Performance of Recycled Rubber Modified Binders in Warm Mix Asphalt Mixtures



The past few years have seen the introduction of the warm mix asphalt (WMA) technology in efforts to reduce the required energy for the production and construction of the asphalt concrete layer. The basic principle of the WMA technology is to lower the mixing and compaction temperatures of the produced mixture through lowering the viscosity-temperature relationship of the asphalt binder.

This paper evaluates the performance of terminal blend tire rubber-modified binder in WMA mixtures manufactured with two WMA technologies; Advera and Sasobit. The evaluation consisted of measuring the mechanistic properties of mixtures with and without moisture damage. The resistance of the mixtures to moisture damage was evaluated in terms of the impact of multiple freeze-thaw cycling on the dynamic modulus property.

The paper presents the results of the study showing the performance of terminal blend tire rubbermodified binder in WMA mixtures as compared to WMA manufactured with neat and polymermodified binders. The use of terminal blend tire rubber-modified binder with WMA mixtures significantly improves their resistance to moisture damage in terms of increased retained strength/modulus and reduced tensile/vertical strains within the asphalt layer. Among all mixture evaluated in this study, the best performance was obtained from the terminal blend tire rubbermodified mixtures treated with hydrated lime. This observation was true for control, WMAAdvera, and WMA-Sasobit mixtures.


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