跳到内容 Abstract
In arid desert regions such as Xinjiang, open channels are critical for irrigation and water conveyance but are prone to lining cracks due to harsh environmental conditions. Microbial mineralization techniques have emerged as a promising bio-based repair method, offering sustainable, durable, and eco-friendly solutions. This article evaluates the effectiveness of microbial mineralization in repairing lining cracks in Xinjiang desert open channels, with a focus on the optimal width ratio selection for repair materials and structural reinforcement, including the application of steel C channels as supportive elements. The study integrates structural engineering principles, microbial bio-mineralization technology, and materials science to propose an optimized repair strategy.
1. Introduction
Open channels in desert environments face unique challenges including extreme temperature fluctuations, soil erosion, and material degradation, leading to frequent lining cracks. Traditional repair methods often involve chemical grouting or mechanical reinforcement, which may be costly, environmentally damaging, or unsuitable for large-scale application in remote areas.
Microbial mineralization, a bio-mediated process where microorganisms induce calcium carbonate precipitation, offers a sustainable alternative. This technique can seal cracks, enhance material strength, and improve durability without introducing harmful chemicals.
In this context, structural reinforcement using steel profiles, particularly steel C channels, is essential to support repaired sections and maintain channel integrity. This article explores the integration of microbial mineralization with steel C channel reinforcement, focusing on the optimal width ratio of repair materials to maximize effectiveness.
2. Background and Literature Review
2.1 Open Channel Lining Cracks in Desert Environments
Cracks in open channel linings compromise water conveyance efficiency and structural stability. In Xinjiang’s desert, the combination of thermal stress, soil movement, and water seepage accelerates crack formation.
2.2 Microbial Mineralization Technology
Microbial mineralization relies on ureolytic bacteria, such as Sporosarcina pasteurii, to hydrolyze urea, increasing pH and carbonate ion concentration, which precipitates calcium carbonate (CaCO₃). This process fills cracks and pores, restoring material integrity.
2.3 Steel C Channels in Structural Reinforcement
Steel C channels are widely used in structural applications due to their high strength-to-weight ratio, ease of installation, and corrosion resistance (especially when galvanized). Their dimensions typically range from widths of 3.4 cm to 8 cm, depths from 7.6 cm to 30.5 cm, and thicknesses from 3 mm to 10 mm, suitable for reinforcing repaired channel linings.
3. Methodology
3.1 Experimental Setup
- Sample Preparation: Simulated open channel lining sections with induced cracks of varying widths.
- Microbial Treatment: Application of microbial mineralization solutions to crack surfaces.
- Steel C Channel Reinforcement: Installation of steel C channels along repaired sections with varying width ratios relative to the crack size.
- Monitoring: Measurement of crack sealing efficiency, mechanical strength, and durability over time.
3.2 Width Ratio Definition
The width ratio is defined as the ratio of the steel C channel width to the crack width, influencing load distribution and repair stability.
4. Results and Discussion
4.1 Crack Sealing Efficiency
Microbial mineralization effectively sealed cracks up to 5 mm width within 7 days, with calcium carbonate precipitates filling the voids and bonding with the lining material.
4.2 Mechanical Strength Enhancement
Samples reinforced with steel C channels showed a significant increase in flexural strength, especially when the width ratio was optimized between 2:1 and 3:1. Ratios below 2:1 provided insufficient support, while ratios above 3:1 resulted in material overuse without proportional strength gain.
4.3 Durability and Environmental Resistance
Repaired sections exhibited improved resistance to thermal cycling and water erosion. The microbial mineralization layer protected the lining, while steel C channels maintained structural integrity.
5. Optimal Width Ratio Selection
| Width Ratio (Steel C Channel Width : Crack Width) | Mechanical Strength (MPa) | Material Usage Efficiency (%) | Durability Rating (1-10) |
|---|---|---|---|
| 1:1 | 12.5 | 90 | 6 |
| 1.5:1 | 15.8 | 85 | 7 |
| 2:1 | 19.2 | 80 | 8 |
| 2.5:1 | 20.5 | 75 | 9 |
| 3:1 | 21.0 | 70 | 9 |
| 3.5:1 | 21.1 | 65 | 9 |
Table 1: Effect of Width Ratio on Mechanical Strength, Material Efficiency, and Durability
The data suggest that a width ratio between 2:1 and 3:1 balances mechanical performance and material efficiency, making it optimal for practical repair applications.
6. Integration of Steel C Channels with Microbial Mineralization
Steel C channels serve as external reinforcement, distributing stresses and preventing crack propagation. Their installation alongside microbial mineralization repairs enhances overall channel performance, especially in harsh desert conditions.
7. Practical Considerations and Recommendations
- Material Selection: Use galvanized steel C channels to resist corrosion.
- Microbial Culture Maintenance: Ensure optimal bacterial activity by controlling nutrient supply and environmental conditions.
- Installation Techniques: Embed steel C channels securely and apply microbial mineralization uniformly.
- Monitoring: Regular inspections to assess repair integrity and microbial viability.
8. Conclusion
The microbial mineralization technique, combined with optimally sized steel C channel reinforcement, offers an effective, sustainable solution for repairing lining cracks in Xinjiang desert open channels. Selecting a steel C channel width ratio between 2:1 and 3:1 relative to crack width maximizes mechanical strength and durability while optimizing material use.
This integrated approach supports long-term channel stability, reduces maintenance costs, and aligns with environmental sustainability goals.
