Sofia, October 10, 2025 The Territorial Cluster Centre for Circular Construction (TCCC) in Kremikovtsi, established under the MOBICCON-PRO project hosted the scientific session of the International Conference “Modern Trends and Innovations in Construction”, organized by the Faculty of Structural Engineering at the University of Architecture, Civil Engineering and Geodesy (UACEG). The workshop gathered more than 40 representatives of academia, businesses and public authorities engaged in the process of management of construction and demolition waste (CDW).
The session began with a practical presentation of the concept for construction and demolition waste (CDW) treatment, developed within the MOBICCON-PRO project. Mr. Alexander Tanev, Director for Circular Construction Technologies at Glavbolgarstroy, guided participants through the process of construction waste treatment – from collection and sorting to crushing, washing, and producing valuable secondary raw materials. During the visit, the guests observed the full cycle of operation and examined the range of materials produced at the facility. The installation developed and deployed under the MOBICCON-PRO project stands as a tangible example of how circular economy principles can be successfully implemented in the construction sector, turning innovation into measurable environmental and economic impact.
The academic session, moderated by Assoc. Prof. Dr. Eng. Rumyana Zaharieva, brought together leading researchers who presented results from recent studies in the field of sustainable and circular concrete technologies. Assoc. Prof. Dr. Eng. Zaharieva opened the session by highlighting the growing importance of integrating research, industry practice, and policy in order to achieve meaningful progress toward low-carbon construction.
The session presented a concise yet comprehensive picture of current research trends – from lab-scale innovation to applied engineering — all centered on making concrete a smarter, greener, and more resource-conscious material.
Assoc. Prof. Dr. Eng. Ivan Doykov explored the potential of trass as an active mineral additive through a comparative analysis of concretes designed for different exposure classes (XC2 and XC3). His research demonstrated that traditional materials can be optimized for durability and sustainability through precise mix design and mineral activation.
Building on the theme of resource recovery, Assoc. Prof. Dr. Eng. Zaharieva presented her pioneering work on using recycled fine concrete fractions as a partial substitute for cement. Her experiments showed that finely ground recycled materials can successfully replace a portion of clinker without compromising structural performance – a breakthrough approach that directly supports carbon reduction targets in construction. Many of the presented outcomes of the research work of Assoc. Prof. Dr. Eng. Zaharieva are elaborated during the activities under the MOBBICON-PRO project.
Further expanding the conversation on alternative binders, Prof. Dr. Eng. Ivan Rostovski introduced research on ground waste glass as a mineral additive, showcasing how waste valorization and material innovation can go hand in hand.
In a more strategic context, Chief Assist. Prof. Dr. Eng. Boyan Petrov addressed the main barriers to using recycled aggregates in concrete production. His analysis emphasized that while the technical feasibility is proven, progress depends on regulatory modernization, standardization, and financial incentives — areas that require immediate institutional attention.
The academic program also looked at long-term structural performance and early-age material behavior, with Assoc. Prof. Dr. Eng. Doykov presenting a structural evaluation of the “Bratska Mogila” Memorial Complex after fifty years of service, and Assoc. Prof. Dr. Eng. Georgi Ivanov and Assoc. Prof. Dr. Eng. Lychezar Hrischev examining the strength and deformation characteristics of concrete in its early stages. Their findings underlined the need for continuous monitoring and adaptive quality control methods.
Closing the research segment, Assoc. Prof. Dr. Eng. Zaharieva presented another compelling study – this time focusing on the rheological properties of concretes containing recycled brick aggregates. Her work revealed how particle morphology and porosity affect flow behavior and consistency, offering practical insights into designing workable, sustainable mixtures for the next generation of construction materials.
Discussions during the session converged on a shared understanding: scientific progress must be matched by regulatory and normative reform. Participants emphasized the urgent need for clear legal frameworks that allow the widespread use of recycled aggregates and secondary raw materials in concrete production. Aligning national standards with European directives was identified as a key step for accelerating the green transition of the construction industry.
The session concluded with a strong message of optimism – that through science, regulation, and cooperation, concrete can become not only stronger and more durable, but also cleaner, smarter, and truly circular
