Study On The Performance Of Nano Modified Asphalt Pavement Materials

Since modern times, nanotechnology is gradually infiltrated traffic materials, and nano modified asphalt is the one. It improves performance of the asphalt from the microscopic scale, which is different from other modified asphalt technology. Put the nanometer materials into the asphalt material, which can improve the performance of asphalt, such as high temperature stability, low temperature crack resistance, fatigue resistance and skid resistance, ageing resistance and durability, water stability, construction workability and so on.Through adding respectively 3% and 5% of nano-Ti O2, nano-Si O2, nano-Zn O, nano-Ti O2/Ca CO3, nano-montmorillonite, nano-diatomite into the 90 # heavy traffic asphalt, the paper synthetically compares the different performance on anti-aging properties, thermal properties and high and low temperature performance. And the paper chooses the best modification effect of nanometer Ti O2/Ca CO3 as modifying agent. The paper mainly concentrates on the following aspects:(1) The process for the preparation of nanometer Ti O2/Ca CO3 modified asphalt and the best content of modifier.(2) Nano-Ti O2/Ca CO3 modified asphalt performance test.(3) The micro modification mechanism analysis by electron microscope, infrared spectrum and X-ray test.(4) Nano-Ti O2/Ca CO3 modified asphalt pavement performance test.(5) The test road paving.Through a series of laboratory tests, the paper gets the following conclusion:(1) When the temperature is 160-170℃,and revolving speed is 5000-6000r/min,and the time is 30-40 min, the modified asphalt achieved the best performance. Compared with the blank matrix asphalt under the same condition, 25℃ penetration, softening point value-added reduced by 19% and 57% after TFOT, residual penetration ratio, 10℃ residual ductility increased 140% and 83%, and 10℃ ductility is slightly lower after TFOT.(2) Nano-Ti O2/Ca CO3 dispersed homogeneously in the matrix asphalt, and formed a good interfacial bonding between the two materials. There are both a physical change and chemical change, which is given priority to with a physical change.(3) Compared with the matrix asphalt, nanometer Ti O2/Ca CO3 modified asphalt owns high temperature stability, and dynamic stability increased by 50.1%. The ability to resist damage of water mixture is improved, and splitting tensile strength and residual stability increased by 6.4% and 6.4% respectively. Low temperature crack resistance also has certain enhancement, but the effect is not obvious.(4) Nano materials can be added directly into asphalt mixture on trial road construction. Except for adding process on the scene and increasing wet mixing time, mixing temperature and other processes are the same as the common asphalt mixture. Mixing of nano modified asphalt mixtures conform to the requirements of the site construction. And the test index also satisfies the requirement of construction technical specification.