Quantifying moisture damage at mastic–aggregate interface

Abstract

This study quantifies moisture damage at the asphalt mastic–aggregate interfaces using finite element method modelling technique in ABAQUS. A model aggregate surrounded by a layer of mastic is subjected to static loads of varying magnitudes and patterns. Using dynamic shear and elastic moduli of wet and dry mastic and aggregate as model inputs, moisture-induced damage is quantified through parameters such as contact stresses at interface, load to initiate damage and de-bonding at the interface. Results show that contact stresses are significantly higher in dry samples than wet samples. It is revealed that damage initiates at a smaller magnitude of deformation (0.0508 mm) in the wet sample than that (0.508 mm) in the dry sample. That is, a stiffer dry sample carries more loads and deforms less before damage initiation than a softer wet sample. In addition, approximately 6.8% interface de-bonding occurs in the dry sample, whereas 49.1% de-bonding occurs in the wet sample.

Keywords::

• moisture damage
• mastic
• interface
• asphalt concrete
• finite element method

Acknowledgement

The project was funded by the National Science Foundation (NSF) through the prestigious CAREER award (NSF grant no. 0644047).

Notes

^1. Email: [email protected]

^2. Force and load are used interchangeably in this paper.