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Optimization of a Binary Concrete Crack Self-Healing System Containing Bacteria and Oxygen
Jinlong Zhang1,2,3, Bixia Mai4, Tingwei Cai5
1Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China. xingf@szu.edu.cn.
Materials (Basel, Switzerland)
|August 5, 2017
Summary
Researchers optimized microbial calcium precipitation for concrete self-healing. They identified optimal conditions for spore viability, nutrient selection, and oxygen supply, enhancing the potential of bacterial concrete repair systems.
Area of Science:
- Materials Science
- Microbiology
- Civil Engineering
Background:
- Microbially induced calcium precipitation (MICP) is a promising method for concrete self-healing.
- Optimizing conditions for bacterial spore viability and activity is crucial for effective MICP.
Purpose of the Study:
- To develop an optimized strategy for enhancing microbially induced calcium precipitation.
- To investigate factors influencing MICP, including spore viability, nutrient selection, and oxygen supply.
Main Methods:
- Determined optimal yeast extract concentration for spore yield and viability.
- Evaluated the effects of oxygen releasing tablets (ORT) and different nutrient sources on MICP by strain H4.
- Assessed the impact of calcium peroxide (CaO2) dosage and spore concentration on calcium precipitation.
Main Results:
- An optimal yeast extract concentration of 5 g/l was identified.
- Calcium peroxide (CaO2) was found to be superior to other peroxides for enhancing MICP.
- Optimal conditions included a CaO2 dosage of 7.5-12.5 g/l, a spore concentration of 6 × 10^8 spores/ml with ~50% viability, lactate as the carbon source, and nitrate as the nitrogen source for aerobic incubation.
Conclusions:
- The study established an optimized strategy for MICP, improving spore viability and nutrient utilization.
- These findings provide a foundation for a ternary self-healing system (bacteria, ORT, nutrients) for deep concrete crack repair.
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