Multi-Scale Asphalt Pavement Drilling Hole Backfill Experiment And Modeling Analysis

In highway engineering,drilling hole on the asphalt pavement is a very important test method in highway engineering.However,after drilling hole,it needs to be backfilled to restore the integrity of pavement structure.If improper backfill method is used,such as improper mixing proportion,improper compaction method,etc...Drilling hole point on the asphalt pavement will exist pavement distress such as water damage,cracking and potholes,etc.according to field detection methods of subgrade and pavement for highway engineering.Same asphalt mixture should be used to backfill the drilling hole.But there exists two problems:(1)drilling hole damages the original gradation,at the same time,the aggregate gradation of the specimen is different from the overall pavement mixture;(2)choose the original aggregate gradation to backfill may be very hard to compact and cause damage to the pavement structure.Based on the above problems.Laboratory test and calculation analysis are carried out.Two different compaction methods,including static compaction and dynamic compaction are compared by modelling simulation.Three-dimensional scanners are used to restructure different mineral aggregate.Additionally,as for the original aggregate gradation,in order to get target compactness,it may cause damage to the surrounding boundary,so two different software PFC3 D and FLAC3 D are used to modelling the compaction process.Moreover,five different gradations are chosen to be compared by compaction characteristics and deformation characteristics.For each aggregate gradation,the optimum moisture content,asphalt content,and cement content is determined by experiment.At the same time,proper compaction time and height are chosen by experiment.Strength value and resilience modulus value are obtained by experiment,additionally,a new compaction equipment is developed to achieve the target compactness.