Calcium lignosulfonate is used in masonry mortar and cement plaster as a plasticizer. It lowers the water needed for a workable mix, which helps bond and limits shrinkage cracking from excess water. This page gives the dosage, the tests and the points that differ from concrete.
Dosage
| Parameter | Construction Grade (GAC-CaLS-Construction), TDS Rev. 2.0 |
|---|---|
| Form | Light brown powder |
| Bulk density | 0.8 g/cm³ |
| Moisture | 5% max |
| pH (5% solution) | 4–6 |
| Recommended dosage | 0.20–0.30% by weight of cement; higher dosages may retard set beyond specified limits |
| Water-demand reduction | Up to 12% |
| Packaging | 25 kg woven bags with PE liner; 500 kg or 600 kg jumbo bags |
| Shelf life | 12 months |
Typical values from the current TDS. Each lot ships with a COA.
Mortars have a high cement or binder content per volume, so a dose in percent of cement gives more admixture per batch than in concrete. Begin at 0.20% and test flow and set before going higher.
Mortar vs Concrete
| Point | Mortar and plaster | Concrete |
|---|---|---|
| Main goal | Workability, water retention, bond | Water reduction, strength |
| Consistence test | Flow table (ASTM C1437 or EN 1015-3) | Slump (ASTM C143 or EN 12350-2) |
| Set concern | Board life vs early set on the wall | Haul time vs early strength |
| Admixture standard (EU) | EN 934-3 | EN 934-2 |
Testing a Mortar
- Mix control and trial mortars to the same flow; record water used.
- Measure air content (ASTM C185 or EN 1015-7) and setting time.
- Check board life: time until the mortar stiffens too much to use.
- Test compressive strength at 7 and 28 days.
- For plaster, check workability on the wall and surface cracking after drying.
Dry-Mix Mortar Notes
- Use the powder grade; it has 5% max moisture.
- Store bags dry and sealed; shelf life is 12 months.
- Check compatibility with cellulose ethers and other additives in the formula.
Frequently Asked Questions
What does calcium lignosulfonate do in mortar?
It works as a plasticizer: the mortar reaches the target flow with less water. The construction grade TDS lists masonry mortars as a typical application.
What dosage is used in mortar?
Start from the GAC-CaLS-Construction TDS range of 0.20–0.30% by weight of cement and adjust by flow test. Higher doses delay set.
Can it be used in dry-mix mortar?
Yes, the powder grade can be blended into dry-mix mortar. Check that it disperses quickly on mixing and does not cake in storage.
Which standards apply?
ASTM C270 covers mortar for unit masonry; flow is measured by ASTM C1437. In Europe, EN 934-3 covers admixtures for masonry mortar and EN 1015-3 measures consistence.
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: cement grouts · precast and blocks · all construction uses
