| Adhering to the concept of green low carbon cycle development,the application of waste tire rubber powder in China’s road projects is gradually popularized.Scrap tire powder asphalt mixture in high and low temperature performance,fatigue performance and noise reduction and environmental protection has shown great advantages for the environment,resources and sustainable development of the economy is of great significance,has a very good development prospects.However,there are problems such as poor stability and inadequate compatibility of waste mastic modified asphalt,and the design of SMA-13 structural gradation corresponding to waste mastic asphalt needs further study.In this paper,the main properties of the modified asphalt,grade design and verification optimization of the mixture,road performance analysis and test road paving are further investigated and discussed with the activated waste mastic composite modified asphalt(ARPCMA)and its mixture.Test results show that:ARPCMA performance is significantly better than CRMA,and the level of difference with SBS modified asphalt is small.Gradation design and optimization:(1)Through the grade-by-grade filling test of coarse aggregate,the best ratio of particle size of each grade is obtained when the coarse aggregate skeleton strength is most stable and the density is high.(2)According to the orthogonal test results,the influence of different key particle sizes on the volume and performance index of asphalt mixture is obtained through the extreme difference analysis,and five preliminary gradations are formulated by combining the grade-by-stage filling test results of coarse and fine aggregates,orthogonal test results and actual engineering experience.(3)Through VCADRF method,Bere method and fractal theory to test the 5 preliminary gradation and 16 gradation in the orthogonal test,according to the test results,give the recommended range of gradation suitable for rubber powder modified asphalt SMA-13 structure.Road performance:Through orthogonal test,we analyzed the influence of key particle size on asphalt mixture indexes,combined with the grade by grade filling test results and actual engineering experience,we proposed three grades with stable skeleton structure,good strength and compactness,and then selected the best grade from the three grades by traditional Marshall test,based on Marshall test,precipitation and dispersion test as a reference,we determined the best grade in ARPCMA-13,CRMA-13 and SBSMA-13 modified asphalt mixes,the best oil to stone ratio was determined.Through the road performance tests of ARPCMA-13,CRMA-13 and SBSMA-13,the comparative analysis of road performance found that ARPCMA-13 has excellent performance in water stability,rutting resistance,fatigue resistance and low temperature crack resistance.Finally,combined with the actual application of the project,through the test section paving and performance testing,including test road raw materials,proportional design,test road construction and quality testing,the test-results are consistent with the results of the indoor road performance test. |
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