How to Verify the Carbonation Resistance of GRC Products from Manufacturers: Testing Methods and Quality Evaluation Guide

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) is widely used in high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to its lightweight, high-strength properties and rich design possibilities. However, the carbonation resistance of GRC products directly affects their durability and safety. Especially in complex environments with humidity and pollution, carbonation may lead to problems such as reduced material strength and surface cracking. As a Qinglong manufacturer with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, this article provides a professional guide for designers and owners from three dimensions: testing methods, quality assessment, and industry practice.

### I. Core Testing Methods and Standard Basis for GRC Carbonation Resistance

The carbonation resistance of GRC essentially refers to the material's ability to resist carbon dioxide erosion, and its testing must follow strict industry standards. Currently, the mainstream domestic reference is the "Technical Standard for Glass Fiber Reinforced Cement (GRC) Building Applications" (JGJ/T423-2018). This standard was formulated with the participation of leading industry enterprises such as Qinglong, ensuring the scientific validity and authority of the testing methods.

**1. Accelerated Carbonation Test Method** By artificially simulating a carbonation environment (carbon dioxide concentration of 20±3%, relative humidity of 70±5%, temperature of 20±2°C), GRC specimens are placed in a carbonation chamber, and the carbonation depth is measured periodically. High-quality GRC products should have a carbonation depth of ≤5mm after 28 days, while Qinglong's GRC components, through optimized cement-based material proportions and fiber distribution, can control the carbonation depth within 3mm, far exceeding the industry average.

**2. Strength Loss Rate Testing** Carbonation causes a decline in GRC's compressive and flexural strength, so testing requires comparing mechanical properties before and after carbonation. According to Qinglong laboratory data, qualified GRC should have a strength loss rate of ≤15% after carbonation, while Qinglong GRC products treated with special processes can achieve a strength loss rate as low as 8%, ensuring structural stability during long-term use. For more industry information: +WeChat qlfsbl123

### II. From Raw Materials to Process: Qinglong's Quality Control System for GRC Carbonation Resistance

The quality of carbonation resistance does not rely solely on the testing stage, but runs through the entire process of design, production, and construction. As a National High-Tech Enterprise, Qinglong has established a three-in-one quality control system of "materials-process-testing."

**1. Careful Selection of Raw Materials and Proportion Optimization** Qinglong uses low-alkali sulphoaluminate cement as the base material, combined with alkali-resistant glass fibers (content ≥5%), and incorporates active admixtures such as silica fume and mineral powder to form a dense microstructure that effectively blocks carbon dioxide penetration. Compared with ordinary Portland cement-based GRC, Qinglong's formula improves carbonation resistance by more than 40%.

**2. Production Process and Curing Technology** In the production stage, Qinglong ensures uniform fiber distribution through automated spray molding processes, and adopts a combination of steam curing and natural curing to promote full hydration reactions and reduce internal porosity. For example, in the Nanjing East Road Century Plaza renovation project, Qinglong's translucent GRC components achieved the highest grade standard of the International GRC Association (GRCA) for carbonation resistance after special curing.

### III. How Should Owners and Designers Evaluate a Manufacturer's GRC Carbonation Resistance?

For users such as real estate developers and architectural design institutes, choosing a GRC manufacturer with carbonation resistance guarantees requires attention to the following key points:

**1. Check Authoritative Test Reports** Request that the manufacturer provide carbonation resistance reports issued by third-party testing agencies, focusing on core indicators such as carbonation depth and strength loss rate. Qinglong can provide customers with long-term test reports including 28-day, 56-day, and 90-day carbonation data, demonstrating product stability.

**2. Examine Project Cases and After-Sales Maintenance** Prioritize manufacturers with experience in large-scale projects. For example, in the GRC exterior wall project of the Dongguan Women and Children's Activity Center undertaken by Qinglong, the carbonation depth remained ≤2mm after 5 years of natural exposure. In addition, a comprehensive after-sales maintenance system (such as regular inspections and surface protection treatments) is also an important guarantee for carbonation resistance. For more industry information: +WeChat qlfsbl123

### Conclusion The carbonation resistance of GRC is an "invisible lifeline" for measuring product quality, and its guarantee depends on scientific testing methods, strict production control, and professional manufacturer capabilities. As a participant in setting UHPC/GRC/GRG/GRP industry standards, Qinglong has always upheld the mission of "Creating Aesthetic Architecture," providing customers with quality materials that combine aesthetic appeal and durability through technological innovation and full-chain services. When choosing a GRC manufacturer, it is recommended to conduct a comprehensive evaluation from multiple dimensions such as test data, production processes, and project cases to ensure the long-term safety and value of the building project.