Research On The Influence Of Plasticizer On The Performance Of Organic Viscosity-reducing Warm Mix Asphalt And Asphalt Mixture

Organic technology can reduce the mixing and construction temperature of asphalt mixtures,and has great advantages in reducing energy consumption and toxic and harmful gas emissions.It is one of the important means to achieve energy saving and emission reduction and create low-carbon and environmentally friendly transportation.However,the organic viscosity-reducing temperature mix asphalt has the disadvantage of poor lowtemperature performance during use,which limits the promotion of this technology.In view of this,dioctyl phthalate(DOP),tributyl citrate(TBC)and dioctyl maleate(DOM)was used to modify the organic warm mix asphalt.The performance of plasticized modified warm-mix asphalt and asphalt mixture was studied.The main conclusions obtained are as follows:Through the Brookfield viscosity test,it is found that Sasobit and PE-wax can reduce the mixing temperature of the asphalt mixture by 15°C and 12°C,respectively.The cooling effect of PE-wax is slightly worse.Plasticizers can also reduce the hightemperature viscosity of asphalt,and plasticizers have a greater increase in the cooling effect of PE-wax.Under the same plasticizer type and content,the cooling effect is sorted from large to small as plasticized PE-wax>plasticized Sasobit>Sasobit>PE-wax.By using the fuzzy analytic hierarchy process to comprehensively evaluate the plasticizer modification effect,it is found that DOP has the best comprehensive modification effect on Sasobit and PE-wax warm-mix asphalt,which is the best plasticizer component,and the best amount is 3%;the comprehensive evaluation results of warm-mix asphalt show that the economic and technical feasibility of DOP/PE-wax warm-mix asphalt are better than Sasobit warm-mix asphalt,and DOP/PE-wax warmmix asphalt is a low-cost warm-mix solution with good modification effect.The results of dynamic shear rheology test and multiple stress creep recovery test show that adding Sasobit and PE-wax can reduce the phase angle and irrecoverable creep compliance of asphalt,increase rutting factor and creep recovery rate,and improve the elastic recovery ability and resistance to permanent deformation of asphalt.The plasticizers will increase the phase angle and irrecoverable creep compliance of asphalt,reduce rutting factor and creep recovery rate,and gradually deteriorate the resistance to permanent deformation of asphalt.But compared with matrix asphalt,plasticized modified warm mix asphalt has better high temperature performance.The test results of force ductility test and bending beam rheology show that Sasobit and PE-wax will weaken the ductility of asphalt in low temperature environment,and the low temperature performance of asphalt is obviously worse.The addition of plasticizers can improve the low-temperature ductility and stress relaxation capabilities of warm-mix asphalt.Among the three plasticizers,DOP and TBC have the most obvious effect on improving the low-temperature performance of warm-mix asphalt,which can restore the low-temperature performance of warm-mix asphalt to the level of matrix asphalt.The addition of the organic additives improves the high temperature stability of the hot mix asphalt mixture,but is disadvantageous to the low temperature performance and water stability.DOP can improve the low-temperature performance and water stability of warm-mix asphalt mixtures.While reducing the molding temperature of 20°C,the road performance of DOP-modified warm-mix asphalt mixtures is equivalent to that of hotmix asphalt mixtures.Compared with Sasobit,DOP/PE-wax has better warm mixing effect.