Experimental Study On Vacuum Compaction Of Asphalt Pavement

In the rapid development of highway traffic construction, the key problems and technical difficulties of highway construction and development need to be solved to improve the pavement performance, avoid the early local damage and extend the service life of pavement. Thinking about the deficiencies of the prior method of compacting, this paper puts forward a new compaction method namely vacuum compaction.The experimental prototype is initially design and processed. Taking a conventional asphalt mixture for the study, the volume parameters of asphalt mixture and the mechanical properties of asphalt mixture are determined through test. This paper also carries on the preliminary exploration to prove the superriority of the vacuum compaction in the application of asphalt mixture compacting process.Firstly, this paper analyses the influence of the vacuum compaction on asphalt mixture, based on the mechanism of the vacuum compaction and the theory composition structure of asphalt mixture. Secondly, to evaluate the advantage of the vacuum compaction technology in the process of asphalt mixture compacted, the macroscopic evaluation index is given to measure vacuum compaction quality, for example porosity,stability and cleavage strength and other indicators. At last, The vacumm compaction specimen and conventional compaction specimen are distinguishedby using porosity, marshall stability and cleavage strength as the standard. To evaluate application advantages of vacuum compaction technology used in asphalt pavement compacting process,this paper has studied and constrasted the relate parameters of asphalt mixture in vacuum compaction condition and theother conventional compaction condition(non vacuum compaction) based on the test.The research results indicate that vacuum compaction technology has a significant impact on the volume parameter and the mechanical properties of asphalt mixture. Through the asphalt mixture relevant test, the macro-mechanical behaviors of contrast samples are compared and evalulated. Firstly, vacuum has positive effect to reduce the void fraction, especially it’s obvious in the early stage, in final pressure, void fraction in static+vacuum condition is decreased by 4.53% than in static condition; porosity in vibration condition with vacuum is decreased by 5% than in vibration condition, secondly, in the aspect of mechanical properties, splitting strength in static condition with vacuum is increased by 5.7% than in static condition; splitting strength in vibration condition with vacuum is also improved by 9.8%;marshall modulus in static condition with vacuum is increased by 6.32% than in static condition;marshall modulus in vibration condition with vacuum is also improve by 8.26%.