Two admixtures can show the same type, similar dosage and the same colour on a data sheet and still behave very differently on your cement. The technical data sheet (TDS) is where a supplier tells you what the product is and how it should be used. Reading it well helps you spot missing information, compare products fairly and avoid expensive surprises.
This guide goes section by section through a typical TDS for concrete admixtures, explains what each field really tells you, shows how to compare dosage across different units, and lists the red flags to watch for.
TDS, SDS, COA, DoP and Test Report: What Is the Difference?
Buyers often receive several documents, and each answers a different question.
| Document | Question it answers | Typical content |
| Technical data sheet (TDS) | What is this product and how do I use it? | Description, dosage, properties, storage, compliance statements |
| Safety data sheet (SDS) | Is it safe to handle, store and transport? | Hazards, first aid, PPE, fire, spill, transport class |
| Certificate of analysis (COA) | What did this specific batch measure? | Batch number, density, pH, solids, chloride, alkali |
| Declaration of performance (DoP) | What performance is declared under the applicable standard? | Essential characteristics and declared values |
| Test report | What did an independent lab find when it tested the product? | Standard method, results, conditions, lab details |
A TDS describes the product in general. A COA describes your batch. A test report proves a claim. Do not accept one in place of another.
Anatomy of a TDS, Section by Section
1. Product Name and Type Designation
Look for the product name, its function (water reducer, retarder, accelerator, waterproofing admixture) and any standard type. Under EN 934-2, for instance, a high-range water-reducing admixture can be designated as T3.1 and T3.2. Under ASTM C494, the equivalent is a letter such as Type F.
The designation should match the claim in the sales brochure, and a standard claim should be backed by a test report or DoP. Our guide to ASTM C494 admixture types explains how to read the type and its limits.
2. Description and Intended Use
This section says what the product is for and what it is based on, such as polycarboxylate, naphthalene sulfonate or lignosulfonate. It should also state where the product is not suitable.
What to check: the chemical base, because it changes dosage, slump behavior and compatibility. A vague line such as “high-performance admixture” with no chemistry is a weak signal.
3. Technical Data Table
This is the core of the sheet. Typical fields include:
| Field | What it tells you | Why it matters |
| Form and colour | Liquid or powder, appearance | Quick identity check on delivery |
| Density or relative density | Mass per volume, usually with a tolerance such as about 1.09 ± 0.02 kg/dm³ | Converts litres to kilograms, checks batch consistency |
| pH | Acidity or alkalinity | Compatibility and handling |
| Solids or dry material content | Share of active material | Needed to compare dosage between products |
| Chloride content | Chloride by mass, often stated as no more than 0.1% by mass | Reinforcement corrosion risk |
| Alkali content (Na₂O equivalent) | Alkali contribution | Alkali-silica reaction control |
| Sulfate content | Sulfate contribution | Setting and compatibility behavior |
| Air content | Effect on entrained air | Strength and durability |
| Corrosion behaviour | Statement on steel compatibility | Reinforced concrete suitability |
What to check:
- Chloride: “Chloride-free” should come with a number and a method. Declared limits vary, and a TDS that gives only the words “chloride-free” tells you less than one that gives a value
- Alkali: values differ widely between chemistries. Typical examples range from about 3% in some high-range products to under 8.5% for a naphthalene product. If your mix has to stay within a total alkali limit, this number matters
- Density tolerance: a stated tolerance gives you a quick incoming check against the COA
4. Dosage
This is the section most often misread, because suppliers use different units. Examples from published data sheets include:
- grams per kilogram of cement
- percent of the cement mass
- litres per 100 kg of binder
A range such as 0.2 to 3.0% is wide, so the range itself is not a recommendation for your mix. It tells you the product’s working window, and the correct dose within it comes from trial mixes. See our guide to finding the saturation dosage of a superplasticizer for how to set it.
What to check:
- Is the dose on cement or on total binder?
- Is it by mass or by volume?
- Is it as-supplied product or active solids?
- Does it apply to liquid and powder forms equally?
5. Performance Data
Performance tables, such as water reduction, slump, setting time and strength, are the claims buyers rely on most. They are also the easiest to misread.
- Check the test conditions. Published data sheets often state that values are laboratory results at 21°C ± 2°C and 50% relative humidity, which may be different from your site
- Check the basis. A strength figure given at equal consistence, for example at least 140% at 24 hours and 115% at 28 days, is relative to a control mix, not an absolute strength
- Check the cement and dose used in the test
- Look for typical versus guaranteed values. A typical result is not a limit
6. Compatibility and Mixing Guidance
A good TDS tells you which cements and other admixtures the product works with, the order of addition, mixing time and any combinations to avoid. If the sheet claims compatibility with all cements, treat it as a marketing statement. Real compatibility is shown by test results on your cement. See our guide to cement-superplasticizer compatibility tests.
7. Storage, Shelf Life and Packaging
Look for storage temperature, frost protection, shelf life and available packaging. Examples include a shelf life of about one year from the date of production when stored properly in sealed original packaging. Liquids can freeze, crystallize or separate, so storage limits matter for imports and long supply chains.
8. Standards and Safety References
The TDS should list the standards it claims compliance with and refer to the SDS for hazards. A DoP, where required, includes items such as homogeneity, conventional dry material content, effective component, chloride content, alkali content and air content. Verify that the document, version and issue date are current.
