BESIX is actively taking steps to make a positive environmental impact and reduce its carbon footprint. One of these initiatives involves participating in research endeavours. In collaboration with a Ph.D. Researcher from Ghent University, Yasmina Shields, BESIX Engineering is playing an instrumental role in the SMARTINCS project as an industrial sponsor.
Funded by the EU Horizon 2020 research and innovation programme, the SMARTINCS (Self-healing, Multifunctional, Advanced Repair Technologies in Cementitious Systems) project aims to incorporate new life cycle thinking and durability-based approaches in the concept and design of concrete structures. Key enabling technologies such as self-healing concrete, repair mortars, and grouts are utilised for this purpose.
BESIX’s contribution
BESIX's involvement in the project includes the construction of nine concrete walls, serving as demonstrators, under various experimental conditions. The objective is to assess the efficacy of self-healing or repairing agents in repairing cracks within concrete structures, as well as to address any practical issues that may arise with regards to constructability and the implementation of this technology into common practice. These 2 m² and 10 cm-thick demonstrator walls were meticulously built on the Henneaulaan bridge site in Zaventem, adhering to real job-site execution conditions. The site was selected due to its availability of necessary formwork materials and convenient concrete delivery.
Unconventionally, deliberate efforts were made during the construction process to induce cracks in the concrete walls. Techniques such as excessive cement usage, minimal reinforcement, absence of horizontal reinforcement, rapid formwork removal, and other unfavourable building conditions were implemented.
Yasmina Shields: “I express my deep gratitude to BESIX for not only locating the site but also providing the necessary resources and skilled workforce for this project. This truly exemplifies BESIX’s unwavering dedication to exploring every avenue in the pursuit of sustainability.”
A heartfelt appreciation to Gontran Herrier, Concrete Technologist at BESIX Engineering, Jaques van Niekerk, Technical Office Engineer, and his dedicated on-site team, for their invaluable contributions to the successful completion of this project.
The technique used
The researcher employed a system that involves embedding a network of polymeric tubes assembled and fixed to the steel rebars, prior to concrete casting operations. These perforated tubes facilitate the injection of products to fill cracks or apply water-repellent substances. The vascular network system is partially fabricated using a 3D printer and extruded tubes.
The reason why
The motivation behind this project lies in the fact that concrete, despite being a widely used construction material, is prone to cracking due to a number of factors like drying, shrinkage, insufficient reinforcement, restrained connections, etc. Such cracks pave the way for water and harmful elements like carbon dioxide or chloride (in marine environments) to penetrate, thereby reducing the lifespan of the concrete. Addressing cracks in concrete is an innovative approach towards sustainability, ensuring longer life cycles for concrete structures.
What’s next
Currently, the researcher is monitoring and testing the effects and benefits of the self-healing agent. Various healing products like resin, polyurethane, and water repellents are being examined for their efficiency in a laboratory setting. Tests are conducted both before and after the injection of these products into the vascular network. Additionally, core drilling will be performed on the walls where the product was injected to assess the efficiency of the process by several testing methods (water absorption, wave velocity,…).
Following the research and development phase, if the tests yield positive results, several subsequent steps such as certification, standardisation, and commercialisation will be necessary to bring the solution to market.
