Estimation method for sequence of voids in mineral aggregate of asphalt mixture

Abstract

The invention relates to an estimation method for the sequence of voids in mineral aggregate of an asphalt mixture. The estimation method comprises the following steps: firstly, based on mineral aggregate without asphalt, establishing physical models of voids in mineral aggregate in a skeleton void form, a skeleton dense form and a suspension dense form, and analyzing a change rule of voids in the mineral aggregate without asphalt; and verifying the sequence predicted by the models according to a result of test on voids in mineral aggregate of a compact asphalt mixture. With the method, the trouble of obtaining voids in mineral aggregate by a Marshall compacting or rotary compaction piece is eliminated, the test workload is reduced greatly, the design efficiency is improved, and feasible theoretical and technical support is provided for grading optimization design of asphalt mixtures.

Description

technical field [0001] The invention belongs to the technical field of asphalt pavement materials, and in particular relates to a method for sorting and estimating the interstitial ratio of asphalt mixture ore during the design process of hot mix asphalt mixture. Background technique [0002] Mineral material gradation design is one of the core contents of hot mix asphalt mixture design, and the rationality of its design is directly related to the road performance of the mixture. At present, the design method at the specification level, whether it is my country's asphalt pavement construction specification or the US Superpave system, the technical index based on the mineral material gradation design is the mineral material void ratio. Since it is impossible to grasp the relationship between the index of the mineral material void ratio and the gradation in advance, and it is also impossible to know the relationship between the size and size of the mineral material gap ratio i...

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Problems solved by technology

[0004] 1. The preliminary gradation curve drawn up artificially is limited by the theoretical and experience level of the designers, so it inevitably has a certain degree of blindness, and the color of experience is strong, so there is a possibility that none of the drawn gradation curves meet the requirements, but it is still possible Unpredictable, which will lead to unnecessary experimental work later

[0005] 2. Marshall compaction or Superpave rotary compaction asphalt mixture production process is relatively cumbersome, the test workload is large, the time required to obtain the mineral gap ratio is long, and the design efficiency is low. Moreover, Superpave’s empirical formula for the conversion of the mineral gap ratio is not yet available. There are inaccuracies, so there is the possibility of incorrect design results

[0006] 3. The lack of the above two aspects may lead to a possible situation that a lot of tests have been done and it took a long time to design a qualified gradation; and even if a qualified gradation is designed, there is no guarantee The result is optimal

[0007] In view of the importance of the aggregate void ratio index in the gradation design and its explanatory effect on the road performance of asphalt mixture, such as high-temperature performance, many literatures have studied many factors that affect its size, and have drawn some useful conclusions , but these conclusions are mostly obtained based on the analysis of mathematical statistics principles, and are often regular cognitions in the average sense. When used to guide gradation design, they may not always be reliable, or even have the opposite effect. Guidance also has obvious limitations

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