| Inorganic powder modified asphalt has been the research focus of road materials because of its good road performance and cost advantages.In this paper,the ceramic polishing powder(PP)of industrial solid waste was used as inorganic filler type asphalt modifier,and the surface modification was carried out with silane coupling agent and NaOH alkali solution.The effect of process parameters on the performance of PP modified asphalt is studied.Based on the research method and evaluation index of the modified asphalt by polymer and inorganic nano material,the basic technical properties of modified asphalt were tested and analyzed,and the modification mechanism of PP on asphalt was discussed.The main conclusions are as follows:(1)Compared with traditional filler ore powder,PP has the characteristics of light quality,small size,large surface area,hydrophobicity,surface roughness and so on.The surface of PP is acidic and is poor in compatibility with asphalt.The shear rate and the shearing time after adding powder have the most significant influence on the three major indexes and the degree of segregation of the modified asphalt,the preparation temperature is the second significant,and the effect of the pre-shearing time is the least.The best shearing process is: the preparation temperature is 145?,the shear rate is 4000 r/min,the pre shearing time is 15 min,and the shearing time is 60 min after adding powder.Based on the above process,it is determined that 6wt% is the best dosage of PP,and the segregation degree of modified asphalt is relatively small.(2)The silane coupling agent can introduce organic groups on the surface of PP,and the NaOH alkali solution has corrosion on the surface of powder particles,which makes the surface more rough and weakly alkaline.The above two surface modification methods can make up for the poor compatibility between PP and asphalt.The rational solution to the surface modification of PP by KH-550 silane coupling agent is that the water alcohol ratio of the mixed solvent is 3:7,pH is 5,the time of hydrolysis is 30 min,and the soaking time is 60 min,and the reasonable solution for the surface modification of PP by NaOH water solution is: the solution concentration is 2 mol/L,and the soaking time is 2 h.(3)Compared with matrix asphalt,when the content of PP is 4wt%~6wt%,the adhesion of the asphalt and the coarse aggregate can be increased from 3 to 4 under the condition of non surface modifier treatment,and the modified asphalt with 6wt% PP has temperature sensitivity,high temperature energy,heat resistance and oxygen aging performance and its rough set.After treatment with different surface modifiers,the modified modification effect of KH-550/PP is the best.The adhesion property of the material is the best,but it is not conducive to the low temperature cracking resistance when the temperature is below-10?.The temperature sensitivity,high and low temperature performance and thermal oxygen aging properties of the modified asphalt are all better,and the temperature sensitivity,high and low temperature performance and thermal oxygen aging properties of the NaOH/PP composite asphalt are all between the single PP modified asphalt and matrix asphalt.(4)AFM test analysis shows that after the modification of the 6wt% PP,the comparison of the two-phase distribution in the asphalt is obvious,and PP was dispersed evenly in the matrix asphalt,and the surface roughness of the modified bitumen is higher.The results of FTIR test show that KH-550 and NaOH have little influence on the infrared spectrum of modified asphalt.There is no obvious chemical reaction between PP before and after surface modification and the matrix asphalt.The two are blending through physical meaning,and using the adsorption,wetting,dispersing and crosslinking between the phases to achieve the modified effect. |
PDF Full Text Request