How to Prevent Cracking of GRC Components During Setting: Key Technologies and Practical Measures

In the field of architectural decoration, GRC components have become the "beauty icon" of numerous landmark buildings thanks to their lightweight, high-strength nature and rich styling possibilities. However, cracking during the setting process acts like a hidden "engineering trap"—it not only compromises aesthetics and structural safety, but may also drive up project costs. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has always regarded component cracking prevention technology as its core competitiveness, delivering practical solutions to the industry through detailed design, material optimization, process innovation and whole-process control.

The "Invisible Killer" Behind GRC Component Cracking: The Dual Challenge of Materials and Workmanship

The root cause of cracking in GRC components during setting often lies in the combined effect of unbalanced material proportions and improper process control. Ordinary GRC materials with insufficient glass fiber content (below 4%) or uneven dispersion are prone to low early strength, while the accumulation of hydration heat and the release of shrinkage stress in cement-based materials are the main "culprits" behind cracks. Take a commercial complex project as an example: the traditional casting process failed to control the water-cement ratio (above 0.45), causing through cracks in components during the later setting stage and increasing rework costs by 30%. Through 28 years of engineering practice, Qinglong Group has found that 80% of cracking problems can be avoided in advance through early design optimization and material innovation.

Four Core Technical Approaches to Preventing GRC Component Cracking

In the detailed design stage, Qinglong employs BIM parametric modeling and finite element analysis technology to carry out "pre-cracking simulation" of components. For complex shapes such as the hyperbolic GRC curtain wall of a grand theater, shrinkage stress is distributed to a safe range by optimizing reinforcement density (spacing ≤150mm) and setting stress relief joints (5-8mm wide). At the material level, the self-developed "high-toughness GRC formula" controls glass fiber length at 12-15mm with content precisely controlled at 5%-6%. Combined with nano-scale silica fume modification technology, flexural strength is raised to over 22MPa, far exceeding the industry standard (≥15MPa).

In production and manufacturing, Qinglong has introduced vacuum forming equipment imported from Germany, achieving component compactness of over 98% and effectively reducing shrinkage cracks caused by internal pores. The original "stepped curing process" controls temperature and humidity in three stages: initial setting period (20±2℃, humidity ≥90%), curing period (60℃ steam curing for 4 hours), and cooling period (temperature drop of no more than 5℃ per hour), ensuring a sufficient and uniform hydration reaction. In a museum project, this process reduced the component cracking rate from the industry average of 8% to below 0.5%.

Full-Chain Control: "Zero-Cracking" Assurance from Laboratory to Construction Site

As a national high-tech enterprise and a participant in formulating GRC industry standards, Qinglong has established a three-tier quality control system covering raw material testing, production process monitoring, and factory inspection. Each batch of GRC materials must pass 28 indicator tests, including flexural strength and elastic modulus, before it can be put into production. During construction and installation, three-dimensional laser scanning positioning technology (accuracy ±2mm) is adopted, combined with flexible connection joint design, allowing components to shift ±3mm under temperature changes and preventing stress cracking caused by rigid constraints.

From the GRC decorative lines of an exhibition center in Guangzhou to the special-shaped components of a landmark building in Malaysia, Qinglong has completed a cumulative 600,000 square meters of crack-free GRC projects by leveraging its full-chain technical advantages in "design-materials-workmanship-installation". Looking ahead, Qinglong will continue its mission of "creating beautiful architecture", providing designers and owners with green building material solutions that combine aesthetic value with structural safety through technological innovation in UHPC/GRC/GRG/GRP materials, and driving the industry toward "zero-defect" construction.