Evaluation of Polymer Modified Asphalt Mixtures in Pavement Construction. (Dept. C)

Abstract

Traditional bitumen is expected to become brittle material at low temperatures therefore it may crack easily under repeated traffic loading or by thermal changes. On the other hand at high temperature, it is a soft material that ruts under traffic loading. Furthermore, the bitumen is not able to cope with the increase in traffic volumes/loading on roads. The use of the Polymer Modified Asphalt (PMA) in hot asphalt mixtures may improve the pavement performance and can increase the service life of the road. In this paper, the characterization of hot mix asphalt (HMA) modified with the PMA was evaluated and compared with the conventional mixtures. A comprehensive laboratory testing was conducted at Mansoura University Highway and Airport Engineering Laboratory (H&AE-LAB). The asphalt mixtures were designed by Marshall method and the percentage of the PMA ranged between 0 and 6% by the weight of the binder. The laboratory testing program include penetration test, softening point test, rotational viscometer test which was conducted on the PMA. For the asphalt mixtures, the experimental programs are the indirect tensile strength (IDT) and the percentage of loss of stability. The results showed that the asphalt mixture with 4% percentage PMA had the highest Marshall Stability and mix bulk density. In general, the findings of this study demonstrated that the use of PMA in asphalt mixes decrease the pavement rutting and increase the pavement life.