When added to bitumen, polyphosphoric acid enhances Ring & Ball and maintains or reduces Fraas point or BBR. However, it has no impact on the elastic recovery.
Applied between 0.1 and 1.5% by weight of bitumen depending on the applications,
it makes it possible to:
- Manufacture multigrade bitumen with lower sensibility of binder at high temperature and preservation of properties at low temperature
- Reach the required Ring & Ball when the elastic recovery specification is met with the addition of elastomer, thus reducing significantly the quantity of polymer necessary
- Improve storage stability of crumb rubber modified bitumen and optionally elastomer. Especially, it can reduce the quantity of crumb rubber required to meet the specifications, leading to lower viscosity and manufacture of bitumen at a temperature around 180°C
- Catalyses and strengthens the modification of bitumen resulting from terpolymers