How to Control the Thickness of Reinforcement Cover in GRC? Qinglong GRC Cover Control Standards Explained

In GRC, the thickness of the steel reinforcement cover should be determined comprehensively based on the environment class, component type, and service life. Generally, the cover thickness for indoor components should be no less than 15mm, for outdoor components no less than 20mm, and for corrosive environments no less than 25mm. This control ensures the steel reinforcement remains rust-free for 50 years.

For cover control, Qinglong GRC uses positioning fixtures to ensure precision, with thickness deviation controlled within ±2mm. Accelerated corrosion testing verified that for components with a 20mm cover in an environment with a Cl- concentration of 0.1%, the time before corrosion onset of the steel reinforcement exceeds 30 years. Inspection of a coastal project after 10 years of use showed the cover thickness was still 18mm with no corrosion on the steel reinforcement, proving the control is effective.

Thickness Design Standards

Indoor dry environment: 15mm; general outdoor environment: 20mm; corrosive environment: 25mm; these standards ensure durability.

Construction Control Measures

Use positioning fixtures (spacing ≤500mm); concrete spacer strength ≥ component strength; these measures ensure accurate thickness.

Acceptance Testing Methods

100% inspection with a rebar detector; allowable deviation ±3mm; these tests ensure quality.

Treatment of Special Areas

Increase by 5mm at corners and edges; enhanced sealing at joints; these treatments prevent localized defects.

Cover control is a guarantee of durability. Qinglong GRC strictly implements the standards to ensure long-term safety.