Research On Performance Of Warm Mix Permeable Asphalt Mixture

Permeable asphalt pavement mostly uses high-viscosity asphalt,which has extremely high viscosity and is very sensitive to temperature.Therefore,the pavement rolling temperature and time of permeable asphalt pavement are more difficult to control.Especially in cold areas and under night construction.Due to the low temperature of the construction environment and the long transportation distance during construction,the temperature of the mixture dropped quickly,which led to a serious increase in mixing and paving.Problems such as high rates will ultimately affect the road performance and longterm performance of the permeable asphalt mixture,which seriously affects the application and development of the permeable asphalt pavement.The purpose of the warm mixing technology is to reduce the mixing and compaction temperature of the asphalt mixture,and at the same time ensure that the warm asphalt mixture has the same performance and construction and ease of use as the hot asphalt mixture,thereby expanding the wide mixing and paving As well as compacting the temperature range,extending the construction season.First,the basic properties of the material composed of permeable asphalt mixture were measured,including high-viscosity asphalt,aggregate,mineral powder and fiber.After that,20% porosity was used as the target volume ratio to design the mix ratio of the permeable asphalt mixture.Most of the materials are in point contact.The 2.36 mm sieve pass rate is the key to controlling the target void ratio.The precipitate test and the scattering test can be used to determine the upper and lower limits of the amount of asphalt.Based on the action mechanism of surface active warm mix,the effect of warm mix on the basic performance of permeable asphalt mixture was studied in asphalt binder and asphalt-mineral powder system.First,based on the conversion of the ratio,combined with the action mechanism of the surface active warm mix,it is proposed to replace the coarse and fine aggregates in the permeable asphalt mixture with mineral powder having the same total particle size to obtain a new set of powder to rubber ratio.Afterwards,the performance of the asphalt binder,the actual powder-to-binder ratio and the converted powder-to-binder ratio were measured separately,including: viscosity-temperature characteristics,shear deformation resistance,high temperature deformation ability and low temperature performance.The results show that the asphalt-mineral powder system is more in line with the overall characteristics of the mixture,and can more accurately characterize the actual effect of the anhydrous surface active warm mix in the mixture.According to the rheological principle,the mechanical properties of warm-mixed high-viscosity asphalt and asphalt rubber were studied.Using temperature scanning,the temperature-sensing properties of warm-mixed high-viscosity asphalt and asphalt mortar were analyzed using complex shear modulus G * and deviation angle θ as indicators.The rutting factor G * / sinθ was used to study the deformation resistance of warm-mixed high-viscosity asphalt and asphalt mortar.The MSDR test gradually introduced the mechanical properties of warm-mixed high-viscosity asphalt and asphalt mortar.The initial loading characteristics of 1s under different stresses are obtained.Afterwards,the repeated creep recovery curve law and the conversion strain value at different dispersions of warm mix were studied.The results show that warm mix can improve the mechanical properties of asphalt,but the overcoming amount should not be too high.The macro performance and benefits of warm-mixed permeable asphalt mixture were studied.Firstly,with VV,VMA and VFA as parameters,the influence of warm mix on the overall structural characteristics of permeable asphalt mixture was analyzed.Secondly,the key to warm-mixed permeable asphalt mixture.Finally,the economic and energy-saving benefits of warm-mixed permeable asphalt mixture were analyzed.The results show that the warm mix enhances the high temperature of the mixture.The performance reduces the water stability and has little effect on anti-scattering properties.The comprehensive benefits of warm-mixed permeable asphalt mixture are better.