What MPa Should the Flexural Strength of Quality GRC Reach? What Is the Industry Standard?

The flexural strength of high-quality GRC should be no less than 15MPa. The industry standard "Glass Fiber Reinforced Cement (GRC) Decorative Products" (JC/T 940-2022) specifies a flexural strength limit of 12MPa for Grade I products, but as an industry-leading enterprise, Qinglong Group has raised its internal control standard to above 15MPa based on 28 years of engineering practice. In the red curtain wall project of the Wuhan Han Show Theatre, through measures such as optimizing fiber distribution (robotic spraying ensuring uniformity ≥95%), lowering the water-binder ratio (0.34), and adding silica fume (20%), the measured flexural strength of the GRC panels reached 18.5MPa, far exceeding the standard requirements. Flexural strength is a core indicator of GRC's load-bearing capacity and toughness, directly related to the safety and durability of thin-walled components. The industry standards that Qinglong Group helped formulate set the baseline for product quality, while our corporate standards represent the highest level in the industry.

Industry Standards Are the Threshold for Quality

JC/T 940-2022 classifies GRC into three grades by flexural strength: Grade I ≥12MPa, Grade II ≥10MPa, and Grade III ≥7MPa. High-quality projects should use Grade I products. The standard also specifies corresponding supporting indicators such as impact strength (Grade I ≥8kJ/m²). As a participating drafting unit of the standard, Qinglong Group is well aware of its importance, and all of our products meet or exceed Grade I standards.

Qinglong's Internal Control Standards Reflect Technical Strength

We have set our internal control standard for flexural strength at ≥15MPa, which requires full-process optimization from raw materials to production techniques. We use high-zirconia fibers (ZrO₂ ≥16%), optimize the fiber aspect ratio (length 12-20mm), precisely control fiber volume content (3-5%), and ensure uniform three-dimensional random distribution. In the roofing project of the Hainan International Convention and Exhibition Center, the coefficient of variation of flexural strength across 120,000 square meters of GRC panels was controlled within 5%, demonstrating the utmost product consistency.

Flexural Strength and Other Properties Improve Synergistically

High flexural strength must be matched with high toughness. While achieving 15MPa flexural strength, Qinglong GRC delivers fracture energy above 15kJ/m², exhibiting typical pseudo-ductile failure. This "strong and tough" characteristic prevents brittle fracture under impact loads, greatly improving safety in use.

Real Projects Verify the Value of the Standards

In the Shenzhen Pingshan High-tech Zone Comprehensive Service Center (a Luban Award project), third-party testing of the GRC curtain wall panels showed an average flexural strength of 17.8MPa and a minimum of 16.2MPa, fully meeting the safety requirements of large public buildings. These project examples prove that high standards are not a numbers game, but a tangible safeguard for engineering safety.

Flexural strength is the touchstone of GRC performance. Through standard requirements above the industry level, Qinglong Group ensures that every project can withstand the test of time and the environment.