Impact of Construction Practices on Air Voids and Permeability of Asphalt Mixtures

Several isolated premature failures on the rehabilitated portion of the Lahore-Islamabad M-2 Motorway were observed within a year of opening to traffic. Based on the visual evaluation of the distresses, failure causes could be attributed to poor in-pavement and surface drainage on the rehabilitated sections, segregation of HMA mixture, HMA mix-design, and the presence of heavy axle loads in the outer lanes. Cores in the distressed and normal areas were taken in different sections along the south and north bound directions and several destructive tests were conducted on the HMA materials to determine the field compacted air voids. Also, field permeability in-situ tests were conducted on the same locations where cores were taken. Results showed that the mix segregation occurring in the fast lanes resulted in higher field air voids than the plant mixed-lab compacted samples. Thus, the permeability of mixes in these locations was significantly higher than expected, which caused water to seep through the surface mixes in all lanes. Additionally, due to the cross-fall of the HMA and aggregate base layers, the moisture entering in the fast and middle lanes accumulated under the outer lanes in both directions.

Language

  • English

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  • Accession Number: 01897735
  • Record Type: Publication
  • ISBN: 9783030486785
  • Files: TRIS
  • Created Date: Oct 28 2023 4:45PM