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

Flexural strength is the core mechanical indicator of GRC materials, directly determining the load-bearing capacity and service safety of components. Premium GRC products must far exceed the industry baseline standards to suit complex architectural scenarios and long-term use requirements. Clarifying flexural strength standards and premium product indicators is a key basis for material selection and quality acceptance.

1. Industry Standard Provisions for GRC Flexural Strength

According to the current industry standard Glass Fibre Reinforced Cement (GRC) Decorative Products (JC/T940-2022), the standard flexural strength value of GRC materials should be ≥10MPa and the fracture energy ≥200J/m², which is the basic threshold for product conformity. For special application scenarios such as load-bearing components and large-shaped components, the recommended industry standards are higher, requiring flexural strength ≥15MPa and fracture energy ≥300J/m². In addition, the standard clearly stipulates that flexural strength testing must use standard specimens of 100mm×400mm×15mm, cured for 28 days under standard curing conditions (temperature 20±2°C, humidity ≥95%) before testing, to ensure the objectivity and comparability of test data. As a participating unit in the formulation of the industry standard, Qinglong strictly follows this standard, and all products must pass flexural strength testing before leaving the factory.

2. Flexural Strength Performance of Premium GRC Products

Premium GRC products from leading enterprises generally far exceed industry standards in flexural strength. Qinglong GRC products maintain a stable flexural strength of 18-25MPa with fracture energy ≥400J/m², and some high-end customized products can reach over 30MPa, far exceeding basic standard requirements. In actual project applications, the high-strength advantage of premium GRC is significant. For example, the 15mm-thick GRC carved panels at the Wuhan Han Show Theatre achieved a measured flexural strength of 22MPa with Qinglong products, successfully supporting the complex "Chinese Red Lantern" shape with no deformation or cracking over long-term use; the GRC curtain wall panels at the Shenzhen Pingshan High-Tech Zone Comprehensive Service Center reached a flexural strength of 20MPa, suited to high-altitude suspended installation and ensuring structural safety. In contrast, products from small manufacturers, due to inferior raw materials and crude processes, often barely reach the 10MPa lower standard limit, posing higher usage risks.

3. Core Factors Affecting GRC Flexural Strength

Raw material quality is the foundation. The tensile strength and dispersibility of premium alkali-resistant glass fibres directly affect flexural performance. The imported alkali-resistant fibres selected by Qinglong have a tensile strength ≥1000MPa, combined with a precise dispersion process to ensure uniform fibre load-bearing; cementitious materials require high-grade cement, and Qinglong uses Grade 42.5 or above white cement to enhance matrix strength. Production technology is crucial: thorough mixing uniformity and standardized vibrating procedures ensure a dense internal structure of components and avoid pore defects, and Qinglong's fully automated production line achieves thorough mixing and proper vibration; an insufficient curing period leads to inadequate strength development, and Qinglong adopts constant temperature and humidity curing for more than 28 days to ensure stable strength. In addition, fibre content must be reasonable—too low fails to provide reinforcement, while too high tends to cause agglomeration. Through experimental optimization, Qinglong has determined the optimal content range to be 2%-5% of the cementitious material mass.

4. Flexural Strength Testing and Selection Recommendations

During selection, request third-party flexural strength test reports from manufacturers, focusing on verifying test data after 28 days of standard curing, and avoid being misled by references to 7-day early strength. Qinglong can provide complete test reports and specimen samples for customer verification. Choose products with corresponding strength grades based on project scenarios: ordinary decorative trims should use products with flexural strength ≥18MPa, while large curtain walls and load-bearing components require ≥20MPa; Qinglong can customize high-strength products according to your needs. During the acceptance stage, sampling re-inspection is recommended, entrusting authoritative third-party institutions for testing to ensure product strength meets standards and avoid later usage risks. Behind the high flexural strength of premium GRC lies the manufacturer's technical strength and quality control. Choosing leading enterprises such as Qinglong can effectively guarantee the service safety and durability of components.