An Interlaboratory Test Program on the Extensive Use of Waste Aggregates in Asphalt Mixtures: Preliminary Steps

In view of increasing social and environmental consciousness, a circular approach in waste materials management in order to convert them into new secondary resources is becoming more necessary. Given this context, an interlaboratory testing program (ILTP) focusing on maximizing the use of waste aggregates replacing conventional virgin ones has been launched in the framework of the RILEM Technical Committee on “Valorisation of Waste and Secondary Materials for Roads”. Construction and demolition wastes, recycled concrete aggregates and steel slags were selected as waste aggregates to be investigated. A reference mixture prepared with natural virgin aggregates was also considered for comparison purposes. This paper describes the results achieved during the first steps of the ILTP concerning: (i) the basic characterization of the selected marginal aggregates; (ii) the Marshall mix design of different asphalt mixtures prepared with one or more waste aggregates. Overall, the experimental results collected during these preliminary steps seem to confirm that the selected marginal aggregates can be considered as valid alternatives for the traditional road materials, while not jeopardizing their performance.