Acid Rain Regions: What Protection Should Be Strengthened for GRC Exterior Walls? GRC Acid Rain Resistance Technical Measures

Protection of GRC exterior walls in acid rain areas needs to be strengthened in three aspects: material corrosion resistance, surface protection grade, and construction measures. Materials should use acid-resistant cement or incorporate silica fume (≥8%); surface protection should adopt fluorocarbon coating (thickness ≥40μm); and drainage cavities should be provided in the construction design. Through these measures, GRC can achieve a service life of more than 50 years in acid rain environments with pH≥4.0.

Protective layer performance requirements: acid resistance (no change after 720h immersion in pH=3.0 solution), corrosion resistance (no blistering after 3000h salt spray test), and adhesion (≥1.5MPa). A project in an industrial zone used GRC panels with enhanced protection; inspection after 10 years showed the surface remained intact with a carbonation depth of only 0.8mm, demonstrating significant protective effectiveness.

Material Acid-Resistance Modification

Use sulfoaluminate cement or incorporate 30% slag powder to improve acid resistance. Keep the water-binder ratio below 0.35 to reduce porosity and minimize acid penetration.

Enhanced Surface Protection

Fluorocarbon coating thickness ≥40μm, with acid resistance reaching Grade 0. Clean the surface regularly to prevent accumulation of acid rain residues.

Construction Protection Measures

Install drainage cavities to promptly discharge acid rainwater. Cantilevered eaves should extend ≥600mm to reduce rain exposure on facades. Add protective baffles at critical locations.

Maintenance and Inspection System

Test surface pH values annually and inspect coating condition every 3 years. Establish corrosion records and schedule maintenance predictively.

Acid rain environments require special protection. Through systematic protective measures, the durability of GRC exterior walls in acid rain areas can be ensured.