温动态模量和FT循环下的优异耐久性方面具有最合适的性能。根据AFM和SFE测试结果，皂类预配料法制备的样品表面粗糙度最低，附着力最大，内聚能和表面自由能最高，有效提高了混合物性能。总体而言，后共混和共磨方法在力学和纳米力学性能方面分别位居第二和第三位。最后，与 CaCl ₂相比，CMA 盐显着降低了 FT 循环对回收混合物机械性能的破坏性影响。