Parameter Analysis And Optimization Of High Pressure Water Jet Cleaning Asphalt Pavement Markings

Since the 18 th National Congress of the Communist Party of China,China’s transportation industry has achieved historic achievements and undergone historical changes,ushering in a landmark leap from a transportation powerhouse to a transportation powerhouse.Domestic asphalt pavement has entered a stage of simultaneous construction and maintenance,and asphalt pavement markings also need to be re-cleaned and adjusted accordingly.In response to the shortcomings of traditional marking methods,such as high operating costs,marking efficiency,and high environmental pollution,high-pressure water jet technology is introduced to remove asphalt pavement markings.In the high-pressure water jet cleaning of asphalt pavement markings,the structure and jet parameters of the nozzle will directly affect the efficiency of asphalt pavement markings cleaning.Studying the process of high-pressure water jet cleaning asphalt pavement markings through a combination of simulation technology and experiments is beneficial for theoretical research on asphalt pavement marking removal,and adjusting different parameters can scientifically and effectively improve removal efficiency.Analyze the mechanism of removing asphalt pavement markings,elaborate on the principle of water jet marking,select an appropriate jet method to remove asphalt pavement markings,and obtain the variation laws of jet outlet velocity,force,and axis velocity.A three-dimensional nozzle model was constructed.Fluent fluid simulation software was used to simulate the jet process of conical and conical straight nozzles and to change structural parameters such as inlet diameter,contraction angle,and aspect ratio.The optimized nozzle type and structure were obtained.A marking particle model was constructed using the JKR contact model in Edem to reflect the bonding force between marking particles.The optimized conical straight nozzle model was simultaneously imported into Fluent and Edem using the CFD-DEM coupling method.The number of bond bond bond breaks between particles was used as the evaluation index for the asphalt pavement marking effect.The effects of jet working parameters such as inlet pressure,target distance,and feed speed on the asphalt pavement marking effect were simulated and analyzed.The simulation shows that as the pressure increases,the de-labeling effect gradually improves and tends to stabilize;As the target distance and feed speed increase,the demarcating effect increases and decreases.A three-factor four-level orthogonal experiment was designed to remove the working parameters of asphalt pavement markings.16 sets of demarcating experiments were completed using a high-pressure water jet CNC machine tool.The photos of the removed asphalt markings were binarized,and the demarcating rates under different working parameters were obtained.The best combination of demarcating parameters was analyzed and compared through range analysis,consistent with the optimal demarcating parameters determined by numerical simulation under single-factor conditions.