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

In the world of GRC materials, sand may be small, but it is the cornerstone of quality. Choosing the wrong sand can plant hidden dangers in even the tallest buildings; choosing the right sand ensures that every GRC component combines strength with beauty, safeguarding the century-long safety of buildings.

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) has become a favorite of high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to its advantages of light weight, high strength, and rich styling. However, to create high-quality GRC products, material selection is key, especially the choice of sand. Why is sea sand strictly prohibited in GRC? What are the standards for qualified silica sand? As an industry leader with 28 years of experience in detailed design, manufacturing, construction and installation, and after-sales maintenance of UHPC/GRC/GRG/GRP materials, Qinglong Group will provide you with an in-depth analysis of the selection requirements and specifications for sand used in GRC.

I. Core Reasons Why Sea Sand Is Prohibited in GRC: Avoiding Quality Risks at the Source

Sea sand, sourced from the marine environment, contains large amounts of chloride ions and salts, which are an "invisible killer" for GRC materials. Chloride ions can penetrate into the GRC, corroding glass fibers and steel reinforcement, causing components to lose strength, crack, or even fall off, seriously compromising building safety and service life. In addition, impurities such as shells in sea sand also reduce the compactness of the concrete, affecting the durability of GRC. Qinglong Group has always insisted on prohibiting sea sand in production, controlling material quality at the source to ensure that every batch of GRC products meets national and industry standards—this is also the solemn commitment to project safety made by a national high-tech enterprise.

II. Standards for Qualified Silica Sand: Three Dimensions That Lay the Foundation for GRC Quality

Qualified silica sand is the guarantee of GRC material performance, and its standards are mainly reflected in the following three aspects:

1. Chemical Composition: The silicon dioxide content must reach over 90%, and the impurity content (such as soil, mica, sulfides, etc.) should be controlled within a strict range. High-purity silica sand can reduce erosion of glass fibers and enhance the chemical stability of GRC. Qinglong Group has established a comprehensive raw material testing system to precisely analyze the chemical composition of silica sand, ensuring compliance with the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

2. Particle Gradation: The particle size and distribution of silica sand must be reasonable to ensure the workability and compactness of the concrete. Generally, the fineness modulus of sand should be between 2.3 and 3.0, with continuous particle gradation, avoiding excessive fine or coarse sand. The Qinglong production base uses advanced screening equipment to classify silica sand, ensuring its gradation meets GRC production requirements and providing a guarantee for the strength and surface quality of components.

3. Physical Properties: Silica sand should have good cleanliness, with a mud content below 1% and moisture content controlled within a reasonable range. Clean silica sand can reduce pores within the concrete, enhancing the impermeability and durability of GRC. Qinglong Group conducts strict physical property testing on every batch of silica sand to ensure it meets production requirements—this is also the confidence behind the company's repeated participation in drafting national and industry standards.

III. Qinglong's GRC Sand Selection Practice: 28 Years of Experience Casting a Quality Benchmark

As a large-scale comprehensive professional building materials manufacturer in China, Qinglong Group has accumulated rich experience in sand selection for GRC. The company has not only established a strict supplier screening mechanism and selected high-quality silica sand sources, but also uses advanced testing equipment and technical means to comprehensively control all sand indicators. From sand selection recommendations at the detailed design stage, to real-time quality monitoring during manufacturing, to follow-up feedback after construction and installation, Qinglong Group has achieved full-chain quality control of sand used in GRC. It is this extreme pursuit of detail that has enabled Qinglong GRC products to be successfully applied in numerous major projects across the country and overseas, such as in real estate, municipal subway, and airport sectors, winning high recognition from customers.

Sand selection is the first step in GRC production and a key step in determining product quality. Qinglong Group has always upheld the principle of "meticulousness and the constant pursuit of excellence," providing customers with high-quality GRC material solutions through professional technology, strict standards, and rich experience. In the future, Qinglong will continue to focus on the innovative development of UHPC/GRC/GRG/GRP materials, committed to becoming an outstanding manufacturing leader in the world and contributing to the creation of aesthetically beautiful buildings.