Abstract

Asphalt tanks are key equipment in road engineering, construction, and asphalt mixing plants. Long-term exposure to high temperature, humidity, and chemical media leads to serious corrosion problems, which directly affect structural safety, sealing performance, and service life. This paper focuses on corrosion causes, anti-corrosion design, coating systems, construction technology, daily maintenance, and intelligent monitoring, aiming to provide a complete set of solutions for corrosion protection and service life extension of asphalt tanks.

Keywords: Asphalt tank; corrosion protection; anti-corrosion coating; service life; maintenance

1. Introduction

Asphalt storage tanks usually work under medium-high temperature conditions and are affected by water vapor, acid-base media, thermal cycle, and external environment. The main failure forms include:

Shell and bottom corrosion perforation

Structural strength reduction

Support and attachment rust damage

Leakage and safety risks

Effective corrosion protection can extend the service life of asphalt tanks from 5–8 years to more than 15 years, greatly reducing operation and replacement costs.

2. Main Causes of Corrosion in Asphalt Tanks

High temperature and thermal cycle effect

Heating and heat preservation lead to coating aging, cracking, and falling off.

Moisture and condensation

Water vapor forms condensation inside the tank, causing electrochemical corrosion.

Chemical corrosion

Impurities in asphalt, acidic substances in oil, and corrosive media in the soil.

External environment corrosion

Rain, salt spray, industrial gas, and soil corrosion at the tank bottom.

Aging of insulation layer

Damaged insulation traps moisture and accelerates metal corrosion.

3. Overall Corrosion Protection Design of Asphalt Tanks

3.1 Material Selection

Use corrosion-resistant carbon steel or alloy steel plate.

Improve rigidity to reduce deformation and coating damage.

3.2 Structural Anti-corrosion Design

Optimize tank bottom drainage to avoid water accumulation.

Reinforce key parts: welds, corners, supports, and inlet-outlet nozzles.

Reasonable layout of heating pipes to reduce local overheating.

3.3 Thermal Insulation System Matching

Use closed-cell, waterproof insulation materials.

Ensure good sealing of the insulation protective layer.

4. High Performance Anti-corrosion Coating System

4.1 Internal Anti-corrosion Coating

High-temperature resistant epoxy coating

Heat-resistant inorganic zinc-rich primer

Special anti-corrosion coating resistant to asphalt medium

Features: high temperature resistance, strong adhesion, not easy to peel.

4.2 External Anti-corrosion Coating

Epoxy primer + epoxy mica intermediate paint + polyurethane topcoat

Salt spray resistance, UV resistance, weather resistance

Suitable for outdoor long-term exposure

4.3 Tank Bottom Anti-corrosion

Heavy-duty anti-corrosion coating

Cathodic protection can be used for important large tanks

Isolation from corrosive soil and groundwater

5. Key Construction Technology for Corrosion Protection

Strict surface treatment: sandblasting to Sa2.5–Sa3 grade.

Weld grinding and transition treatment to avoid stress concentration.

Coating construction under suitable temperature and humidity.

Multi-layer coating with sufficient thickness and uniform thickness.

Heating system installed after coating fully cured.

6. Daily Maintenance to Extend Service Life

Regular appearance inspection and coating damage detection.

Timely repair of damaged coating parts.

Keep the tank foundation dry and free of water accumulation.

Control heating temperature to avoid overheating aging.

Regular cleaning and drainage inside the tank.

Check and maintain insulation layer regularly.

7. Intelligent Monitoring and Safety Management

Temperature monitoring to avoid local overheating

Liquid level and leakage monitoring

Regular thickness testing of tank wall and bottom

Establish corrosion records and life prediction system

8. Conclusion

Corrosion protection of asphalt tanks is a systematic project involving material, design, coating, construction, and maintenance. Through scientific anti-corrosion design, high-performance coating systems, strict construction technology, and standardized daily maintenance, the corrosion rate can be effectively controlled, safety risks reduced, and the service life of asphalt tanks significantly extended.