Microstructure of warm mix asphalt binder exposed to UV light and heat

Ilaria Menapace, Eyad Masad, Mohammed Sadeq

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

This paper aims to evaluate the suitability of using warm mix asphalt (WMA) technology in countries with hot climates such as Qatar. For this purpose, an original and two WMA binders were investigated before and after aging. A new aging protocol that takes into account the combined effect of UV radiation, oxygen and typical summer day and night temperatures registered in Qatar is here proposed. The parameters were chosen in order to simulate the weather conditions in Qatar. The microstructure of the exposed binder surface was investigated with atomic force microscopy (AFM) and compared with the unaged surface. This evaluation is more accurate than previously used microstructural evaluations based on the observation of asphalt binder after Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV) aging. In the proposed method, the exposed surface is directly observed and any rearrangements of the binder components after aging (i.e. during heat treatment to obtain a smooth surface) is prevented. Profound changes in the microstructural features were observed due to aging. Each binder presented a different microstructure of the aged surface and the common feature among the different binders was the disappearance of the bee-like structures. Degradation of the binder surface was correlated with chemical reactions caused by UV radiation and oxygen. Moreover, the effect of a relatively high temperature during the aging process may have aggravated the damage, due to the synergic effect of many factors. This may be the reason of the short service life of pavements in Qatar.

Original languageEnglish
Title of host publication8th International Conference on Maintenance and Rehabilitation of Pavements, MAIREPAV 2016
PublisherResearch Publishing Services
Pages260-269
Number of pages10
ISBN (Electronic)9789811104497
DOIs
Publication statusPublished - 2016
Externally publishedYes
Event8th International Conference on Maintenance and Rehabilitation of Pavements, MAIREPAV 2016 - Singapore, Singapore
Duration: 27 Jul 201629 Jul 2016

Other

Other8th International Conference on Maintenance and Rehabilitation of Pavements, MAIREPAV 2016
CountrySingapore
CitySingapore
Period27/7/1629/7/16

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Keywords

  • Accelerated weathering tester
  • Aging
  • Asphalt binder
  • Microstructure
  • UV light

ASJC Scopus subject areas

  • Building and Construction
  • Civil and Structural Engineering

Cite this

Menapace, I., Masad, E., & Sadeq, M. (2016). Microstructure of warm mix asphalt binder exposed to UV light and heat. In 8th International Conference on Maintenance and Rehabilitation of Pavements, MAIREPAV 2016 (pp. 260-269). Research Publishing Services. https://doi.org/10.3850/978-981-11-0449-7-040-cd