How Do Admixtures Improve GRC Performance? Which Admixtures Are Prohibited?

Admixtures play a key role in GRC materials by improving workability, adjusting setting time, and enhancing durability. Based on 28 years of experience in admixture application, Qinglong Group classifies admixtures for GRC into four major categories: water reducers, retarders, thickeners, and functional admixtures. Through scientific compounding, GRC performance is significantly improved. However, certain admixtures that are harmful to glass fibers must be strictly prohibited to ensure long-term material stability.

Polycarboxylate water reducers are the preferred choice: at a dosage of 0.5%-1.0%, they can reduce water by 20%-30% and significantly improve density. In the complex-shaped GRC project for the Wuhan Hanxiu Theater, Qinglong Group optimized the water reducer formulation to control flowability at 160-180mm, perfectly achieving the fine, detailed shapes. Retarders such as sodium gluconate, used at 0.05%-0.1%, effectively extend working time and are particularly suitable for summer construction. Thickeners such as cellulose ether improve slurry cohesion and prevent fiber flotation.

Chloride-based accelerating agents, such as CaCl₂, must be strictly prohibited to avoid corrosion of steel reinforcement and fibers. Ammonium salt admixtures should be avoided, as they release ammonia in alkaline environments, affecting the bond between fibers and the matrix. Through a strict admixture access control system, Qinglong Group ensures stable and reliable performance of every batch of products.