| Biomass energy is a kind of renewable energy,and most of the current research uses biomass energy to prepare bio-asphalt Applying bio-asphalt in road engineering can effectively resolve its shortage of petroleum asphalt and enhance its environmental friendliness and sustainability.However,the poor high-temperature stability with added bio-oil is a crucial obstacle restricting its broad utilization.In order to improve the applicability of bio-asphalt in road engineering,this research uses a composite modification technology using biological solid waste as raw materials to explore the possibility of widespread application of bio-asphalt in road engineering.Firstly,the performance optimization plan of rock asphalt modified bio-asphalt was determined based on the central combination design.The content of bio-oil,the rock asphalt,and the shearing time were factors influencing factors.Combined with China’s national conditions and Superpave evaluation system,the penetration,softening point stiffness modulus,and creep rate in-18℃,as well as the non-recoverable creep compliance under 0.1 kPa and 3.2kPa stress levels were determined to use as the evaluation index.The optimal bio-oil content,rock asphalt content and shear time were determined by establishing a response surface model.The neat asphalt,bio-asphalt,rock asphalt modified asphalt,and rock asphalt modified bioasphalt were prepared under the optimal factors.Then,the performance differences of the four asphalts were compared and analyzed.Secondly,aiming at whether rock asphalt modified bio-asphalt can be widely used in road engineering,this research further studied the performance of rock asphalt modified bio-asphalt mixture.The high-temperature stability,low-temperature crack resistance,and water stability performance tests of asphalt mixtures were carried out The differences in road performance of four asphalt mixtures were compared and analyzed.Then,the indirect tensile test under stress control is selected to evaluate the asphalt mixture’s strength fatigue performance.The indirect tensile strength test under different temperature and different stress levels were conducted.The indirect tensile failure strength prediction models of four asphalt mixtures were established using linear fitting and Sigmoidal fitting.The fitting effects of the two functions were compared and analyzed,and the strength characteristics of the four asphalt mixtures were compared and analyzed using the master curve theory.Through the indirect tensile fatigue test the fatigue characteristics of the four asphalt mixtures were compared and analyzed,and the relationship between the fatigue life of the asphalt mixture and the stress level or stress ratio was revealed.In summary,this study optimized the performance of rock asphalt modified bio-asphalt through theoretical analysis,model establishment,and experimental testing.The feasibility of applying bio-asphalt in road engineering was comprehensively evaluated regarding road performance,strength,and fatigue performance.It solves the scientific problem of poor hightemperature performance of bio-asphalt and provides an effective method for applying bioasphalt in road engineering. |
