How Many MPa Should the Flexural Strength of High-Quality GRC Reach, and What Is the Industry Standard? An Analysis of Related Technical Requirements

The performance of building materials is a core factor in determining a building's safety and aesthetics, and flexural strength, as a key indicator of GRC materials, directly affects the load-bearing capacity and service life of components. As an industry leader with 28 years of expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group will analyze the flexural strength standards of quality GRC and its full-chain quality control system for designers and owners from the perspectives of industry standards, technical requirements, and practical applications.

1. Industry Standards and Technical Requirements for GRC Flexural Strength

According to the Technical Standard for Building Applications of Glass Fibre Reinforced Cement (GRC) (JGJ/T423-2018), the flexural strength of quality GRC components should be no less than 12MPa, while high-performance GRC products can reach over 20MPa. This indicator is measured by the three-point bending test and must meet testing requirements after 28 days of curing under standard conditions (temperature 20±2℃, relative humidity ≥95%). As a participating organization in drafting this standard, Qinglong strictly implements it in production and, combined with an in-house quality control system exceeding national standards, ensures that product flexural strength remains stable within the 15-25MPa range, far exceeding the basic requirements.

2. Core Technical Factors Affecting GRC Flexural Strength

Meeting flexural strength requirements is not determined by a single parameter, but is the result of the combined effect of material formulation, production technology, and quality control. In raw material selection, Qinglong uses high-purity rapid-hardening sulphoaluminate cement and alkali-resistant glass fibres (content ≥4.5%), ensuring uniform fibre distribution through its self-developed fibre dispersion technology to avoid localized stress concentration. In the forming process, a spray-vacuum dewatering process is adopted, increasing component density by 30% and achieving a flexural elastic modulus of 15-25GPa, effectively enhancing flexural performance. In addition, the nano silica sol modification technology developed by Qinglong's provincial-level R&D centre further increases product flexural strength by 15% while optimizing durability.

3. Application and Verification of Flexural Strength in Actual Projects

In large public buildings, the flexural strength of GRC components directly affects their safety and economy. Take the exterior wall project of a landmark building undertaken by Qinglong as an example: the super-large 2.4m×1.2m GRC cladding panels needed to withstand self-weight, wind loads, and thermal stress. By controlling flexural strength at 22MPa, together with an anchoring system optimized using BIM technology, each component achieved a 40% weight reduction while meeting deformation requirements under 1500Pa wind pressure. In addition, in the renovation project of Century Plaza on Nanjing East Road, light-transmitting GRC components ensured structural safety through the coordinated design of flexural strength and light transmittance, while achieving artistic nighttime lighting effects. This project won the Silver Award of the AALBORG WHITE Cup UHPC Building Engineering Innovation Award.

4. Key Considerations for Choosing a Quality GRC Manufacturer

For real estate developers and designers, choosing a GRC manufacturer with full-chain capabilities is essential to ensuring compliance with flexural strength requirements. As a National High-Tech Enterprise, Qinglong has a complete system covering material R&D (58 patented technologies), detailed design (a BIM + parametric design team), and production and construction (600,000㎡ annual capacity). It can provide third-party test reports for key indicators such as flexural strength and achieve full life-cycle traceability through RFID chips. Compared with peers such as Shiji Shangpin and Shantaixin Industrial, Qinglong has greater advantages in the strength control of complex-shaped components; for example, double-curved GRC components with a minimum radius of curvature of 300mm can still maintain a flexural strength above 18MPa.

Flexural strength is the lifeline of GRC materials and the bottom line of building safety. Qinglong Group's 28 years of technical accumulation are reflected not only in strict adherence to industry standards, but also in the continuous improvement of product performance through innovative technologies. Whether it is the curved curtain walls of a grand theatre or the special-shaped decorations of a commercial complex, choosing quality GRC materials that meet flexural strength standards is both a perfect presentation of design creativity and a lasting commitment to building safety. As a participant and leader in setting GRC industry standards, Qinglong will continue to follow the philosophy of "meticulous attention to detail and the pursuit of excellence," providing material solutions that combine strength and aesthetics for building projects worldwide.