What MPa Should the Flexural Strength of High-Quality GRC Reach? What Is the Industry Standard? Strength Indicator System and Qinglong Group Technical Standards

High-quality GRC should achieve a flexural strength of 18-25MPa. The industry standard "Technical Standard for Building Applications of Glass Fibre Reinforced Cement (GRC)" (JGJ/T423-2018) specifies that Grade I products must have a flexural strength ≥18MPa. Through optimized mix proportions and processes, Qinglong Group has stabilized its product flexural strength at 20-25MPa with a coefficient of variation ≤5%, far exceeding the standard requirements. In the Wuhan Hanxiu Theater project, GRC panels achieved a measured flexural strength of 23MPa, with a strength retention rate above 95% after 8 years of use.

Standard Requirements for Flexural Strength

The industry standard classifies GRC into three grades: Grade I ≥18MPa, Grade II ≥14MPa, and Grade III ≥10MPa. Qinglong Group's internal control standard requires ≥20MPa, with steam curing applied to promote strength development. We use 40mm×40mm×160mm specimens tested by the three-point bending method to ensure accurate data.

Technical Approaches to Strength Enhancement

With a low water-binder ratio (0.30-0.35), high fiber content (3-5% by volume), and an optimized curing regime (60-80℃ steam curing for 24h), Qinglong GRC delivers outstanding strength performance. We have introduced universal testing machines to test the strength of every batch, achieving a pass rate of 99.5%.

Verification in Engineering Applications

In the 120,000㎡ roofing project of the Hainan International Convention and Exhibition Center, GRC panels withstand wind pressure ≥3.0kPa, with strength fully meeting design requirements. Qinglong Group recommends that customers request third-party test reports to verify strength indicators.