Identification and Quantification of High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), and Polypropylene (PP) in Asphalt Binders Using Differential Scanning Calorimetry (DSC)

Abstract

The use of plastics in road construction has gained significant traction in recent years, and iden-tifying the type and quantity of plastic in asphalt blends is important for quality control. Previously the au-thors demonstrated that the Fourier Transform Infrared Spectrometer (FTIR) can only identify PP, while nei-ther FTIR spectrometer nor the force ductility test can detect polyolefin plastomers like HDPE and LDPE. This study presents a DSC-based method to identify and quantify HDPE, LDPE, and PP in asphalt-plastic blends using a calibration curve. The curve was developed using enthalpy (Hm) and plastic percentage data from HDPE, LDPE, and PP-modified PG 67-22 and PG 58-28 binders. The calibration was validated with PG 64-22 binder modified with the same plastics. The results confirm that DSC is a reliable and efficient tech-nique for accurate and precise identification and quantification of HDPE, LDPE, and PP plastics in asphalt binders.