Document Type : Research Paper


1 civil engineering, university of technology, Baghdad, Iraq

2 Civil Eng. Dept., University of Technology, Baghdad, Iraq

3 Civil Engineering Department , University of Technology, Iraq,


Introducing nanotechnology to the pavement industry witnessed a great interest due to the proven benefits of nanotechnology in various scientific fields. However, the reduction in the binder's characteristics might be disadvantageous to the durability of the recycled mixture, making it more susceptible to external factors such as moisture. Therefore, using nanotechnology is expected here to treat this issue. The goal of the current paper is to report on the influence of the nano-clay montmorillonite (MMT) powder (MMT k10) on the resistance to moisture in the hot recycled mixtures or the Reclaimed Asphalt Pavement mixtures (RAP mixtures). In this work, different proportions of rejuvenated RAP were employed. These proportions are 30, 40, and 50% as a percent of the overall weight of the mix. The percentages were mixed with a nano-modified neat binder with  (0, 1, 3, and 5)% nono-clay MMT as a proportion of the bitumen’s weight. Two types of mixtures are prepared and used in this paper: nano-modified RAP mixtures and unmodified RAP mixtures. On both types of mixtures, the compressive strength test, the index of retained strength (IRS), the indirect tensile strength tests (ITS), and the tensile strength ratio (TSR) were carried out to compare and evaluate the moisture resistance of rejuvenated RAP mixtures. The experimental test results indicated that using 5 percent nono-clay in regenerated RAP mixes provides better performance than not using it.  where it increased moisture damage resistance by5.53% for IRS value and 3.66% for TSR for 50 percent RAP mixes.

Graphical Abstract


  • It was found that both RAP and MMT enhanced the compressive strength of the mixtures and produced a stiffer mixture.
  • The introduction of MMT to RAP enhances the ITS values, where 5% MMT had the highest values. 
  • The nono-clay improved the moisture resistance, as proved by the IRS values and the TSR values, where 5% of MMT rated the highest.


Main Subjects

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