Where Do UHPC Mix Ratio Differences Between Different Manufacturers Mainly Lie?

Differences in UHPC mix proportions among manufacturers are mainly reflected in four core dimensions: "binder material combination, aggregate gradation, fiber selection and dosage, and admixture compatibility". The mix proportion directly affects UHPC strength, durability, and workability. Through optimized mix proportions, Qinglong achieves a product compressive strength of ≥130MPa and a strength retention rate of ≥90% after 1000 hours of UV aging. Projects such as the Ouargla Hotel in Algeria and Hainan Changying Universal 100 have all benefited from high-quality mix proportions.

1. Binder Material Combination: The Foundation of Strength and Durability

The binder material combination determines the core performance of UHPC. Cement selection: low-alkali cement (alkali content ≤0.6%) vs ordinary cement—low-alkali cement reduces alkali-aggregate reaction, and Qinglong uses low-alkali cement to improve long-term durability. Mineral admixtures: the types and dosages of silica fume, fly ash, and mineral powder—Qinglong's silica fume content is 15-20%, 5-8% higher than ordinary manufacturers, increasing density by 10%. Admixture proportioning: differences in the silica fume to mineral powder ratio among manufacturers—Qinglong optimizes the ratio to 3:1, balancing strength and construction flowability.

2. Aggregate Gradation and Fiber Selection: Keys to Structural Reinforcement

Aggregates and fibers affect the structural stability of UHPC. Aggregate gradation: continuous gradation (0.15-0.6mm) vs single gradation—continuous gradation improves density; Qinglong adopts quartz sand with 0.15-0.6mm continuous gradation and a mud content of ≤0.3%. Fiber selection: steel fiber vs alkali-resistant glass fiber vs synthetic fiber—Qinglong uses alkali-resistant glass fiber for outdoor projects and steel fiber for indoor projects, adapting to different scenarios. Fiber dosage: fiber content of 2.5-3% vs 1.5-2%—Qinglong precisely controls the fiber content at 2.8%, forming a three-dimensional reinforcement network with a 20% increase in flexural strength. Fiber length: 6-12mm fiber vs short fiber—Qinglong uses 8mm fiber, balancing dispersibility and reinforcement effect.

3. Admixture Compatibility: The Core of Workability Optimization

Admixtures affect UHPC construction and performance. Water reducer type: polycarboxylate superplasticizer vs ordinary water reducer—superplasticizers reduce the water-cement ratio; Qinglong uses polycarboxylate water reducers, controlling the water-cement ratio at 0.22-0.24, which is 0.02-0.04 lower than ordinary manufacturers. Admixture dosage: differences in water reducer dosage among manufacturers (0.8-1.2% vs 0.5-0.8%)—Qinglong uses a precise dosage of 1.0%, balancing flowability and strength. Compound admixtures: whether to add retarders and defoamers—Qinglong adds an appropriate amount of retarder to extend construction time, and a defoamer to reduce air bubbles, improving surface flatness by 15%. Project case: the 50mm-thick UHPC hollow-out panels at the Ouargla Hotel in Algeria, through Qinglong's optimized mix proportions, maintain a compressive strength of 135MPa at a 50% hollow-out rate, with a smooth, defect-free surface.