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A lot has been said and written about Polyurethane (PU) Grouts.
We want to talk about the grouts that we know the best - WEBAC injection
grouts.
PU grouts are divided in two major categories, hydrophobic
and hydrophilic grouts. The main difference is characterized by
the reaction with water. Hydrophobic materials use water as an reacting
agent only thus absorbing very little water. The cured material
is essentially free of water making it very resistant to post-cure
shrinkage.
Hydrophilic grouts can incorporate large amounts of water
into their chemical structure, thereby creating a gel with a variable
water content. The incorporated water however can evaporate in a
dry environment causing the cured hydrophilic material to shrink.
On the other hand hydrophilic grouts may incorporate more water
and water soluble, possibly harmful substances while expanding.
The capacity of shrinking and swelling due to absorption and evaporation
may decrease within time and leaves the hydrophilic grouts more
vulnerable to physical and chemical breakdown.
Knowing about these differences in grouts is very important
in selecting the right material. Based on our extensive lab and
field testing, and our many years of experience, we recommend hydrophobic
resins for concrete crack injection and hydrophilic grouts only,
where moisture content of the environment is guaranteed such as
in soil injection and curtain injection.
Hydrophobic grouts (WEBAC 151, 157, 160, 1403, etc.) are
most versatile and can be applied with single component equipment.
WEBAC 151 and 157 are polyurethane water-activated
foams. The spectrum of application is extremely wide for these products.
Both materials can be adjusted to stop water almost instantly as
well to react very slowly allowing for superior penetration
in fine cracks. The foams work in concrete cracks and in injection
behind structures where they stabilize soil and create a membrane
to protect the structure.
But not all polyurethane resins are designed to foam. WEBAC
1403 PU resin is a two-component product that does not need water
to react. The product cures to a very flexible solid sealant in
dry areas. Water is not necessary, but does not inhibit the reaction
if present. WEBAC 1403 and other products of the 1400 line are used
for hairline crack injection, and for areas that are partly wet
or even completely dry at the time of application. WEBAC 1403 is
fully compatible with the foaming polyurethanes and is often used
in combination.
Hydrophilic grout (WEBAC FLEXGEL) can be mixed with large
quantities of water, up to 15 times by volume. It offers an economical
alternative in some areas such as curtain injection behind walls
or manhole injection. WEBAC FLEXGEL is foam and gel in one product.
Small amounts of water (up to three times by volume) provoke the
material to foam. Higher water content results in a solid, extremely
flexible gel.
Polyurethane grouts are becoming more popular cutting into
areas where epoxy injection had been dominant. The reasons are obvious.
PU grouts work very well in wet areas where they offer superior
bond strength. They typically require only single component equipment
and provide flexibility. The degree of durability and the ability
to withstand chemicals and bacteria is comparable to epoxy resins.
Wherever concrete has to be sealed polyure-thanes are the first
choice. The spectrum for PU-grout applications is extremely wide.
It includes residential work such as leaky basement repair, sealing
of pools and concrete balconys and countless applications
in commercial areas. Tunnels are being fixed, bridges sealed, parking
garages repaired. Cracks in below grade walls are injected, and
liquid membranes behind walls are created with polyurethanes by
curtain injection. Drinking and wastewater tanks are sealed, leaky
manholes and pipes are sealed.
The injection can be done from the negative-side without
digging and without access to the waterside. Polyurethanes work
in the crack and behind the structure where they create a reliable
barrier to prevent water intrusion. In combination with packers,
inject pipes and inject-tubes, grouts offer a dimension of applications
unmatched by any other injection material.
The WEBAC product line is system-oriented. WEBAC has been
dedicated to offer you professional, job-tested, innovative
injection technology since 1978.
Detailed information including the comprehensive 'Introduction
to the WEBAC Pressure Injection System' and our product catalog
is available through WEBAC distributors or directly from our California
sales office.
Please contact us at 714-662-4445, fax us at 714-662-4446
or visit our web-site and send us an e-mail. We will gladly mail
you the requested materials and answer the questions you might have.
WEBAC - Our formula is your solution.
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WEBAC 1403 - the UN-FOAM, is one of WEBAC's popular injection resins
known to many of you who read this.
With a newly reduced mixed viscosity of approximately 70 cps, WEBAC
1403 is the thinnest polyurethane resin in our program.
The material is absolutely solvent free and 100% solids.
The versatile product is designed to be of non-foaming quality
and works in wet and dry environments offering excellent crack
penetrating properties.
Due to the outstanding flexibilty and high density
WEBAC 1403 is a superior waterproofing product. WEBAC 1403
might be the solution for your waterproofing problem where water-activated
foams just won't work.
WEBAC 1403 can be used in combination with foaming products such
as WEBAC 151 and WEBAC 157.
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The WEBAC Injection Tube System offers superior performance in
Cold Joint sealing.
