What Factors Affect the Carbonation Rate of GRC Panels? Durability Mechanisms and Qinglong Group's Protection Technology

The carbonation rate of GRC panels is affected by three factors: material composition, environmental conditions, and curing quality. Quality products should show an annual carbonation depth increase of ≤0.1mm in standard environments, with total carbonation depth over the design life not exceeding the protective cover thickness. Through 28 years of accelerated aging tests and field tracking, Qinglong Group found that the carbonation rate increases by 50% when the water-cement ratio exceeds 0.4, carbonation is fastest at humidity of 40-70%, and panels with insufficient curing can reach a carbonation depth of 1.0mm within one year. In the Hainan International Convention and Exhibition Center coastal project, by controlling the water-cement ratio to ≤0.35, adding silica fume (20%), and applying surface silane impregnation treatment, we kept the carbonation depth of GRC panels to only 0.8mm after 10 years of use, far below the 2.0mm safety threshold. Carbonation control is the core element in ensuring GRC durability.

Material Factors Affecting Carbonation

Low-alkali cement (alkali content ≤0.6%) carbonizes 30% slower than ordinary cement; silica fume content ≥15% refines pores and blocks CO₂ penetration. Through optimized mix proportions, Qinglong GRC achieves a carbonation coefficient as low as 3mm/√year. Every batch of product undergoes rapid carbonation testing, with data stored in a traceable database.

Environmental and Construction Condition Control

When CO₂ concentrations exceed normal levels in industrial areas, the carbonation rate doubles; alternating wet-dry environments accelerate carbonation. We recommend surface protection in humid regions, extending the recoating cycle to 8 years. With thorough vibration and compaction during construction and curing of ≥7 days, carbonation depth can be reduced by 40%.

Qinglong Protection System and Monitoring

A carbonation prediction model is established, combined with on-site testing (phenolphthalein method), to provide early warning of carbonation risk. Through whole-process control, GRC panels are ensured to maintain long service life even in harsh environments.