Preliminary Characterization of Concrete Made with RAP Aggregate

The use of recycled aggregates allows to reduce the environmental impact of concrete materials, by reducing the amount of waste and limiting the consumption of natural resources. Recycled asphalt pavement (RAP) is a granular material that comes from the milling of road pavements whose size and distribution make it suitable as aggregate for concrete. The environmental benefits of the replacement of natural aggregate with RAP need to be assessed with a better understanding of the long-term behavior of RAP concrete, considering the evolution of its performance in time and its ability to guarantee an adequate service life when exposed in operating conditions. This note presents the preliminary results of a research on the effect of RAP on concrete properties. The addition of RAP aggregate affects concrete properties at fresh and hardened state. Some parameters showed clear trends with the percentage of RAP, however also other factors (e.g. w/c ratio and curing time) seem to play a role. Compressive strength and dynamic modulus of elasticity of RAP concrete were always lower compared to reference concrete, while the electrical resistivity did not show a clear trend. Further investigations will be carried out to clarify the role of RAP aggregate.