Bituminous Binder

Bitumen is a complex material with specific visco-elastic properties. Modifiers are now commonly used to enhance the performances of asphalt materials. This makes bituminous binders even more complex with different phases and interphases in the binder. Within the RILEM TC 272-PIM, the TG1 aimed at investigating complex bituminous binders through multiple testing. An inter-laboratory program was conducted with 17 laboratories. Seven binders were evaluated, in two groups, one with polymer modified bitumen and the second with liquid additives. In addition to conventional property measurements, extensive efforts were undertaken to investigate fundamental physical properties, including rheological measurements, chemical, thermal, and morphological characterisations. Current conventional tests, used for binder characterisation, were initially developed for pure bitumen. The extensive experiment, conducted by TG1, clearly highlights the limits of conventional properties, and brings more fundamental understating how the morphology of complex bituminous binders can affect the overall behaviour of bituminous binders in a wide range of conditions. This chapter first describes the experimental plan as conducted by the different laboratories. After that, it displays in detail the results of each test for each group of binders and includes some comparisons between parameters according to the expected conditions and performances. Already numerous standalone publications have been published for specific test results to address variability and in-depth interpretation of outcomes. The results discussed in this chapter are mostly focusing on the relevance of each test to better distinguish between complex bituminous binders and not addressing variability of results.