Understanding Loss on Ignition in Waterproofing Admixtures
Understanding what’s inside your waterproofing admixture can make or break a concrete project. One way to evaluate this is through a test called Loss on Ignition (LOI), which is a fast, reliable method for identifying how much of a product is reactive and effective.
What is LOI?
- Loss on Ignition (LOI) testing is putting a material in a super-hot oven at 950°C (1742°F) to see what burns off or evaporates.
- The weight lost shows the active ingredients or reactive parts that disappear, while what’s left are the non-reactive ingredients.
Why It Matters
The results of LOI testing demonstrate how much of a waterproofing admixture or active ingredient is doing the heavy lifting (the reactive part) versus just taking up space (the filler). This ensures that owners and design Professionals (Engineers, Architects, Consultants) choose the right product for strong, lasting concrete.
Independent LOI tests compared Xypex crystalline admixture to other admixtures available.
Xypex consistently showed 51–54% LOI, while others ranged from 20–35%.
This shows that Xypex has more reactive chemistry available to self-heal cracks and block water pathways.
Dosage Matters Too
LOI is tested by weight, not by application dosage. When both LOI and dosage are low, the total reactive content per cubic meter (yard) of concrete drops significantly.
Xypex is dosed at 1% with results of 50% LOI, Competitor A is dosed at 1% with results of 25% LOI.
HOWEVER
If competitor A is actually dosing at 0.8% the LOI results drop to 20%.
Supporting Test: Temperature Rise
A secondary test tracked the heat released when each admixture was mixed with sand and water.
The higher the temperature spike, the greater the chemical reactivity.
What Engineers Should Know
LOI is a practical performance indicator—one that can help ensure your next waterproofing solution is as effective as it claims to be.
Conclusion: Higher LOI, Better Performance
Independent LOI testing confirms Xypex’s superior formulation, with 51-54% reactive content versus competitors’ 20-35%. This scientific validation, combined with proven field performance, makes Xypex the optimal choice for durable, waterproof concrete.
Contact your local representative or our Technical Services team for detailed LOI test results or a custom evaluation.