Sea Sand Ban and Silica Sand Standards: The Core Material Selection Key for GRC Durability

As the core aggregate of GRC (Glass Fiber Reinforced Concrete), the quality of sand directly determines the material's service life and safety performance. Qinglong's 28 years of GRC production experience proves that even the slightest deviation in material selection can lead to major failures in later use. Prohibiting sea sand and screening qualified silica sand are the first line of defense in safeguarding GRC performance.

⚠️ Why Must GRC Production Reject Sea Sand?

With its high salt content, sea sand is an "invisible killer" in GRC production. First, the chloride ions in sea sand corrode the reinforcement materials inside GRC. Qinglong's laboratory testing found that sea sand with excessive chloride content causes the strength of alkali-resistant glass fiber to decline by more than 40% within 5 years, directly leading to cracking and spalling of components. Second, salt residue triggers efflorescence and frosting, damaging the decorative finish of GRC surfaces. A project in Hainan once mistakenly used sea sand, causing large-scale whitening of GRC curtain walls within 3 years, severely compromising the building's appearance. Finally, the salt in sea sand dissolves when exposed to water, increasing internal porosity and reducing GRC's impermeability and durability. In humid coastal environments, this damage emerges at an accelerated pace.

???? Three Core Standards for Qualified Silica Sand

As an enterprise that participated in drafting the Technical Standard for Architectural Application of Glass Fiber Reinforced Cement (GRC), Qinglong has always followed strict silica sand screening standards. First, chemical composition must meet standards: SiO₂ content must be ≥95% and impurity content ≤1%. High-purity silica sand enhances GRC's strength and weather resistance; the silica sand used at Qinglong's production bases all undergoes spectral testing to ensure stable composition. Second, particle gradation must be reasonable: particle size must be controlled between 0.15-0.6mm, with rounded particle shapes. Such silica sand forms a dense bond with the cement matrix and reduces internal voids, and Qinglong achieves precise control of particle gradation through professional screening equipment. Third, harmful substance content must be extremely low: chloride ion content ≤0.01%, and sulfide and sulfate content ≤0.5%, preventing harmful substances from causing long-term erosion of GRC's internal structure.

???? Qinglong's Material Selection Control System Builds a Solid Quality Foundation

To ensure aggregate quality, Qinglong has established a full-chain material selection control mechanism. In raw material procurement, long-term partnerships have been established with large silica sand mines, and every batch of incoming silica sand must pass a four-fold inspection: "appearance inspection - composition analysis - particle gradation testing - harmful substance screening." During production, automated batching systems precisely control silica sand dosage, combined with high-efficiency water reducers to optimize the mix ratio, allowing silica sand to fully integrate with cement and glass fiber. In the Panzhihua Third-Front Construction Culture and Tourism Project, the qualified silica sand selected by Qinglong enabled GRC curtain wall panels to fulfill the promise of no strength loss for over 20 years, meeting both fidelity and durability standards.

Material selection is the source of GRC quality. Rejecting sea sand and adhering to qualified silica sand standards is the bottom line Qinglong has upheld throughout its 28 years in the industry. As a national-level high-tech enterprise, Qinglong always takes standards as its guide and testing as its basis, ensuring through stringent material selection controls that every GRC product delivers reliable durability and safety. For construction projects pursuing long-term value, choosing the right aggregate means choosing the service life of GRC materials.