# Experimental Study on Repairing Corroded Cracks by Electrophoretic Deposition
## 5 Conclusions  
Electrophoretic deposition method is a new method for the repair of rust-cracked reinforced concrete; it can be seen from the test results that this method can not only seal  
Figure 16: Schematic diagram of electrophoretic deposition repair process. concrete cracks, but also form epoxy resin protective film on the concrete surface and improve the performance of the reinforced concrete system against the overall performance of the hybrid current, carbonization resistance, and waterproof performance, and the method can be repaired within 24 h. Other repair methods cannot simultaneously achieve the repair goal of this method. In this study, the influence of repair time on the waterproofing and carbonization resistance of the cracking reinforced mortar specimens repaired by electrophoretic deposition was explored, and the improvement principle of the two properties of repaired specimens was analyzed and explained by using MIP, SEM, and other test methods. Finally, based on the observation of the experimental process and the analysis of the experimental results, this paper summarizes three main stages of the electrophoretic deposition repair process. Obtaining a comprehensive understanding of the repair principle of electrophoretic deposition is necessary to enable the reasonable development and application of this method. Moreover, the corresponding repair equipment and process must be further designed and optimized to establish the applicability of this method. The main conclusions of this study are as follows:  
1. Longer electrophoretic deposition repair time increases the thickness of the resin film on the mortar surface, the filling depth of resin in the cracks, the resistance of the mortars, the more obvious the anti-carbonation, waterproof performance, and anti-stray current ability of the mortar are improved. However, the maximum carbonization depth and water absorption of specimens after 18 h and 24 h of repair are not very different, so the repair time can be appropriately shortened according to actual needs and cost consideration. 2. After electrophoretic deposition repair, the epoxy resin penetrates into the interior of the mortar, and the porosity and number of harmful pores on the mortar surface and inside edges of cracks decrease. After electrophoretic deposition, epoxy resin penetrates into the mortar and fills the harmful pores in the mortar, reducing the porosity and the number of harmful pores on the mortar surface and the inner edge of cracks. In addition, the generated epoxy resin film has a dense structure. These findings can well explain the observed improvements in the carbonization and waterproofing performance of the specimens after repair. 3. The physical and chemical processes of electrophoretic deposition restoration can be divided into three stages. During the immersion stage, the solution penetrates into the cracks and comes into contact with the steel bars, thereby laying a foundation for electrophoretic deposition repair. During the repair stage, an electric field is generated, and the charged cationic curing agent and cationic epoxy resin molecules are deposited onto the mortar surface by electrophoresis under the action of this force. During the curing stage, the water between deposited molecules slowly evaporates, and the epoxy resin is gradually consolidated and hardened. Conceptualization, Y.W. ; methodology, Y.W. ; validation, C.W. ; formal analysis, Y.W. ; investigation, Y.W. ; data curation, S.Z. ; writing--original draft preparation, Y.W. ; writing--review and editing, Y.W. ; visualization, C.W. ; supervision, S.Z. All authors have read and agreed to the published version of the manuscript. This work was supported by the National Nature Science Foundation of China (Grant No. 51778485 and 51608384). We would like to thank [PERSON], [PERSON], [PERSON], and [PERSON] for their help with preparing the experiment. We also would like to thank [PERSON] from Shiyanjia Lab (www.shiyanjia.com, accessed on 1 June 2022) for the TG-DSC analysis.