Application of FTIR ATR method to examine the polymer content in the modified bitumen and to assess susceptibility of bitumen to ageing

Abstract

The infrared spectroscopy is suitable for the assessment of chemical compounds based on the plots of light intensity as a function of wavelength within the infrared range of electromagnetic spectrum. It enables the fingerprinting of substances, as well as detection and quantitative analysis of admixtures and additives present in a given substance. In case of bitumen binders the FTIR method may be adopted for the assessment of presence of ageing products. It effectively identifies impurities and discloses the presence of additives, e.g. adhesion agents. The FTIR device is also used for checking the presence of polymers in bitumen and even for determining the modification degree through an appropriate quantitative assessment. The present paper outlines practical applications of FTIR to testing bitumens, which include assessment of several types of binders prepared under control conditions, i.e. with a known polymer concentration and ageing degree. For comparison purposes, some commercial bitumens available on the Polish market and currently used for road pavement construction, have also been examined.