The MAIN OBJECTIVE of the project Fostering the Circular Economy through the recycling and valorisation of residual fibers for the manufacturing of more sustainable and durable asphalt mixes (ASFIVAL) is to reduce the environmental and economic impact of the transport infrastructures by means of the optimized design of new bituminous mixtures incorporating residual fibers to improve their mechanical performance
The specific objectives that must be reached at the end of this project are the following:
Complying with this first objective will have as starting point a detailed state-of-the-art of the materials likely to be used in bituminous mixtures. A study of the potential companies that may generate useful waste or by-products to improve the mixtures properties will be carried out, including companies producing aramid and the textile, paper and plastic industries.
The fibers composition, physical properties like length and thickness, thermal properties or resistance to loads are variables that will determine their performance when incorporated to the bituminous mixtures. Besides, with the aim to select the most suitable fiber not only from a mechanical point of view, variables like homogeneity, amount generated or possible alternative applications will also be considered.
Fibers can work in different ways depending on their characteristics, either varying the rheological performance of the mastic, strengthening the mortar or modifying the mixture modulus. Their characteristics will determine, therefore, their dosage as well as the final mixture design.
Given the different performance of bituminous mixtures, both the design of an asphalt concrete and a porous mixture adapted to the selected residual fibers will be optimised determining in each case the type of optimal fiber, its dosage and possible modifications to carry out in each mixture with respect to the conventional ones in order to improve their mechanical properties.
The pavement durability will be studied both by numerical simulation with a last generation software used in the assessment of pavements and, in parallel, by means of laboratory tests of recent development in USA. The use of this software and the application of these tests are possible thanks to the previous collaboration of the GITECO with the laboratory of bitumen and asphalt mixtures of the US Federal Highway Administration (FHWA).
The aim of this project is to improve the resilience of the roads by developing an enhanced asphalt mixture with fibers coming from different industrial processes in order to reduce the necessary maintenance level. However, it would be senseless to use those residual fibers in bituminous mixes for the sake of the Circular Economy if these new mixtures cannot be further reused. The recyclability of the mixes with residual fibers will be studied accordingly. Fibers will be incorporated in the mixtures as if they were RAP material, ensuring this way their proper reuse.
The environmental impacts associated to the application of the technology developed along this project will be assessed through a Life Cycle Analysis (LCA). Similarly, a Life Cycle Cost Analysis (LCCA) will be carried out that helps to determine the benefits provided to the promotors and potential users of this technology, as well as their economic interest from the point of view of the national and international road construction markets.
On the basis of the international context where the GITECO-UC research group currently works, their participation in European projects and the collaboration with FHWA of the US, the dissemination of the project will be maximised at international level. The collaboration with research groups and European companies interested in the topic of the project allows to foresee a more than adequate transfer of the knowledge achieved. Finally, the results obtained along the project will be taken to several national and international congresses and published in open access journals of the highest possible impact, all novelties been announced in the bilingual website published to this end.