What Are the Main Factors Affecting GRC Strength Degradation?

The core factors affecting GRC strength degradation fall into three categories: material quality, environmental erosion, and production processes. Through full-chain quality control and targeted protection solutions, Qinglong achieves a 20-year strength retention rate of ≥85% for its products—far exceeding the industry average—and its durability has been verified by numerous landmark projects.

I. Material Quality: The Root Cause of Strength Degradation

The intrinsic quality of materials directly determines the long-term strength stability of GRC. Fiber quality: insufficient tensile strength of alkali-resistant glass fibers or defects in alkali-resistant coatings can cause strength loss exceeding 30% over 5 years; Qinglong uses imported alkali-resistant fibers with tensile strength ≥1800MPa, retaining ≥85% strength after the 1000h alkali resistance test. Cement type: ordinary Portland cement has high alkalinity and is prone to alkali-aggregate reactions; Qinglong prefers low-alkali sulphoaluminate cement (alkali content ≤0.6%) to reduce fiber corrosion. Aggregate purity: aggregates with mud content ≥1% reduce matrix compactness; Qinglong's quartz sand has a mud content ≤0.3%, ensuring clean particles. Admixture compatibility: inferior admixtures can damage the structure of hydration products; Qinglong uses high-range water reducers compatible with the cementitious system, eliminating hidden risks of strength degradation.

II. Environmental Erosion: External Factors Accelerating Strength Degradation

Harsh environments accelerate GRC strength decline, with different risks in different scenarios. Temperature and humidity alternation: high-temperature and high-humidity environments accelerate the decomposition of cement hydration products, causing an annual strength decline of 2%-3%; Qinglong applies hydrophobic coating protection in South China projects. Corrosive media: chloride ions in coastal areas and sulfates in industrial environments erode the matrix, increasing the strength loss rate by 50%; Qinglong's coastal projects use anti-corrosion formulations with a chloride ion penetration coefficient ≤1.0×10⁻¹²m²/s. Freeze-thaw cycles: northern regions experience more than 50 freeze-thaw cycles annually, which can cause internal pore expansion and cracking; Qinglong's frost-resistant GRC shows strength loss ≤3% after 300 freeze-thaw cycles. UV exposure: long-term outdoor UV radiation ages the interface between fibers and the cement matrix; Qinglong's outdoor products contain UV stabilizers, with a 10-year strength decline ≤10%.

III. Production Process: Key Link Affecting Strength Stability

Non-standardized processes can plant hidden risks of strength degradation. Mixing uniformity: uneven fiber dispersion leads to localized strength weakness; Qinglong uses forced-action mixers plus mechanical dispersion devices, with a fiber distribution coefficient of variation ≤5%. Curing quality: insufficient early curing results in inadequate hydration, increasing the strength degradation rate by 15%; Qinglong cures products for more than 7 days in constant temperature and humidity curing rooms (humidity ≥90%). Installation joints: improper joint treatment causes stress concentration, accelerating localized strength degradation; Qinglong optimizes joint design through BIM and uses flexible connections to reduce stress transmission. Surface defects: cracks, honeycombing, and other defects can become channels for erosion; Qinglong products undergo 100% visual inspection before leaving the factory, with a defect repair rate of 100%.