Results of surface hot-in place recycling (remix) of modified and alternative asphalt mixtures in Finland. Part I: mixture scale

Surface hot-in place recycling of asphalt mixtures has been conducted on Finnish roads for several years. The procedure is performed either in full-lane ('remix') or shorter widths ('rut-remix'). In a 2020–2021 project, different mixture types were subjected to both kinds recycling; reference mixtures, and modified with aramid fibres, FEP elastomer pellets, polymer, Storelastic rubber additive, recycled shingles, steel slag, soft bitumen. This paper (Part I) presents the results an extensive laboratory test plan at scale. Asphalt cores recovered from four roads. Various tests original state (aged, before recycling) after (remix rut-remix), including strength (ITSR), stiffness, Prall abrasion, creep permanent deformation, as well bulk, air voids, thickness measurements. effect remix/rut-remix assessed using scores calculated mixture-scale results. show that remix rut-remix are highly heterogeneous processes, affecting every material differently sometimes erratically. Adequate void contents evenness compaction critical good performance. provide performance database extended group materials. Data appendices accessible link bottom page.