Asphalt Pavement Texture Characterization And Road Performance Study Based On Enveloped Profile

The road skid resistance of asphalt pavement has a direct impact on road traffic safety,which has always been a tough research topic in Road engineering research field,while tire-road rolling resistance is a new challenge in this field.The tire-road interaction characteristics and road surface texture comprehensive characterization are the key points to road skid resistance study and tire-road rolling resistance reduction.With the Complexity of Asphalt pavement surface texture and the limitation of measurement technology,it is very difficult to characterize the Asphalt pavement surface texture.At the meaning time,analysis on tire-road interaction is very hard based on the common tire-road simulation model,which can not consider the properties of both tire and road.So in road skid resistance research,tire-road interaction is seldom considered,and the research on tire-road rolling resistance at home is almost blank.In order to supplement the shortage of current research on pavement texture characterization and road performance,the laser vision measurement technology,statistics and probability theory and multi-scale characterization theory were applied in this dissertation to characterize asphalt pavement surface texture,a multi-dimension characterization parameter system was established.Tire-road contact enveloped profile was calculated according to tire-road contact theory and models.The effects of pavement texture to road skid resistance and tire-road rolling resistance were studied based on the enveloped profile.The laser vision measurment technology was applied to measure the two-dimensional profile?2-D profile?and three-dimensional morphology?3-D surface?of asphalt pavement surface with a high resolution.Statistics and probability method,multi-scale representation theory such as fractal theory and power spectrum analysis method were used to make 2-D and 3-D characterization to the surface texture,a multi-dimension characterization parameter system was established at the same time.Finally,with the field testing,surface texture level with one-third octave band and the piecewise variable fractal dimension parameter were calculated,which verified the asphalt surface texture have spectral characteristic and multi-dimension characteristic.In order to study and quantify tire-road contact characteristics,this dissertation made a deep analysis on tire-road contact mechanism and models,the enveloped profile was used to illustrate the real tire-road contact area,Von Meier model and indentor method were introduced in detail and indentor method was improved.A contrastive analysis was made between original texture profile and enveloped profile based on the texture parameters,such as MPD,L_Maa and L_Me.The enveloped profile provided a new idea for the study on tire-road contact characteristics.In order to predict the road skid resistance according to surface texture,the texture level with one-third octave band was calculated,the characteristic wavelength and level of spectrum was proposed according to the result of correlation between spectral energy variation of texture level and frictional coefficient.The correlation between texture level of characteristic wavelength and frictional coefficient was studied.By using tire-road contact stress empirical model,tire-road contact stress was calculated with the enveloped profile.Statistical analysis was made to study the distribution characteristics of tire-road contact stress and stress distribution characteristic value was proposed.Finally,a model using stress distribution characteristic value as function variable was proposed to predict the frictional coefficient.It is significant to study the effect of surface texture to tire-road rolling resistance.Firstly,this dissertation introduce the influence factors of rolling resistance and the measurement method along with the outdoor measurement equipments,then correlation between texture parameters such as L_Me,L_Maa and MPD and rolling resistance coefficient was studied,finally,the impact of enveloped profile on rolling resistance was studied.