Effect of low VMA in hot mix asphalt on load-related cracking resistance

Khalid Al-Shamsi*, Hossam F. Hassan, Louay N. Mohammed

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

Voids in mineral aggregate (VMA) is an important parameter in hot mix asphalt (HMA) mix design. It is believed that a minimum VMA requirement is necessary to ensure adequate binder content and durability for HMA. This paper investigates the effect of lower than typically acceptable VMA on the load-related cracking resistance of four dense-graded asphalt mixes. The mixes were prepared with three aggregate types: limestone, sandstone, and granite. Three different approaches were used to evaluate the cracking resistance of the mixes: the dissipated creep strain energy (DCSE), the fatigue parameter (|E|sin φ), and the mechanistic-empirical pavement design guide (M-E PDG) cracking models. The indirect resilient modulus (Mr), indirect tensile strength (ITS), and dynamic modulus (E) tests were performed on the mixes. Finite element analysis was used together with the M-E PDG cracking models to predict the expected longitudinal and alligator cracking performance of the mixes when used in a typical pavement structure. Both DCSE and (|E| sin φ) results showed that lower VMA decreases the cracking resistance of the mixes. DCSE parameter decreased by 50%, while |E| sin φ increased by 12%, for a 3.8% reduction in VMA. The analysis results of M-E PDG cracking models were consistent with the experimental findings. The predicted longitudinal cracking increased by 73%, while the alligator cracking increased by 24% for the same reduction in VMA.

Original languageEnglish
Pages (from-to)386-394
Number of pages9
JournalConstruction and Building Materials
Volume149
DOIs
Publication statusPublished - Sep 15 2017

Keywords

  • Asphalt mixes
  • Cracking
  • DCSE
  • Dynamic modulus
  • M-E PDG
  • Voids in mineral aggregates

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)

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