What Are the Main Factors Affecting GRC Strength Deterioration? An In-Depth Analysis of Key Factors in Qinglong GRC Durability

GRC strength degradation is a complex process driven by multiple factors. The main influencing factors fall into four major categories: material deterioration, environmental effects, load damage, and construction defects. Based on 28 years of engineering tracking data, Qinglong GRC has identified 12 key factors affecting strength degradation, among which alkali-aggregate reaction, carbonation depth, freeze-thaw cycles, and fiber corrosion are the primary issues.

In a coastal project, sampling analysis of GRC components after 15 years of service revealed: components with a carbonation depth of 3.2mm showed 25% strength degradation; components with chloride ion penetration depth exceeding 5mm suffered severe fiber corrosion; components subjected to 300 freeze-thaw cycles had surface spalling as deep as 2mm. In contrast, components made with low-alkali cement (alkali content ≤0.6%), silica fume addition (8%), and a controlled water-cement ratio (0.32) retained over 85% of their strength after 15 years. This demonstrates that scientific mix proportioning and refined construction are the key to ensuring long-term performance.

Analysis of Material Factor Influence

Cement alkali content (influence degree 25%): when alkali content exceeds 0.8%, the annual degradation rate can reach 3%; fiber alkali resistance (influence degree 20%): fibers with ZrO₂ content below 16% have a strength retention rate below 60% after 5 years; these material factors require strict control.

Quantitative Analysis of Environmental Effects

Carbonation: for every 1mm increase in carbonation depth, strength degrades by 8%-10%; chloride ion attack: when Cl- concentration exceeds 0.1%, the annual corrosion rate reaches 0.1mm; freeze-thaw cycles: strength degrades by 5%-8% per 100 cycles. These environmental effects need to be evaluated.

Cumulative Effects of Load Damage

Under sustained load (over 30% of ultimate load), the annual degradation rate increases by 50%; fatigue load (10⁶ cycles) causes a strength reduction of 15%-20%; these load effects need to be considered.

Key Points for Preventing Construction Defects

Improper curing reduces early strength by 20%; uneven fiber distribution leads to a strength variation coefficient exceeding 15%; these construction problems must be avoided.

Strength degradation requires systematic prevention and control. Qinglong GRC ensures long-term product performance through whole-process control.