INCORPORATION OF POLYMER MODIFIED RECYCLED CONCRETE IN ASPHALT MIXES: A SUSTAINABLE APPROACH

Abstract: This paper delves into the use of a non-conventional approach to sustainable construction practices in road building. It focuses on exploring the practicality of using recycled concrete aggregates (RCA) in polymer-modified asphalt mixes, aiming to foster the sustainable utilisation of natural aggregate resources and alleviate the burden on landfill space. To effectively employ RCA in asphalt mixes, it is imperative to understand its physical, mechanical, and chemical properties comprehensively. Unlike natural aggregates, RCA bears a cement paste residue on its surface, which is inherently more reactive. This heightened reactivity holds the potential for both positive and negative performance impacts on asphalt pavements.
A review of existing literature underscores the efficacy of RCA as a substitute for natural aggregate in both unbound layers and hot mix asphalt (HMA). However, the quality of the resulting mix is significantly influenced by the source of the RCA. Hence, the core objective of this laboratory-scale study is to ascertain the appropriateness of incorporating RCA from different sources into polymer-modified HMA for their potential use in road construction in South Africa. The outcome of this laboratory-scale investigation would guide practitioners and contribute to the sustainable use of RCA in the country, aligning with the broader commitment to environmentally friendly infrastructure development.