How to Control Steel Reinforcement Cover Thickness in GRC — Key Technologies and Quality Assurance Measures

In the field of architectural decoration, GRC (Glass Fibre Reinforced Concrete), with its lightweight, high-strength and flexible formability, has become an ideal choice for high-end buildings such as grand theatres and commercial complexes. As a core indicator of the durability and safety of GRC components, the thickness of the steel reinforcement cover directly affects project quality and service life. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group will systematically analyze the key control points of steel reinforcement cover thickness in GRC—from material properties and process standards to full-process management—providing professional solutions for designers and owners.

Steel Reinforcement Cover Thickness in GRC: Dual Consideration of Material Properties and Technical Standards

GRC material is composed of cement-based composite and glass fibres, and its steel reinforcement cover thickness must simultaneously satisfy structural load-bearing and durability requirements. According to the Technical Standard for Building Application of Glass Fibre Reinforced Cement (GRC) (JGJ/T423-2018), the cover thickness of load-bearing reinforcement shall be no less than 15mm, and must be adjusted according to the component's service environment (e.g., a 20% thickness increase is required in coastal high-humidity areas). During the detailed design stage, Qinglong Group uses BIM technology to simulate stress distribution under different working conditions, ensuring optimal matching between cover thickness, reinforcement diameter and component span. For example, in large GRC exterior wall cladding panels using φ8mm reinforcement, the cover thickness is strictly controlled at 20-25mm, which avoids the risk of exposed reinforcement while ensuring structural stability.

Full-Chain Control: Millimeter-Level Precision Management from Production to Installation

As a national high-tech enterprise integrating detailed design, manufacturing, construction and installation, Qinglong Group has established a cover thickness control system covering the entire process. At its production base in Nanning, Guangxi, an automated mold positioning system is adopted, with laser rangefinders ensuring that the distance error between the reinforcement cage and the inner wall of the mold is ≤2mm; during mixing, mortar fluidity is strictly controlled to prevent uneven cover thickness caused by insufficient vibration; during curing, a constant temperature and humidity environment is maintained to prevent drying shrinkage cracks from compromising cover integrity. Notably, the core technologies of the General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC) industry standard, which Qinglong participated in drafting, have also been applied in reverse to GRC production, further improving the stability of cover thickness.

Quality Assurance: Practical Verification through Testing Technology and Engineering Experience

To address durability issues of widespread concern to customers, Qinglong Group has established a three-tier inspection mechanism: before delivery, the electromagnetic induction method is used to scan the cover thickness of every GRC component, with a required pass rate of 100%; on construction sites, sampling re-verification is conducted using the drilling method, with data deviation controlled within ±3mm; after project delivery, 5 years of maintenance follow-up is provided, with regular monitoring of cover carbonation depth. In award-winning projects such as the Dongguan Women and Children's Activity Center, Qinglong's “reinforcement positioning + cover thickness dual-control technology” ensured that components showed no corrosion or cracking throughout a 10-year service period, far exceeding the industry average.

From material formulation optimization to intelligent construction management, the control of steel reinforcement cover thickness in GRC is a concentrated embodiment of technical strength and engineering experience. Supported by 28 years of full-chain service experience, Qinglong Group integrates its commitment of “meticulousness and excellence” into every step, not only providing customers with standard-compliant, high-quality products, but also driving industry standard upgrades through technological innovation. In the future, Qinglong will continue to leverage its advantages as a national Specialized, Refined, Distinctive and Innovative enterprise, providing GRC solutions that combine aesthetic value and structural safety for more landmark buildings, and contributing to its mission of “creating beautiful architecture.”