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Sustainable pavement recycling: Utilization of cement and asphalt waste dust to improve CBR and permeability
Author(s)
Thatmas, Natthapong
Nguyen, Trong Nghia
Huan, Vo Nguyen Phu
Mase, Lindung Zalbuin
Ayawanna, Jiratchaya
Date Issued
September 1, 2025
Type
Article
Abstract
This study aims to utilize asphalt waste dust, a pollutant by-product of the asphalt production process, to improve the quality of recycled pavement materials for use as base course materials, under the standards of the Department of Rural Roads and the Department of Highways, Thailand. The mixture consisted of 70 % by weight (wt%) reclaimed asphalt pavement (RAP), 30 wt% crushed rock (CR), 3.5 wt% cement (C), and 20 wt% asphalt waste dust (AD), in comparison to the general pavement recycling (RAP-CR-C). Compaction test, permeability test, California Bearing Ratio (CBR) test, and scanning electron microscope (SEM) analysis were performed under all testing conditions. The highest performance was achieved for the recycled pavement materials, containing 3.5 wt% cement and 20 wt% asphalt waste dust (RAP-CR-C-AD20). The coefficient of permeability was 2.32 × 10-7 cm/s under pressurized constant head, 2.40 × 10-7 cm/s under an 8 mm falling head, and 2.59 × 10-7 cm/s under a 14 mm falling head. The CBR values were 493 % at 0.1 in (2.54 mm) penetration and 491 % at 0.2 in (5.08 mm) penetration. The RAP-CR-C-AD20 exhibited a low coefficient of permeability but a high CBR, compared to those of RAP-CR-C, and above the minimum base course requirement (CBR > 80 %). This study highlights the potential of using asphalt waste dust in pavement recycling as an innovative solution that not only reduces waste but also contributes to sustainable road construction practices.
Citation
Results in Engineering, 27, 2025