Experimental Study On Vacuum Compaction Of Asphalt Mixture

Compaction is an important part of the construction of asphalt pavement,and the performance of compaction method and equipment directly affect the compaction efficie nc y and the quality of asphalt pavement.Thinking about the deficiencies of the prior method of compacting,for the study of asphalt mixture vacuum compaction properties,the multifunctio na l asphalt mixture vacuum loading test bench is designed and processed.Taking a conventio na l asphalt mixture for the study,the contrast experiments of different vacuum degree under different loading modes were carried out.Firstly,this paper introduces the composition structure and strength theory of asphalt mixture,and analyzes the influence of vacuum compaction on the compaction characterist ics of asphalt mixture.Secondly,through the bench test,it analysis of the characteristics of the vacuum compaction from two aspects of compaction process and macro mechanical properties after comparative.finally,through the three different loading methods of static load test,vibration and shock,and the contrast test of different vacuum combination,the conventio na l compaction method and compaction were contrasted.The test results show that vacuum compaction has remarkable influence on the compacting process and macro mechanical properties of asphalt mixture.Under the same test conditio ns,the single rebound and cumulative rebound of asphalt mixture decrease with the increase of vacuum degree,and the cumulative settlement increases with the increase of vacuum degree.Under the same test conditions,the void content decreases with the increase of vacuum degreee,and the mechanical parameters such as Marshall stability,splitting strength and compressive strength all increase with the increase of vacuum degree.Under the same loading methods,compared with non vacuum,the void content of-0.08 MPa decreases by more than 8.5%,and the Marshall stability,splitting strength and compressive strength increase by 3.79%,4.55% and 9.23%,respectively.It is proved that vacuum compaction not only has obvious compaction advantages,but also has universal applicability to different loading methods.