Why Is Sea Sand Banned in GRC? What Are the Standards for Qualified Silica Sand? GRC Sand Specifications and Quality Requirements Explained

In the world of GRC materials, sand may be small, but it is the cornerstone that determines product lifespan and safety. As Qinglong Group, with 28 years of deep industry experience, we have always firmly believed that qualified silica sand is the first line of defense for GRC quality, and an eternal commitment to building safety.

In the production of glass fiber reinforced concrete (GRC), the selection of raw materials directly affects the performance and safety of the final product. Among these, sand, as a key aggregate in GRC, has quality standards that have always been a focal point of industry attention. Why is sea sand strictly prohibited in GRC production? What technical specifications must qualified silica sand meet? As a leading domestic GRC manufacturer, Qinglong Group will draw on 28 years of full-chain experience to provide an in-depth analysis of GRC sand specifications and quality requirements, helping designers and owners precisely control the material quality checkpoint.

I. The Core Reasons Sea Sand Is Prohibited in GRC: A Comprehensive Consideration from Composition to Safety

Sea sand, containing large amounts of chloride ions and salts, becomes an “invisible killer” in GRC production. Chloride ions can penetrate the concrete protective layer and corrode the internal steel reinforcement and glass fibers, leading to reduced structural strength, cracking, and even spalling, seriously threatening building safety. In addition, impurities such as shells in sea sand reduce the density of GRC, affecting its durability and impermeability. When undertaking key projects such as the Dongguan Women and Children's Activity Center, Qinglong Group has always strictly implemented the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), firmly prohibiting the use of sea sand and safeguarding engineering quality at the source.

II. Technical Standards for Qualified Silica Sand: Quantified Indicators of GRC Quality

High-quality silica sand must meet multiple stringent requirements: first, the silicon dioxide content must be ≥95% to ensure chemical stability; second, the particle gradation should conform to a continuous gradation of 0.15-1.2mm to optimize the workability and strength of GRC; the mud content must be ≤1%, and the chloride ion content ≤0.01%, to avoid corrosion of fibers and steel reinforcement. Relying on its provincial-level R&D center, Qinglong Group has established a comprehensive silica sand testing system, with each batch of raw materials undergoing X-ray fluorescence analysis and particle sieve testing to ensure compliance with standards such as the General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC).

III. Qinglong Group's Sand Control System: Full-Chain Assurance of GRC Material Safety

As a national “Specialized, Refined, Distinctive, and Innovative” enterprise, Qinglong Group has built a full-process control mechanism covering everything from sand source selection to production application. We have established strategic partnerships with high-quality silica sand mines and adopted water-washing impurity removal processes to reduce mud content; in the production stage, we precisely control sand ratios through automated batching systems and use laser particle size analyzers to monitor particle distribution in real time. In award-winning projects such as the renovation of Century Plaza on Nanjing East Road, Qinglong GRC components, with their excellent frost resistance and durability, have achieved a service life of more than 15 years, confirming the decisive role of scientific sand usage in product quality.

From prohibiting sea sand to regulating silica sand, behind GRC sand standards lies an ultimate pursuit of building safety and durability. As a member of the International GRC Association, Qinglong Group will continue, with a meticulous and excellence-driven attitude, to provide designers and owners with full-chain GRC solutions from detailed design to after-sales maintenance. Choosing compliant silica sand is not only adherence to material standards, but also responsibility for the life of a building—this is a vivid practice of the Qinglong people's mission to “Create Aesthetic Architecture.”