Evaluation Of Asphalt Mixture Compaction Workability Based On Shear Compactor

Pavement compaction workability is the index to evaluate the compacted ease or complexity of asphalt mixture,which affects the road use performance in the future directly.There are many deficiencies on the current traditional lab compact methods,and it can't evaluate the quality of road material workability.Generally,compaction workability was evaluated by the viscosity temperature curve of asphalt.However this evaluation method which focus on the asphalt performance appear more and more problems.On the other hand,warm mix asphalt pavement has been widely applied due to favorable compaction workability in a low temperature,whereas it is lack of discrimination and regulation methods in asphalt mixing agent usage,research suggests that we can test asphalt mixing agent usage from the compaction workability distinction of the hot mix asphalt pavement and the warm mix asphalt pavement.On the basis of the questions above,asphalt mixture compaction workability research based on the asphalt prism shear box compactor(PReSBOX)has been carried out in this paper.First,the paper makes a comparison between current traditional lab compact methods and PReSBOX,which analyses their advantages and disadvantages and choose the latter to conduct workability evaluation test.Through the mixture design,eight types of pavement materials are selected.Aiming at different types of pavement materials,the PReSBOX could compact specimen in proper temperature range,which can save the evaluation index of shear stress,porosity and cycle.With the comprehensive analysis of every index,the paper finds a widely applicable evaluation method of asphalt mixture compaction workability,then it tests the performance of pavement materials and analyzes the relationship between compaction workability temperature and performance to back up the reasonability of compaction workability evaluation method.By the correlative research,the following conclusion is drawn in this paper:(1)PReSBOX can avoid the shortage of the conventional compact equipment,it can also record indicators of both mechanics and volume currently and develop more potential application value.(2)The paper get a pervasive workability evaluation indicators and methods through different kinds of asphalt mixture test,and define the Shear stress Rate of change as SRC,the best compaction workability temperature as T,the shear stress of the best compaction workability as S.The compaction temperature of road construction is guided by using the T and the pavement compaction workability is estimated by using the S.(3)workability evaluate methodology can make a distinction of the best compaction workability temperature between hot and warm mix asphalt pavement,and identify if the warm-mixed agent has been adding in turn.It can also distinguish different kind of asphalt mixture,the application value will became more widely.(4)The workability of asphalt mixture has some influences on the road performance,It impacts continuous graded pavement's low temperature property and fatigue performance,and it also affects gap graded pavement's high and low temperature property and fatigue performance.(5)On the basis of PReSBOX the workability is evaluated.The reasonable compaction temperature of adding 0~10? is recommended for the compaction temperature range,and the production and paving of asphalt mixture can be guided in this range.