Pore Structure Evaluation of Asphalt Concrete and Its Influence on Permeability and Moisture Damage

This study evaluates the pore structure of asphalt concrete (AC) samples by quantifying the different components of pore space and their contribution to permeability and moisture damage. Three components of the total pore space (i.e., air voids) namely permeable, dead-end and isolated pores are quantified using tracer and other methods. It is shown that AC has more permeable pores than impermeable pores (sum of isolated and dead-end pores). AC samples become impermeable if they are compacted below 5% air voids as opposed to 6-7% air voids. For given air void, permeable pore increases with an increase in sample radius. In other words, a 6 in. diameter sample exhibits more permeable pores than a 4 in. diameter sample, which is middle cored from the same 6 in. diameter sample. The ratio of permeable pore to impermeable pore increases exponentially with an increase in total pore. This indicates that the affinity of impermeable pores to be connected increases with an increase in total pore. It is observed from this study that the permeable pore has a good correlation with permeability whereas total pore shows a poor correlation with permeability. The effects of permeable and dead-end pores on moisture damage of AC are evaluated using a Moisture Induced Sensitivity Testing (MIST) device and the AASHTO T 283 method. It is observed that permeable and dead-end pores do not contribute to moisture damage of AC samples.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK40 Characteristics of Asphalt-Aggregate Combinations to Meet Surface Requirements. Alternate title: Pore Structure Evaluation of Asphalt Concrete and Their Influence on Permeability and Moisture Damage.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Tarefder, R A
  • Ahmad, M
• Conference:
  • Transportation Research Board 94th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2015-1-11 to 2015-1-15
• Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 18p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Air voids; Asphalt concrete; Laboratory tests; Moisture damage; Permeability
• Uncontrolled Terms: Pore structure
• Subject Areas: Highways; Materials; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01553013
• Record Type: Publication
• Report/Paper Numbers: 15-5821
• Files: TRIS, TRB, ATRI
• Created Date: Feb 9 2015 4:31PM