Correlation between rheological tests on bitumen and asphalt low temperature cracking tests

Choosing an asphalt binder capable of withstanding low temperature cracking in the field is a challenging task; particularly, tests that scrutinise the binder's low temperature cracking behaviour do not always capture the corresponding performance of the asphalt mixture. The primary goal of this study is to determine the correlations that possibly exists between bitumen and asphalt tests at low temperature. This research considers various types of laboratory tests on the binders and corresponding asphalt mixtures as specified by various road authorities in their guidelines and specifications, such as the Glover-Rowe parameter (G-R) through frequency sweep (FS) test, indirect tensile strength (IDT St) through indirect tensile test (IDT) and fracture strength, fracture energy and secant modulus through semi-circular bending (SCB) at low temperature. Several types of polymer-modified bitumen utilising both elastomers and plastomers as well as standard unmodified bitumen were tested and the results were statistically compared with those from the asphalt mixtures tested at the same temperature. The IDT St, fracture strength, fracture energy, and secant modulus of the asphalt mixtures at various temperatures (-10, 0, 10 ℃) were correlated with the G-R parameter of the binders. The correlation was further examined by grouping some of the binders into families of similar polymers to confirm the statistical fit between bitumen and asphalt mixtures testing. The results show that the SCB fracture energy is a better indicator for capturing the low-temperature performance of asphalt materials than other parameters. In addition, the strength properties of asphalt mixtures from IDT tests are strongly correlated with the G-R parameter of binders.