PAVEMENT DESIGN INCORPORATING POLYMER-MODIFIED ASPHALT USING VARIOUS LABORATORY FATIGUE TESTS

Abstract

Recently, there has been growing interest in pavements constructed with polymer-modified asphalt, largely driven by the significant increase in traffic volumes and loads. This study aims to improve the understanding of polymer-modified asphalt's detailed mechanical behaviour and to support the development of reliable pavement designs that incorporate it. This study employed styrene-butadiene-styrene (SBS), including one hard and one soft variant, to modify asphalt binders used in two distinct types of mixtures. A series of laboratory fatigue tests - including the beam wheel tracker fatigue test (BWTFT), 4-point bending test (4PBT), and indirect tensile fatigue test (ITFT) - were conducted, covering both unmodified and polymer-modified asphalt materials under various testing conditions. The findings indicate that data from the beam wheel tracker fatigue test can provide a way forward in pavement design, enabling the application of standard laboratory fatigue tests with a shift factor. Furthermore, the laboratory results suggest that polymer-modified asphalt pavements can be designed similarly to conventional asphalt pavements, but with an adjusted fatigue characteristic. This shift can be derived from data obtained through the BWTFT, 4PBT, or ITFT.