Optimization Design of PCB/WCF Modified Asphalt Mixture Based on Response Surface Methodology
In order to improve the water stability of waste tire pyrolysis carbon black(PCB)modified asphalt mixture,by using the wool fiber of waste chicken feather(WCF),which is beneficial to the improvement of water stability of asphalt mixture,PCB/WCF modified asphalt mixture with gradation AC-13 is prepared.First,the microstructure and surface chemical element distribution of PCB and WCF are analyzed by using a laser particle size analyzer,scanning electron microscope and energy dispersive spectrometer.Subsequently,an experimental plan based on the response surface methodology(RSM)is designed to investigate the effects of PCB content,WCF content and asphalt-aggregate ratio on the porosity,Marshall stability and freeze-thaw split tensile strength ratio of asphalt mixture AC-13.Finally,the impact of 3 independent variables and their interactions on the asphalt mixture's porosity,Marshall stability and freeze-thaw split tensile strength ratio is studied by using analysis of variance(ANOVA),and a predictive model for the performance of PCB/WCF modified asphalt mixture AC-13 is established.The result shows that.The particle size distribution of PCB is concentrated in the range of 197-358 nm,and the surface ash content reduces the compatibility between PCB and asphalt.The feathers on both sides of the WCF shaft are distributed fan-shaped with the main chemical elements of carbon,nitrogen,oxygen and sulfur.The optimal parameters obtained from the optimization model for PCB/WCF modified asphalt mixture AC-13 are PCB content of 0.52％,WCF content of 0.36％and asphalt-aggregate ratio of 5.5％.The corresponding predicted values are porosity of 3.85％,Marshall stability of 11.79 kN and freeze-thaw split tensile strength ratio of 84.56％.The validation experiments for AC-13 PCB/WCF modified asphalt mixture prepared based on the optimal parameters result in porosity of 3.69％,Marshall stability of 11.6 kN and freeze-thaw split tensile strength ratio of 84.9％,all within a 95％confidence interval,indicating that the model has good predictive capability.The predicted values and experimental verification values of the optimized design for PCB/WCF modified asphalt mixture AC-13 meet the performance requirements for modified asphalt mixtures in China.
road engineeringexperimental design and optimizationresponse surface methodologyPCB/WCF modified asphalt mixtureperformance prediction model
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