Development And Application Of Warm Mix-Modified Double-Effect Additive For Asphalt Mixture

With the vigorous development of highway construction in China,the quality requirements of highway construction are gradually improving.At present,under the requirement of resourcesaving and environment-friendly society,the application limitation of hot-mix asphalt mixture is getting bigger and bigger,and the warm-mix asphalt mixture comes into being.However,warm mix asphalt mixture also has some shortcomings.For example,poor low temperature performance and insufficient water stability and durability.Therefore,this thesis combines the traditional warm mixing technology with the modification technology,and develops an asphalt mixture additive which can achieve both warm mixing effect and modification effect.The asphalt mixture mixed with this additive can have the advantages of energy saving and environmental protection of the traditional warm mixing asphalt mixture and good road performance of the modified asphalt mixture,and at the same time make up for their shortcomings.It is an ideal asphalt pavement material.Firstly,epoxy resin/polyolefin elastomer(POE)was used as the main modifier,and auxiliary agents such as quaternized polyacrylamide quaternary ammonium salt were added to prepare two functional components A and B of warm mix-modified double-effect additive.Both components A and B have the function of reducing the production temperature of asphalt mixture,but A mainly improves the high-temperature performance of asphalt mixture,while B mainly improves the low-temperature performance of asphalt mixture.The appropriate ratio of the two will be comprehensively determined by their influence on the performance of asphalt and asphalt mixture.Secondly,the influence of two functional components A and B on the performance of matrix asphalt was studied,and the tests of penetration,ductility,softening point,Brinell viscosity and fluorescence microscope scanning of asphalt with different content were carried out.By analyzing the test results,the suitable content of warm mix-modified double-effect additive applied to matrix asphalt was initially selected.Thirdly,the asphalt mixture AC-20 is selected,and the asphalt mixture is mixed with the primary additive content,and the road performance of the asphalt mixture is tested.According to the asphalt mixture mixed at different mixing and molding temperatures,by controlling the porosity,the cooling range that additives can achieve is finally determined,that is,the best mixing and molding temperature of additives for asphalt mixture preparation is obtained.Finally,the warm mix-modified asphalt mixture is prepared according to the best mixing and molding temperature.Through Marshall volume index test,rutting test,low temperature trabecular bending test and freeze-thaw splitting test,the suitable content of two components of warm mix-modified double-effect additive for asphalt mixture is further screened.In addition,through Hamburg rutting test,APA rutting test and four-point bending fatigue test,this thesis verifies and evaluates the best additive content,and finally obtains the best additive content of warm mix-modified double-effect additive developed in this thesis for asphalt mixture.