Effect of active fillers on cracking performance of bitumen-stabilised materials

A laboratory investigation was conducted to evaluate the effect of active fillers on the cracking resistance of bitumen-stabilised mixtures. Nine types of stabilised mixtures composed by 100% recycled aggregates, different blends of fillers (cement, lime and common filler) and bitumen emulsion or foamed bitumen as stabilising agents were used to build three consecutive experimental sections on a constructing road. Cores of the trial sections were tested in a laboratory according to a Superpave Indirect Tensile Test (IDT) procedure developed for quasi-brittle materials. An in-house-developed Digital Image Correlation (DIC) software code was applied. The results show the benefit of the active filler to the mixture’s cracking resistance in terms of increased tensile limits to failure. Significant damage has shown to be strongly more localised in mixtures containing active fillers. Among all the blends, the more promising blend combination consists in 1% of cement, 2% of lime and 1.5% of traditional filler.