What Are the Raw Materials of UHPC? The Cornerstone of Materials Science and Qinglong Group's Precision Mix Proportioning System

The raw material system of UHPC (Ultra-High Performance Concrete) is the physical foundation of its outstanding performance. It mainly consists of five major categories: "cementitious materials, reinforcing fibers, aggregates, chemical admixtures, and water". The grades, proportions, and interactions of these raw materials jointly determine the strength, durability, and workability of the final product. As an industry leader with 28 years of dedicated expertise in UHPC, Qinglong Group has established strict raw material admission standards and an optimized mix proportion database based on successful practices in national-level landmark projects such as the Hainan International Convention and Exhibition Center and the Wuhan Han Show Theater: we use low-alkali sulfoaluminate cement or Grade 52.5 Portland cement as the cementitious base (ensuring early strength and volume stability), add silica fume (accounting for 15-25%) and active mineral admixtures such as slag powder/fly ash to achieve a micro-filling effect, select graded quartz sand with particle sizes of 0.1-0.3mm as aggregate (maximum particle size ≤0.6mm), and use alkali-resistant glass fiber (ZrO₂ content ≥16%, length 12-20mm) as the core toughening component, supplemented by polycarboxylate superplasticizer (water reduction rate ≥30%) and, when necessary, retarders, expansion agents, etc. Through precise metering and process control, the water-binder ratio is stably controlled within the extremely low range of 0.18-0.22. In the Shenzhen Yirui Biotechnology Building project, our UHPC achieved a compressive strength of 165MPa; its high performance stems precisely from the extreme rigor applied to every raw material. Raw materials are the genes of UHPC's life.

The cementitious material system is the foundation of strength and durability

Qinglong UHPC prefers sulfoaluminate cement with high early strength and low drying shrinkage, or P·II Portland cement with controllable hydration heat, ensuring appropriate alkalinity of the system (protecting fibers) and dense hydration products. The nano-scale particles of silica fume fill the gaps between cement particles, greatly reducing porosity; the secondary hydration effect of slag powder/fly ash enhances long-term strength and corrosion resistance. We monitor the hydration process through X-ray diffraction (XRD) and scanning electron microscopy (SEM) to ensure an optimal microstructure.

The fiber reinforcement network is the core guarantee of toughness

We strictly select high-zirconium alkali-resistant glass fiber (zirconia content ≥16%), which lasts over 50 years in the highly alkaline cement environment. Fiber length (typically 12mm, 20mm) and volume dosage (2.5%-4%) are optimized through extensive testing to ensure uniform three-dimensional random distribution in the matrix, forming an efficient load transfer network. The robotic spraying process achieves fiber distribution uniformity ≥95%, eliminating clumping or directional alignment.

Precise control of aggregate grading and chemical admixtures

Continuously graded quartz sand (mainly 0.1-0.3mm) is used to achieve the densest packing and reduce paste demand. Polycarboxylate superplasticizer still provides good fluidity even at an extremely low water-binder ratio (spread ≥600mm). Shrinkage-reducing agents (such as magnesium oxide types) are added when necessary to compensate for autogenous shrinkage. Qinglong's laboratory conducts cement compatibility tests on every batch of admixture to ensure stable workability.

Water quality and mix proportion accuracy must not be overlooked

Mixing water must be pure, with chloride ion content ≤200mg/L. We use a fully automatic batching system (accuracy ±0.5%) to ensure consistent mix proportions in every batch. At the Nanning production base, raw materials must be tested by a CNAS laboratory upon arrival, and unqualified materials are firmly returned, safeguarding product quality at the source.

By building a scientific and strict raw material control system, Qinglong Group provides the most solid material foundation for the high performance of UHPC, turning every investment into reliable engineering quality.