Welcome to the second edition of the CIRCUIT newsletter! Since our last update, the project has reached a critical phase, transforming innovative research into tangible results across Europe. We're excited to share major progress from our five pilot sites—in Spain, Croatia, Slovenia, the Netherlands and Italy—where our partners are implementing groundbreaking circular solutions, from 3D-printed bridge elements to adaptive energy systems and innovative asphalt mixtures. This newsletter also highlights our commitment to collaboration, featuring key presentations at major European forums like the RTR and ETRA Conferences. Read on to see how CIRCUIT is accelerating the transition towards a more circular and resilient transport infrastructure.

The CIRCUIT Spanish Pilot, led by MITMA with support from ACCIONA and the Universidad de Cantabria (UC), is deploying four essential use cases in the Cantabria Region across the Energy, Digitalisation, and Recycle Pillars.

The pilot enhances transport infrastructure by implementing adaptive lighting and efficient ventilation systems in the Lantueno tunnel (A-67), where the necessary purchase of frequency variators for the ventilation system is a critical next step. Additionally, a wrong-way driver detection system is being deployed on the A-8 highway, leveraging the UC's completed work on algorithm training and web application design.

The Recycle Pillar is a major focus, validating three innovative asphalt mixtures—the sulfur-based UBERBINDER™, which has been proven scalable , Bio-binders from tall oil (CTO), and Advanced Polymer Modified Bitumen (PMB). Extensive laboratory characterisation is ongoing for the CTO and PMB mixes, with the next steps focusing on defining optimal mix formulations (e.g., 30%RA+PTO with Reclaimed Asphalt) and preparing slabs for Accelerated testing via the Circular Road Simulator (CRS) between late 2025 and early 2026.

Installation and real-track testing for all use cases are scheduled to proceed throughout 2026, with the project concluding in April 2027.

Pilot 3: The Netherlands - Soil Stabilization and Recycling

The Dutch Pilot, led by WSHD and TU Delft, focuses on stabilising the Oostmolendijk dike using circular materials and advanced modelling. The team has tested soil mixtures incorporating secondary raw materials—wood ash and fly ash—sourced from regional by-products, demonstrating improved strength and reduced moisture sensitivity.

Next, these optimized mixtures will be tested with local organic soils, and full-scale implementation at the pilot site is expected by the end of 2025. Numerical and life-cycle analyses planned for 2026 will assess performance, sustainability, and cost-efficiency. Parallel studies using LEM and FEM models are evaluating dike stability and potential reinforcement solutions, including berms, sheetpile walls, and ground mixing.

Pilot 4: Slovenia - Recycling and Modular Construction

The CIRCUIT Slovenian Pilot, led by ZAG and CRNA (Road Management Agency), focuses on rebuilding the Center Bridge over the Meža river in Črna na Koroškem.

This project implements circular concepts across the Reuse, Recycle, and Digitalisation Pillars, despite initial setbacks with the Innovation Partnership procurement process. Key innovations include designing for reuse by incorporating Geosynthetic Reinforced Soil (GRS) Abutments built with local river debris , which was proven to have high frictional properties through large-scale shear and triaxial tests.

The project also focuses on the Reuse of reclaimed structural elements for the superstructure (e.g., steel I-beams and concrete T-beams) and the use of recycled materials in the prefabricated concrete slabs (e.g., recycled aggregates and waste bio-ash powders). The bridge's design will integrate a 3D Printed Safety Wall and a comprehensive Building Information Model (BIM) to generate a Digital Product Passport (DPP).

With the building permit documentation submitted , the next steps involve finalizing the construction documentation, conducting industrial-scale testing of RFID sensors within small-scale slab prototypes, and starting green public procurement for the construction contractor.

Pilot 5: Italy - Energy Efficiency in Road Tunnels

The CIRCUIT Italian Pilot, led by ANAS with support from ALGORAB and ACCIONA, is centered on the Energy Pillar through the comprehensive modernisation of infrastructure along the A91 motorway and the Selva Candida Tunnel, Casaleo and Nualetto Tunnels.

The core innovations include the design and implementation of the full Adaptive Lighting System (FAI) for both the motorway tunnels and the outdoor lighting plant. This involves the development of control algorithms and preliminary simulator tests in a simulated environment.

The pilot also focuses on designing and implementing a remote control and monitoring platform for the tunnel's ventilation systems. A significant deliverable is the deployment of hybrid (photovoltaic and wind) energy generators for light poles. The design phase for these poles is complete, and the tender process for the procurement and installation of the eleven hybrid lighting poles is currently underway. Following the contract awarding, production and installation will proceed, leading to the experimental monitoring phase and the final project report in April 2027.

Bringing Circularity to Life: CIRCUIT's Engagement Tools

At CIRCUIT, we believe that inspiring the next generation and engaging local communities is key to driving change. That’s why we’ve developed fun, accessible tools to explain complex circular economy concepts. We are thrilled to introduce two new communication assets focused on the local impact of our pilots in Slovenia and the Netherlands.

Meet the CIRCUIT Comics!

CIRCUIT Events: Key Milestones

 CIRCUIT Presents Holistic Approach to Sustainable Infrastructure at RTR Conference

In February, our partner Irina Stipanović (Infra Plan Consulting) presented the CIRCUIT Project at the RTR Conference in Brussels on 11-13 February 2025, where leading experts, innovators, and stakeholders gathered to discuss the latest road transport research results.

Her talk highlighted CIRCUIT’s holistic approach to circular and resilient transport infrastructures, focusing on how the project supports the deployment of green and innovative public procurement while promoting sustainable engineering practices to reduce environmental impact.

