RIDIAS project: Innovative and sustainable pavement with second life aggregates

The objective of the RIDIAS project was to demonstrate the technical feasibility of substituting a certain percentage of mixed recycled aggregates in the composition of foundations and concrete pavements for housing estate roads. The use of (more) second life materials is cost-saving (20 to 30%) and more environmentally friendly.

To achieve this, various innovative pavement structures were implemented on an experimental site (the Ridias road in Gembloux).

In a first phase, different types of recycled materials were collected to determine two compositions for the foundations and four compositions for the pavement. The objective was to define compositions that would ensure the performance necessary for the durability of the pavement, while maximising the use of recycled materials.

In a second phase, prior to the works, samples of the recycled materials selected in the preliminary phase were taken from the stocks intended for the worksite. The compositions were adapted to these materials, but also to make maximum use of the natural materials available in the concrete mixing plant, and to minimise the number of different fractions to be stored there.

In a third phase, the mixes were applied on site. BRRC monitored the various stages of the construction site and carried out control tests and sampling of newly laid materials. Destructive and non-destructive tests were carried out to evaluate the performance of the materials.

In a fourth and final phase, the properties of the concrete pavements on the Ridias site were compared with concrete pavements also containing mixed materials that were poured several years ago and from which samples were taken.

For more information on the chosen types of foundations and pavements and the results of this project, we invite you to consult our 2019 Activity Report in French or Dutch.