In recent years, the use of crumb rubber as modifier or additive within asphalt concretes has allowed obtaining mixtures able to bind high performances to recovery and reuse of discarded tires. To date, the common technologies that permit the reuse of rubber powder are the wet and dry ones. In this paper, a dry-hybrid technology for the production of Stone Mastic Asphalt mixtures is proposed. I...

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. ...

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 ...

The Athel silicilyte is an enigmatic, hundreds of meters thick, finely laminated quartz deposit, in which silica precipitated in deep water (>~100-200 m) at the Ediacaran-Cambrian boundary in the South Oman Salt Basin. In contrast, Meso-Neoproterozoic sinks for marine silica were dominantly restricted to peritidal settings. The silicilyte is known to contain sterane biomarkers for demosponges, ...

Abstract As one of the most widely used nanomaterials in asphalt modification, nano-silica (nano-SiO 2 ) can significantly improve self-healing behavior eco-friendly. However, understanding mechanism nano-SiO is still limited. The objective study to reveal by using molecular dynamics (MD) simulations from nanoscale. A 10 Å (Å) vacuum pad was added between two same stable models represent micro-...

The aim of this study is evaluating the interaction between several base pen grade asphalt binders (35/50, 50/70, 70/100, 160/220) and two different recycled plastics (EVA and HDPE), for a set of new polymer modified binders produced with different amounts of both recycled plastics. After analysing the results obtained for the several polymer modified binders evaluated in this study, including ...

The functional silica/polyamide-imide composite films were prepared via simple ultrasonic blending, after the silica nanoparticles were modified by cationic surfactant-cetyltrimethyl ammonium bromide (CTAB). The composite films were characterized by scanning electron microscope (SEM), thermo gravimetric analysis (TGA) and thermomechanical analysis (TMA). CTAB-modified silica nanoparticles were ...

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...