Degree of Binder Activity on 100% Recycled Mixtures and Its Linear Viscoelasticity Behavior

To increase the content of Reclaimed Asphalt Pavement (RAP) in new recycled mixes, it is necessary to have a better understanding of the activation phenomena of the Reclaimed Asphalt binder, so it can better interact with the recycling agent in Recycled Asphalt Mixtures (RAM). Studies have reported temperature as an important influencing factor related to the RAP binder activity. This paper analyzed the influence of three mixing and compaction temperatures: 100, 140 and 170 °C, in the Degree of Binder Activity (DoA) of two different RAPs. One of them has neat asphalt binder (penetration 50–70) on its composition, and the other one has Polymer Modified Binder (PMB) (60/85, softening point/elastic recovery limits, respectively). To this comparison, artificial RAP mixes with similar characteristics to those of the original RAP (including the same conditions such as binder, grading curves, aggregate types and binder content) were produced in the laboratory. The DoA was estimated using the ratio between the indirect tensile strength result from 100% RAM and artificial RAM, for the same temperature. The type of RAP and the temperature influenced in DoA, since the first RAP presented short ratios, 8.9, 32.0 and 10.2% for 100 , 140 and 170 °C respectively, and the second RAP, presented 54,4 88,2 and 95.8% ratios for respective temperatures. The 100% RAP mixtures were furthermore evaluated with respect to their complex modulus; the rheological model 2S2P1D was used and it was possible to relate DoA to the linear viscoelastic behavior of the analyzed mixes.