Estudio de viabilidad del uso de polímeros reciclados para la mejora estructural de infraestructuras de transporte

Zusammenfassung

The increase in loads and traffic experienced in recent decades by transport infrastructures derived from globalization has resulted in an increase in their structural demands. Within the scope of bituminous mixtures, the use of polymer-modified bitumen has traditionally served to meet these demands by preventing the main problems that cause premature deterioration of infrastructure. However, the increased investment costs involved leave such solutions out of the reach of most of the infrastructure network and the maintenance tasks that concentrate the bulk of today's investment. As a measure to alleviate this problem, the use of recycled polymers plays a dual role: on the one hand, obtaining the benefits of polymers at a lower cost and, on the other hand, helping to alleviate the environmental problem arising from the increase in the consumption of plastics today and the generation of waste that this entails. Nevertheless, to achieve this objective it is necessary to provide mixtures incorporating recycled polymers with sufficient guarantees both from a technical and economic point of view. This gives way to the research contained in this doctoral thesis whose main objective is the study of the feasibility of incorporating recycled polymers into transport infrastructures as an economical and sustainable alternative to improve their structural capacity. Although several studies have analyzed the use of this type of material, its use is not yet widespread, which is why it is necessary to improve confidence about the potential of its use at different levels of the mixture and throughout its useful life. This way it will be possible to extend its employment to a greater number of routes and applications. To achieve these objectives, a series of work steps were carried out, including (i) the assessment of the interaction between the binder and recycled polymers as a means of determining the optimal modification process; (ii) the study of the influence of recycled polymers on the different scales of the bituminous mixture in order to improve understanding of the benefits of their use and to select the most appropriate; (iii) the study of the influence of the method of addition of the polymer to bituminous mixtures; (iv) a study of the long-term mechanical behaviour of bituminous mixtures modified with recycled polymers applied to different transport infrastructures; (v) and a structural analysis, a comparison of costs and potential consumption of recycled polymers by the mixtures incorporating them. The results obtained at the different study scales have made it possible to determine the feasibility of the use of recycled polymers of type LDPE, LLDPE with fibres and PNFVU for the structural improvement of different transport infrastructures. Both from technically point of view, being able to obtain properties similar to the high performance mixtures currently used, as from an economic point of view, with lower manufacturing costs and potential thickness reductions that invite the use of these mixtures to be extended. Alongside this, the use of these materials opens up a new avenue to increase the recycling rate of plastics, helping to alleviate one of the most important environmental problems in today's society.