Semi-circular Bending (SCB) Test—Modified Method and New Test Parameters

For several years the crack propagation test data of bituminous mixtures according to CSN EN 12697-44 have been collected and evaluated at CTU in Prague. Over time the standardized test procedure was adapted to the conditions more suitable to be used in the Czech Republic—in terms of test specimen compaction, availability of cutting discs of suitable thickness, diameter of test specimens, loading speed etc. Some of the other conditions of the test were adapted as well as the procedures of data logging and subsequent evaluation of raw data. Over the years it has been identified that the strict focus only on fracture toughness is probably not correct or at least not sufficiently effective. The characteristics of fracture energy have been introduced and further studied. This paper compares the fracture toughness and fracture energy characteristics of selected sets of various types of asphalt mixtures.