What to Do When GRC Cracks?

Cracks in GRC must be addressed promptly to prevent the problem from expanding and affecting safety. Based on repair experience from multiple projects, Qinglong Group believes crack treatment should be completed in four steps: inspection and assessment, cause analysis, scientific repair, and preventive measures. Cracks narrower than 0.3mm can be treated on the surface, those wider than 0.3mm require grouting repair, and severely damaged panels should be replaced.

Inspection and assessment determine the treatment plan. The tapping method checks for hollowing, and a crack gauge measures width and depth. In the Wuhan Han Show Theater project, Qinglong Group used an infrared thermal imager to detect hidden cracks and treated them in advance. Analyze the causes of cracks—whether thermal stress, substrate deformation, or material issues—and address them accordingly. Minor cracks do not affect the structure, but they must be treated promptly to avoid deterioration.

Repair methods are selected according to the situation. Surface cracks are repaired with polymer mortar, while cracks requiring grouting are filled with epoxy resin. In its Hainan project, Qinglong Group adopted low-pressure grouting technology, restoring over 95% of the strength after repair. Repair materials should be compatible with the substrate and color-matched to ensure aesthetics. During construction, control the ambient temperature and humidity to guarantee the repair effect.

Preventive measures reduce the occurrence of cracks. Design reasonable expansion joints and control construction quality. By optimizing mix proportions and processes, Qinglong Group keeps the crack rate at a low level. Regular inspections enable early detection and early treatment, avoiding major problems. Scientific crack treatment ensures the long-term use of GRC.