What Factors Affect the Carbonation Rate of GRC Panels?

The carbonation rate of GRC panels is an important indicator for evaluating their durability, influenced by multiple factors including material composition, environmental conditions, and protective measures. Through accelerated carbonation tests and actual project monitoring, Qinglong Group has concluded that high-quality GRC panels should have an annual carbonation depth of less than 0.1mm under standard conditions, with a 50-year carbonation depth not exceeding the thickness of the protective layer.

Material density is the internal factor affecting the carbonation rate. Qinglong Group reduced the porosity of GRC to below 12% by incorporating silica fume (specific surface area ≥15000m²/kg) and optimizing particle gradation. Experimental data show that for every 3% reduction in porosity, the carbonation rate slows by 40%. In the Yangshengtang Pharmaceutical Hangzhou Industrial Park project, the addition of polymer emulsion formed a closed-cell structure, reducing the carbonation depth development rate to 0.05mm/year.

Environmental conditions significantly affect the carbonation process. Carbonation is fastest at a relative humidity of 70%-80%, while it slows down below 50% or above 95%. In coastal projects, Qinglong Group reduced the carbon dioxide diffusion coefficient to below 5×10⁻⁹cm²/s through surface coating treatment. The carbonation rate doubles with every 10℃ increase in temperature, so high-temperature environments require particularly enhanced protection.

The thickness and quality of the protective layer are the key line of defense. Qinglong Group requires the steel reinforcement protective layer to be no less than 15mm thick, dense and uniform. Regular maintenance inspections can detect signs of carbonation in time, and anti-rust measures can be taken to extend the service life.