How Strong Is GRC? Mechanical Properties Verified by 28 Years of Technical Data from Qinglong Group

The strength of GRC (Glass Fiber Reinforced Cement) is a core indicator for measuring its structural performance, mainly including flexural strength, compressive strength, tensile strength, and toughness. According to the national standard "Glass Fiber Reinforced Cement (GRC) Decorative Products" (JC/T 940-2004), premium GRC products should have a flexural strength of no less than 12MPa, a compressive strength of no less than 40MPa, and a tensile strength of no less than 8MPa. As an industry leader with 28 years of dedicated expertise in the GRC field, Qinglong Group has, through continuous material R&D and process optimization, raised GRC flexural strength to 15-25MPa and compressive strength to 50-80MPa, far exceeding the basic national standard requirements. In the 9,000-square-meter hyperbolic curtain wall project at the Wuhan Han Show Theater, the GRC panels we supplied achieved a measured flexural strength of 18.5MPa, successfully realizing rib-free design for large-area thin-walled (12-15mm thick) components, ensuring structural safety while meeting complex shapes. GRC strength depends not only on the material mix ratio but is also closely related to fiber distribution, production process, and curing regime.

Flexural Strength Determines Load-Bearing Capacity

The flexural strength of GRC is a key performance attribute for its use as curtain walls and decorative components. Qinglong Group uses alkali-resistant glass fiber (ZrO₂ content ≥16%), optimizes fiber length (typically 12-20mm) and volume content (3-5%), and applies a robotic spray-up process to ensure uniform three-dimensional fiber distribution, keeping flexural strength stable above 15MPa. In the Hainan International Convention and Exhibition Center project, our GRC panels achieved a maximum deflection ≤L/250 (L = span) under typhoon loads, fully meeting design requirements. High flexural strength enables GRC to produce large-span, thin-section components, achieving lightweight construction.

Compressive and Tensile Strength Ensure Overall Performance

Compressive strength reflects the material's ability to withstand pressure. Through optimizing the cement matrix mix ratio (adding silica fume and high-range water reducers), Qinglong GRC achieves high density, with compressive strength reaching 50-80MPa. Tensile strength reflects the material's resistance to tensile failure, typically 1/5 to 1/8 of its compressive strength. Through good bonding between fibers and the matrix, our products achieve a tensile strength of 8-12MPa, effectively suppressing microcrack propagation.

Toughness Achieves "Cracks Without Shattering"

GRC's greatest feature is its excellent toughness combined with high strength (fracture energy up to 15-30kJ/m²). Under impact loads, GRC exhibits multiple cracking rather than brittle fracture. This "cracks but does not shatter" characteristic greatly improves safety in use. Qinglong Group's GRC products have been verified by ball drop impact tests (1kg steel ball in free fall from 1m height) with no fragment spalling on the back face, demonstrating extremely high safety.

Qinglong Group's 28 years of engineering practice fully demonstrate that, through scientific material design and strict production control, GRC can fully meet a wide range of strength requirements from decorative components to secondary structural components, making it an excellent building material that combines aesthetics and performance.