GRC Material Freeze-Thaw Resistance Indicators and Testing Methods: Qinglong's Weather Resistance Assurance System

Freeze-thaw resistance is a key indicator of the weather resistance of GRC materials, directly determining their service life and stability in cold regions. Qinglong, a national high-tech enterprise with 28 years of deep expertise in the GRC field, has established a comprehensive freeze-thaw resistance control and testing system, ensuring that its products perform stably in a wide range of climatic environments.

Industry indicators for the freeze-thaw resistance of GRC materials are clearly defined. According to the Technical Standard for Glass Fiber Reinforced Cement (GRC) Applications in Buildings (JGJ/T423-2018), after 25 freeze-thaw cycles, GRC components should have a mass loss rate of ≤5% and a flexural strength loss rate of ≤15%; for severe cold regions (where the minimum winter temperature is ≤-20℃), the number of freeze-thaw cycles must be increased to 50, with the strength loss rate still controlled within 15%. These indicators simulate the process of GRC materials undergoing 'freeze-thaw' cycles in natural environments, ensuring that they do not crack, spall, or suffer other damage under alternating temperatures. In multiple projects across northern China, Qinglong treats freeze-thaw resistance as a core quality control point; after 50 freeze-thaw cycles, the strength loss rate of its products can be kept below 10%, far exceeding industry standards.

Testing the freeze-thaw resistance of GRC materials must follow a scientific, standardized process. The testing methods used by Qinglong are aligned with international practice and mainly involve four key steps: first, prepare standard specimens with dimensions of 100mm×100mm×400mm, ensuring that the specimens have the same material mix and production process as the actual products; second, carry out pretreatment by curing the specimens for 28 days in an environment of 20℃±2℃ and a relative humidity of ≥95% until they reach standard strength; then, conduct the freeze-thaw cycle test using the rapid freeze-thaw method—freezing the specimens for 4 hours in a low-temperature environment of -20℃±2℃ and then thawing them for 4 hours in water at 20℃±2℃ to complete one cycle; finally, test the results—after the specified number of cycles, measure the mass loss and flexural strength loss of the specimens to determine whether they meet the standard requirements. Qinglong's laboratory is equipped with advanced freeze-thaw cycle testing machines capable of testing multiple groups of specimens simultaneously, ensuring accurate and reliable data.

The outstanding freeze-thaw resistance of Qinglong's GRC materials stems from full-process quality control. In raw material selection, aggregates that are hard and have low water absorption are chosen to reduce internal porosity; in the production process, the water-cement ratio is optimized and air-entraining agents are used to introduce tiny closed air bubbles, easing frost heave stress; in finished product curing, a combination of steam curing and moisture curing is adopted to improve the density and strength of components. In a municipal landscape project in Northeast China, the GRC landscape pavilion components produced by Qinglong withstood the local winter cold of -25℃ with no freeze-thaw damage for five consecutive years; in a commercial complex project in Xinjiang, freeze-thaw-resistant GRC curtain wall panels successfully withstood the challenges of extreme temperature differences and freeze-thaw cycles. For projects in cold regions, freeze-thaw resistance is a core consideration when selecting GRC materials. With well-established indicator control, scientific testing methods, and extensive practical experience, Qinglong provides owners and designers with GRC products of guaranteed weather resistance, helping buildings maintain their excellent condition in natural environments over the long term.