What raw materials mainly make up UHPC, and what are the approximate proportions of each component?

The raw material system of UHPC comprises four major categories: cementitious materials (50-60%), aggregates (20-30%), fibers (2-5%), and chemical admixtures (0.5-1.5%). The specific mix ratio must be adjusted according to performance requirements. A typical mix is: cement 40%, silica fume 10%, quartz sand 25%, quartz powder 15%, fiber 3%, water reducer 1%, and water 7% (the above percentages are by mass of solid materials).

In Qinglong's UHPC production practice, the mix ratio is optimized for different application scenarios: structural components adopt a high-cementitious system of cement 45% + silica fume 12%; decorative components are adjusted to cement 35% + quartz powder 25% to improve surface texture; translucent UHPC introduces optical glass aggregates to replace part of the quartz sand. Particularly in the red UHPC project for the Wuhan Hanxiu Theater, through the synergistic color matching of iron red pigment and cement, ΔE≤2 color difference control was achieved while ensuring strength, demonstrating the unity of artistry and science in mix design.

Cementitious Material System

Grade 52.5 Portland cement serves as the base cementitious material. Silica fume fills micropores and participates in pozzolanic reactions. Slag powder improves long-term performance. The ternary cementitious system achieves complementary performance.

Aggregate System Design

Quartz sand (0.1-0.3mm) serves as the main skeleton. Quartz powder (0.04-0.1mm) fills medium pores. The maximum particle size is controlled below 0.6mm. The gradation curve conforms to the Fuller distribution.

Fiber Reinforcement Scheme

Steel fibers (diameter 0.15-0.2mm) provide primary reinforcement. Polyvinyl alcohol fibers improve early-age crack resistance. The optimal fiber length is 13mm. Orientation control enhances reinforcement efficiency.

Chemical Admixture Compounding

Polycarboxylate superplasticizer (water reduction rate ≥30%). Defoamers control air content ≤2%. Retarders adjust setting time. Shrinkage reducing agents reduce early cracks.

Raw material selection requires systematic consideration. Qinglong UHPC has established a supplier audit system to ensure stable material quality.