An automated image analysis procedure to evaluate compacted asphalt sections

Abstract

A new image analysis program is presented to determine morphological and textural properties of aggregates, asphalt binder and air voids in compacted asphalt mixes. The procedure involves scanning cut sections of laboratory or field specimens and estimating volumetric properties based on a pseudo 3D algorithm. Properties that are calculated include gradation, asphalt content, air void content, amount of flat/elongated particles, distribution of particle orientations, air void profiles, and various particle shape and textural measures. Validation of the code for specimens for which reference values were available indicates generally good predictions, particularly with regard to gradation and asphalt content. The objective of the study has been to develop a robust procedure that is easy to use, cost efficient, environmentally friendly and that can be used as a means to determine asphalt characteristics for quality control and quality assurance purposes. The new analysis technique may also find application in the study of SEM resin-impregnated soil thin sections and concrete cross sections.

Keywords:

• image analysis
• asphalt mixes
• aggregates
• computer programming
• grain size
• void ratio

Acknowledgements

This study was conducted in part by a grant from the Hawaii Department of Transportation and the Federal Highway Administration. Their support is gratefully acknowledged. The early work of Curtis Nagata, as well as the advice from JoAnne Nakamura and Steven Ege at the Hawaii Materials Testing and Research Branch, were invaluable.

Notes

^1. [email protected]

Additional information

Notes on contributors

Jennifer G. Hirata

1. 1. [email protected]