CHARACTERIZATION AND EVALUATION OF ASPHALT MODIFIED WITH SOME THERMOPLASTIC POLYMERS

A. El-Kholy, S; A. Hassan, E.; M.M. Abd El-Rahman, A.; M. Nassar, I.

doi:10.21608/erjm.2004.82617

CHARACTERIZATION AND EVALUATION OF ASPHALT MODIFIED WITH SOME THERMOPLASTIC POLYMERS

Document Type : Original Article

Authors

¹ Egyptian Petroleum Research Institute( EPRI), Nasr City, Cairo, Egypt.

² Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.

10.21608/erjm.2004.82617

Abstract

Some commercial thermoplastic polymers such as styrene-butadiene rubber (SBR),
polyacrylonitrile (K), polystyrene (PS), polypropylene (PP) and polychloroprene (PC) are used for
the modification of two types of asphalt which are: asphalt 60/70 Suez (L) and asphalt 80/100
Alex (H). The best ratio of modifying polymer to be added by hot mixing method at 150-170°C to
asphalt, was determined by measuring the values of penetration, softening point, penetration
temperature susceptibility (PTS) and penetration index (PI) for the obtained cooled blended
formulations.
For asphalt (L), such optimum ratio was 6% for (SBR and PP), 9% for (PS) and 12% for (PC),
while in case of asphalt (H) the optimum ratio was 6% for (SBR), 9% for (PP and K) and 12% for
(PS and PC).
Dynamic viscosity tests i.e. shearing in (RV 12) for 5 mins at a high shear rate of 1198.08s?
and then for 10 mins at a low shear rate of 149.76s", at different temperatures (30, 40, 50 and
60°C) showed that formulation samples LSBR and HSBR have high yield stress values (To) which
give promising indications about the validity of their possible use for pavement. Moreover
formulations based on asphalt (H) and modified with SBR gave the highest value of tensile
strength as well as thermal stability at 250°C for time period of 150 hours. All the prepared
formulations modified with such thermoplastic polymers were resistant to different application
media as compared with parent unmodified asphalt.

Keywords