Predicted performance of hot mix asphalt modified with nano-montmorillonite and nano-silicon dioxide based on Egyptian conditions

ABSTRACT

This paper focused on predicting the performance of asphalt mixes modified with nano-montmorillonite (NMMT) and nano silicon dioxide (NSD) using the Quality-Related Specifications Software (QRSS), which is a simplification to the Pavement ME Design. The nanomaterials were thoroughly mixed with the binder at a temperature of 145 ± 5°C. The conventional and the rheological properties were determined for the penetration grade 60–70 control binder as well as binders modified by 3, 5 and 7% of NMMT and NSD by the weight of asphalt. The optimum nanomaterial content was found for each modifier and was then used for preparing asphalt mixtures by the conventional Marshall method. Finally, Witczak 1-40D complex shear modulus (G*) based predictive model was used to estimate the dynamic modulus (E*) for the control and nanomodified asphalt mixtures. The field performance in terms of asphalt concrete (AC) layer rutting and fatigue cracking was predicted using the QRSS software for two typical pavement sections and three different climatic locations in Egypt (Alexandria, Cairo and Aswan). The simulation runs revealed that both nanomodified asphalt mixtures exhibited superior pavement performance in terms of AC rutting compared to the control mix without a significant effect on fatigue life.

KEYWORDS:

• Nanomaterials
• modified binder
• QRSS
• pavement ME
• rutting
• fatigue