What to Do About GRC Cracks? Complete Analysis of Crack Causes and Repair Techniques

Cracks in GRC components require differentiated repair solutions based on crack width, depth, location, and cause. Qinglong Group classifies crack treatment into three levels: surface micro-cracks (width <0.2mm), medium cracks (0.2-1mm), and structural cracks (>1mm), and has established a complete crack diagnosis and repair system. During the maintenance of the Wuhan Hanxiu Theater project, we precisely repaired multiple micro-cracks caused by temperature stress through microscopic observation and cause analysis, ensuring the overall safety of the building.

Precise Diagnostic Techniques for Crack Causes

The cause must be accurately determined before crack repair. Qinglong uses professional equipment such as crack microscopes and ultrasonic detection, combined with the stress state of components and environmental factors for comprehensive analysis. Common crack causes include drying shrinkage, temperature stress, structural deformation, and construction damage. In the Dongguan Women and Children's Activity Center project, stress analysis revealed that some cracks were caused by structural displacement, so elastic repair materials allowing a certain degree of deformation were adopted.

Material and Process Selection for Graded Repair

For cracks of different levels, Qinglong adopts different repair materials and processes. Micro-cracks are treated with low-viscosity epoxy resin pressure grouting, medium cracks with polymer-modified cement mortar, while structural cracks require grooving and joint sealing reinforced with fiber cloth. In the repair of the Shenzhen Pingshan High-tech Zone Comprehensive Service Center, we customized dedicated repair solutions based on the crack characteristics of different locations, achieving good results.

Refined Control of the Repair Process

Every step of crack repair requires fine control. Surface treatment must thoroughly remove loose material, grouting must ensure fullness, and timely curing is required after repair. Qinglong Group has developed a series of GRC-specific repair materials, including grouting materials, repair mortar, and surface treatment agents, ensuring compatibility and durability between the repair layer and the substrate. After the repair is completed, we also conduct continuous monitoring to verify the repair effect.

Prevention-Oriented Crack Control Strategy

Compared with post-repair, crack prevention is more important. Qinglong reduces shrinkage cracks during the GRC production stage through measures such as mix ratio optimization and curing regime control; avoids stress concentration during the installation stage through sound connection design; and establishes a regular inspection system during the service stage to promptly detect and treat early cracks. This preventive maintenance strategy can effectively extend the service life of GRC.