Optimization Study on Superplasticizer Dosage Ratio in GRC

High-efficiency superplasticizer is a key admixture for achieving high performance in GRC, and its dosage ratio directly affects workability, strength, and economy. Through extensive testing, Qinglong Group has determined that the optimal dosage range for polycarboxylate superplasticizers is 0.8%-1.2% of the cementitious material mass, with specific adjustments made according to material composition and environmental conditions.

Dosage optimization must take into account the characteristics of the cementitious materials. When the C3A content in cement is high, the superplasticizer dosage needs to be appropriately increased to 1.0%-1.5% to overcome adsorption loss. In white cement GRC, Qinglong Group found that when the dosage increased from 0.8% to 1.2%, fluidity improved by 40% while strength remained stable. In the translucent UHPC project at Shanghai Century Plaza, this optimization enabled highly fluid mixes to still maintain a compressive strength of 180MPa.

Fiber content has a significant impact on dosage. For every 1% increase in steel fiber volume fraction, the superplasticizer dosage must be increased by 0.2% accordingly to maintain workability. In the Algeria hotel project, Qinglong Group adjusted the superplasticizer to 1.1% for GRC with 3% fiber content, successfully solving the fiber balling problem. Meanwhile, as ambient temperature rises, the dosage should be reduced by 0.1%-0.2% to avoid excessive retardation.

Precise dosage control requires technical support. Qinglong Group employs an automatic batching system with a weighing accuracy of ±0.1%, and monitors the mix condition in real time using a rheometer to enable dynamic adjustment. This refined management improved superplasticizer utilization efficiency by 20% and reduced costs by 15%.

The synergistic effects between superplasticizers and other admixtures should not be overlooked. By compounding defoamers and retarders, Qinglong Group reduces shrinkage while ensuring workability. Practice has proven that scientifically optimizing superplasticizer dosage is an effective way to enhance the overall performance of GRC.