Performances Study On Asphalt Modified By Plasticizers

Plasticizer can reduce the glass-transition temperature Tg of the plasticized object, change the flexibility and stretchability of it, reduce the viscosity of it in high temperature, increase the toughness and improve the shock resistance. Plasticizer is widely used in the plastics industry, but the research on modifying asphalt by using plasticizer is little. Plasticizer can be regarded as a new kind of materials to modify asphalt, this thesis uses the plasticizer to modify asphalt in order to obtain good mod ification effect and meet the need of the road construction.This thesis focuses on the needle penetration, temperature sensitivity, low-temperature ductility and low-temperature measuring-stress ductility, toughness, softening point, elastic recovery of modified asphalt and the mass loss, penetration, low temperature ductility and softening point test after TFOT. The thesis is aimed at a comprehensive understanding of the performance of modified asphalt. The thesis also discusses the feasibility and applicability of using this new type of modifying agent — plasticizer — to modify asphalt, analyses the performance of the modified asphalt in each dosage of each kind of plasticizer to determine the proper dosage.The thesis does such research about the mixture of modified asphalt: high-temperature rutting, low-temperature bending, Marshall immersion, freeze-thaw splitting test and Kentabao before and after aging. And the thesis analyses and evaluates the stability of the mixture in high temperature, the crack resistance of the mixture in low temperature, water stability and durability of the mixture, tests the modification effects of using plasticizer and recommends suitable dosage of modifier.The following are the results of the research. The plasticizer has improved the temperature sensitivity, low-temperature performance and anti-aging ability of asphalt, but it has certain negative influence on high-temperature performance of asphalt. The performance of the modified asphalt from natural asphalt by using double- mixed plasticizer is worse than the performance of single-doped modified asphalt in a single aspect, but it also has the advantages of the single-doped modification of the asphalt, temperature sensitivity, high-temperature and low-temperature performance and has good modification effects. The modification effect of plasticizer is very well reflected in performance of the mixture used in road construction. The mixture’s low-temperature crack resistance, water stability and durability have been improved. The high-temperature resistance of the mixture can be guaranteed after adding Xiangweilian or Chezheji. The mixture shows a good prospect of application.