Microsilica —also known as silica fume—is one of the most important mineral admixtures used in American high-performance concrete (HPC), UHPC, precast elements, and shotcrete work. As the demand for durable and sustainable infrastructure continues to grow across the United States, more contractors, ready-mix companies, and precast manufacturers are looking for reliable silica fume suppliers that meet ASTM C1240 standards.
What Is Silica Fume?
Microsilica is an ultrafine, amorphous silicon dioxide (SiO₂) material collected during the production of silicon metal and ferrosilicon alloys.
Typical particle size: 0.1–0.3 μm, which is 100 times finer than cement.
Because of its extremely high pozzolanic activity and micro-filling ability, silica fume is widely used in U.S. concrete for improving:
- Compressive strength (up to 20,000 psi or higher in UHPC)
- Durability and abrasion resistance
- Resistance to chloride penetration
- Freeze–thaw performance
- Water tightness
- Bonding strength
Why Microsilica Is in High Demand in the United States
The U.S. construction sector—especially the infrastructure and precast industries—requires consistent high-performance materials. Silica fume is widely used in:
- Department of Transportation (DOT) bridge and highway projects
- FHWA-approved high-performance concrete
- Precast girders, beams, piles, and panels
- High-strength commercial buildings
- Foundations in high-rise construction
- Offshore structures and marine projects
- Shotcrete for tunnels and mining
As U.S. standards emphasize durability, silica fume has become a key ingredient in meeting long-term service life requirements.
Microsilica Specifications for the U.S. Market (ASTM C1240)
Below is the typical specification range preferred by American customers:
| Item | Requirement / Typical Value |
|---|---|
| SiO₂ | 85–98% |
| Loss on Ignition (LOI) | ≤ 6% |
| Moisture | ≤ 3% |
| Bulk Density (Densified) | 550–650 kg/m³ |
| Bulk Density (Undensified) | 250–350 kg/m³ |
| Color | Grey, white |
| Pozzolanic Activity | Meet ASTM C1240 |
ASTM C1240 compliance is essential for U.S. suppliers.
We provide silica fume that meets the testing requirements for U.S. DOT and concrete applications.
Densified vs Undensified Microsilica : Which One Should U.S. Buyers Choose?
Densified Microsilica (Most common in USA)
- Bulk density: 550–650 kg/m³
- Easier to transport
- Better flow in pneumatic conveying systems
- Recommended for ready-mix, shotcrete, and precast concrete
Undensified Microsilica
- Bulk density: 250–350 kg/m³
- Higher activity due to less agglomeration
- Perfect for UHPC and special cementitious materials
- Most American concrete plants choose densified silica fume, while UHPC producers may prefer undensified.
Applications of Microsilica in the United States
High-Performance Concrete (HPC)
Used in bridges, parking structures, dams, and highways. Silica fume improves compressive strength and reduces permeability.
Ultra-High Performance Concrete (UHPC)
A key component in UHPC mixes to reach strengths over 20,000 psi and extreme durability.
Precast Concrete
Silica fume enhances early strength and allows faster demolding—important for American precast factories.
Shotcrete
Used in:
- Tunnels
- Slope stabilization
- Mining projects
- Repair and rehabilitation
Increases adhesion and reduces rebound—major cost savings.
Industrial Flooring and Marine Concrete
For abrasion resistance and lower chloride penetration.
Packaging Options for U.S. Customers
We provide multiple packaging solutions suitable for American importers:
- 25kg bags
- 750–900kg jumbo bags
- Customized palletized packaging
- FCL (20ft containers)—most common
All packaging is moisture-proof and suitable for long-distance ocean shipping.
Shipping Microsilica to the United States
We regularly ship silica fume to:
- Los Angeles / Long Beach
- Houston
- Savannah
- New York / New Jersey
- Seattle / Tacoma
Typical lead time: 7–12 days production + 20–30 days sea freight depending on the destination port.
FOB, CIF, and DDP terms are available.
Why U.S. Customers Choose Our Microsilica
We supply high-quality densified and undensified silica fume for the U.S. concrete market with:
- Stable production capacity
- Strict QC and full test reports
- ASTM-compliant performance
- Competitive FOB China prices
- Fast delivery to major U.S. ports
- Experience supporting U.S. precast and UHPC manufacturers
Our silica fume has been used in bridges, precast plants, UHPC components, tunnels, and infrastructure projects across the U.S. (customer names hidden for confidentiality).
FAQ
1. Where can I buy silica fume in the USA?
You can import directly from reliable global suppliers like us, offering ASTM-compliant silica fume with competitive prices and fast shipping to U.S. ports.
2. What is the typical silica fume price in the U.S.?
Prices vary by SiO₂ content (85%–98%) and packaging. Contact us for the latest FOB/CIF pricing.
3. Does silica fume meet ASTM C1240?
Yes—our silica fume meets the chemical and physical requirements of ASTM C1240.
4. Which type is better: densified or undensified?
Densified is common for concrete; undensified is preferred for UHPC and advanced cementitious systems.
5. Do you offer free samples for U.S. customers?
Yes, small samples can be shipped for testing.
Request Microsilica Quote for USA
If you are a ready-mix plant, precast manufacturer, UHPC producer, or distributor in the United States looking for a stable silica fume supplier, feel free to contact us.
We offer:
- ASTM-compliant silica fume
- FOB / CIF / DDP to USA
- Technical support
- Fast loading and stable supply
Send us your required SiO₂ %, packaging type, and destination port—we will provide a quotation immediately.
Email: sales@superior-abrasives.com
