Pavement Performance Of Waste Oil-based Bioasphalt

Petroleum asphalt, which is by-product of petroleum refining, is widely used in road engineering, while petroleum is increasingly scarce as non-renewable resource, resulting in the short supply of petroleum asphalt. In this circumstance, asphalt substitute development is a new way to solve the problem. Using some by-products or waste materials of other industries to partially substitute asphalt, which can not only reduce asphalt content but also improve the pavement performance of asphalt, this will have great economic and social significance to the resources recycling and alleviating the contradiction between supply and demand of asphalt. This dissertation focuses on the common waste oil in our life, which is used to partially substitute asphalt for bioasphalt, some researches on its basic pavement performance and modification mechanism are carried out. The main research contents and results are as follows.Fourier translation infrared spectroscopy (FT-IR) was used to analyze the chemical composition of waste oil and asphalt, laboratory preparation method of bioasphalt was introduced, and the basic performance of bioasphalt, such as penetration, softening point and ductility, was studied.High-temperature and low-temperature rheology properties of bioasphalt was researched based on rheology principle, the research results indicated that waste oil decreased the rut factor and complex modulus of asphalt, which is disadvantageous to its high-temperature rut resistance. And waste oil reduced creep stiffness modulus, increased creep rate, improved the stress relaxation ability of asphalt, which is advantageous to its low-temperature crack resistance. There was a significant relativity between waste oil content and low-temperature performance indexes (creep stiffness modulus and creep rate), and corresponding prediction models were put forward.Viscosity-temperature curve of bioasphalt was determined, and construction performance of bioasphalt was evaluated from the mixing temperature and compaction temperature point of view, the research results showed that waste oil decreased the construction temperature of asphalt, increased its workability and reduced the energy consumption during construction. Viscosity and toughness test was carried out to evaluate the comprehensive mechanical properties of bioasphalt when stretched, the test results indicated that waste oil significantly decreased the viscosity, toughness and maximum tension of asphalt, which is disadvantageous to its comprehensive mechanical properties.Surface physical and chemical methods were used to determine the surface free energy of bioasphalt and the adhesion work between bioasphalt and aggregate, the research results showed that waste oil increased the surface free energy of asphalt and the adhesion work between asphalt and aggregate, improved the adhesion property between asphalt and aggregate, reduced the possibility of moisture damage. Fourier translation infrared spectroscopy (FT-IR) was used to analyze the chemical bond action between waste oil and asphalt from the functional group point of view, the research results indicated that the physical reaction was principal, but did not rule out the weak coupling effect of chemical reaction.