Introduction

This invention refers to the performance of new additives for bitumen and bituminous conglomerates to reduce the fumes generated during the processing of asphalt concrete. The new additive is able to trap toxic molecules, avoiding their dispersion in the environment at high temperatures, with advantages both on the health of the operators and on the environment itself.

Technical features

ANSES recommends limiting worker exposure to bitumen and bituminous emissions. The only additives present in the market (waxes, zeolites, and surfactants) limit the fume emission by decreasing the temperature during the application and consequently, mechanical properties of the bitumen are strongly modified. The new additives – silica-based mesoporous powders – are able to entrap volatile fumes avoiding their release at high temperatures, leaving the functionality and quality of the bitumen unchanged. To quantify and characterize the emitted fumes, thermogravimetry (TGA) and gas chromatography-mass spectrometry (GC-MS) have been used along with Dynamic Shear Rheology (DSR) to check the rheological properties of the bitumen after the insertion of specific additives. The analyses showed, at the typical processing temperatures, a significant reduction in the weight loss of the treated bitumen compared to the original one.

Possible Applications

• The additive is added to bitumen for road paving;
• The use is particularly indicated in refineries where huge masses of hot bitumen are moved;
• Research purposes.

Advantages

• Absorption of the fumes without modification of the temperature of bitumen handling;
• Reduced exposure to emissions;
• Easy application that does not require significant changes to production plants;
• Economic savings for companies that produce conglomerate and refineries.