Research On Central Plant Hot Recycling Technology Based On RAP Pretreatment

As the rush period of expressway construction is over, the performance ofpavement constructed in late1980s and early1990s in our country has been graduallydecreasing, and breakages and diseases in various degrees have arisen. Therefore, it isreasonable to refer that asphalt pavements in our road network are facing with overalland intermediate maintenance, and maintenance and protecting have become the majorproblem in the next rush period for highway industry. In those processes, numeroususeless asphalt mixtures inevitably come into being. Plant mix hot recycling techniquescan recycle the useless asphalt mixtures. It has important social consequences,economic benefits and environmental environmental, not only exerting benefits onresources economization but environmental protection.Adopting coefficient of variation as evaluating indicator, through analyzing thevariability of each properties of asphalt mixtures in RAP(Reclaimed Asphalt Pavement)material storage pile, such as humidity content, asphalt content, penetration degree,ductility and aggregate grading, this paper firstly analyzes the RAP of Chongqing YHcorporation. It shows that there are great variability in each properties of RAP. Toaddress the issue, based on analysis of technics and methods of RAP pretreatment, thispaper evolves a set of technics and methods for RAP pretreatment plant mixhot-recycling techniques. Then aged-asphalt regeneration techniques for RAP are alsoanalyzed and standard mixture synthetic-method based on gray relating grade.Meanwhile our group think that the mixing plant for successive double drum RAPproduced by ASTEC, which has added new aggregate pre-screening system, is fit forour project.Finally, taking AC-16Ⅰasphalt mixture as an example, we design amixture-proportion for RAP, analyze the production theory of ASTEC successivedouble-drum RAP mixing plant and sum up that in practice production, the quality andheating temperature for drying of primary recycled cold materials, adding order and time of materials, temperature of RAP and outloading are important controlling pointsin the quality.