Performance Research Of Polyphosphoric Acid Modified Asphalt

With the rapid development of highway in China, traffic volume and axle load are increasing, which puts forward higher requirements for the construction of new road and the maintenance of old road. With more and more research on asphalt modifier, acidic modifiers have increasingly become one of the hot research issues. Polyphosphoric acid can improve the high temperature performance of asphalt binder or asphalt concrete, improve asphalt pavement performance, extend the life of asphalt pavement, has high temperature storage stability, and is difficult to isolate. Polyphosphoric acid has more socio-economic benefits than some other polymers.In this paper, through a series of laboratory tests, we did research on the temperature performance, high temperature stability, and low temperature stability and anti-aging properties for polyphosphoric acid modified asphalt. We did tests to research the high temperature stability, water stability and low temperature cracking performance of polyphosphoric acid modified asphalt concrete, this method helped explore the different percentages of polyphosphoric acid, and improve the performance of the modified asphalt and modified asphalt concrete.The results showed that:with the increase of polyphosphoric acid percentage can improve the temperature performance and high temperature stability of modified asphalt significantly; when polyphosphoric acid percentage is less than 1.5%, the low temperature cracking performance of modified asphalt is improved significantly; when the percentage of polyphosphoric acid is 0.5%, the improvement effect of the anti-aging properties of modified asphalt is outstanding, while improving effect of other percentages is less obvious. By adding polyphosphoric acid, the high temperature stability of modified asphalt improves slightly, and improvement of the water stability of modified asphalt is less obvious. Furthermore when we replace filler by lime, the high temperature stability and water stability of asphalt concrete improve significantly.