Moisture damage in asphalt mixes can be defined as loss of strength and
durability due to the presence of moisture at the binder-aggregate interface (adhesive
failure) or within the binder (cohesive failure). This research focuses on the evaluation
of the susceptibility of aggregates and asphalts to moisture damage through
understanding the micro-mechanisms that influence the adhesive bond between
aggregates and asphalt and the cohesive strength and durability of the binder.
Moisture damage susceptibility is assessed using surface energy measurements
and dynamic mechanical analysis (DMA). Surface energy is defined as the energy
needed to create a new unit surface area of material in vacuum condition. Surface
energy measurements are used to compute the adhesive bond strength between the
aggregates and asphalt and cohesive bond strength in the binder.
DMA testing is used to evaluate the rate of damage accumulation in asphalt
binders and mastics. The DMA applies a cyclic, torsional strain controlled loading to
cylindrical asphalt mastics until failure. The DMA results are analyzed using continuum
damage mechanics that focuses on separating the energy expended in damaging the
material from that associated with viscoelastic deformation. A new approach is
developed to analyze the DMA results and calculate the rate of damage.
The developed approach is used to evaluate six asphalt mixtures which have
performed either well or poorly in the field. The resistance of the field mixes to
moisture damage is shown to be related to the calculations of bind energies and the
accumulated damage in the DMA.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/2320 |
| Date | 29 August 2005 |
| Creators | Zollinger, Corey James |
| Contributors | Masad, Eyad |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 3873143 bytes, electronic, application/pdf, born digital |
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