Mechanism and Performance Control Methods of Sulfate Attack on Concrete: A Review

Area of Science:

• Civil and Structural Engineering
• Materials Science
• Environmental Science

Background:

• Sulfate attack is a primary cause of concrete degradation in marine and groundwater settings.
• Understanding these mechanisms is crucial for durable infrastructure.

Purpose of the Study:

• To comprehensively review sulfate attack mechanisms on cement-based materials.
• To analyze external and internal factors influencing concrete performance under sulfate attack.
• To summarize methods for improving concrete sulfate resistance and identify future research directions.

Main Methods:

• Literature analysis of chemical reactions and physical crystallization effects of sulfate attack.
• Experimental investigation of concrete performance evolution under various environmental and material conditions.
• Synthesis of existing knowledge on degradation mechanisms and resistance enhancement.

Main Results:

• Sulfate attack involves complex chemical reactions and physical crystallization, leading to concrete deterioration.
• External factors (temperature, humidity, sulfate type/concentration, cycles, coupling effects) and internal factors (cement composition, w/c ratio, C-S-H gel, Ca(OH)2) significantly influence degradation.
• Five key methods for enhancing concrete sulfate resistance were identified.

Conclusions:

• Sulfate attack poses a significant threat to concrete infrastructure in aggressive environments.
• A multi-faceted approach considering both environmental and material properties is essential for mitigating sulfate attack.
• Further research is needed to address current challenges in understanding and preventing concrete corrosion.