How to Verify a Manufacturer's GRC Product Carbonation Resistance? Scientific Testing Methods and Qinglong Group's Durability Assurance System

Verifying the carbonation resistance of GRC products requires combining three approaches—accelerated testing, on-site inspection, and long-term data—to scientifically evaluate their durability under carbon dioxide attack. Based on 28 years of materials research, Qinglong Group has established a verification system of "laboratory accelerated carbonation testing – on-site core sampling inspection – retrospective review of completed projects", ensuring that the annual growth of product carbonation depth is ≤0.1mm and the design service life exceeds 50 years. Carbonation resistance directly affects the neutralization rate of GRC and the risk of steel reinforcement corrosion, making it a hard indicator of a manufacturer's technical strength.

Standard Laboratory Testing Methods

In accordance with the Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete, specimens are placed in a carbonation chamber with a concentration of 20±3%, a temperature of 20±2℃, and a humidity of 70±5% to measure the 28-day carbonation depth. High-quality GRC should have a carbonation depth of ≤5mm, while Qinglong products measure only 2-3mm. We submit samples to the provincial quality inspection institute for testing every year, and the data is publicly available.

On-site Non-destructive Testing Techniques

Using the phenolphthalein alcohol solution spray method, a hole is drilled on the component surface and the solution applied; uncarbonized areas turn red, enabling precise measurement of carbonation depth. Qinglong Group conducts on-site testing at project acceptance—for example, the roof of the Hainan International Convention and Exhibition Center showed a carbonation depth of only 0.8mm after 5 years of use. Combined with ultrasonic testing, internal damage conditions are also evaluated.

Long-term Performance Data Accumulation

Through retrospective review of completed projects—for example, core sampling tests on the Wuhan Han Show Theater after 8 years of use showed a carbonation depth of 1.2mm, corroborating the laboratory data. We recommend that owners require manufacturers to provide third-party test reports and data from past projects in order to comprehensively assess carbonation resistance.