Research On Influence Mechanism Of Mixture Moisture Damage By Adhesive Performance Of Aggregate And Asphalt

In recent years,the design and construction technology of asphalt pavement is becoming mature.Because of the short period of construction and comfortable performance of driving,asphalt pavement is now universal and the asphalt pavement structure and pavement material type are increasingly rich.But due to the defect of the key technologies reserve of the road,new pavements damage early,especially the moisture damage of asphalt pavement that is one of the most common damage forms seriously affects the road quality and shorten its service life.Adhesion of aggregate and asphalt is one of the most important influence factors of asphalt mixture moisture damage,this paper studies mainly on the following four aspects: firstly,this paper examines the general adhesion and the reliability of evaluation method of the mixture water stability.Secondly,based on the theory of surface energy,this paper uses the method of drop shape analysis(DSA)under the normal temperature to study the quantitative evaluation method of adhesion of three kinds of aggregate and modified asphalt with and without water.thirdly,through different freeze-thaw cycles,this paper researches the strength attenuation of freeze-thaw splitting of 15 kinds of structure of 75 kinds of asphalt mixture,and analyzes influence regularity of mixture void rate on the moisture damage.Fourthly,through the method of dynamic mechanics analysis(DMA),this paper analyzes the reliability evaluation index of adhesion work referring to attenuation of the dynamic mechanical parameters of the mixture before and after it is immersed and the change rule of the mixture phase transformation temperature,and establishes an effective evaluation system of asphalt mixture moisture damage.This paper proves that traditional test method about adhesion of aggregate and asphalt basically makes an accurate evaluation,but lacks of quantitative requirements,fails to make a distinction between the different material adhesion.As the theory of surface free energy to calculate the adhesion work,This paper proposes the index of residual adhesion work to evaluate adhesion performance,it is found that residual adhesion work of different aggregate with modified asphalt keeps big difference,the residual adhesion work of diabase with modified asphalt is much better than that of limestone.In addition,the asphalt mixture freeze-thaw cycle and dynamic mechanics test indicate that under a same type asphalt mixture,water stability performance of diabase asphalt mixture is much better than that of two kinds of limestone asphalt mixture.The study conclusion and the research results of asphalt mixture moisture damage in this paper have a good correlation,which shows that it is reliable to use the adhesion work to predict the water stability performance of asphalt mixture.