Effectiveness of Hydrated Lime Filler on Fracture and Cracking Properties of Polymer and Crumb Rubber–Modified Asphalt Mastics

This study evaluates fracture and toughness behavior of different types of mastics prepared using polymer-modified asphalt (PMA) and crumb rubber–modified asphalt (CRMA), in combination with basalt (B) and hydrated lime (HL) fillers. The asphalt mastics were prepared for filler to binder (F/B) ratio of 0.6 and 1.0. For F/B = 0.6, 2 combinations of mastic, namely, B = 60 % and HL = 0 % and B = 40 % and HL = 20 %, were prepared using PMA and CRMA asphalt binders. Likewise, for F/B = 1, 2 combinations of mastic, namely, B = 100 % and HL = 0 % and B = 80 % and HL = 20 %, were prepared using PMA and CRMA asphalt binders. Therefore, four different asphaltic mastic were prepared for PMA and CRMA to understand performance of asphalt mastic with and without HL in combination with B fillers. The fracture and toughness behavior of asphalt mastic was investigated using double-edge-notched tension (DENT) and force ductility (FD) test, respectively. The overall test results infer that, in addition to nature of fillers, filler quantity and type of binders have significant impact on the fracture and toughness potential of asphalt mastic at intermediate and sub-intermediate temperature. The DENT test results indicate that the inclusion of HL had an effective contribution in enhancing the fracture resistance of base PMA mastic prepared with low F/B ratio (0.6), whereas the addition of HL filler did not show improvement in the fracture resistance potential of the base CRMA mastic. Similarly, the toughness ratio signifies that the cracking resistance potential of PMA and CRMA mastics can be improved with the addition of HL filler irrespective of F/B ratio.