How to Prevent Cracking of GRC Components During Setting? Qinglong GRC Anti-Cracking Technology System

Preventing cracking of GRC components during the setting period requires a three-pronged approach: material modification, process optimization, and enhanced curing. By adding polypropylene fibers (0.9kg/m³), controlling the early shrinkage rate at ≤0.02%, and applying low-temperature steam curing (40°C×36h), the cracking risk can be reduced by 80%.

Comparative tests showed that specimens without fibers developed 0.3mm-wide cracks within 3 days, while fiber-reinforced specimens showed only micro-cracks (<0.05mm). A large relief sculpture project using Qinglong GRC anti-cracking mix proportions (fiber content 1.2%) produced components up to 8m long without expansion joints, and they remained crack-free after 2 years in service. Components of the same type with conventional mix proportions require joints at a maximum of 4m.

Key Points of Material Modification

Polypropylene fiber length 12-18mm, dosage 0.9-1.2kg/m³; shrinkage-reducing agent dosage 1.5%-2%; these modifications effectively suppress cracks.

Key Parameters of Mix Proportion Optimization

Cement-sand ratio 1:1-1:1.2; water-cement ratio 0.30-0.33; early shrinkage rate ≤0.02%; these parameters control shrinkage.

Core Process Control Measures

Secondary vibration eliminates settlement cracks; surface troweling closes surface cracks; these measures reduce cracking.

Scientific Curing Regime Settings

Cover with plastic film immediately after initial setting; steam curing temperature 40±5°C; these settings prevent cracking.

Crack resistance requires a systematic solution. Qinglong GRC proprietary technology effectively prevents and controls cracks.