热塑性和热固性聚氨酯改性沥青混合料路用性能研究OA

Polyurethane(PU)modified asphalt is demonstrated as a promising material for highway and steel bridge deck pavement layers.Different formulations of thermoplastic and thermosetting PU modified asphalt were prepared,and the optimal formulation was selected.The road performance was further evaluated to deter-mine advantages and disadvantages compared with commonly used engineering mixtures.Results indicate that PU modified asphalt mixtures exhibit better flexibility and low-temperature cracking resistance than conven-tional mixtures.Thermosetting PU modified asphalt mixtures show the best rutting resistance,with dynamic stability values all exceeding 10 000 passes/mm.The high-temperature performance of thermoplastic PU modi-fied asphalt mixtures approaches that of SBS modified asphalt.Both thermoplastic and thermosetting PU modi-fied asphalt mixtures demonstrate significant low-temperature damage resistance.Flexural-tensile strength in-creases by 26.7％and 40.8％respectively compared with base asphalt mixtures.The low-temperature beam flexural tensile strain increased by 72％and 77％,respectively,compared with that of the base asphalt mix-ture.Overall performance differs substantially between the two mixture types.This difference is closely re-lated to the mass fraction and properties of the modified asphalt.The result demonstrates that binder perfor-mance requires adjustment according to different road environmental conditions.