Comparative Research Of Material And Structure Performance Of Crumb Rubber Asphalt Pavement In Russia And China

In Russian Federation and People's Republic of China,use of waste tire rubber in road construction asphalt mixtures has been gaining more and more attention from researchers in the field of transportation engineering due to the associated economic,technical,and environmental benefits.Existing research shows that the addition of shredded waste tire rubber to asphalt can effectively increase asphalt pavement resistance to high temperature rutting,fatigue cracking and low temperature cracking.Properly constructed rubber asphalt pavement also has better long-term performance than traditional asphalt pavement.However,in Russia,due to the outdated standards and documents,implementation of the modern technologies like crumb rubber modified asphalt is going slower than in the other countries despite the amount of studies conducted in the last decade.Thus,to implement Russian scientific and technical achievements related to the crumb rubber modified asphalt pavements,it is first necessary to compare the most advanced rubber asphalt application practices in the modern world,analyze the pavement desig n and quality assurance methods,establish asphalt mix performance prediction methods,and juxtapose the results against the current progress of Russian resear ch.Based on this,this paper comprehensively carries out a comparative study of the mechanical response of rubber modified asphalt,asphalt mixture and pavement between China and Russia.First of all,a comparative analysis was conducted on the current ap plication specifications of rubber powder modified asphalt and asphalt mixture in China and Russia.The technical specifications and particle size distribution of rubber powder in the specification,rubber modified asphalt,aggregate technical requirements,raw material requirements and design methods of rubber asphalt SMA are fully compared.The results show that the particle size of rubber powder in the Russian specification is finer.The gradation difference of rubber modified asphalt SMA between the two countries is small,but the performance control index of the mixture is quite different.Secondly,combined with laboratory tests and data collection,the performance of rubber powder modified asphalt was compared and analyzed.It was seen that Russian and Chinese researches reached similar conclusions about most effective rubber asphalt modification conditions such as temperature and time,SBS and crumb rubber modifier contents.Test result analysis showed that all binders exceed the requirements before and after short-term aging.Per the test results,it was noted that Chinese rubber binder outperforms all the other binders in high-temperature properties with the rest of the binders including Russian rubber performing equally well with little deviation between the corresponding results.Then,a comparative test and analysis were carried out on the pe rformance of crumb rubber modified asphalt mixture.Research analysis again showed similar conclusions about the optimal modifier content and low/high temperat ure qualities of the modified mix which proved the general validity of both Russian and Chinese approaches.Lab test results comply with both standard requirements and analyzed research with SBS and Chinese Rubber having almost identical stability results.Russian rubber had lower stability and performed worse than Chinese rubber but still showed decent results.Finally,using finite element technology,a theoretical comparison analysis of the structural mechanical response of rubber modified asphalt paveme nt in China and Russia was conducted.Comparison results were validated computationally and referentially.Analysis results showed that three modified Chinese SMA mixes were significantly better performance-wise than the Russian rubber SMA.In terms of deformation,Russian rubber SMA performs about 30% worse than the other mixes.Therefore,the conclusion was made that while Russian rubber is a decent option performance-wise and economically,more importance should be paid in Russia to the modern approaches of predicting pavement performance like finite-element method and related modern parameters like dynamic modulus to get the maximum performance from the mix.