ASTM C494 is the US specification for chemical admixtures for concrete. Lignosulfonate-based admixtures are usually tested as Type A (water-reducing) or Type D (water-reducing and retarding). This page explains what those types require and how calcium lignosulfonate fits.
The Types That Matter
| ASTM C494 type | Water content, max % of control | Initial set vs control |
|---|---|---|
| Type A: water-reducing | 95% | Not more than 1:00 h earlier nor 1:30 h later |
| Type B: retarding | — | At least 1:00 h later, not more than 3:30 h later |
| Type D: water-reducing and retarding | 95% | At least 1:00 h later, not more than 3:30 h later |
| Type F: high-range water-reducing | 88% | Not more than 1:00 h earlier nor 1:30 h later |
| Type G: high-range water-reducing and retarding | 88% | At least 1:00 h later, not more than 3:30 h later |
Summary of ASTM C494/C494M water content and initial set requirements. Check the current edition for full requirements, including strength.
Type A: Water-Reducing
Water content at most 95% of the control and setting close to the control. A calcium lignosulfonate admixture fits here at doses that do not delay set too much. The GAC-CaLS-Construction TDS gives up to 12% water reduction at 0.20–0.30% by weight of cement.
Type D: Water-Reducing and Retarding
The same water reduction, plus an initial set at least 1 hour and not more than 3.5 hours later than the control. Higher lignosulfonate doses, or grades with more sugar, move an admixture toward Type D. See the set retarder guide.
Tests Used in a C494 Evaluation
| Property | Test method |
|---|---|
| Slump | ASTM C143 |
| Air content | ASTM C231 or C173 |
| Time of setting | ASTM C403 |
| Compressive strength | ASTM C39 |
What the Raw-Material Maker Provides
- TDS with dosage range and typical properties.
- COA for each lot.
- SDS.
- Samples for the admixture maker to formulate and test.
Frequently Asked Questions
Is calcium lignosulfonate ASTM C494 Type A or Type D?
It can be either, depending on the formulated admixture and dose. Type A requires normal setting; Type D requires a set delay of 1 to 3.5 hours. The admixture as sold is what gets tested.
What water reduction does Type A require?
Water content no more than 95% of the control, that is at least 5% water reduction.
Can it meet Type F?
Not on its own in normal use. Type F requires water content no more than 88% of the control, which is high-range performance typical of SNF or PCE.
Is the raw powder certified to C494?
No. ASTM C494 applies to the admixture product tested in concrete. A raw-material maker provides TDS and COA data; the admixture maker tests the finished product.
Samples and Documents
Send the cement type, mix design, target slump or setting time, and the test standard you work to, to info@greenagrochem.com or use the contact form.
Related: EN 934-2 and GB 8076 · water reducing agent dosage · superplasticizer question
