Description
VF-21 Expansion Agent is a new-generation sulfoaluminate-calcium concrete expansion agent developed by Luke Chemicals. It offers coordinated expansion rates, strength development, high expansion performance, and stable expansion over time. The product is safe, reliable, and minimizes dependency on water replenishment during the later stages of curing.
The product complies with the Chinese standard GB23439-2009 “Concrete Expansion Agent.” It is ideal for formulating shrinkage-compensating concrete and filling mass concrete, particularly suitable for mass concrete structures requiring shrinkage compensation and waterproofing.
USES
VF-21 Expansion Agent is widely used in various engineering fields, including:
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Underground Structures: High-rise basements, subways, underground parking lots, warehouses, tunnels, mines, civil air defense projects, pedestrian underpasses, and large foundation slabs.
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Water Storage: Construction of various pools, water towers, storage tanks, and mountain cave depots.
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Mass Structures: Mass concrete structures, ultra-long slab extension shrinkage seams, or seamless construction.
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Infrastructure: Large frame structures, seamless floor construction, airport runways, highway pavements, bridge surfaces, marine engineering, hydraulic structures, seaports, wharves, dams, and spillways.
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Specialty Concrete: High-performance concrete, steel tube concrete, impact-resistant concrete, and large-scale backfill concrete.
CHARACTERISTICS / ADVANTAGES
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High Efficiency: High expansion efficiency and low alkali content.
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Density: Enhances concrete microstructure, increasing density.
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Durability: Improves impermeability, frost resistance, and concrete longevity.
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Crack Resistance: Effectively compensates for shrinkage during hardening and drying, improving crack resistance.
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Protection: Non-corrosive to steel reinforcement; prevents alkali-aggregate reactions, enhancing concrete durability.
MAIN TECHNICAL INDICATORS
The following data represents the typical characteristics of the product:
| Test Item | Standard Index (GB23439-2009) | Test Result |
|---|---|---|
| Magnesium Oxide (%) | ≤ 5 | 3.2 |
| Alkali Content (%) | ≤ 0.75 | 0.45 |
| Fineness: Specific Surface Area (m²/kg) | ≥ 200 | 410 |
| Fineness: 1.18mm Sieve Residue (%) | < 0.5 | 0.1 |
| Restricted Expansion Rate (%): 7d in Water | 0.025 | 0.029 |
| Restricted Expansion Rate (%): 21d in Air | -0.02 | -0.011 |
| Compressive Strength (MPa): 7d | ≥ 20 | 22.5 |
| Compressive Strength (MPa): 28d | ≥ 40 | 43.7 |
Conclusion: The tested items comply with the requirements of GB23439-2009 “Concrete Expansion Agent.”
APPLICATION INFORMATION
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Trial Mixes: Due to adaptability differences between VF-21 Expansion Agent and cement, admixtures, and water reducers, concrete trial mixes should be conducted in the laboratory to determine the optimal mix ratio.
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Recommended Dosage:
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General shrinkage-compensating concrete: 6-10% of the cementitious material mass.
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Mass expansion shrinkage-compensating concrete (e.g., strengthening bands or self-stressing concrete): 8-12%.
Adjustments can be made according to design requirements.
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Mixing Time:
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For ready-mixed concrete, the mixing time is the same as ordinary concrete.
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For on-site mixing, the time should be extended by 60 seconds to ensure uniformity.
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Vibration: Concrete must be vibrated densely during construction. Do not miss, under-vibrate, or over-vibrate.
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Curing: Poured concrete should be cured for at least 14 days. During winter construction, take thermal insulation measures if the ambient temperature is below 5°C.
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Temperature Limit: Use with caution in environments where the working temperature is long-term above 80°C.
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Standards: Refer to the “Technical Specification for Application of Shrinkage-Compensating Concrete” if necessary.
PACKAGING, STORAGE & TRANSPORTATION
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Packaging: Available in 50kg or 25kg moisture-proof bags. Packaging weight can be customized.
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Storage: Store in a ventilated, dry place. Protect from damage and moisture. Do not use if caking occurs.
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Shelf Life: 12 months.
Safety Information and Transportation: Non-toxic, non-flammable, and can be transported as general goods.
LEGAL NOTES
The information provided in this document is given in good faith based on our current knowledge and experience of the product when properly stored, handled, and applied under normal conditions. However, due to variations in materials, substrates, and site conditions, no warranty regarding fitness for a particular purpose or merchantability is implied. The user is responsible for testing the product’s suitability for their specific applications.
We reserve the right to change the properties of our products. All orders are accepted subject to our current terms of sale and delivery. Users must always refer to the most recent Product Data Sheet for this product, which can be provided upon request.
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