Research On Oil Corrosion For TLA Modified Asphalt And Its Mixture

With the increasing traffic volume, the situation that oil leakage of heavy vehicles in poor condition on the roads is getting more serious. As the asphalt is dissolved by harmful oil (which is mainly diesel), the asphalt pavement is made to appear to soften and loose. Thus, in comprehensive action of heat and rain, there are a series of early damage phenomenon such as pits and so on. How to prolong the service life of the asphalt pavement and to prevent the early damage of oil corrosion, which is one of technical issues which have became widespread concern in pavement engineering. However, there are few researches in this area and it is lack of relevant technical requirements and standards currently, so in this paper combined with practice of TLA modified asphalt pavement project in the First Loop Expressway of Fast Main Highway of Foshan City, the performances of TLA modified asphalt and its mixture after oil corrosion were tested. The mechanism of oil corrosion damage is analyzed to make reference for the anti-corrosion of oil performance of asphalt pavement.1. 4 factors, which are the diesel erosion time, the diesel erosion temperature, shear rate and TLA mixing amount, have been selected, and the 4 kinds of corresponding level as well. The oil corrosion experiments were arranged and carried on with the L16(45) orthogonal experiment table. The impact extent of various factors and levels to the mass loss was analyzed by the range method, so it shows that the sequence of impact extent of each the factors to the mass loss: TLA mixing amount > diesel erosion temperature > diesel erosion time > shear speed. Meanwhile, in accordance with the sensitivity of impact by the factors and levels, the methods and standards of the oil corrosion experiment indoor had been determined.2. Oil corrosion experiments were operated on matrix asphalt and TLA modified asphalt in different conditions, and the anti-corrosion oil capacity was evaluated by testing the mass loss. Subsequently, asphalt samples after oil corrosion were tested on the three major indexes, equivalent softening point, density, viscosity and so on. The results shows that the asphalt performance decreased significantly after oil corrosion, but with the increased mixing amount of TLA, the sensitive-temperature property, high temperature performance and anti-deformation capacity of asphalt samples were improved. 3. The matrix asphalt and TLA modified asphalt after oil corrosion were tested in SHRP experiments. The results of dynamic shear rheological experiment show that the high temperature performance of TLA modified asphalt reduced after oil corrosion, but when the mixing amount of the TLA was increased, high-temperature performance would be improved. With the time of oil corrosion extending, anti-rutting factor of TLA modified asphalt was decreased. As the temperature was rising, the phase angle was increased, however, anti-rutting factor was reduced. It is concluded on the rotary viscometer experiment that with the temperature rising, the viscosity of matrix asphalt and TLA modified asphalt were decreased significantly. Meanwhile, the results of anti-rutting factor in high-temperature and viscosity index of TLA modified asphalt after oil corrosion to conventional indicators were in correlation analysis. It shows that there were very good correlations among the anti-rutting factor in high-temperature of 70℃, 64℃, 58℃, viscosity of 100℃and the mixture dynamic stability. In addition, the correlation of the anti-rutting factor in high-temperature of 70℃of TLA modified asphalt and softening point, penetration, equivalent softening point after oil corrosion were all good.4. The matrix asphalt and TLA modified asphalt mixture in different mixing amount were compared by the indoor experiments on high temperature stability and water stability after oil corrosion. The results shows that with the time of oil corrosion extending, mixture performances were decreased, but increasing the mixing amount of TLA can improve the sensitive-temperature property and high temperature performance of the TLA modified asphalt mixture after oil corrosion significantly.In short, the oil corrosion has a great impact on the performances of TLA modified asphalt and its mixture. The impact extents are different with different TLA mixing amount. It can be concluded that by integrating performance indexes of samples after oil corrosion, the anti-corrosion of oil effect is most significantly when TLA mixing amount is 30%～40%.