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Asphalt mixture composed of discrete and continuous rigid adhesive cementation medium composition, typical of multiphase composite materials. From a macro perspective, asphalt non-linear response of external loads, as a solid body with viscoelastroplasticity joint response, but the asphalt cement viscoelastic-plastic body is very sensitive to temperature, so that the composite materials is very complicated. From the microscopic point of view, Asphalt Mixture with fine to coarse aggregate particles as rigid solids, asphalt cement material body, and aggregate volume of asphalt about 90% of the total volume. Between the aggregate particles will produce embedded crowded, friction, therefore aggregates physical and mechanical properties of the components, geometry, and the interactions between them inevitable mixture composed of various sizes on the mechanical properties of the asphalt mixture has a very big impact. In view of this, the paper in the following aspects were studied: one, composed of asphalt aggregate strength analysis. Using AC-20I, SUP-19, AM-20 and SMA-20 sample, the typical structure of the four shear strength of asphalt mixture were compared with experimental studies. Test uses coarse aggregate large direct shear apparatus discussed spherical and ellipsoidal aggregate on shear strength, and to the shear strength of SMA skeleton structure formation mechanism was studied. The results showed that: From the aggregate gradation look, SMA-20 maximum shear strength, AM-20 and SUP-19 shear strength little difference, AC-20I minimum shear strength; see from the shape of aggregates, SMA -20 and SUP-19 on the shear strength graded aggregate particle shape is very sensitive. Skeleton dense structure entirely by the shear strength of coarse aggregate skeleton part of the undertaking, fine aggregate extra padding will weaken the shear strength of the skeleton structure. 2, the aggregate skeleton geometry sensitivity study. Rounded to angular gravel and pebble-like (which is in turn divided into spheres and ellipsoids) for the coarse aggregate, tested aggregate particle shape on the skeleton structure VCA DRC effects. The results confirmed that the angular gravel VCA DRC significantly greater than the rounded shape of pebbles VCA DRC , which went ellipsoid particles VCA DRC greater than spherical particles of VCA DRC ; due to multi-group interaction between the filler aggregates, graded coarse aggregate skeleton clearance rate than a single packet size skeleton gap is small; against VCA DRC size is set to take a major role in the nature of the material itself, such as the studied particle shape, gradation VCA DRC of relatively weaker; purpose of this article experimental conditions, the Rounded shaped pebble VCA DRC With the change of gradation than the angular graded gravel with a significant number of changes to; different particle shapes combination causes the same three graded VCA DRC changes in the relative magnitude relationship. 3, laboratory test method parameter sensitivity analysis. Paper compares the structure of asphalt suspended theoretical maximum relative density vacuum method of calculation methods and the theoretical maximum relative density G mm of variation; analysis and calculation of the various methods and vacuum method G mm on the asphalt mixture VV, VMA, VFA were investigated. While including the United States and our country, including four kinds of asphalt mixture specimen volume parameters calculation method were compared. 4, aggregates for asphalt geometry physical states affected. Three typical for SMA-20 mixture proportions were used Marshall and SGC molding material by mixing volume indicators will be measured and comparative analysis found that in terms of relative rounded pebbles shaped by angular gravel mixture composed of particles has a large VV, VMA, VCA mix , and resistance to deformation mixture and stability are optimum. In the same particle shape, the same compaction work and aggregate ratio in the case, SMA coarse-graded compacted bulk density of the hair specimens largest porosity, voids in mineral aggregate and coarse aggregate minimum clearance rate; SMA fine gradation gross specimens compacted bulk density minimum, porosity, voids in mineral aggregate and coarse aggregate maximum clearance rate; SMA Intermediate with various volume indicators centered.
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