What process parameters influence polyphosphoric acid modified asphalt proposed mechanisms in asphalt or bitumen modification?

The modification of asphalt with polyphosphoric acid (PPA) is influenced by several key process parameters. These include the concentration of PPA, temperature during mixing, and the duration of the modification process. Higher PPA concentrations can enhance the viscosity and thermal stability of asphalt. Elevated temperatures facilitate better dispersion and interaction between PPA and bitumen components. Additionally, prolonged mixing times can improve the chemical bonding and overall performance of the modified asphalt.