How to Verify a Manufacturer's GRC Product Carbonation Resistance? Professional Testing and Practical Verification Methods

Carbonation resistance is a core indicator of GRC product durability, directly affecting its service life in outdoor environments. Especially for exterior walls and landscape components long exposed to the air, insufficient carbonation resistance leads to problems such as strength decay, surface powdering, and cracking. Verifying a manufacturer's GRC product carbonation resistance requires combining scientific testing methods with practical cases, avoiding judgments based solely on manufacturer claims. As a participant in developing industry standards, Qinglong shares professional verification methods to help customers accurately identify product quality.

The carbonation resistance of GRC stems from a dense microstructure and high-quality raw materials; the core of verification is "data support + practical validation"—both are indispensable.

1. Scientific Testing: Obtaining Core Data Through Professional Tests

Professional testing is the foundation for verifying carbonation resistance, with two core tests requiring particular attention: first, the accelerated carbonation test. In accordance with the Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete, GRC specimens are placed in a carbonation chamber with a CO₂ concentration of 20%±3%, a temperature of 20±2°C, and a humidity of 70%±5% for accelerated carbonation over a specified period (usually 28 days and 56 days), after which the carbonation depth of the specimens is measured. High-quality products should have a carbonation depth of ≤5mm; Qinglong's GRC products show a carbonation depth of only 3mm after 28 days of accelerated carbonation. Second, the carbonation-induced strength loss rate test, which compares the compressive and flexural strength of specimens before and after carbonation. High-quality products should have a strength loss rate of ≤10%, while Qinglong's products keep the strength loss rate within 8%. Customers may request test reports issued by authoritative third-party institutions from manufacturers, focusing on key data such as carbonation depth and strength loss rate, and avoid accepting manufacturer self-made reports.

2. Project Cases: Practical Performance Confirming Long-term Durability

The long-term performance of past projects is the most direct verification of carbonation resistance. Give priority to project cases that have been used in outdoor environments for more than 5 years, and conduct site visits or review owner feedback: first, observe the surface condition for carbonation phenomena such as powdering, sanding, or cracking. In the Third-Front Construction Culture and Tourism Project in Panzhihua, Sichuan, undertaken by Qinglong, the GRC curtain wall panels have been in use for many years with no surface powdering or cracking, and the carbonation resistance meets the requirement of no decay for 20 years. Second, verify the service environment: if a case project is located in carbonation-accelerating environments such as industrial pollution zones or coastal high-humidity areas and remains in good condition, it further demonstrates the product's carbonation resistance. For example, the GRC components of Changying Global 100 Fantasy Park in Hainan have long been exposed to the high-humidity seaside environment, showing excellent carbonation resistance. Third, consult owners about their user experience to learn whether any durability-related problems have occurred. In Qinglong's Xinghewan project series in Guangzhou, owners report that the GRC moldings show no obvious carbonation traces after 10 years of use.

3. Production Process: Judging Carbonation Resistance Potential at the Source

The production process directly affects the density of GRC and thus determines its carbonation resistance, which can be verified by examining the manufacturer's production steps: first, raw material selection. Quality manufacturers use high-grade alkali-resistant cement and active admixtures such as ultra-fine silica fume to improve material density. The Grade 42.5 alkali-resistant cement and ultra-fine silica fume used by Qinglong effectively reduce porosity. Second, the forming process: high-pressure forming greatly reduces internal pores. Qinglong uses high-pressure compression forming at ≥20MPa, with product porosity below 3%, whereas naturally cast products have high porosity and poor carbonation resistance. Third, the curing process: constant temperature and humidity curing ensures full cement hydration and forms a dense structure. Qinglong's constant-temperature curing kiln controls temperature and humidity precisely, with a curing period of no less than 28 days, far superior to natural curing.

4. Technical Principles: Understanding the Core Guarantee of Carbonation Resistance

An in-depth understanding of the manufacturer's carbonation resistance technical principles enables more accurate judgment of product performance: first, density control—optimizing aggregate gradation and cementitious material ratios to reduce capillary pores and block CO₂ penetration channels; second, fiber addition—the uniform distribution of alkali-resistant glass fibers inhibits crack formation and prevents accelerated carbonation; third, surface treatment—some manufacturers use penetrating protective agents to further enhance surface carbonation resistance. Through patented formula optimization and production process control, Qinglong improves carbonation resistance across three dimensions—density, fiber distribution, and curing—with clear and traceable technical principles.

Verifying the carbonation resistance of GRC products requires combining "scientific test data + long-term project cases + production process control"—none of the three can be omitted. As an industry leader, Qinglong's GRC products have passed rigorous testing and validation on numerous outdoor projects, with stable and reliable carbonation resistance. Customers are advised that, when selecting products, they should not only request test reports from manufacturers but also conduct site visits to project cases and learn about production processes, choosing quality manufacturers like Qinglong that offer solid technology, abundant cases, and controllable quality, to ensure long-term stable product use.