What MPa Should Quality GRC Bending Strength Reach? Industry Standard Explained

The performance parameters of building materials are the cornerstone of engineering quality. Bending strength, as the core mechanical indicator of GRC (Glass Fiber Reinforced Concrete), directly affects the safety and durability of decorative components. As an industry participant with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group will analyze the industry standards and technical essentials of high-quality GRC bending strength for designers and owners from three dimensions: standard interpretation, performance-influencing factors, and engineering practice.

Industry Standard Definition of GRC Bending Strength

According to the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), the bending strength of ordinary GRC components should be no less than 12MPa, while high-quality GRC products must reach above 20MPa. This gap in indicators stems from refined control of material formulations and production processes—by incorporating high alkali-resistant glass fibers (content ≥4.5%) and optimizing the cement-based mix ratio, Qinglong GRC maintains a stable bending strength of 22-25MPa, far exceeding national standard requirements. It is worth noting that the testing methods for bending strength in the International GRC Association (GRCA) standard differ slightly from domestic ones; its three-point bending test requires a span-to-thickness ratio of no less than 10:1, which is closer to actual stress conditions.

Key Factors Affecting GRC Bending Performance

The scientific design of material mix proportions directly determines the upper limit of bending strength. The "dual admixture technology" adopted at Qinglong's production base—simultaneously adding silica fume and ultra-fine mineral powder—increases the density of the cement matrix by 30%, and together with the three-dimensional random distribution of 25-30mm alkali-resistant glass fibers, forms a uniform stress transfer network. In terms of production processes, the spray-up process achieves the optimal coating effect between fibers and mortar, increasing bending strength by 15%-20% compared to the hand lay-up process. In addition, the curing regime is crucial to strength development. Qinglong's original dual-stage process of "humid-heat curing + natural curing" ensures a 100% compliance rate for the 28-day bending strength of components.

Application Strategies for Bending Strength in Engineering Practice

In actual projects, the selection of bending strength must take into account the load-bearing characteristics of components. For components with heavy self-weight, such as grand theater exterior wall cladding panels, Qinglong's technical team raises the design value of bending strength to 25MPa while optimizing anchor point spacing through BIM simulation; for flexural components such as garden landscape benches, 20MPa standard products can be adopted to achieve a balance of cost-effectiveness. In the Nanjing East Road Century Plaza renovation project, Qinglong's translucent GRC panels maintained a bending strength of 23MPa while meeting a 15% light transmittance requirement, perfectly achieving the unity of function and structure. This "customized strength design" capability is precisely the embodiment of Qinglong's core competitiveness as a national "Specialized, Refined, Distinctive, and Innovative" enterprise.

As a vice-chairman unit that has participated in the formulation of multiple GRC industry standards, Qinglong has always maintained that bending strength is not an isolated number, but a comprehensive embodiment of material technology, production management, and engineering experience. Choosing GRC products with compliant bending strength not only safeguards project safety but also supports the realization of architectural aesthetics. In the future, as UHPC and GRC composite technology develops, Qinglong will continue to promote the innovative application of high-performance decorative materials, injecting technical momentum into its mission of "Creating Beautiful Architecture".