Modified Test Method to Investigate Low-Temperature Behavior of Bitumen and Mastic

Cracks from low-temperature shocks or exposure to diurnal freeze-thaw temperature variations are a serious concern for asphalt pavements, limiting their service life. Accurately assessing pavement behavior under these conditions and identifying the relevant characteristics may help to extend pavement service life and minimize maintenance costs. Hence, reliable tests for simulating the pavement’s low-temperature performance and providing data for a reliable behavior prediction are required. The objective of this research is to evaluate thermally induced cracking performance of mastic as key constituents of asphalt mixtures. An enhanced laboratory approach, the annular restrained cold temperature induced cracking (ARCTIC) test, which induces thermal cracks in a ring-shaped sample surrounding a core made of invar steel, was used to evaluate the low-temperature cracking behavior of one bitumen and three mastic types. The materials’ low-temperature viscoelastic and strength properties were also measured with the standard dynamic shear rheometer (DSR) and fracture toughness test (FTT). Based on the obtained experimental results, it is shown that the addition of filler changes the low-temperature cracking resistance of bitumen profoundly, which is attributed to the reduction of the material’s thermal contraction coefficient. The results also indicate that the ARCTIC test can capture the combined effect of the material’s viscoelastic properties, strength, and thermal contraction on its low-temperature performance.