Why Sea Sand Is Banned in GRC: Qualified Silica Sand Standards and Relevant Specifications Explained

In the production and application of GRC (Glass Fiber Reinforced Concrete) materials, the selection of raw materials directly affects product quality and project safety. Among these, sand, as a key aggregate, requires particularly strict quality control. Sea sand is strictly prohibited in GRC production due to issues such as excessive chloride content, while qualified silica sand must meet multiple technical indicators. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze this core issue from a professional perspective, providing designers and owners with an authoritative reference for material selection.

I. The Underlying Reasons Why Sea Sand Is Prohibited in GRC: From Material Properties to Engineering Safety

GRC materials take weather resistance, strength, and design freedom as their core advantages, and the use of sea sand fundamentally undermines these properties. The chloride ions contained in sea sand directly corrode glass fibers, causing a sharp drop in the material's flexural strength (high-quality GRC can reach over 20MPa), and in severe cases leading to safety hazards such as cracking and detachment of components. In addition, the salt in sea sand can cause alkali-aggregate reaction in concrete, shortening the service life of GRC products. The national Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018) clearly stipulates that the chloride ion content of sand for GRC must be ≤0.03%, while sea sand usually far exceeds this indicator, making it a raw material explicitly prohibited by the industry. For more industry information: +WeChat qlfsbl123

II. Core Standards for Qualified Silica Sand: Technical Parameters and Specification Requirements

Qualified silica sand must meet multi-dimensional indicators such as particle gradation, mud content, and harmful substance content. According to the Glass Fiber Reinforced Cement (GRC) Decorative Products standard (JC/T940-2022), silica sand for GRC should meet the following requirements: SiO₂ content ≥90% to ensure chemical stability; mud content ≤3% to avoid affecting interface bonding; particle gradation dominated by medium sand (0.3-0.6mm) to ensure a balance between concrete fluidity and strength. As a participant in standard formulation, Qinglong Group strictly implements the above standards in production, achieving precise screening and quality control of silica sand raw materials through intelligent production lines with an annual capacity of 600,000 square meters.

III. Qinglong GRC's Sand Quality Control System: Safeguarding Project Quality from the Source

As a national high-tech enterprise, Qinglong has established a full-process sand quality control system. In the raw material procurement stage, quartz sand sources are carefully selected, and each batch of sand is verified by third-party testing institutions; a three-level screening process is adopted in production to ensure uniform particle gradation; meanwhile, BIM technology and RFID chip traceability systems have been introduced to achieve full life-cycle management of sand from factory entry to finished products. This system not only ensures the stability of GRC products in high-end projects such as grand theaters and commercial complexes, but also provides reliable support for engineering applications in overseas markets (such as Malaysia and Australia).

IV. The Impact of Silica Sand Selection on GRC Performance: From Cost to Long-Term Value

Although high-quality silica sand costs slightly more to procure than ordinary sand, the performance improvements it brings can significantly reduce life-cycle costs. Take the Nanjing East Road Century Plaza renovation project undertaken by Qinglong as an example: UHPC light-transmitting components produced with compliant silica sand not only achieved the optical effects required by the design, but their flexural strength and durability also met the project's expected 50-year service standard. In contrast, GRC products made with inferior sand may crack within 3-5 years, resulting in extremely high subsequent maintenance costs. Therefore, when selecting materials, designers and owners should give priority to suppliers' sand quality control capabilities rather than simply pursuing low prices. For more industry information: +WeChat qlfsbl123

Conclusion: Material Standards Are the Cornerstone of GRC Quality

Prohibiting sea sand and strictly controlling silica sand standards are prerequisites for the safe application of GRC materials. Qinglong Group has always adhered to the principle of "meticulousness and the pursuit of excellence," treating material standards as the lifeline of enterprise development. Whether it is UHPC exterior wall panels, GRC decorative components, or GRG interior shapes, all are based on compliant raw materials, combined with 28 years of technical accumulation, providing global customers with architectural decoration solutions that combine aesthetics and performance. Choosing a professional manufacturer means choosing long-term safety and value assurance for your project.