What Are the Core Constituent Materials of GRC? What Are the Requirements for Alkali-Resistant Glass Fiber?

GRC (Glass Fiber Reinforced Concrete), as a high-performance composite material, owes its exceptional physical properties and decorative effects to a scientifically proportioned raw material system. As a group with 28 years of experience in GRC R&D and manufacturing, Qinglong Group believes that the core constituent materials of GRC mainly include cementitious materials, reinforcing materials, aggregates, admixtures and supplementary materials, and water. Among them, alkali-resistant glass fiber, as the key reinforcing material, directly determines the long-term durability of GRC.

The cementitious material for GRC typically uses Portland cement of grade 42.5 or above, while premium projects may select white cement to meet aesthetic requirements. The aggregate is high-quality silica sand with a particle size not exceeding 1.2mm, with mud content strictly controlled below 1%. The admixture system includes superplasticizers, polymer emulsions, etc., to improve workability and mechanical properties. In the Wuhan Han Show Theater project undertaken by Qinglong Group, optimizing the grading of cementitious materials and aggregates enabled the precise engraving of 15mm ultra-thin GRC panels, perfectly presenting the complex shape of the "Chinese red lantern".

Alkali-resistant glass fiber is the core material that distinguishes GRC from ordinary concrete, and its zirconia (ZrO₂) content is a key indicator for measuring alkali resistance. According to the industry standard "Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC)" (JGJ/T423-2018), the zirconia content of premium alkali-resistant glass fiber should be no less than 16%. The glass fiber used in Qinglong Group's products achieves a zirconia content of over 16.5%, ensuring long-term stability in the highly alkaline cement environment (pH>12.5). Fiber length is typically 12-38mm, with volume content controlled between 3%-5% to achieve the best toughening effect.

Requirements for alkali-resistant glass fiber are not limited to chemical composition but also include its mechanical properties and dispersion uniformity. The fiber's tensile strength should be no less than 1700MPa, and its elastic modulus no less than 70GPa. At Qinglong Group's production base in Nanning, Guangxi, we use advanced spraying processes and mixing control systems to ensure that fibers are uniformly distributed in three-dimensional random orientations within the cement matrix, preventing performance defects caused by fiber clumping or uneven distribution. In the 120,000-square-meter roofing project of the Hainan International Convention and Exhibition Center, this strict control ensured the outstanding performance of the GRC finish layer in the high marine salt-spray environment.

In summary, performance optimization of GRC materials is a systematic project that requires refined proportioning and strict quality control of each constituent material. Backed by a comprehensive quality management system and 28 years of project experience, Qinglong Group ensures that every batch of GRC products meets or even exceeds industry standards, providing durable and reliable material assurance for all types of construction projects.