Achieve C80-C120 ultra-high-strength concrete, reduce column cross-sections, increase usable floor area, and improve structural durability. Professional silica fume solutions and technical support for supertall buildings.
In supertall building design, bottom-floor columns and core walls bear enormous axial loads. Conventional C30-C40 concrete requires oversized cross-sections, not only occupying valuable usable space but also increasing structural dead load and foundation loads. Silica fume (microsilica), as a highly reactive pozzolanic material, can significantly improve concrete strength and density, and is the key component for achieving C80-C120 ultra-high-strength concrete.
Handan Chengyuan Technology supplies high-density silica fume (SiO₂ 90%-98%) with special surface treatment, excellent flowability and dispersion, achieving good workability at low water-binder ratios — the ideal choice for high-rise and supertall building projects.
Silica fume has an average particle size of only 0.1-0.15μm, approximately 1/100 the size of cement particles. These ultra-fine particles fill the microscopic voids between cement grains, significantly improving concrete particle grading and density. This physical filler effect reduces concrete porosity and refines pore structure, thereby enhancing strength and durability.
The amorphous SiO₂ in silica fume reacts with Ca(OH)₂ produced by cement hydration through a pozzolanic reaction, generating additional C-S-H gel:
This reaction not only consumes strength-detrimental Ca(OH)₂ crystals but also generates more C-S-H gel, making the cement paste structure denser and significantly improving the interfacial transition zone (ITZ).
In normal concrete, the interfacial transition zone between aggregate and cement paste contains many oriented Ca(OH)₂ crystals and microcracks, making it the weakest link in concrete. Silica fume consumes Ca(OH)₂ in the interfacial zone through pozzolanic reaction, while the micro-filler effect refines interfacial pore structure, significantly improving ITZ strength and density, thereby enhancing overall concrete performance.
Surface-treated densified silica fume exhibits a "ball-bearing effect" that improves concrete workability. At low water-binder ratios (0.25-0.35), silica fume concrete maintains excellent flowability and pumpability, meeting the requirements of high-rise pumping construction.
The following are reference mix designs for silica fume concrete at different strength grades for high-rise buildings. Actual projects should be adjusted through testing based on raw material properties, construction conditions, and design requirements.
| Strength Grade | W/B Ratio | Silica Fume Dosage (%) | Cement (kg/m³) | Silica Fume (kg/m³) | Application |
|---|---|---|---|---|---|
| C60 | 0.32-0.35 | 5-8% | 420-460 | 25-40 | Mid-high rise columns, walls |
| C80 | 0.28-0.30 | 8-10% | 480-520 | 45-55 | Supertall bottom-floor columns |
| C100 | 0.25-0.27 | 10-12% | 520-560 | 55-70 | Supertall core walls |
| C120 | 0.22-0.24 | 12-15% | 560-600 | 70-90 | Special structural elements |
This project used C80-C100 high-strength concrete with 10% silica fume (our high-density gray silica fume, SiO₂≥92%) for bottom-floor columns and core walls. Through optimized mix design, 28-day compressive strength reached 95-110 MPa, meeting design requirements. Compared with C50 concrete solution, bottom-floor column sections reduced by 25%, each floor gained ~80㎡ usable area, total building gained over 6,400㎡. The excellent durability of silica fume concrete also ensured 100-year design service life.
Located in a high-temperature arid region of the Middle East, this project had extremely high requirements for concrete heat resistance and durability. The project used C70-C80 silica fume concrete with 8% silica fume. The micro-filler effect and pozzolanic reaction significantly improved concrete density and sulfate resistance, reducing chloride diffusion coefficient by 70%, effectively resisting underground high-salt environment. The low hydration heat of silica fume concrete also reduced thermal cracking risk in mass concrete.
This high-end residential tower had strict owner requirements for interior usable area and space efficiency. By using C80 silica fume concrete in bottom 1-20 floor columns, column sections reduced from 1200×1200mm to 900×900mm, each unit gained average 3-5㎡ usable area, significantly improving project market competitiveness. The high elastic modulus (≥45GPa) of silica fume concrete also effectively reduced structural lateral displacement under wind loads, improving occupant comfort.
| Product Type | SiO₂ Content | Features | Applications |
|---|---|---|---|
| Gray High-Density Silica Fume | 90%-94% | Good flowability, low dust, cost-effective | C60-C80 standard high-strength concrete |
| Gray Semi-Densified Silica Fume | 92%-96% | Higher reactivity, good dispersion | C80-C100 ultra-high-strength concrete |
| White High-Purity Silica Fume | 96%-98% | Light color, extremely high reactivity, low impurities | C100+, decorative concrete, UHPC |
| Black Silica Fume | 85%-90% | Economical price, meets basic performance requirements | C50-C60 standard high-strength concrete |
Our technical team can provide professional mix design, construction guidance, and quality control services for your project. Contact us for free technical consultation and product quotes.