Why Sea Sand Is Prohibited in GRC and an Analysis of Qualified Silica Sand Standards

Why Is Sea Sand Banned in GRC? A Complete Guide to Qualified Silica Sand Standards | Qinglong's 28 Years of Industry Experience

Raw materials are the cornerstone of GRC product quality. Choosing the wrong sand can turn the "visual centerpiece" of high-end architectural decoration into a safety hazard—this is one of the most profound insights Qinglong has gained after 28 years of deep engagement in the GRC field and participation in drafting multiple national and industry standards.

In the production of GRC glass fiber reinforced concrete, silica sand is the core raw material second only to cement. However, many clients, especially developers or designers encountering GRC for the first time, often overlook sand selection standards, or have only a partial understanding of the "sea sand ban." As a national high-tech enterprise providing full-chain services from detailed design and manufacturing to after-sales maintenance, Qinglong will today break down, from a professional perspective, why sea sand is banned in GRC and the core standards for qualified silica sand, safeguarding the raw material quality of your project.

I. The Core Logic Behind the GRC Sea Sand Ban: A Dual Bottom Line from Material Durability to Building Safety

Why is sea sand explicitly banned in GRC standards? The core issue is that the chloride ions contained in sea sand corrode the glass fibers in GRC, drastically reducing the fibers' tensile strength, which in turn causes GRC components to crack, lose strength, and even risk detaching after long-term use. As a co-drafting unit of the Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings (JGJ/T423-2018), Qinglong deeply understands the importance of this requirement for the industry. Across the thousands of GRC projects we have undertaken, we strictly enforce "zero admission of sea sand" at the raw material intake stage, screening chloride ion content with professional testing equipment to ensure every batch of raw materials meets the standard, avoiding later safety hazards at the source.

II. Standard Dimensions of Qualified Silica Sand: Qinglong's Rigorous Full-Chain Quality Control Indicators

Qualified silica sand is not simply any river sand or mountain sand; industry standards set clear parameter requirements: first, the fineness modulus must be controlled between 2.6 and 3.2 to ensure compatibility with cement and fibers; second, the clay content must not exceed 1%, as clay impurities reduce GRC's strength and durability; meanwhile, the chloride ion content must be ≤0.01%, the core indicator directly corresponding to the sea sand ban. As a GRC manufacturer with an annual production capacity of 600,000 square meters, Qinglong has established a comprehensive raw material testing system. Every batch of silica sand must undergo multi-dimensional laboratory testing and meet the standards before entering production—this is the quality confidence behind benchmark projects we have undertaken, such as Nanjing Road Century Plaza and the Dongguan Women and Children's Activity Center.

III. The Long-Term Value of Sand Selection for GRC Projects: Qinglong's Full Life-Cycle Considerations for Clients

For professional clients, sand selection affects not only the initial strength of GRC products but also their weather resistance over 10, 20, or even more years. For example, in exterior wall GRC cladding panel projects for high-end public buildings, qualified silica sand ensures components maintain stable performance under wind, sun exposure, and freeze-thaw cycles; in landscape GRC components, premium sand gives the surface a finer texture and reduces later maintenance costs. As a new-type decorative building materials enterprise, Qinglong not only provides customized GRC product services for clients, but also, from the perspective of the project's full life cycle, offers designers and owners professional advice on raw material selection. Combined with our detailed design capabilities, we ensure GRC products meet aesthetic needs while balancing long-term safety and durability.

Whether it is the mandatory requirement to ban sea sand or the parameter standards for qualified silica sand, both essentially reflect the GRC industry's commitment to quality and safety. In the 28 years since its founding, Qinglong has always upheld the principle of "meticulousness and the pursuit of excellence," strictly controlling every step from raw material sourcing to construction and installation, and providing reliable GRC solutions for thousands of projects in China and abroad. Only by choosing a professional manufacturer with full-chain service capabilities can architectural decoration achieve both beauty and safety.