Characterisation of asphalt mixture cracking behaviour using the three-point bending beam test

Abstract

The use of a three-point bending beam (3PB) test was investigated to characterise hot mix asphalt (HMA) cracking behaviour. Fundamental HMA fracture properties, identified as tensile strength and fracture energy density at first fracture, were determined for six different asphalt mixtures (two natural and four SBS polymer modified) applying the HMA Fracture Mechanics framework. Full-field strain maps obtained from an in-house developed digital image correlation-based method were observed to better understand the crack initiation and propagation mechanisms in the 3PB specimen. The resulting fracture behaviour was predicted using a displacement discontinuity boundary element method to model the microstructure of the six asphalt mixtures and to predict their fracture properties. Both numerical and experimental results indicate that the fracture mechanism of asphalt mixtures can be properly described from 3PB test results when appropriate interpretation models are used.

Keywords:

• hot mix asphalt
• fracture mechanics
• SBS polymer modifier
• three-point bending test
• digital image correlation
• displacement discontinuity method

Notes

1. Email: [email protected]

2. Email: [email protected]

3. Email: [email protected]

Additional information

Notes on contributors

Bjorn Birgisson

1

Antonio Montepara

2

Gabriele Tebaldi

3