DETERMINATION OF THE BITUMEN CONTENT OF MIXES OF ROAD TAR AND BITUMEN

BESTIMMUNG DES BITUMENGEHALTES IN MISCHUNGEN AUS STRASSENTEER UND BITUMEN

IN CONNECTION WITH THE REVISION OF DIN 1995, IT IS DESIRED TO DEVELOP A RELIABLE METHOD OF DETERMINING THE BITUMEN CONTENT OF ROAD MIXES WITH ROAD TAR, TO REPLACE THE INADEQUATE TEST METHOD U23. AN ATTEMPT WILL BE MADE TO DETERMINE WHETHER AN ANALYTICAL METHOD CAN BE ESTABLISHED ON THE BASIS OF CHROMATOGRAPHIC SEPARATION INTO HYDROCARBON GROUPS. IN ORDER TO DETERMINE WHAT HYDROCARBON GROUPS ARE CONTAINED IN ROAD TAR, VARIOUS SPECIMENS WILL BE SEPARATED BY COLUMN CHROMATOGRAPHY ON SILICA GEL BY ELUTRIATION WITH ISO-OCTANE OR N-PENTANE, BENZENE AND ACETONE, INTO NON- AROMATIC HYDROCARBONS, AROMATICS AND RESINS. BY INFRARED AND ULTRAVIOLET SPECTROSCOPY, IT IS HOPED TO ESTABLISH HOW PRECISE THE DIVISION IS AND WHICH CLASSES OF SUBSTANCES THE FRACTIONS CONTAIN. IF NECESSARY THESE SPECTROSCOPIC MEASUREMENTS WILL BE SUPPLEMENTED BY GAS- CHROMATOGRAPHIC STUDIES.