ما المواد الأساسية المكونة لـ GRC؟ وما متطلبات الألياف الزجاجية المقاومة للقلويات؟

The core constituent materials of GRC (Glass Fibre Reinforced Cement) comprise four major systems: cementitious materials, reinforcing fibers, aggregates, and admixtures. Among these, alkali-resistant glass fiber is the key reinforcing material of GRC, and its quality directly determines the service life of the products. According to the JC/T 572 standard, high-quality alkali-resistant glass fiber must contain no less than 16% zirconia (ZrO₂) and no less than 4% titanium dioxide (TiO₂), with a strength retention rate of ≥80% after boiling in alkali solution (NaOH, pH=12.5) at 100°C for 4 hours.

In the Wuhan Han Show Theatre project, Qinglong GRC used alkali-resistant glass fiber with a zirconium content of up to 18.5%. The fiber surface was treated with a silane coupling agent, achieving a bond strength of 3.2MPa with the cement matrix. Accelerated aging tests showed that, after simulating 50 years of service conditions, the fiber's strength retention rate remained above 75%. The fibers used in the project were 12-38mm in length and 13-20μm in diameter, with an aspect ratio of 60-80. Through precise control of the fiber volume content (4.5%-5%), a flexural strength of 23MPa was achieved, far exceeding the national standard requirement of 18MPa.

Cementitious Material System Configuration

Grade 52.5 low-alkali cement is used, with an alkali content (Na₂Oeq) ≤0.6%. Silica fume (SiO₂ ≥92%) is added to fill micropores. Fly ash (water demand ratio ≤95%) improves workability. Sulphoaluminate cement is used where rapid hardening is required.

Key Points of Aggregate Gradation Control

Quartz sand must have an SiO₂ content ≥98% and a mud content ≤0.3%. Maximum particle size ≤0.6mm, fineness modulus 1.8-2.2. Three-grade gradation is adopted to achieve the densest packing. Sea sand is strictly prohibited, with chloride ion content ≤0.01%.

Key Fiber Performance Indicators

Total zirconium and titanium content ≥20% to ensure alkali resistance. Monofilament tensile strength ≥1500MPa. Elastic modulus ≥70GPa. Alkali resistance retention rate (in 80°C Ca(OH)₂ solution) ≥85%.

Admixture Selection Principles

Polycarboxylate superplasticizer with a water reduction rate ≥25%. Cellulose ether with a water retention rate ≥95%. Redispersible polymer powder improves bond strength. Chloride-containing early strength agents are strictly prohibited.

Raw material quality control is the foundation of GRC durability. Qinglong GRC has established a strict supplier audit system to ensure stable material quality.