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

The exceptional performance of UHPC stems from its precise raw material composition and scientific mix design. Based on extensive testing and project experience, Qinglong Group deconstructs the UHPC raw material system into four core components: "cementitious materials, reinforcing fibers, aggregates, and chemical admixtures". Each component plays a different role within the system, and synergistic effects are achieved through optimized mix proportions.

Cementitious materials are the "flesh" of UHPC, typically accounting for 20%-30% of the total dry material mass. They not only serve as the basis for bonding the other components, but their hydration products are also the main source of strength. Qinglong UHPC typically uses high-strength-grade Portland cement (such as P·II 52.5) blended with a large proportion of microsilica (silica fume), accounting for approximately 20%-30% of the total cementitious materials. The extremely fine particles of microsilica effectively fill the gaps between cement particles, improving density while enhancing later-age strength and durability through its pozzolanic effect.

Reinforcing fibers are the "sinews and bones" of UHPC and are the key to endowing it with high toughness. Steel fibers are the most common choice, with a volume content typically between 2%-3% (approximately 157-235 kg/m³). Qinglong selects steel fibers of different lengths (such as 13mm), diameters, and end-hook forms according to the specific toughness requirements of each product, ensuring their uniform distribution in the matrix and an optimal anchoring effect. The addition of fibers transforms UHPC from a brittle material into a quasi-ductile material.

Aggregates and chemical admixtures are the finely tuned "joints". UHPC typically does not use traditional coarse aggregates, but instead adopts refined quartz sand with a maximum particle size of no more than 0.6mm (sometimes even finer), accounting for approximately 40%-50%. This fine aggregate helps achieve the tightest possible particle packing. High-range water reducers (polycarboxylate-based) are crucial, with a dosage (calculated by cementitious material weight, typically 1.5%-2.5%) that ensures the mixture retains good fluidity and workability even at low water-binder ratios (0.18-0.22). Every Qinglong UHPC formula is the result of repeated laboratory testing and project validation, aiming to achieve the optimal balance between performance and constructability.