HEALCON - Self-healing concrete to create viable and sustainable concrete structures

Project start January 2013. Completed December 2016.

Summary

The Danish Technological Institute is one of partners in the HEALCON project, which is a project funded by the European Union's FP7 Programme and coordinated by Ghent University in Belgium. The project aims at designing smart concrete with self-healing properties to create durable and sustainable concrete structures, helping reduce structural maintenance costs. Cracks in concrete structures are limited to a width of 0.2-0.4 mm depending on concrete exposure class and type. Such small cracks do not impair structural stability, but they may compromise concrete durability. Thus, regular inspections, maintenance, and eventual repair are compulsory to ensure safety and service-life of concrete structures, yielding enormous public expenditure. The project partners estimate that annual savings of EUR 120 million on structural maintenance could be reached if existing bridges, tunnels, and earth-retaining walls in Europe were produced with self-healing capable materials. The HEALCON partners are exploring three main techniques to make large-scale and cost-effective self-healing concrete a reality in the construction industry. The investigated solutions are tailored for different structural applications. Specifically, non-elastic healing materials, e.g. calcium carbonate precipitated by bacteria or new cement hydrates whose formation is stimulated by the presence of hydrogels, are being investigated as an alternative to heal early-age cracks. Whereas elastic polymeric healing agents are suggested to heal moving cracks under dynamic load. Laboratory tests using adapted monitoring techniques and supported by computer models will determine the self-healing efficiency of the developed solutions. After laboratory investigations, HEALCON partners will focus on scaling up lab-scale applications into cost-effective industrial processes and products. At a final stage, large-scale lab tests and concrete structures will validate the efficiency of the developed materials. Life-cycle cost analysis will evaluate the impact of self-healing technologies on economy, society, and environment compared to traditional construction methods. Self-healing concrete is expected to be more expensive than regular concrete, but the trade-off between price and structural durability is of advantage to the public budget. At present, ministries of public work have expressed an interest in using the new techniques in situations where cracks would be particularly problematic or difficult to repair.

Project objectives

• Design, develop, test, apply, and evaluate self-healing methods for concrete structures
• Develop lab-scale and industrial proof-of-concept

Participants

• Acciona Infraestructureas S.A., ES
• Avecom N.V., BE
• Comercializadora Espanola De Innovaciones Y Materiales, ES
• COWI A/S, DK
• Danish Technological Institute, DK
• Delft University of Technology (Coordinator), NL
• Devan-Micropolis, PT
• Fescon OY, FI
• Gent University, BE
• Technical University of Munich, DE
• TTI-Technologie-Transfer-Initiative GmbH, DE
• VVT Technical Research Centre of Filand, FI