Strengthening of Reinforced Concrete Structures with Carbon Reinforced Concrete—Possibilities and Challenges

• Published in: CivilEng 2022-06, Vol.3 (2), p.400-426
• Main Authors: Wagner, Juliane, Würgau, Carolin, Schumann, Alexander, Schütze, Elisabeth, Ehlig, Daniel, Nietner, Lutz, Curbach, Manfred
• Format: Article
• Language: English
• Subjects: bending tests; Carbon; Carbon fiber reinforced concretes; carbon reinforced concrete; Composite materials; Concrete; concrete cover separation; Concrete structures; Consortia; Construction industry; CRC; Demolition; Failure; Investigations; Methods; Regulation; Reinforced concrete; Renovation & restoration; Separation; Strengthening; Tensile strength; textile reinforced concrete; Textiles
• ISSN: 2673-4109; 2673-4109
• DOI: 10.3390/civileng3020024

The strengthening of existing reinforced concrete structures (RC) with carbon reinforced concrete (CRC) has a high potential to save resources and to increase the lifespan of the whole strengthened structure immensely. However, when strengthening structures with CRC, in some cases, failure due to concrete cover separation is detected, leading to the fact that the potential of the carbon reinforcement cannot be exploited. The prediction and prevention of this type of failure is the subject of current research. In this paper, a strut-and-tie-model is presented for calculating a critical tensile force leading to failure due to concrete cover separation. Additionally, possible methods to avoid that kind of failure are suggested. One of these is doweling the ends of the strengthening layer. This paper presents the first experiments to test this method, which show that doweling the strengthening layer leads to much higher failure loads compared to a structure without doweling. However, further investigations have to be examined to verify these first results.