Worked Example: Comparing Two Data Sheets Fairly
Two sheets are rarely written in the same units. To compare them, convert both to the same basis. The numbers below are hypothetical.
| Product A | Product B | |
| Dosage as written | 0.5 to 1.2 L per 100 kg binder | 0.4 to 1.0% of cement mass |
| Density | 1.05 kg/L | 1.10 kg/L |
| Solids content | 20% | 40% |
Step 1: convert to mass of product per 100 kg cement
- Product A: 0.5 to 1.2 L × 1.05 = about 0.53 to 1.26 kg
- Product B: 0.4 to 1.0 kg (already in mass)
Step 2: convert to active solids per 100 kg cement
- Product A: 0.53 to 1.26 kg × 20% = about 0.11 to 0.25 kg of solids
- Product B: 0.4 to 1.0 kg × 40% = 0.16 to 0.40 kg of solids
Step 3: compare cost per cubic metre at the dose that actually works on your cement
For a mix with 350 kg of cement per cubic metre, multiply cement mass by the trial dose and by the price per kilogram of product. A product with a lower price per kilogram can still cost more per cubic metre if its solids content is low and the working dose is high.
The method also answers a common buyer question about how to calculate admixture percentage in concrete. State whether the percentage is by cement or binder and whether it refers to solids or as-supplied product, and keep that basis constant.
Red Flags in a TDS
- No chemical base or standard type given
- No test conditions or cement stated behind performance claims
- “Chloride-free” with no value or method
- Missing alkali content
- Dosage range with no unit basis (cement or binder, mass or volume, solids or product)
- No density, pH or solids data
- Compatibility claimed with “all cements” without evidence
- No issue date, version number or manufacturer details
- Values that match another supplier’s sheet word for word
- Performance claims with no test report available on request
Questions to Ask the Supplier
- Which standard and edition does the product comply with, and can I see the test report or DoP?
- What cement and aggregates were used in the performance tests?
- What is the solids content and how is it measured?
- What are the chloride and alkali values, and which method gave them?
- What dose works on a cement like mine, and can you share dose-response data?
- How does the product behave at high and low temperature?
- What is the shelf life and what happens if it freezes?
- What is the batch-to-batch tolerance for density and pH?
- Can I get a COA with every shipment?
From TDS to Site: What Still Needs Testing
A TDS is a starting point. Before approving a product:
- Check the COA of the delivered batch against the TDS
- Run paste screening with your cement
- Find the saturation dosage and set a working dose
- Confirm slump, retention, setting time and strength in trial mixes at your temperature
- Keep a retained sample from each lot
For retention-sensitive mixes, our guide to slow-release PCE slump retention explains what to test beyond the data sheet.
Common Mistakes
- Treating the dosage range as a recommendation for every cement
- Comparing products on price per kilogram without checking solids content
- Reading laboratory performance as site performance
- Ignoring alkali content in projects with ASR risk
- Accepting a TDS without a COA for the shipped batch
- Using an outdated data sheet version
- Assuming two products with the same type letter are interchangeable
Why It Matters in the Market
Competition across the concrete admixtures market and the concrete superplasticizer market means many suppliers publish similar-looking sheets. A clear TDS, backed by a test report and COA, is one way to separate reliable construction chemicals suppliers from the rest. For buyers importing from overseas, our guide to importing concrete admixtures from China lists the full document set to request.
Luke Chemicals provides technical data for its concrete admixtures and can supply supporting documents on request, so buyers can check specifications against their own materials.
Best Practices Checklist
- Ask for the TDS, SDS, COA and a relevant test report together
- Check the issue date and version
- Convert dosages to a common basis before comparing
- Verify chloride, alkali and solids values against the COA
- Treat compatibility statements as hypotheses to test
- Run trial mixes at your site temperature
- Keep records of every TDS and COA you accept
- Re-check data when the supplier reformulates or changes source
Conclusion
A TDS is useful when you know what to look for: the chemical base, the standard claimed, solids, chloride and alkali values, the dosage basis, the test conditions behind each performance figure and the shelf life. Convert dosages to a common basis, ask for the COA and the test report, and treat the data sheet as a starting point for your own trials.
Frequently Asked Questions
What is a technical data sheet for a concrete admixture?
A TDS is the supplier’s document that describes the product, its intended use, dosage range, key properties, storage conditions and compliance statements.
What is the difference between a TDS and an SDS?
A TDS explains how to use the product and what it does. An SDS explains the hazards and how to handle, store and transport it safely.
What is the difference between a TDS and a COA?
The TDS covers the product in general. A COA reports the measured properties of a specific batch, such as density, pH, solids, chloride and alkali.
How do I compare dosage between two data sheets?
Convert both to mass of product, then to active solids, per 100 kg of cement or binder, and compare cost per cubic metre at the dose that works on your cement.
What chloride and alkali values should I look for?
It depends on the standard and the project. Many data sheets for reinforced concrete state chloride at or below 0.1% by mass, and alkali varies by chemistry. Check the limits in your specification and the values on the COA.
Can I rely on the performance data on a TDS?
Treat it as laboratory data under stated conditions. Confirm with trial mixes on your cement, temperature and aggregates.
How often should I request an updated TDS?
Whenever the supplier changes formulation, source or packaging, and at least when you renew a supply contract.
