Measurement of Aggregate–Mastic Bond Strength in Presence of Moisture: Combined Experimental-Computational Study

Moisture infiltration into asphalt mixes is known to have an adverse effect on the material characteristics of the individual components and may damage the bond between the components. This can lead to separation of the aggregates from the asphalt mixture commonly referred to as stripping or raveling. In any study of moisture induced damage in asphalt mixes the influence of moisture on the strength reduction of the aggregate-mastic bond is of paramount importance. This contribution describes an ongoing research effort between Delft University of Technology and Turner Fairbank Highway Research Center to determine the bond strength between asphalt aggregates and the mastic film around it as a function of moisture in the interface. A novel procedure is presented in which direct tension tests on coated diabase stones are combined with numerical simulations of moisture infiltration into the stone, in order to relate the reduction of bond strength with the quantity of moisture present in the interface. The paper discusses the sorption behavior of two different types of diabase stones and concludes that temperature induced cracking may cause the initial sorption behavior to be predominantly due to hydraulic suction followed at a later stage by a molecular diffusion process. To accurately capture this moisture infiltration behavior in the stones, finite element analyses were performed in which a combined action of hydraulic suction and molecular diffusion are simulated and they were compared to experimental data. In the last part of this contribution a relationship is presented for bond strength reduction in the presence of moisture.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 19p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044224
  • Record Type: Publication
  • Report/Paper Numbers: 07-1829
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 6:32PM