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

High-quality GRC should have a flexural strength of ≥20MPa, while the industry standard minimum requirement is ≥15MPa. This indicator is a core mark distinguishing GRC from ordinary cement components. Qinglong's mass-produced GRC generally achieves a flexural strength of 20-25MPa, far exceeding industry standards and ensuring project safety.

1. Flexural Strength Requirements in Industry Standards

Industry standards set clear provisions on GRC flexural strength, which serves as the baseline for product qualification. Core standards: the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018) and Glass Fiber Reinforced Cement (GRC) Decorative Products (JC/T940-2022) both stipulate that the standard value of GRC flexural strength shall be ≥15MPa, with the test method being the three-point bending test (specimen dimensions 100mm×400mm×15mm); classification requirements: products are classified by use into decorative class (≥15MPa) and load-bearing class (≥20MPa), with load-bearing products such as railings and walkway panels required to meet higher requirements; inspection rules: 3 groups of specimens must be randomly sampled from each batch for testing, with the average value ≥ the standard value and the minimum value ≥ 85% of the standard value. Qinglong achieves a 100% pass rate in every batch inspection.

2. Flexural Strength Standards and Value of High-Quality GRC

High-quality GRC sets a higher threshold for flexural strength, demonstrating product competitiveness. Strength indicators: high-quality GRC has a flexural strength of ≥20MPa; through optimized formulations and processes, Qinglong's mass-produced products maintain a stable strength of 20-25MPa, with some special formulations reaching 30MPa; performance value: higher flexural strength means better crack resistance and toughness, enabling thinner component thickness (such as 10mm-thick decorative panels), reducing self-weight while enhancing impact resistance. Qinglong's 15mm-thick GRC carved panels for the Wuhan Hanxiu Theater achieve a flexural strength of 22MPa and can withstand minor impacts without damage; project suitability: for major projects, complex-shaped components, and outdoor high-stress scenarios, high-quality GRC with a flexural strength ≥20MPa should be preferred. Qinglong's products of this strength grade have been adopted in projects such as the Shenzhen Pingshan High-tech Zone Comprehensive Service Center (Luban Award) and the Guangxi New Media Center.

3. Technical Support and Corporate Practices for Achieving Strength Standards

Achieving high-quality GRC flexural strength relies on whole-process technical control. Raw material assurance: high-strength low-alkali cement and high-modulus alkali-resistant glass fibers are selected, with Qinglong's fibers having a tensile strength of ≥1800MPa to ensure reinforcement effectiveness; formulation optimization: fiber content is controlled at 2.5%-3%, water-binder ratio ≤0.45, and density is improved through particle grading; in Qinglong's patented formulation, the synergistic effect between fibers and cementitious materials increases strength by more than 40%; process control: automated mixing ensures uniform fiber dispersion, vibration-press molding improves matrix density, and constant temperature and humidity curing promotes strength development—the intelligent curing system at Qinglong's Nanning, Guangxi production base makes strength development more uniform; testing and verification: in addition to routine testing, major projects also require on-site loading tests; components randomly sampled on site at Qinglong's Shanghai Xinghewan project achieved a measured flexural strength of 23MPa, far exceeding design requirements.