Over the recent years, bitumen modification with polymers, acids, or mineral fillers has gained relevance to adjust its performance properties. This work reports the use of polyphosphoric acid (PPA) for the modification of formulated bitumen. With this objective, an in-depth literature review on PPA modification was firstly performed. Subsequently, five individual refinery components were selec...

In a large project of the German Bitumen Forum, almost all branches of industry in Germany that use bitumen have been examined with regard to bitumen exposure. A total of 1272 samples were gathered between 1991 and 2005. The measuring method includes vapours and aerosols emitted from hot bitumen; the proportions of these two components and their dependency on bitumen temperature are described. ...

Confocal Laser Scanning Microscopy (CLSM) has gathered interesting new results regarding the microstructure of bitumina as part of a comprehensive study on bitumen and asphalt concrete. Compared to normal fluorescence microscopy, the CLSM technique has been proven to be the method of choice for bitumen. The main advantage is a much stronger fluorescence signal due to the higher intensity of the...

Layered double hydroxides (LDHs) are an ultravioletlight (UV)-resistant material. In this study, two types of LDHs (Mg-Al-LDHs and Zn-Al-LDHs) were applied to modify bitumen by melt-blending. The effect of ultraviolet aging on the rheology and chemistry of LDH-modified bitumen was studied by means of dynamic shear rheometer (DSR), thin-layer chromatography with flame ionization detection (TLC-F...

INTRODUCTION An industrial hygiene database has been constructed for the exposure assessment in a study of cancer risk among asphalt workers. AIM To create models of bitumen and polycyclic aromatic hydrocarbons (PAH) exposure intensity among paving workers. METHODS Individual exposure measurements from pavers (N = 1581) were collected from 8 countries. Correlation patterns between exposure ...

BACKGROUND We conducted a nested case-control study in a cohort of European asphalt workers in which an increase in lung cancer risk has been reported among workers exposed to airborne bitumen fume, although potential bias and confounding were not fully addressed. OBJECTIVE We investigated the contribution of exposure to bitumen, other occupational agents, and tobacco smoking to the risk of l...

A new interpretive algorithm has been developed for bitumen spectra analysis in tar sands. This algorithm utilizes Low Field NMR method for measurements. With the use of appropriate basic components spectra database the algorithm extracts information on bitumen contents, immovable and movable water saturations. The basic components spectra database can be built by analysis of spectra for simila...

We conducted a cross-shift study with 66 bitumen-exposed mastic asphalt workers and 49 construction workers without exposure to bitumen. Exposure was assessed using personal monitoring of airborne bitumen exposure, urinary 1-hydroxypyrene (1-OHP), and the sum of 1-, 2 + 9-,3-,4-hydroxyphenanthrene (OHPH). Genotoxic effects in WBC were determined with nonspecific DNA adduct levels of 8-oxo-7,8-d...