Research On Skid Resistance Mechanism Of Asphalt Pavement Based On Characteristics Of Aggregate Surface Texture

Skid resistance of asphalt pavement which is directly related to physical propertiesof aggregates itself, the microscopic structure of the road, the macro-structure of theroad, mineral aggregate gradation and construction control. This paper carried out onthe different characteristics of their aggregate surface morphology angularity, profileshapes, etc. Quantifying morphological characteristics of coarse aggregate is studied byIPP digital image processing techniques,two-dimensional and three-dimensionalindicators of aggregate geometry features are proposed, seven key indicators areincluded convex degree (P), the degree of axis (AS), roundness (ROUND),elongation,flatness,sphericity (DS) and the shape factor (SF). evaluating the relationshipbetween the various indicators for different kinds of aggregate of the same size,Comingto a conclusion: roundness and convex degree of basalt aggregate particles are close to1,elongation ranges from1.07to2.31, and the degree of axis ranges from1.09to2.08,slenderness ratio is relatively small, flat and flakiness are smaller,basalt9.5mmaggregate particles can be obtained good rutting performance.In this paper, OGFC design method of asphalt mixture composition design takesexample by Japanese design method, using our "Technical Specifications forConstruction of Highway Asphalt Pavement" recommended mixture ratio designmethod to carry on the design. First of all different types and different sizes of aggregatetechnical indicators are tested, preparation of high viscosity SBS modified asphalt isselected by the Ministry of Transport and scientific research institutes which developroad HVA modifier, modified asphalt is prepared by high shear tester.12.5%isdetermined by the relationship between HVA modifier content and viscosity of the totalmass dosage of SBS modified asphalt.2.36mm sieve key relationships with differentporosity through rate, adjusted by the aggregate gradation. Use Cantabro asphalt testingand analysis Xie Kronenbourg leak testing to determine the optimum asphalt ratio is5.0%.Through performance testing of drainage asphalt mixture in three differentaggregate characteristics composed of Limestone, broken gravel and basalt, Coming toa conclusion: Residual stability of each mix is more than85percent, splitting strengthof the mixture composed of limestone and basalt aggregates is more than the mixturecomposed of crushed gravel about0.1MPa. The asphalt mixture composed of crushedgravel under wheel loads exists maximum displacement when it is60min, dynamicstability is small, its ability to resist deformation is weak, and dynamic stability of basaltasphalt mixture has reached7495times/mm. To study adhesion of the surface energy ofasphalt and aggregate based on theory, water damage theoretical model is established.Test results can be obtained through the surface: under water, the anti-stripping abilitybetween the SBS modified asphalt and limestone is strongest.Using dimension algorithm of the Fractal Theory for Minkowski-Bouligand dimension, using matlab to calculate the apparent morphology fractal dimension,reaching the highest pixel share of basalt feature mixture, the corresponding fractaldimension is the largest, to explain that is the highest complexity of surface topography.With a standard wheel rutting test apparatus testing different load of the condition ofroad simulation test in different temperature20℃and40℃, the British pendulumnumber can be determinate, the anti-sliding performance attenuation rule of differentcharacteristics of aggregate mixture is analyzed, finally the results are studied bymathematical model fitting, obtain the linear attenuation law between wheel load X andBritish pendulum number Y under the condition of20℃,it is the hyperbola attenuationlaw that under the condition of40℃.