GRC Panel Chloride Ion Content Testing Method and Operating Procedures Explained

In the field of construction engineering, the durability and safety of materials have always been core concerns of the industry. GRC (glass fiber reinforced concrete), as a new building material combining both strength and molding advantages, has chloride ion content that directly affects the service life and safety performance of structures. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will explain in detail, from a professional perspective, the testing methods and key operational points for chloride ion content in GRC boards, providing authoritative technical reference for designers, owners, and engineering parties.

The Importance of Chloride Ion Testing for GRC Boards: From Material Nature to Engineering Safety

Chloride ions are one of the main causes of corrosion in concrete structures. Especially in humid and coastal environments, excessive chloride ions will accelerate the rusting of steel reinforcement, causing problems such as component cracking and strength reduction. As key components such as exterior wall cladding panels and decorative moldings, GRC boards must have their chloride ion content strictly controlled within the national standard range. Qinglong Group optimizes material formulations at the detailed design stage to keep chloride ion content below 0.06%, and, relying on the testing capabilities of its national-level R&D center, has established a full-process quality traceability system to ensure that every batch of products complies with the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

Standard Testing Methods: Dual Assurance of Laboratory and On-Site Testing

For chloride ion content testing of GRC boards, common industry methods mainly include laboratory chemical analysis and on-site rapid testing. Laboratory testing requires sampling from GRC boards, which are then crushed and ground before being measured by silver nitrate titration or ion chromatography; this method offers high accuracy and is suitable for factory inspection and type inspection. Qinglong's production base is equipped with an advanced testing laboratory, enabling full-cycle chloride ion monitoring from raw materials to finished products. On-site testing uses portable chloride ion content meters to quickly obtain data through the electrode method, suitable for quality spot checks during construction. Qinglong's construction teams are equipped with such devices at every project site, ensuring controllable material quality during installation.

Detailed Operating Steps: A Standardized Process from Sampling to Result Determination

1. Sample Collection: Select representative GRC boards and drill at least 3 samples from different locations, each weighing no less than 50g, avoiding sampling near embedded parts or defective areas. Qinglong strictly follows the "random sampling + stratified sampling" principle to ensure sample representativeness.
2. Sample Preparation: Crush the samples to a particle size of less than 0.15mm, dry at 105°C to constant weight, then leach out chloride ions using distilled water or extraction solution for no less than 24 hours.
3. Testing and Analysis: The laboratory uses potentiometric titration, titrating the leachate with standard silver nitrate solution and calculating the chloride ion content based on the consumed volume; on-site testing reads data directly through calibrated electrodes, with error controlled within ±0.01%.
4. Result Determination: According to the JGJ/T423-2018 standard, the chloride ion content of GRC boards should be ≤0.06% (calculated as a percentage of cement content). Qinglong's corporate standard further tightens this to ≤0.05% to meet the stringent requirements of high-end projects.

Qinglong's Full-Chain Quality Control: Technical Advantages from Source Control to Project Delivery

As a national specialized, refined, distinctive, and innovative enterprise and a participant in formulating GRC industry standards, Qinglong Group integrates chloride ion control into the entire process of material R&D, production, and construction. At the raw material stage, low-chloride cement and mineral admixtures are carefully selected to reduce chloride ion introduction at the source; automated proportioning systems are used during production to ensure uniform mixing of each batch of materials; during construction, BIM technology is used to simulate installation joints, avoiding secondary chloride ion contamination caused by cutting, drilling, and other processes. To date, Qinglong has provided low-chloride GRC solutions for hundreds of projects, including the Dongguan Women and Children's Activity Center and Century Plaza on Nanjing East Road, with weather resistance and safety verified by projects over 10 years.

Controlling the chloride ion content of GRC boards is a key link in ensuring the long-term safety of building structures. Relying on 28 years of technical accumulation, Qinglong Group provides trustworthy GRC application solutions for the industry through a three-dimensional system of "material innovation + standard testing + full-process control". In the future, Qinglong will continue to drive the technological upgrading of UHPC/GRC/GRG/GRP materials and, with the mission of "creating beautiful architecture", help more landmark projects achieve a perfect fusion of safety and aesthetics.