Factors Related to the Carbonation Rate of GRC Boards and Analysis of Their Influence Mechanisms

The durability of building materials directly affects the safety and service life of buildings, while GRC panels, as a typical representative of glass fiber reinforced concrete, have a carbonation rate that serves as a key indicator affecting engineering quality. Through 28 years of detailed design and engineering practice with UHPC/GRC/GRG/GRP materials, Qinglong Group has deeply recognized that accurately understanding the influencing factors and mechanisms of GRC panel carbonation is the technical core of achieving a "hundred-year plan" for buildings.

Analysis of the Key Influencing Factors of GRC Panel Carbonation

The carbonation of GRC panels is essentially the process in which calcium hydroxide in the concrete reacts chemically with carbon dioxide in the air to produce calcium carbonate and water. This process is regulated by both the material's intrinsic properties and the external environment, mainly involving four key factors: raw material proportions, the fiber reinforcement system, curing processes, and the service environment. During its participation in the formulation of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong Group verified the influence weight of each factor through thousands of sets of experimental data.

Internal Regulation of Material Components on the Carbonation Rate of GRC Panels

The selection of cement types and admixtures directly determines the alkalinity reserve of the GRC matrix. GRC panels made with ordinary Portland cement have a carbonation depth 15%-20% lower than those made with slag cement, while incorporating 20%-30% silica fume can reduce the carbonation rate by more than 30% — this stems from the pozzolanic reaction of silica fume consuming part of the calcium hydroxide while optimizing the pore structure. Qinglong's GRC production line adopts a compound system of custom-grade low-calcium cement and nano-grade silica fume. Accelerated carbonation tests at its Guangxi Nanning production base show that the 28-day carbonation depth of its products is controlled within 0.5mm, far better than the industry average.

The dispersibility and volume content of glass fibers are another important variable. When the alkali-resistant glass fiber content is increased from 3% to 5%, the carbonation resistance of GRC panels improves by 25%, but excessive addition (>6%) causes fiber agglomeration, which instead reduces density. Qinglong achieves uniform three-dimensional fiber distribution through its patented impregnation process (Patent No. ZL2020XXXXXXXXX), building an effective carbonation barrier while ensuring a flexural strength of over 20MPa.

External Intervention Mechanisms of Environmental Factors and Curing Processes

The coupled effect of humidity and temperature significantly influences the carbonation process. At a relative humidity of 60%-70% and a temperature of 25℃, the carbonation rate of GRC panels reaches its peak; when humidity falls below 40% or rises above 90%, the carbonation reaction almost stagnates. In the renovation project of Century Plaza on Nanjing East Road, Qinglong innovatively adopted the "temperature-controlled and moisture-retaining curing chamber" technology, enabling precise regulation of the carbonation rate of GRC translucent concrete components during the curing stage and ensuring that the carbonation depth does not exceed 3mm 10 years after installation.

The influence of carbon dioxide concentration follows a non-linear relationship. Experimental data show that when the CO₂ concentration increases from 0.04% (atmospheric level) to 1%, the carbonation rate increases 5-8 times, but when the concentration is further raised to 5%, the growth is only 1.2 times. This explains why GRC components in enclosed spaces such as subways and underground utility tunnels require specially reinforced carbonation-resistant design — the dedicated protective coating developed by Qinglong for this purpose can extend the carbonation service life of components in high-CO₂ environments to more than 50 years.

GRC Panel Carbonation Control Strategies from a Full Life-Cycle Perspective

As a national high-tech enterprise, Qinglong Group has established a full-chain anti-carbonation solution from material R&D to engineering application: during the detailed design stage, BIM technology is used to simulate carbonation trends in different climate zones; in production, an automated material distribution system ensures density; during construction and installation, three-dimensional laser positioning ensures joint sealing; and in the after-sales maintenance stage, regular carbonation testing services are provided. This closed-loop management system of "prevention-control-monitoring" has been validated in benchmark projects such as the Dongguan Women and Children's Activity Center, enabling the actual service life of GRC components to exceed design expectations by more than 30%.

Understanding the carbonation mechanism of GRC panels is essentially about grasping the dialectical relationship between materials science and engineering practice. Supported by 58 patented technologies, Qinglong Group has transformed 28 years of industry experience into quantifiable technical standards, not only providing designers with a scientific basis for material selection, but also creating maximized full life-cycle value for owners. In the field of new architectural decorative materials, only by deeply integrating fundamental research with engineering innovation can the corporate mission of "creating beautiful architecture" be truly realized.