What it does
Improves cohesion and viscosity to reduce washout, helping keep fines/cement in the mix during underwater placement.
Product Construction Chemicals
Anti-Washout Admixture
Underwater concrete viscosity-modifying admixture (VMA) used to reduce cement washout, improve cohesion, and stabilize workability for tremie and pumped placements in underwater or slurry environments.
For tremie & pumped underwater pours
Improves cohesion & washout resistance
Bag / drum / IBC (grade dependent)
Packaging: bags / drums / IBC (grade dependent)
Documentation: SDS / COA / TDS (as available) on request
Lead time depends on lane & volume
Anti-washout grades are typically selected based on placement method (tremie/pump), target slump/flow, cement type, water conditions (turbulence/salinity), and compatibility with other admixtures.
Project note: Performance is mix-design dependent. Trial mixes and site QA/QC are required to confirm dosage, fresh properties (slump/flow, stability), and washout resistance under site conditions.
Applications
Typical usage patterns. Share your mix design and placement conditions and we’ll align a suitable grade and supply lane.
- Tremie concrete placements (underwater pours)
- Diaphragm walls, secant piles, bored piles (underwater or slurry environments)
- Seal slabs and marine foundations (ports, bridges, offshore structures)
- Underwater repairs and grouting applications (project dependent)
- Mixes requiring increased cohesion and reduced segregation/bleeding
How it’s selected
By slump/flow target, cement/fines content, temperature, placement method, and local water conditions.
Program compatibility
Often used alongside superplasticizers; compatibility depends on binder chemistry and dosage strategy.
Note: Final dosage and performance targets must be validated by trial mixes and site QA/QC procedures.
Technical alignment
What engineers typically confirm before approving an anti-washout admixture for underwater work.
Washout resistance target
Define the acceptance requirement (if specified) and the placement environment (still water, flowing water, slurry). This helps align a grade and dosage window for your site conditions.
Workability & stability
Underwater mixes often need high flow with strong cohesion. VMAs help reduce segregation and bleeding while maintaining stable slump/flow for placement duration.
Compatibility with PCE
Anti-washout VMAs are frequently paired with polycarboxylate superplasticizers. Compatibility depends on binder chemistry, dosage sequence, and targeted rheology.
Binder & fines content
Cement type, SCMs (fly ash/slag/silica fume), and total fines influence viscosity and stability. Sharing your binder plan helps prevent over-thickening or pumpability loss.
Placement method drivers
Tremie diameter, pump line length, pour rate, and drop height affect turbulence and washout risk. Provide basic placement details to align a practical program.
QA/QC verification
Trial mixes typically confirm slump/flow retention, stability (segregation/bleeding), washout resistance, and finishability—followed by site validation.
Common outcomes teams target
- Reduced cement paste loss and turbidity during placement
- Improved cohesion and resistance to segregation
- Stable workability for the full pour window
- Better surface quality and fewer defects in underwater pours
If you have trial results (slump/flow vs time, washout observations, pump pressure), include them for faster grade alignment.
Use guidance & operational notes
Practical notes for batching, placement, and procurement alignment.
Typical dosing approach
Dosage is mix-specific and set by trial mix performance targets. Avoid assuming a fixed dosage without validation. Provide your binder and flow target to narrow the recommendation.
Addition sequence
Addition timing (and whether to pre-dissolve powder grades) affects dispersion and rheology. The best sequence depends on the full admixture package (especially PCE).
Pumpability
Excess viscosity can increase pump pressure and reduce flow. Balance VMA with PCE and fines content to maintain pumpability over the placement window.
Temperature & time
Higher temperatures can reduce workability retention and increase washout risk under turbulence. Share expected concrete temperature and pour duration for proper alignment.
Water conditions
Salinity and flow/turbulence influence washout behavior. Under slurry conditions, consider interaction with bentonite/polymer slurry systems.
Site QA/QC
Align acceptance criteria (slump/flow, stability, washout observation) with project specifications and inspection requirements. Document trial mixes and dosage for repeatability.
Safety note: Use only in industrial construction applications aligned with applicable regulations. Follow SDS for handling, PPE, storage, and disposal.
Typical specifications & formats
Values depend on grade and customer requirements. Confirm details on quotation and COA.
Type
Underwater concrete admixture / viscosity-modifying admixture (VMA)
Form
Powder or liquid (grade dependent)
Use level
Dosage set by trial mix and performance targets (confirm on offer)
Packaging
25 kg bags / drums / IBC (as applicable)
Documentation
SDS and COA (and TDS as available) on request
Notes
Confirm compatibility with cement chemistry and other admixtures; project standards may apply
Indicative procurement specification (example)
Below is a common procurement/QC format. Exact limits should be confirmed in your RFQ and via the supplied COA.
| Parameter | Typical listing (indicative) | Commercial / QC note |
|---|---|---|
| Product | Anti-washout admixture (VMA) for underwater concrete | Confirm placement method (tremie/pump) and environment (water/slurry) |
| Form | Powder or liquid (grade dependent) | Powder grades may require pre-dissolution depending on site practice |
| Key performance | Washout resistance, cohesion, stability (project-defined) | Confirm acceptance criteria and test method in project spec |
| Compatibility | Designed for use with PCE and other admixtures (mix-specific) | Trial mix required to validate dosage and sequence |
| Documentation | SDS / COA / TDS (as available) | Request language/format and onboarding templates upfront |
| Packaging | 25 kg bags / drums / IBC (as applicable) | Define net weight, palletization, and storage constraints |
If you have a project spec template or QA checklist, share it—our quotation can mirror your required fields.
Specifications may vary depending on batch, origin, and packaging selection.
Procurement & commercial details
Anti-washout admixtures are typically purchased on a project basis. The fastest RFQs specify placement method, performance targets, packaging, destination, and the required documentation pack.
Supply options
Project-based supply with repeat-call-offs when pours are staged. Lane depends on destination and packaging.
Incoterms & routing
Common terms: EXW / FCA / FOB / CIF / DAP (subject to lane). Share your preferred Incoterms and delivery window.
Lead time drivers
Origin availability, packaging preparation, documentation requirements, and export booking windows.
What to specify in your PO
- Product: anti-washout admixture (VMA) + grade/form (powder/liquid)
- Placement method + project spec reference (if any)
- Packaging, palletization, and storage constraints
- Destination + Incoterms + delivery window
- Required documents (SDS/COA/TDS, origin/compliance notes)
Commercial terms (MOQ, price breaks, and payment conditions) depend on grade/form, packaging, lane, and destination. These details are clarified in the quotation.
FAQ
Quick answers for engineering, site teams, and procurement workflows.
What does an anti-washout admixture do in underwater concrete?
It increases cohesion/viscosity so cement and fines are less likely to wash out during placement, which helps reduce turbidity, segregation, and paste loss—supporting more consistent placement quality.
Is it the same as a VMA?
Anti-washout admixtures are typically a type of viscosity-modifying admixture (VMA) formulated for underwater conditions. The correct grade depends on the required flowability and stability.
Can it be used with superplasticizers (PCE)?
Yes—often they are used together. Compatibility is mix-specific and depends on binder chemistry, dosage, and addition sequence. Trial mixes are required to confirm pumpability and flow retention.
What information helps you recommend a grade?
Placement method (tremie/pump), target slump/flow, binder/fines content, w/c, other admixtures, and water/slurry conditions (turbulence, salinity, temperature, pour depth).
How do I get a faster quotation?
Provide your target performance, basic mix design, pour schedule/volume, packaging preference, destination + Incoterms, and the document pack you require (SDS/COA/TDS).
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