Discussion on Alkalinity Issues and Solutions When Using Sulphoaluminate Cement in GRC

In the field of architectural decoration materials, material performance and application details often determine the quality and lifespan of a project. Especially in the application of composite materials such as GRC (Glass Fiber Reinforced Concrete), alkalinity issues are like hidden technical reefs—if not handled properly, they may at best compromise the decorative effect, and at worst threaten structural safety. As an industry player with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group has profoundly realized through thousands of project practices that scientific alkalinity control is the core prerequisite for GRC materials to achieve the unity of aesthetics and durability.

I. Technical Roots and Industry Pain Points of the Alkalinity Problem in GRC Materials

Sulphoaluminate cement is widely used in GRC component production thanks to its rapid hardening, early strength, and low shrinkage properties, but its inherent high alkalinity can trigger a chain reaction. When the concentration of hydroxide ions released during cement hydration exceeds the threshold, it not only causes alkaline corrosion of glass fibers (known as the "alkali-aggregate reaction"), reducing the material's flexural strength (premium GRC can reach above 20MPa, which may plummet by 30% after alkaline corrosion), but also leads to surface defects such as whitening and cracking. A landmark project once neglected alkalinity control, resulting in extensive crazing of exterior wall GRC cladding panels within 3 years, ultimately requiring complete replacement and causing economic losses of tens of millions of yuan.

The industry currently faces three major challenges: first, some manufacturers excessively pursue production efficiency without strictly controlling cement alkali content; second, fluctuations in raw material quality make alkalinity difficult to stabilize; third, the construction phase shows weak awareness of alkalinity management in the curing environment. These problems have directly undermined confidence in the application of GRC materials in high-end buildings such as grand theaters and commercial complexes.

II. Qinglong's 28 Years of Technical Accumulation: A Systematic Solution for Alkalinity Control

To address the alkalinity challenge of sulphoaluminate cement in GRC, Qinglong Group, relying on its national-level R&D center and 58 patented technologies, has built a full-chain solution of "source control - process optimization - later-stage monitoring":

1. Precise Raw Material Proportioning Technology: Through the self-developed "alkalinity balance formula", sulphoaluminate cement is scientifically blended with low-alkalinity mineral admixtures, keeping the system's pH value stably within the safe range of 11.5-12.5. At the Nanning production base, every batch of raw materials is tested with an X-ray fluorescence spectrometer to ensure that alkali content fluctuation does not exceed 0.5%.

2. Fiber Surface Modification Treatment: Imported alkali-resistant glass fibers are used, combined with silane coupling agent surface treatment technology, to form an alkali-resistant protective layer. Verified by accelerated aging tests, this process can raise the fiber strength retention rate in alkaline environments to over 85%, far exceeding the industry average.

3. Intelligent Curing Environment Management: An IoT-based curing system is introduced to monitor the temperature, humidity, and alkali mist concentration inside curing chambers in real time, with pH adjusted through automatic spraying. In the Dongguan Women and Children's Activity Center project, this technology raised the 28-day strength compliance rate of GRC components to 100% and reduced the surface defect rate by 90%.

III. From Standard-Setting to Project Implementation: Qinglong's Industry-Leading Practice

As a contributing unit to the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong Group wrote alkalinity control technology into the industry code and promoted the establishment of the "Qinglong Standard" for GRC material alkalinity testing. In the Century Plaza renovation project on Nanjing East Road, when adopting a composite system of light-transmitting concrete and GRC, the interface reaction between the two materials was successfully resolved through an alkalinity buffer layer design, winning the Silver Award of the first UHPC Construction Engineering Innovation Award.

For designers and owners, choosing a GRC manufacturer with full-chain technical capabilities is crucial. Qinglong provides not only material products but also "one-stop" services from detailed design (using Rhino parametric modeling) to after-sales maintenance. For example, in an overseas airport project, BIM technology was used to rehearse the installation nodes in alkali-sensitive areas, preemptively avoiding the risk of alkaline corrosion in a tropical high-humidity environment and ensuring the project smoothly passed international acceptance.

The vitality of architecture lies in the relentless pursuit of detail. Alkalinity control of sulphoaluminate cement in GRC tests both the rigor of materials science and the systematic nature of engineering practice. With 28 years of professional accumulation, Qinglong Group has proven that only by integrating technological innovation into every production step can GRC materials bloom with artistic beauty while upholding safety in the domes of grand theaters and the curtain walls of commercial complexes. This is a profound practice of the "Creating Beautiful Architecture" mission, and Qinglong's eternal commitment to quality as an industry leader.