Corrosion-related damage is currently the leading factor in reinforced concrete structures experiencing reduced strength values. By finding sustainable methods to counteract corrosion-related problems in buildings, as well as alternatives to strengthen structures where corrosion has already occurred, the construction industry can develop where sustainability is the focus.

This study is therefore being conducted out of interest in sustainability within the construction industry where future buildings are desired to be constructed with durability, cost-effectiveness and lifespan in mind. The study has compiled significant information linked to the stated questions from 38 previously published scientific articles and research materials. The study has also obtained information regarding the implementation of these proposals in practice from interviews with people in the construction industry. Since previous research regarding corrosion problems in reinforced concrete structures is relatively extensive, this has a positive impact on this study as relevant information will be available from a broad database.

The results of the study show that a decisive factor in the design of reinforced concrete structures is the accuracy of the preparatory work, as well as regular checks of the structure after construction. Information from the literature study linked to which methods of strengthening reinforced concrete structures with corrosion-related problems, as well as the preventive measures, show clear suggestions for alternative approaches to minimize the risk of corrosion in the structure.

Based on the literature study, several methods of strengthening and preventive measures are compared, where the results show clear improvements in corrosion resistance and strength. Previous studies where fiber-reinforced polymers have been used to strengthen concrete beams have shown an improved load-bearing capacity of 75.88%. This can be a decisive factor in the occurrence of corrosion-related damage as the concrete cover layer does not risk the same degree of unwanted cracks.

Studies on microbial repair agents where Bacillus subtilis is the active component have also shown favorable results in crack repair work. Through a comparative study where control groups with different amounts of Bacillus subtilis were mixed into the microbial repair agent, a clear change can be seen linked to the flexural stiffness of the concrete sample.

Despite differences in cross-sectional area and concrete quality, the results from the different studies where microbial repair agents have been used to enhance the flexural stiffness of the concrete samples show similar responses. From tests where different amounts of Bacillus subtilis have been implemented in the mixture, previous research shows that a 0.1% concentration has the greatest positive impact on flexural stiffness. The difference between the concrete sample with 0.0% concentration and the one with 0.1% shows an increase in flexural stiffness as high as 4.55%. This increase is considered to be crucial for the lifespan of the structure as cracking that can cause corrosion does not occur to the same extent.

Based on the results of the survey where several methods for maintenance, strengthening, and repair of damaged concrete structures are highlighted, a clear comparison can be made between the methods. Since methods for strengthening and repairing these types of damages are often directly tailored to the shape of the structure, the extent of the damages, and the geographical location of the building, it can be practically challenging to determine which of the methods is best suited for the specific work. This has led to a general method often being used in practice, where the damages are addressed in a similar way regardless of the previously mentioned factors.