Determining method of optimal asphalt dosage of porous asphalt mixture

Abstract

The invention relates to a determining method of an optimal asphalt dosage of a porous asphalt mixture. The determining method comprises the following steps: (1) determining a predicted asphalt film thickness according to the relationship between 175 DEG C power viscosity of an asphalt binder and an asphalt film thickness; (2) determining a predicted asphalt dosage according to a specific surface area computational formula of mineral aggregate and the predicted asphalt film thickness; (3) with the predicted asphalt dosage as a median and 0.3% or 0.5% as an interval change, forming five groups of asphalt dosages, performing a schellenberg asphalt leakage test and a cantabro dispersion test, and determining the optimal asphalt dosage range with the inflection points of the two curves as boundary; (4) forming five groups of test specimens through a vibration forming method to measure the connected voidage, and then, performing a uniaxial penetration test and an unconfined compressive strength test under a test temperature condition of 60 DEG C, and calculating a cohesive force C, wherein the asphalt dosage corresponding to the peak value of the cohesive force C is used as the optimal asphalt dosage; and (5) verifying the pavement performance. The invention provides a quick, convenient and reliable determining method of optimal asphalt dosage for designing the mixing proportion of porous asphalt mixture.

Description

technical field [0001] The invention relates to asphalt mixture for road engineering, in particular to a method for determining optimal asphalt dosage of drainage asphalt mixture. Background technique [0002] The optimal amount of asphalt for drainage asphalt mixture is mainly determined by the results of Schellenberg asphalt leakage test and Kentucky flying test. Usually, the amount of asphalt that the asphalt mixture determined by the Schellenberg asphalt leakage test will not produce flowing asphalt is taken as the upper limit, and the amount of asphalt used when the asphalt mixture is not loose, falling off, and scattered after the asphalt mixture is tested by the Kentburg flying test is the lower limit. . [0003] There are two defects in such a design method: one is that this type of method is an empirical method, and the arbitrariness of different people's determination is relatively large, and it has a lot to do with personal practical experience; the other is that...

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Problems solved by technology

[0003] There are two defects in such a design method: one is that this type of method is an empirical method, and the arbitrariness of different people's determination is relatively large, and it has a lot to do with personal practical experience; the other is that the leak test method has a beaker method , enamel pot method and basket method, the test results of the three are quite different, and the determination of the upper limit critical value is also relative, so how to reasonably determine the optimal amount of asphalt needs further research

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