We were also delighted to see our sister project, LIAISON, featured in the same session on road infrastructure, maintenance, and circularity. Together, these initiatives are helping to reshape the future of sustainable transport across its entire life cycle.

♻️ Collaboration and knowledge-sharing are at the heart of innovation—thank you to everyone who joined the discussion!

CIRCUIT Partners ZAG and IECA Advance Circular Solutions

in Madrid

In March 2025, CIRCUIT partners ZAG (Slovenia) and IECA (Spain) met in Madrid for a technical workshop dedicated to innovation and sustainability in construction.

The meeting featured a lab visit at the Polytechnic University of Madrid, where IECA showcased advanced research in construction materials, including concrete prototypes with embedded sensors designed for performance monitoring and reuse.

Partners also reviewed progress on the Slovenian pilot project, exploring the use of recycled materials in 3D-printed bridge safety walls, with a strong focus on durability, safety, and sustainable infrastructure design.

The day concluded with strategic discussions at IECA’s headquarters, reinforcing collaboration and setting the course for the next phases of CIRCUIT.



♻️ By bridging research and real-world applications, CIRCUIT continues to advance circular and resilient solutions for future transport infrastructures.

CIRCUIT at ETRA Conference: Paving the Way for Tyre Recycling in Public Works

From 25 to 27 March, the CIRCUIT Project was presented at the 30th ETRA Conference on Tyre Recycling, a milestone event celebrating three decades of innovation in sustainability and circularity.

During the panel “Public Works Gain Space”, Dr. Thierry Goger (FEHRL) highlighted how CIRCUIT promotes the uptake of recycled tyre materials—including rubber, steel fibers, and textile fibers—in road construction and sustainable cement-based applications. His talk underlined CIRCUIT’s role in driving innovative engineering practices and supporting the transition towards circular, low-impact transport infrastructures.

With natural rubber now classified as a Critical Raw Material (CRM) by the EU, CIRCUIT contributes to exploring new pathways for fine rubber powder, devulcanized rubber, and recovered carbon black, helping unlock the potential of recycled resources for greener transport solutions.



♻️ By integrating circularity into transport infrastructure, CIRCUIT is paving the way for a more resilient and sustainable future.

From Theory to Town: Dutch Open Day Shows Local Impact of Circular Solutions

In April, Waterschap Hollandse Delta hosted an Open Day in the Netherlands, sharing project results with the local community and stakeholders.

Spread across five locations, the event welcomed over 600 visitors and created space for dialogue, feedback, and local perspectives on how circularity can be applied to real infrastructure challenges.

♻️ By engaging communities directly, CIRCUIT helps turn circular solutions into shared progress on the ground.

CIRCUIT at FIRM25 – Advancing Circular and Resilient Transport Infrastructures

On 6 May 2025, the CIRCUIT project was featured during Session 3 of the FIRM25 Meeting, dedicated to “Fostering Circular and Resilient Transport Infrastructures”.

The session brought together leading experts and EU-funded projects driving the transition towards more sustainable, circular, and climate-resilient infrastructure systems. Irina Stipanović, CIRCUIT’s Technical Coordinator from Infra Plan Consulting and Mario Bačić, Associate Professor, University of Zagreb represented CIRCUIT, presenting the project’s vision and achievements in embedding circular principles across transport infrastructure design, maintenance, and lifecycle management.

Alongside CIRCUIT, speakers from the MIRIAM and LIAISON teams shared complementary approaches to resilience and circularity. The discussion, moderated by Prof. Ciaran McNally (University College Dublin), emphasized that building resilient infrastructure is not only a technical challenge but a vital societal mission.

The session reinforced the shared commitment of European projects to accelerate innovation and collaboration for a more sustainable transport future.

CIRCUIT 5th General Assembly

As CIRCUIT enters the second half of its journey, consortium members came together online for the project’s 5th General Assembly.

The meeting confirmed that all work packages are on track, with results set to become increasingly visible across the five pilot sites in the coming months.



♻️ CIRCUIT is moving from planning to tangible impact—the best is yet to come!

CIRCUIT 6th General Assembly in the Netherlands

On 25–26 September 2025, the CIRCUIT consortium gathered in Ridderkerk (Rotterdam) for its 6th General Assembly, generously hosted by Waterschap Hollandse Delta.

As the project officially enters its implementation phase, partners from across Europe came together to exchange updates and define the next milestones.

The two-day meeting provided an opportunity to witness circularity in action during an on-site visit and to discuss the upcoming steps as five pilot projects transition from planning into real-world application.

The energy and collaboration demonstrated in Ridderkerk reaffirm CIRCUIT’s mission: to turn innovative circular concepts into tangible solutions for more sustainable and resilient European transport infrastructures.

Stay tuned for more updates as CIRCUIT moves full speed into implementation!

Slovenian Pilot Community Engagement Success

The CIRCUIT Slovenian Pilot team recently hosted a hugely successful Open Day in Črna na Koroškem, fostering strong community engagement for the Center Bridge project. The day kicked off with a fun and educational session at the local school, where 42 ten-year-old students were introduced to the project through the interactive CIRCUIT game.

The main event at the bridge site saw the ZAG team take the lead, welcoming over 120 students (aged 10 to 15) with detailed technical explanations and real samples of innovative materials like 3D printing components. The outreach continued into the afternoon with local residents, including the Mayor, engaging in project activities such as a quiz and receiving copies of the project comic and ZAG goodies. To ensure the learning continues, the team donated ten CIRCUIT games to the school, the municipality, and the ZAG team, wrapping up a great showcase of teamwork and local collaboration.

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