Study On Characterizing And Controlling Asphalt Pavement Skid Resistance Based On Aggregeate Consensus Propetties In Micro Structure Scale

Asphalt pavement performance is important for transportation,and the skid resistance is taken for granted as one of keys to guarantee the traffic security.The frictional characteristics of asphalt pavements is significantly determined by the mineralogical and morphological properties.However,the high-quality aggregates,being as one sort of non-renewable resources,are going to be faced with resources crisis because the huge amount of aggregates are demanded and exploited every year.Hence,the optimization and efficient application of aggregates are important for national infrastructure construction and modern transportation sustainable development.Seven types of grain particles from different area are collected in this paper because of their distinctive mineralogical properties.The shape properties of aggregates such as grain size,shape,texture and angularity are measured and analyzed based on the same way particles crushed(impact crushing).Four types among those particles are chosen for further research,the change in their morphological characteristics are studied by modified Los Angeles Abrasion Test,and the aggregate shape information are measured and calculated with the aid of Aggregate Image Measurement System(AIMS).The X-ray diffraction analyses are conducted to study the effect of particle mineral properties on their abrasion behavior.It can be learned from the result that the abrasion resistance of granite and volcanic tuff aggregates are both better than that of limestone,though the Abrasion Loss Ratio of Coarse Aggregate(ALRCA)value of granite is 18% higher than that of volcanic tuff.And it can also be known that the chlorite,being as the main content,makes volcanic tuff have a better abrasion resistance than limestone,and chlorite is also the reason which makes volcanic tuff green.It should be emphasized that the contents makes aggregates have a better abrasion resistance when their Moh's hardness is higher than 6.0 according to the test results.It can be known from the results that there are two possibilities for abrasion behavior's effect on aggregates: to make their shape more similar to sphere but with a tougher surface(such as limestone);or to make no effects on their shape but a smoother surface(such as volcanic tuff).On addition,this paper aims to study the effect of aggregate quality on asphalt mixture performance.The aggregates under different abrasion times are applied to form the asphalt mixture samples.The skid resistance of theses sample are then measured by traditional tests and some modern ways including 3D laser test and non-contact imaging test by Coarse Aggregate Exposure Ratio(CAER)value.The optimum testing structure is recommended in this paper,and also define the testing orientation of the laser.It can be known from the results that size 9.5mm and size 13.2mm are two vital types of coarse aggregate as the aspect of skid resistance in AC-16 gradation.And aggregate sized 16 mm can hardly affect the skid resistance of the sample.