The re-use of grinded asphalt as partial replacement of natural aggregates for concrete manufacturing

The paper focuses on the re-use of grinded asphalt as a partial replacement of natural aggregates for concrete manufacturing. Concrete mixtures were designed by considering up to 20% substitution of natural aggregates. The rheological and mechanical properties were compared to the reference concrete manufactured by using natural aggregates. The mixture showed a marked tendency to bleeding and segregation at the highest replacement percentage. Waste aggregates addition produces a positive effect on workability loss. The waste determines a decrease in the compressive strength up to 50% due to the weakness of cement paste/recycled aggregate interface. The maximum substitution was limited to 15% to avoid both rheological and mechanical underperformances. The grinded asphalt re-use in concrete produces also an increase in the dry shrinkage. The experimental results confirmed the possibility of the partial substitution of natural aggregates with grinded asphalt for accessory structures.