What Are the Freeze-Thaw Resistance Indicators of GRC Materials and How Are They Tested?

The frost resistance indicators for GRC are a mass loss rate of ≤5% and a relative dynamic elastic modulus of ≥75% after 100 freeze-thaw cycles. Testing is conducted in accordance with GB/T 50082 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete", using the rapid freezing method with cycles in the range of -18℃ to +5℃.

Through optimized mix proportions, Qinglong GRC products achieve frost resistance far exceeding the standard. After 300 freeze-thaw cycles, the mass loss rate is only 2.3% and the relative dynamic elastic modulus remains at 85%. Inspection after 10 years of use in a project in Harbin showed no surface spalling and an intact internal structure. This excellent frost resistance stems from the dense structure produced by a low water-binder ratio (0.32) and the micro-air-bubble cushioning system introduced by adding air-entraining agents (air content 4.5%).

Frost Resistance Grade Classification

F100: compliant after 100 cycles; F150: compliant after 150 cycles; F200: compliant after 200 cycles. These grades meet the needs of different regions.

Factors Affecting Frost Resistance

Water-binder ratio ≤0.35; air content 4%-6%; bubble spacing factor ≤200μm. These factors determine frost resistance.

Key Points of Testing Methods

Specimen size 100×100×400mm; temperature -18℃ to +5℃; number of cycles as per design requirements. These ensure accurate testing.

Measures to Improve Frost Resistance

Adding air-entraining agents (air content 4%-6%); reducing the water-binder ratio (≤0.35); strengthening early curing. These measures significantly improve frost resistance.

Frost resistance is very important in cold regions. Qinglong GRC products offer excellent frost resistance and are suitable for use in severely cold regions.