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Enhancing the Salt Frost Durability of Concrete with Modified Epoxy Composite Coating
Lu Cong1, Yanchao Wang2, Xuekai Gao2
1Department of Civil Engineering, Shanxi University, Taiyuan 030006, China.
Materials (Basel, Switzerland)
|February 26, 2025
Summary
A novel modified epoxy composite coating (MECC) offers superior protection for concrete structures against chloride and freeze-thaw cycles. This durable coating significantly enhances salt frost resistance and extends concrete service life.
Area of Science:
- Materials Science
- Civil Engineering
- Corrosion Science
Background:
- Traditional epoxy resin protectants face limitations in enhancing concrete structure durability.
- Chloride exposure and freeze-thaw cycles are major causes of concrete degradation, leading to cracking, peeling, and spalling.
- There is a need for advanced protective coatings to improve the longevity of concrete infrastructure.
Purpose of the Study:
- To propose and evaluate a modified epoxy composite coating (MECC) as an advanced protective treatment for concrete structures.
- To assess the efficacy of MECC in enhancing resistance to chloride ingress and salt frost damage.
- To compare the performance of MECC with traditional epoxy resin coating (EC) and silicate coating (SC).
Main Methods:
- MECC was formulated using epoxy resin, dimethyl carbonate solvent, and a composite curing agent (modified amines and polyaniline).
- Salt frost resistance tests were conducted on MECC-treated concrete specimens subjected to freeze-thaw cycles.
- Performance evaluation included measuring water absorption, relative dynamic elastic modulus (RDEM), and mass loss.
- Chloride resistance was assessed after prolonged exposure to a 10.0% NaCl solution.
Main Results:
- MECC specimens exhibited significantly lower water absorption and enhanced salt frost resistance compared to uncoated specimens.
- After 200 freeze-thaw cycles, MECC-treated concrete showed a 21.62% higher relative dynamic elastic modulus and only 19.14% of the mass loss of uncoated specimens.
- MECC effectively prevented the intrusion of environmental liquids and chloride ions after 120 days of 10.0% NaCl erosion.
- MECC outperformed ordinary epoxy resin coating (EC) and silicate coating (SC) in durability tests.
Conclusions:
- Modified epoxy composite coating (MECC) provides a durable and effective solution for protecting concrete structures.
- MECC treatment improves the internal structure of concrete, densifies the surface, and prevents environmental ingress.
- The enhanced durability is attributed to reduced chloride-induced damage and internal icing pressure under freeze-thaw conditions, thereby extending concrete service life.
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