The Xypex process is unique and involves waterproofing by
Crystallization, whereby the addition of Xypex to concrete, with water as
the catalyst, reacts to generate a non-soluble quartz like crystal which
grows in the bleed tracts and capillaries within the concrete.
One of the benefits of this reaction is that of a secondary hydration
process which fills naturally occurring voids formed with the quartz like
crystals. In this manner concrete becomes impermeable to the penetration
of liquids.
How does Xypex work?
When a cement particle hydrates there is a reaction between water and
the cement that causes it to become a hard, solid mass but there are also
chemical by-products given off which lay dormant in the concrete. With
Xypex we introduce a second set of chemicals.
When we combine the by-products of cement hydration and the chemicals
in Xypex in the presence of moisture, a chemical reaction takes place and
the product of this reaction is a nonsoluble, dendritic, crystalline
structure.
This crystalline structure can only take place when moisture is present
and thus Xypex tends to form this crystalline material in the bleed water
tracts, capillary tracts and shrinkage cracks in concrete. Wherever water
is present, Xypex will form.
Does Xypex add Durability & Protection?
Impermeability against liquids. 50mm thick Xypex
treated concrete has withstood hydrostatic pressure equivalent to 405 feet
of head pressure. This was the limit of the testing apparatus. Xypex
treated concrete is impervious to: water, chlorinated water, diesel, fuels
and other petroleum products.
As the crystals are a silica, which is a mineral and not an organic
product, Xypex significantly increases the chemical resistance of
concrete. Numerous tests have shown that Xypex treated concrete is
not affected by a wide variety of aggressive chemicals.
Xypex protects concrete against chloride
attack. The growth of Xypex crystals into the concrete will help
protect reinforcing steel by blocking microcracks and capillary pathways
used by migrating chloride ions. The concrete becomes impermeable and
prevents further entry of chlorides or other chemicals. Normally during
the course of spalling repairs to concrete structures, chlorides are still
trapped and active within the concrete in areas which have not been
repaired. Independent tests have shown Xypex not only prevents further
penetration of chlorides, but also reduces the level of chloride ion
activity within existing structures to below the level required to promote
electrolytic corrosion. As a side benefit, the presence of
crystalline growth within the concrete also tends to directly
interfere with corrosion reactions on imbedded steel.
Xypex crystalline growth reduces carbonation
in concrete structures by a factor of up to 40%.
The filling of capillaries within the concrete significantly increases
strength. In Admix treated concrete, the increases in strength are
typically 5 - 20%. Xypex Admix promotes an extended hydration process
within concrete thereby achieving its design strength at around seven (7)
days.
Does Xypex protect concrete against freeze/thaw damage?
Yes. By blocking the intrusion of water into concrete, Xypex helps
protect the concrete from the damaging effect of repeated freeze/thaw
cycles.
How does Xypex stand up to harsh conditions?
pH Range
-from 3.0 to 11.0 constant contact
2.0 to 12.0 periodic contact
Temperature Range
-from -25 °F to + 265 °F constant
-from -301°F to + 2786 °F periodic
Humidity
-no effect
Ultraviolet
-no effect
Oxygen level (oxidization)
-no effect
Is Xypex toxic?
No. Xypex contains no volatile organic carriers (VOC) and can be
applied safely in enclosed surroundings. Xypex is approved by numerous
country and state health and waterworks departments for use on structures
which contain potable water or foodstuffs. Several are listed below:
NSF International
Swiss Federal Health Service
Japanese Ministry of Public Welfare
United Kingdom Water Fittings Bylaws
Singapore Institute of Standards and Industrial Research
Can Xypex be applied against extreme hydrostatic pressure?
Yes. Because Xypex is not dependent upon adhesion to the concrete
surface and instead becomes an integral part of the concrete mass through
crystallization, it is capable of resisting extreme hydrostatic pressure
from either side (positive or negative) of the concrete.
What are some typical Xypex applications?
Water/Waste water treatment plants
Reservoirs/Tanks
Secondary Containment Structures
Foundation Slabs
Below-grade work
Parking Structures
Tunnels/Manholes
Underground Vaults
Swimming Pools
Elevator Pits
How is Xypex different from other products?
Xypex the material and its technology is completely unique in the
market, not one other product or combination of products creates the same
crystalline growth within cementitious materials.
Xypex creates a crystalline structure deep within the pores and
capillary tracts of the concrete mass to prevent the penetration of
water and aggressive chemicals. In contrast, barrier-type products
function only at the surface of the concrete.
Xypex will seal hairline cracks up to 0.4mm.
Xypex is not subject to the deterioration problems encountered by
membranes.
What are the advantages of using Xypex instead of membranes?
The crystalline nature of the Xypex waterproofing system provides many
application advantages over traditional barrier products:
Xypex does not require a dry surface; in fact, a wet surface is
necessary.
Xypex does not require dry weather to be applied.
Xypex does not require costly surface priming or leveling prior to
application.
Xypex cannot puncture, tear or come apart at the seams.
Xypex does not require protection during backfilling or during
placement of steel, wire mesh or other materials.
Xypex can be applied on either side of the concrete surface, the
negative or the positive (water pressure) side.
Xypex does not require sealing, lapping and finishing of seams at
comers, edges or between membranes.
Xypex is less costly to apply than most other methods.
Are there additional benefits to Xypex?
Resists extreme hydrostatic pressure from either positive or
negative surface of the concrete
Becomes an integral, permanent part of the substrate
Self healing capacity for static cracks up to 0.4mm in width.
Corrosion protection
Neutralizes chloride ion activity
Highly resistant to aggressive chemicals
Reduces carbonation
Prevention of alkali aggregate reaction
Gains in concrete design strength
Added durability
Allows concrete to breathe
Non-toxic
Less costly to apply than most other methods
Increases flexibility in the construction schedule
Is Xypex used to waterproof cracks, joints and other defects in
concrete?
Yes. Xypex has a specific repair system that utilizes its unique
crystalline waterproofing technology to stop water flow through cracks,
faulty joints and other defects. In the case of expansion joints or
chronic moving cracks, a flexible sealant is recommended.
Does Xypex have limitations?
Yes. Xypex will not heal moving cracks. Moving or unsettled ground
causes cracks to move and Xypex will not work. Xypex will not work with
non-cementitious material. Xypex requires Portland cement to create the
crystals.
How long will Xypex last?
A Xypex application, unlike most other systems, is permanent. Its
unique, dendritic crystalline growth will not deteriorate under normal
conditions.
What are the cost savings of Xypex treatments?
There are numerous Cost Savings other than the initial price for the
treatment. The long term benefit of the Xypex treatment may only be fully
realized by our children's children.
SUMMARY
Applied to concrete, Xypex products cause a catalytic reaction
which, in contact with moisture, forms crystals of dendritic fibers in the
natural voids and capillary tracts of the structure. This nonsoluble
crystalline growth is so small as to ensure that water cannot pass
through.
The ability of chloride ions to migrate through concrete is
dependent on salt solutions penetrating into the structure. The integral
waterproofing achieved by Xypex Crystallization prevents the ingress of
such solutions. Once treated with Xypex, concrete structures are protected
from penetration.
Click Here for the Xypex Material
Safety Data Sheet