Chemometrical performance and composition prediction of bituminous binders based on MIR and TD-NMR analyses

The broad characterisation with many techniques of the chemical / rheological properties of bitumen is rather challenging and complex, even more as these properties change during ageing and by using additives. Therefore, it would be highly desirable to reduce the analytical effort by using chemometrics to predict these properties. Here, we present a chemometrical study based on mid-infrared (MIR) and 1H-time-domain-nuclear magnetic resonance (TD-NMR) spectroscopy. The MIR spectra were correlated with various chemical and rheological bitumen properties. A high predictive power could be evidenced for the asphaltene content as well as for rheological parameters (BTSV, elastic recovery of the multiple stress creep recovery, and the softening point). Furthermore, the chemometrical approach could successfully be used to differentiate with high accuracy between fresh and aged samples as well between unmodified bitumen and bitumen modified with different additives. Initial studies based on TD-NMR also yielded good models for most of the parameters under investigation.