What Raw Materials Is UHPC Mainly Composed Of, and What Are the Approximate Proportions of Each Component? An Analysis of the Material Composition and Mix Ratios of Ultra-High Performance Concrete

Ultra-High Performance Concrete (UHPC) is reshaping the limits of architecture like "the Iron Man of the materials world," and the scientific proportioning of its raw materials is the core code to unlocking strength and toughness. As an industry leader with 28 years of deep expertise in the UHPC field, Qinglong Group will start from the essence of the material to reveal the proportioning secrets of this "black technology of architecture" for designers and owners.

In the wave of contemporary construction industrialization, UHPC has become a star material in landmark buildings, bridge engineering, and high-end decoration thanks to its outstanding performance of over 150MPa compressive strength and over 20MPa flexural strength. Its raw material composition may seem simple, but it actually embodies precise scientific proportioning—this is not only a reflection of accumulated technical expertise, but also Qinglong's profound understanding of the material essence as a national high-tech enterprise.

I. UHPC Raw Material System: The Golden Combination of Four Core Components

As a Qinglong manufacturer specializing in UHPC detailed design and production, we always adhere to the philosophy that "materials are the foundation, proportioning is the soul." The UHPC raw material system mainly consists of four core components: cement-based cementitious materials, fine aggregates, steel fibers, and admixtures. The synergistic effect of each component determines the ultimate performance of the material.

1. Cement-based Cementitious Materials: The Cornerstone of Strength (40%-50% of total)

In production, Qinglong carefully selects high-grade Portland cement (such as P.O 52.5R) as the main cementitious material, combined with silica fume (ultra-fine active silica with particle size <1μm) and fly ash to form a composite system. Silica fume accounts for 15%-20% of the total cementitious materials, and its "micro-aggregate filling effect" can greatly reduce porosity; fly ash optimizes the interfacial transition zone through the "pozzolanic reaction," making the matrix structure denser. This proportioning scheme is derived from thousands of test data accumulated when Qinglong participated in drafting the industry standard "General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components."

2. Fine Aggregates: The Precision of the Skeleton (25%-35% of total)

Unlike ordinary concrete, UHPC uses only quartz sand as the sole aggregate, with particle size strictly controlled between 0.15-1.25mm. Qinglong's production base ensures continuous sand gradation through a three-stage sieving process, achieving an aggregate packing density of over 85% of the theoretical maximum. This "fine aggregate single gradation" design, combined with the high fluidity of the cementitious materials, enables precise forming of complex special-shaped components—just as Qinglong successfully achieved a hyperboloid shape with a minimum curvature radius of 300mm in the Century Plaza translucent concrete project on Nanjing East Road.

3. Steel Fibers: The Key to Toughness (2%-5% volume fraction)

Qinglong selects copper-plated micro-twisted steel fibers (length 13-20mm, diameter 0.2-0.3mm). Through a "random distribution + end anchoring" design, the flexural strength of the material is increased by 3-5 times. In the Dongguan Women and Children's Activity Center project, we innovatively adopted a fiber content of 2.5% volume fraction, which not only ensured lightweight components (30% weight reduction compared to traditional GRC) but also met the impact resistance requirements of the curtain wall panels. It is worth noting that fiber dispersion is a challenge in quality control; Qinglong's independently developed double-spiral mixing process can achieve fiber distribution uniformity of over 95%.

4. Admixtures: The Performance Regulator (1%-3% of total)

High-efficiency water reducers are the "magic additives" of UHPC. Qinglong uses polycarboxylate-based high-performance water reducers, and a dosage of just 1.5%-2.5% can control the water-binder ratio within the ultra-low range of 0.18-0.25. Meanwhile, defoamers and thickeners are compounded to resolve the contradiction between air bubble problems in high-cementitious-material systems and construction flowability. This admixture system enables Qinglong UHPC to achieve an initial fluidity of over 250mm, meeting the self-leveling forming requirements of complex molds.

II. The Technical Philosophy Behind the Proportioning: The Quantified Expression of Qinglong's 28 Years of Experience

High-quality UHPC is by no means a simple piling up of raw materials. As an enterprise that has participated in drafting multiple national and industry standards, Qinglong's proportioning design follows three major principles: dense packing theory (achieving over 90% of theoretical density through particle gradation), interface optimization technology (synergistic modification of silica fume and fibers), and performance adaptation concept (dynamically adjusting the mix ratio for different application scenarios). For example, municipal bridge components focus on compressive strength, so Qinglong increases the ratio of cement and silica fume; decorative curtain walls emphasize surface texture, requiring optimization of sand gradation and admixture combinations.

Since its founding in 1997, Qinglong has established a material database covering the full range of UHPC/GRC/GRG/GRP and has completed the transformation of 58 patented technologies. We always believe that the secret of proportioning lies not only in numbers, but also in reverence for the essence of the material—just like Qinglong's values of "honesty, hard work, trust, and collaboration," every mix ratio carries a dual commitment to building safety and aesthetics. In the future, Qinglong will continue its mission of "creating beautiful architecture," allowing UHPC materials to shine with technological beauty in more landmark projects.