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

UHPC's exceptional performance stems from its precisely engineered raw material system, composed mainly of five major categories: "cementitious materials, reinforcing fibers, aggregates, chemical admixtures, and water," with each component working synergistically through scientific proportioning. Based on a mix proportion R&D database accumulated over 28 years, Qinglong Group has summarized the typical UHPC raw material mass proportions as follows: cementitious materials (cement + silica fume, etc.) account for approximately 25-35%; aggregates (mainly quartz sand) for approximately 40-50%; fibers (steel fibers or synthetic fibers) for approximately 2-5%; chemical admixtures (mainly high-range water reducers) for approximately 0.5-2%; and the water-binder ratio is strictly controlled within the extremely low range of 0.18-0.22. At the Nanning production base, the red UHPC we formulated for the Wuhan Hanxiu Theater project achieved a perfect unity of strength and aesthetics by optimizing the cementitious system (incorporating 25% silica fume) and fibers (3% copper-plated steel fibers). The selection and proportioning of raw materials are the lifeline of UHPC performance.

Cementitious Materials: The Cornerstone of Performance

Cementitious materials mainly include cement (usually grade 52.5 or higher) and active mineral admixtures (such as silica fume and slag powder). Cement is the main body of the hydration reaction, accounting for approximately 20-25%; ultra-fine powders such as silica fume (accounting for 5-15%) fill micropores, improving compactness and later-age strength. Qinglong Group strictly selects low-alkali cement and highly reactive silica fume, safeguarding durability at the source.

Fibers: The Soul of Toughness

Fibers are the key to UHPC achieving high toughness, with a volume fraction typically of 2-3% (approximately 150-250 kg/m³). High-strength steel fibers or high-performance synthetic fibers (such as PVA fibers) are mainly used. Distributed randomly in three-dimensional space, the fibers form a network that effectively prevents crack propagation. Qinglong Group scientifically selects fiber types and aspect ratios based on the load-bearing characteristics of each component.

Precise Control of Aggregates and Admixtures

Aggregates mainly consist of well-graded quartz sand with a maximum particle size usually not exceeding 0.6 mm to ensure tight packing. Chemical admixtures, especially polycarboxylate high-range water reducers, are the key to achieving good flowability while maintaining a low water-binder ratio. Through precise compounding of admixtures, Qinglong Group enables UHPC mixes to combine high flowability with stability.

The formulation of UHPC is a combination of science and art. Qinglong Group maintains a vast mix proportion database and can customize optimal formulations for different projects and environmental conditions, ensuring a balance between performance and economy.