How to Verify the Carbonation Resistance of a Manufacturer's GRC Products: Methods, Standards, and Practical Guide

In the field of building materials, carbonation resistance is one of the core indicators for measuring the durability of GRC products, directly affecting the service life and structural safety of architectural decorative components. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will provide designers and owners with a scientifically rigorous solution for verifying GRC carbonation resistance from three dimensions: testing methods, standard basis, and practical validation.

I. Testing Methods for GRC Carbonation Resistance: From Laboratory to Project Site

Verifying the carbonation resistance of GRC products requires combining laboratory testing with field engineering evidence. At the laboratory level, Qinglong adopts the carbonation depth measurement method in the Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete (GB/T 50082), placing standard specimens in a carbonation chamber with a CO₂ concentration of 20±3% and a humidity of 70±5%, and measuring the carbonation depth at different ages through the color reaction of a phenolphthalein indicator. Notably, thanks to the synergistic effect between glass fibers and the cement matrix, high-quality GRC materials typically exhibit a carbonation rate more than 30% lower than that of ordinary concrete.

Field verification on site focuses on two key indicators: first, changes in surface hardness, which can be detected with a rebound hammer to assess the decay of surface strength of GRC components; second, the chloride ion penetration coefficient, analyzed through on-site sampling to judge the impact of carbonation on material durability. Qinglong has established the industry's first GRC carbonation resistance simulation laboratory at its Nanning production base, capable of simulating carbonation conditions in different climate zones (such as high-humidity coastal environments and severely cold northern regions), providing customized testing data for projects.

II. Standard System and Technical Indicators: Establishing the Evaluation Benchmark for GRC Carbonation Resistance

As a participating drafter of the Technical Standard for Building Application of Glass Fibre Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong strictly complies with the national standard's requirements for GRC carbonation resistance: under standard test conditions, the 28-day carbonation depth of GRC specimens should be ≤5mm, and the growth rate of carbonation depth at 56 days must be ≤20%. Meanwhile, Qinglong's corporate standard sets even higher requirements on this basis—for example, for projects in marine climates, the carbonation depth control index is raised to ≤3mm, ensuring the long-term stability of materials in high-salt-spray environments.

Achieving these technical indicators relies on the optimization of material formulations. Qinglong adjusts the glass fiber content (typically controlled at 4-6%), selects low-alkalinity sulphoaluminate cement, and incorporates mineral admixtures such as nano-scale silica fume to form a dense microstructure that effectively impedes CO₂ gas penetration. This technical solution has been validated in projects such as the Dongguan Women and Children's Activity Center, where the GRC exterior wall panels, after 8 years of natural exposure, still keep the carbonation depth within 2mm.

III. Practical Validation and Full Life-Cycle Assurance: Qinglong's Engineering-Grade Solutions

For real estate developers and heads of public projects, the final verification of GRC carbonation resistance lies in actual engineering performance. Qinglong has established a full-chain quality control system covering detailed design, production and manufacturing, and construction installation: at the design stage, BIM technology is used to simulate the stress state of components and optimize reinforcement schemes; in production, an automated spray molding process ensures uniform fiber distribution; during installation, 3D laser positioning is implemented to prevent microcracks caused by stress concentration, reducing carbonation risk at the source.

In the after-sales maintenance phase, Qinglong's proprietary "GRC Component Health Monitoring System" collects real-time data on temperature, humidity, strain, and other parameters through embedded sensors, combined with regular on-site inspections (such as ultrasonic flaw detection), to form full life-cycle carbonation resistance assessment reports. This service model has been applied to the Nanjing East Road Century Plaza renovation project, where the translucent UHPC-GRC composite panels not only achieved an aesthetic breakthrough but also ensured a service life of more than 20 years through carbonation-resistant design.

Choosing GRC products with guaranteed carbonation resistance is, in essence, choosing the long-term value of architectural decoration. Backed by 28 years of technical accumulation, Qinglong Group deeply integrates material performance verification with engineering practice, offering designers creative freedom and safeguarding building quality for owners. In the field of new architectural decorative materials, only by integrating scientific testing, standard implementation, and engineering experience can the mission of "Creating Beautiful Architecture" truly be realized.