This thesis proposes a design with the reuse of decommissioned wind turbine blades (WTBs) as structural elements in highway noise barriers. While wind energy continues to grow rapidly, the decommissioning of turbines is generating a large and increasing stream of composite blade waste. This waste is difficult to recycle and often disposed through environmentally harmful methods such as landfilling or incineration. At the same time, WTBs still possess valuable mechanical properties that make them suitable for structural reuse applications.

The research develops and tests a modular noise barrier concept in which 12-meter blade segments are horizontally placed into U-shaped steel frames. The design takes advantage of the natural blade curvature to improve acoustic performance, while focusing on ease of assembly, durability, safety standards and drainage. Key features include capped and sealed segment ends, anti-graffiti coatings, acoustic cover strips, and integrated emergency exits.

The resulting concept demonstrates that WTBs can be repurposed into feasible, scalable, and structurally reliable noise barriers. The design offers a circular way for storing composite material until advanced recycling technologies become more widely available to reuse it, while it acts as a functional noise barrier. While further development is required in areas such as logistics, cost, and market acceptance, this thesis highlights the potential of structural reuse to extend the material life of blades and contribute to more sustainable infrastructure projects.

This thesis presents the design process of a novel noise barrier design made from horizontally arranged, decommissioned wind turbine blade material.

To address climate change challenges worldwide, wind power is increasingly being adopted. The wind turbine blades (WTBs) used for them are decommissioned after 20-25 years, at which point a problem emerges: the complex material composition makes that current end-of-life options result in the loss of material value without regaining significant economic value. The aim is therefore to structurally reuse WTB material in applications that preserve material integrity and prolong its lifetime. Scalable and long-lasting noise barriers are consequently identified as a fitting opportunity. This thesis focuses on horizontal arrangements of WTB material for use in a noise barrier as this is underexplored and will more closely resemble conventional building materials.

However, due to the variable curved shapes of WTBs, seamless assembly in noise barriers becomes challenging. Especially since gaps compromise the noise attenuation of a noise barrier. The proposed design is a solution to that challenge. It configures WTB panels in modular cassette-panel-cassette sections that allow for tackling alignment issues and can be easily (dis)assembled on frame structures. It attenuates noise by reflecting sound waves into the sky off of tilted, continuous front panels. A second column of panels further reduces sound transmission behind the barrier. Continuity and aesthetic harmony of the barrier in its surroundings is aimed for by use of climbing plants and a green colour palette.

The design follows from a process based on research. Led by a vision on durability, modularity and feasibility, ideas are developed into two concepts that are evaluated with input from experts. Subsequently, one integrated concept is further developed through (CAD) modelling, prototyping, testing, simulating, and a survey.

Three research questions are answered throughout this process. To ensure seamless fitting, a parametric model is developed to inform segmentation strategies. It filters out excessively curving parts to retrieve suitable panels. Alternating the orientation of cladded panels and avoiding seams in the road-side surface of the assembly further tackle alignment issues. Analysis of existing noise barriers reveals that mounting and assembly are facilitated by use of modular cassette-based systems. Cassettes can accommodate the WTB panels that contain variable curvature. A prototype is developed to test fastening options, resulting in an adjustable and reversible clamp design that allows for acoustic sealing. The resulting cassette-panel-cassette modules can be pre-fabricated off-location to reduce time spent on-location. Maintaining opportunities for next material lifecycles is found to largely depend on resizing activities. Large panels are prioritized as they can be more broadly reused than smaller ones. Additionally, protecting exposed core materials of sandwich structures (balsa wood and foam) against weathering is important. An explorative test with epoxy coatings provides starting insights to this end.

Overall, the valuable insights in this thesis culminate in a functional, feasible and desirable noise barrier made of WTB material, and highlights areas for further industry research.