Research On Preparation And Properties Of SBS And PPA Modified Asphalt

The SBS polymer modifiers are expensive.Then the polymer modified asphalt prices also increased,resulting in a generally high cost of pavement construction.While poly phosphoric acid(PPA)has the advantages of low price,simple process and the asphalt performance can be improved obviously.However,PPA has poor performance under low temperature and other factors to restrict its development.Therefore,for the research of low cost,good performance modifier has become an urgent problem to be solved in engineering construction.Based on the study of SBS and PPA modified asphalt at home and abroad,this paper studied the properties of SBS/PPA compound modified asphalt.Firstly,based on orthogonal test,the establishment of four factors and three levels of test plan,research on process parameters of SBS modified asphalt and SBS/PPA modified asphalt mixture,and put forward two kinds of modified asphalt optimum technological parameters;secondly,through the preparation of modified asphalt,asphalt,SBS SBS/PPA composite modified asphalt high temperature performance,low temperature performance and modification mechanism were studied.The changes of the performance of SBS/PPA composite modified asphalt,the modified mechanism of SBS/PPA composite modified asphalt;finally,through the basis of previous research,research on the application of SBS/PPA modified asphalt mixture in practical engineering.And to explore its feasibility in the actual construction of the road.The main results are as follows: the optimum process parameters of SBS modified asphalt: 4.5%SBS+1.8% extract oil +0.2% stabilizer SBS/PPA the best formula of composite modified asphalt: 3.5%SBS+3.5% extract oil +0.5%PPA+1.0%.With the base asphalt and SBS modified asphalt,the high temperature stability of SBS/PPA composite modified asphalt has better temperature and failure,and the SBS modified asphalt and SBS/PPA modified asphalt viscosity is not much;SBS/PPA mixed asphalt short-term aging is poor,but the long-term aging compared with SBS modified asphalt;low temperature performance and low temperature performance of SBS slightly higher than that of SBS/PPA composite modified asphalt,but the difference is not much.After adding DBP in SBS/PPA compound modified asphalt,the chemical crosslinking of SBS was enhanced and the molecular structure was connected with each other to form a stable SBS space network structure,and the storage stability of modified asphalt was improved significantly.PPA price is low,so that the SBS/PPA compound modified asphalt has better application prospects than SBS modified asphalt.