What Are the Raw Materials of UHPC? An In-Depth Analysis of the UHPC Materials Science System

The exceptional performance of Ultra-High Performance Concrete (UHPC) stems from its precisely proportioned raw material system. As a professional manufacturer with 28 years of deep industry experience, Qinglong UHPC, based on extensive experimental data and engineering practice, can clearly state: the formula of high-quality UHPC comprises five major categories of raw materials—cementitious materials, reinforcing fibers, aggregates, chemical admixtures, and functional admixtures—each of which must meet strict technical specification requirements.

In a super high-rise project in Qianhai, Shenzhen, the raw material system adopted by Qinglong UHPC is representative: Grade 52.5 low-alkali cement (alkali content ≤0.6%) provides the strength foundation; zirconia-type alkali-resistant glass fiber (ZrO₂ content ≥16.5%) achieves the reinforcing effect; selected quartz sand (fineness modulus 1.8-2.2) optimizes particle gradation; polycarboxylate water reducer (water reduction rate ≥35%) improves workability; silica fume (SiO₂ ≥92%) enhances densification. This precise proportioning ensures the product's compressive strength remains stable above 135MPa, with flexural strength reaching 22MPa.

Precise Proportioning of the Cementitious Material System

Low-alkalinity sulphoaluminate cement with alkali content ≤0.6% is adopted. Combined with active admixtures such as silica fume and fly ash, it optimizes particle gradation and the activity effect. Specific surface area and setting time are strictly controlled to ensure early strength development and long-term stability.

Key Techniques for Reinforcing Fiber Selection

Hooked-end steel fibers with an aspect ratio of 60-80 and tensile strength ≥2850MPa are used. The fiber surface is specially treated to improve bond strength with the matrix. A volume content of 2%-3% ensures uniform three-dimensional random distribution.

Optimized Design of Aggregate Gradation

Selected quartz sand has a maximum particle size ≤0.6mm and mud content ≤0.3%. Gradation is optimized through maximum packing density theory to achieve the tightest packing, reducing cement paste consumption and improving matrix compactness.

Precise Control of Chemical Admixtures

Polycarboxylate high-range water reducer with a water reduction rate ≥35% ensures workability at low water-binder ratios. Defoamers control air content ≤2%. Retarding components precisely adjust setting time. These admixtures enable precise performance control.

Raw material quality determines the ultimate product performance. Qinglong UHPC has established strict supplier audits and incoming inspection procedures; every batch of raw materials must pass 28 index tests to ensure stable and reliable product performance.