Product comparison
How integral crystalline compares.
Specifiers ask us the same question: why choose an admixture over a membrane, and how does Krystol compare with other crystalline products? Here is the evidence, with sources.
By approach
Four ways to keep water out of concrete.
The difference that matters below grade is not how well a system performs on day one — it is what happens when the concrete cracks, and whether you can reach the failure to fix it.
| Criterion | Integral crystalline (KIM) Our system | Sheet membrane | Liquid / surface coating | Cementitious slurry |
|---|---|---|---|---|
| Where it sits | Dosed into the mix at batching | Applied to the outside face, before backfill | Brushed or sprayed onto the finished face | Applied to the concrete face, positive or negative side |
| Coverage | Whole concrete element, uniform | Only where laid; laps and penetrations are weak points | Surface film only, thickness varies with application | Surface layer, typically 2–3 mm |
| Cracks | Self-seals hairline cracks up to 0.5 mm, repeatedly, for the life of the structure | Bridges cracks only while intact and bonded | Little to no crack-bridging once cured | Rigid; cracks with the substrate |
| Damage risk | Nothing to puncture — the concrete is the barrier | Punctures during backfill and steel fixing are common | Abrasion, UV and substrate movement degrade it | Can debond if the substrate moves |
| Depends on installer? | Dosed at the batching plant; not dependent on site application skill | Highly dependent on installation quality and detailing | Sensitive to substrate prep, weather and film thickness | Needs a sound, saturated substrate and careful curing |
| If it fails | Reactivates on contact with water | Below grade, repair usually means excavation | Recoating, and only if the face is accessible | Re-application to the affected area |
Membranes, coatings and slurries all have legitimate uses — we supply and install them where they are the right answer. The table describes how each behaves below grade, which is where the consequences of failure are highest.
Crystalline vs crystalline
Not all crystalline admixtures work the same way.
“Crystalline” describes a category, not a formulation. The chemistry underneath differs, and it determines how long the product keeps working.
Krystol (KIM)
Reacts with unhydrated cement
Krystol chemistry reacts with water and unhydrated cement particles to grow needle-shaped crystals that fill capillary pores and micro-cracks.
Unhydrated cement remains available throughout the life of the concrete — so the reaction can recur every time water finds a path.
Many other crystalline admixtures
React with free lime
Others react with water and calcium hydroxide — free lime — producing crystals of a rounder form.
Free lime makes up only about 15–25% of hydrated Portland cement. It is a finite resource: once consumed, the mechanism has nothing left to draw on.
| Measured property | Krystol (KIM) | Competing admixtures / standard |
|---|---|---|
| Permeability under hydrostatic pressure | KIM ~3× more effective | vs a competing product |
| Permeability reduction at 1% dosage | KIM 28% | best competing admixture 20% (DIN 1048-5) |
| Crack reduction ratio | KIM 80% | competing admixtures 10% and 15% (ASTM C1579) |
| Crack reduction, modified conditions | KIM 55% | best competing admixture 10% |
| Drying shrinkage | Reduced by up to 25% | AS 1012.13 |
| Warranty | 25 years | Kryton product warranty |
Source: Kryton International, manufacturer test data. These are the manufacturer’s own published comparisons, measured against competing admixtures the manufacturer does not name. Treat them as you would any supplier’s self-reported figures — as a claim to be verified, not as independent evidence. The field study below is independent; this table is not.
Independent evidence
Ten years in a marine tidal zone.
The most useful comparison is not a manufacturer’s own datasheet. It is an independent researcher putting competing admixtures in seawater and coming back a decade later.
“The panel using 2% Kryton Kim performed well during the field exposure. Panels using the remaining admixtures, Rheocrete 222+, FerroGard 901, Xypex Admix C-2000 and latex modifier exhibited inconsistent to poor results.”
Ropert & Robertson, University of Hawaii at Mānoa, 2012 — conclusions, p.53
Quoted verbatim from the published report. Product names are those used by the researchers. We reproduce the finding without alteration and make no claim beyond it.
Test data
What KIM is certified to do.
Each figure below is tied to the standard it was measured against, so you can check it.
| Property | Result | Standard / source |
|---|---|---|
| Hydrostatic head resisted | Up to 140 m (460 ft) | CRD C48-92 (USACE) — 1.38 MPa for 14 days |
| Self-sealing crack width | Up to 0.5 mm | Manufacturer test data |
| Water permeability | Reduced vs equivalent plain concrete | DIN 1048-5 / BS EN 12390-8; Taywood-Valenta |
| Chloride ion penetration | Reduced vs control | ASTM C1202 / AASHTO T277 |
| Compressive strength | +12% to +19% vs control at 3, 7, 28 & 56 days | HBT Agra Ltd., 1993 |
| Potable water contact | Certified safe | NSF/ANSI Standard 61 |
| UK third-party approval | Certificate No. 05/4217 | British Board of Agrément, 2005 |
A note on comparisons
Crystalline admixtures are not interchangeable, and test results depend heavily on mix design, dosage, curing and exposure. Before specifying anything — ours or anyone else’s — ask for independent test reports against a named standard rather than manufacturer claims. We will supply ours, and we are happy to review a competitor’s with you.
Next step
Comparing systems for a live project?
Send us the element, the exposure conditions and the mix design. We’ll give you the test data, the dosage and an honest view of whether crystalline is the right call.