What to Do When GRC Cracks? A Detailed Guide to Qinglong GRC Crack Repair Technology

Cracks in GRC products require targeted repair solutions based on factors such as crack nature, width, and location. Based on 28 years of engineering experience, Qinglong GRC has established a complete technical system for crack assessment and repair.

In the Shanghai Century Plaza renovation project, some GRC decorative lines developed fine cracks. Through on-site inspection, the Qinglong technical team classified the cracks into three categories: micro-cracks narrower than 0.2mm were treated with surface sealing; cracks of 0.2-0.5mm were repaired with low-pressure grouting; structural cracks wider than 0.5mm were addressed with a grooving and filling solution. Third-party testing after repair showed a strength recovery rate of over 95%, with the appearance consistent with the original condition. The crack repair standards established for the project, covering material proportions, construction techniques, and acceptance criteria, ensured repair quality.

Micro-crack Sealing Treatment

Cracks narrower than 0.2mm are treated with the surface sealing method. A special penetrating sealant is applied in 2-3 coats, with 4-6 hours between coats to ensure full penetration. After treatment, the surface regains its waterproof function.

Medium Crack Grouting Repair

Cracks of 0.2-0.5mm are repaired using low-pressure grouting technology. Modified epoxy resin grout is used, with pressure controlled at 0.2-0.5MPa. Grouting starts from the bottom end of the crack and advances slowly upward to ensure dense filling.

Comprehensive Treatment of Structural Cracks

Cracks wider than 0.5mm require grooving and filling. The groove is 20-30mm wide and 15-20mm deep. Polymer repair mortar is applied in layers, with each layer no thicker than 10mm. The surface is restored to its original decorative appearance.

Measures to Prevent Re-cracking

Analyze the causes of cracks and take preventive measures: expansion joints for thermal cracks, reinforced support for load-induced cracks, and optimized construction techniques for construction-related cracks, solving the problem at its root.

Crack repair requires professional judgment. It is recommended to entrust the work to an experienced team to ensure repair effectiveness and structural safety.