presents a comparison of
Xypex vs Hycrete

For more than thirty years, proprietary Xypex Crystalline Technology has set an international standard of excellence in concrete waterproofing. Throughout the years many companies have tried to enter the integral waterproofing market. Noticing Xypex's success they have tried to compare themselves to Xypex. Hycrete is the latest company trying to build off of the success of Xypex.

Hycrete once marketed a product they called "Hycrete Damp Guard." Hycrete has since renamed this product to "W500," which appears to be a play off of Xypex's C-500 admix product. Now Hycrete states that their "W500" product is superior to Xypex. However, here is a quote from Hycrete's website:

"Hycrete W500 is only used to limit moisture absorption in concrete. Users should not expect a 'watertight' system when using Hycrete W500, unless a secondary waterproofing system is used in conjunction with Hycrete W500."

This website has been created to show that Hycrete is not in fact an equal to Xypex. We will include actual testing, company information, and marketing strategy.

There's more to waterproofing concrete than just slowing absorption
(Includes audio)

The following charts are from a Hycrete vendor's presentation depicting testing results intended to promote Hycrete. Note that even testing for Hycrete purposes shows that Xypex is still a superior product.

Note that in the above test, product "H" (Hycrete) reduced the compressive strength of the concrete by about 25% compared to the control, and product "X" (Xypex) increased the strength by approximately 3%.

In above test, Hycrete reduced the compressive strength of the concrete by 15%, while Xypex increased strength by 12%.

In the above absorption test, Hycrete tests better than Xypex. This particular test appears to be the only source for Hycrete's claim that their product is "superior" to Xypex. However, it is important to keep in mind that "low absorption" does not mean "waterproof." Since Hycrete apparently has a lower absorption rate, one might think that it would have lower permeability and do better on a rapid chloride test. However, as the next graph shows, Xypex holds up much better than Hycrete when it comes to permeability and actual waterproofing.

Note that Xypex reduces rapid chloride permeability significantly, compared to Hycrete. Any claim that Hycrete is less permeable than Xypex (based on the absorption testing shown above) does not square with the fact that Hycrete allows in more chlorides. The level of chloride permeability that Hycrete exhibits makes concrete using Hycrete more susceptible to rebar corrosion, as compared to the control.

Comparison

The primary difference between Xypex Admixture and Hycrete Admixture is that Xypex is a hydrophillic product, while Hycrete is hydrophobic, as stated in Hycrete literature. Hydrophobic materials are water-repellant, whereas Xypex is a water-proofing product designed to withstand high hydrostatic pressure.

Xypex has three different Admix products (C-500, C-1000 and C-2000) which are specifically designed for various ambient conditions and mix designs. These products are packaged in pails, bags and dust free, water soluble bags. Hycrete has one liquid admixture.

Permeability

Xypex has been extensively tested using the Army Corps of Engineers CRD-C-48-73 method, as well as the European test procedure DIN 1048, at pressures equal to 350 feet of hydrostatic pressure. These test procedures are designed specifically to determine the permeability of concrete substrates.

Only limited permeability testing of Hycrete is available. The only published permeability test data is based on ASTM-D5385, which is designed to test membranes. It is interesting to note that no concrete mix design is given, nor does it appear that a control sample was used. The test was conducted at 100 psi.

Compressive Strength

Xypex Admixtures will increase the compressive strength of the concrete from 5%-20% depending upon the amount of dosage and cement content.

Hycrete, according to their company data sheets, actually reduces the compressive strength, which is generally true of water repellent materials. To compensate for reduced compressive strength, they suggest that you add water-reducers, additional cement, super-plasticizers, or lower the W/C ratio to regain compressive strength back. Note that adding additional products to compensate for lost compressive strength will increase the cost of a cubic yard of concrete.

Self Healing of Cracks

Xypex will self heal cracks of a width of 0.4mm (1/64 inch), all while under hydrostatic pressure.

Hycrete was tested with sound waves for the ability to self heal cracks, but the results do not state the width of crack that Hycrete can self heal.

Chemical Resistance

Xypex has been tested using ASTM C267-77. Xypex is highly resistant to most aggressive chemicals up to a pH range of 3.0 - 11.0 in constant contact, and 2.0 - 12.0 in periodic contact.

There is no chemical resistance testing available for Hycrete, therefore it is not known what pH range Hycrete is able to withstand.

Dosage / Mix Design

Xypex Admix dosage is 2-3% by weight of Portland cement. Xypex does not require a specific W/C ratio or minimum amount of cement.

Hycrete requires 1 gallon per c.y. with a maximum .40 / W/C ratio. Note that on some test reports up to 2 gallons of Hycrete was added, but the recommondation on their data sheet is that you only add 1 gallon.

Summary

Xypex is one of those rare materials that continues to get better over time. The reaction that Xypex generates in the capillary tracts of the concrete will create a non-soluble, inert, mineral, crystalline structure that continues to develop and densify over time.

Hycrete, in their own literature, describes their product with words such as "water-borne surfactant" (a soap-like material) and "bipolar hydrocarbon chain." As with anything carbon based, it will degrade over time.

The above comparison information was taken from the official Data Sheets from each company's web site.