Relationship between chemical composition and VOCs emission potential of similar paving grade road bitumen

Abstract

ABSTRACT Exposure to bitumen fumes of workers during road pavement is a subject of interest in the field of industrial hygiene. Improvements have been made to technical means of prevention, but recent studies have shown that exposures need to be reduced. The development of early diagnosis method able to assess the volatile organic compounds (VOCs) emission potential would therefore be useful. The objective of this study was to outline a possible relationship between the chemical composition of bitumen and VOCs emission during heating using thirteen 35/50 paving-grade bitumen samples used in France. The samples are similar regarding their physical properties, elemental and SARA compositions. Molecular analysis investigations show that they contain the same class of compounds but in different proportions. Thermal analyses revealed different capacities of volatiles release potential. The combination of these data allowed to establish a relationship between chemical composition and volatile emission, leading to the identification of two groups of samples. We suggest three parameters based on molecular weight distribution, thermogravimetric profile and hydrocarbon release capacity that may distinguish bitumen by their emission potential prior to road pavement application. They may contribute to a methodology aiming to prevent workers exposure to bitumen fumes.