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Service Life Evaluation for RC Sewer Structure Repaired with Bacteria Mixed Coating: Through Probabilistic and
Hyun-Sub Yoon1, Keun-Hyeok Yang1, Kwang-Myong Lee2
1Department of Architectural Engineering, Kyonggi University, Suwon 16227, Korea.
Materials (Basel, Switzerland)
|September 28, 2021
Summary
This study developed a bacteria-coating for reinforced concrete (RC) structures to enhance durability in sulfate environments. The bacteria-coating significantly extends service life compared to traditional repair methods.
Area of Science:
- Civil Engineering
- Materials Science
- Environmental Engineering
Background:
- Sulfate exposure causes concrete swelling and cracking, reducing the service life of structures.
- Engineering modeling is crucial for evaluating the service life of concrete structures in sulfate environments.
Purpose of the Study:
- To develop and evaluate cementitious repair materials with bacteria (Rhodobacter capsulatus) for enhanced concrete durability.
- To assess the service life of reinforced concrete (RC) structures using a novel bacteria-coating through deterministic and probabilistic methods.
Main Methods:
- Developed cementitious repair materials incorporating Rhodobacter capsulatus and porous spores for immobilization.
- Evaluated service life using deterministic and probabilistic methods, considering parameters like coating thickness, diffusion coefficient, surface roughness, and sulfate ion concentration.
- Analyzed the impact of varying mean and coefficient of variation (COV) of design parameters on service life.
Main Results:
- Probabilistic methods yielded more conservative service life estimates than deterministic methods.
- Coating thickness and surface roughness were identified as critical design parameters for ensuring service life.
- In a 200 ppm sulfate environment, the bacteria-coating extended service life by 1.47-1.50 times compared to normal repair mortar.
- The bacteria-coating's effectiveness was significantly enhanced with a low COV (around 0.1).
Conclusions:
- The developed bacteria-coating is a highly effective method for extending the service life of RC structures in sulfate-rich environments.
- The probabilistic approach provides a more realistic assessment of service life under varying conditions.
- Optimizing coating thickness and surface roughness is key to maximizing the benefits of bacteria-coating for concrete durability.
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