The system was tested and proven reliable at the 'IBMB', the official
German material-testing institute for the building industry of the
Technical University Braunschweig following the strict ZTV-RISS
recommendations and the recommendations for "Injection Tubes for
construction joints" which has been published by the
German Building Association 'DBV'. The most outstanding characteristics
revealed in the test are the excellent waterproofing qualities,
its resistance to pressure and its high penetration level of 95%.
The injection tube made of a special pvc blend is evenly perforated
and covered with a membrane which securely prevents water or cement
particles from entering.
During the injection procedure the resin which is fed under pressure
through the tube causes the thin plastic membrane to burst. The
resin then leaves the injection tube to fill existing voids, cracks
and fissures in the area around the tube thereby sealing the cold
joint.
Another related System is the Inject tube System 2 which is being
successfully used in the USA. In this system the inner tube is covered
by two woven membranes. Regardless, if you prefer Type 1 or
Type 2, proven and tested over a period exceeding ten
years, the WEBAC Injection Tube and Resin Systems makes the injection
a cost-saving, simple and efficient sealing method for cold
joints in concrete structures.
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In 1988 WEBAC America Corp. was formed, a California Corporation,
with Mr. Paul Schencking as the C.E.O. and President.
WEBAC America Corp. introduced a new and sophisticated product line
to the United States and Canada. The company further played a major
role in exploring the Asian market. WEBAC America Corp. is a well
known name in the industry in Taiwan and Korea.
WEBAC America specialized in the marketing of injection materials
and techniques. Besides epoxy injection for structural repairs we
offer renowned polyurethane resins and grouts designed to seal water-bearing
cracks in concrete structures.
Over the years a comprehensive line of products emerged and WEBAC
added related waterproofing materials and specialty coatings
of superior quality.
Knowing that any successful technology is a combination of the
right products and tools, WEBAC offers a selection of quality equipment
and accessories to the customer.
WEBAC's innovative leadership results in outstanding products of
high reliability and quality consistence and customer satisfaction
world-wide.
Chemical grouts and epoxies can be injected with a wide range
of equipment. Sometimes a simple grease gun is adequate. But the
serious craftsman employs a variety of tools in his line up.
The choice of the right pump for the injection resin/grout
to be used is an important factor that may determine if a job will
be accomplished successfully and even if it will be finished within
the given deadlines.
Essentially we identify three categories of pumps. Single
component pumps for most hydrophobic polyurethanes, fixed ratio
two component pumps for epoxy injection and multi-ratio pumps for
hydrophilic polyurethanes.
Single component pumps are characterized by a one piston/diaphragm
operation, capable of pumping one material at a time. Hydrophobic
polyurethanes like WEBAC 151, 157 and 1403 can be pumped with single
component equipment. The accelerator/catalyst is mixed into the
material prior to injection thus creating a single component material.
The moisture in the area to be injected will induce reaction of
the material. Pumps for polyurethane injection should be capable
of creating at least 1500 psi since injection into fine cracks sometimes
requires very high initial pressures in order to achieve sufficient
penetration.
Two component pumps with a fixed ratio like two to one are generally
used for epoxy injection. Very small epoxy jobs may be done with
a single component pump (watch the pot life closely), but a true
two component epoxy pump is highly recommended. The injection machine
will provide an accurate mix ratio and the components are kept separately
until thoroughly mixed in the static mixer thus allowing the contractor
to focus on the injection rather than on mixing procedures and pot
life. Due to the nature of the epoxy resin and the injection techniques,
injection pressures are usually lower than those for polyurethane
injection. 300 psi and less might be sufficient, but it does not
hurt if the pump offers a little more “power”, especially
if long pressure lines are necessary. The typical ratios for epoxy
pumps are two to one and one to one.
Some hydrophilic polyurethanes and gels require a multi ratio system
to pump two components of grout or grout and water in a ratio of
five to one or 10 to one. Due to the short pot life, premixing of
the components is not possible.
WEBAC offers a variety of pumps for distinct applications and materials.
The size and frequency of injection jobs and the conditions on the
job site should determine which pump to select. The initial cost
is not always a true indicator of expenses. A hand operated system
might do the job just fine but an electric pump will save labor
on an extensive job and thereby pay for itself over a period of
time.
Accessories such as packers, ports, grout lines and valves
are as important as the pumps. The right combination of pumps, accessories
and grout results in an "Injection System" which enables the contractor
to do his job in a professional, efficient, successful and profitable
manner.
WEBAC is system oriented and we are dedicated to supply you with
professional and job approved injection equipment and materials.
Not just the chemicals, not just the equipment. But complete injection
systems from the company that has been proven to be one of the innovative,
reliable and trustworthy names in the injection industry for over
18 years.
Please contact us for further information.
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You decided on the grout, you have the pump. Now you move
to step three: Which packers and/or ports will you use for your
injection job? Packers come in all sizes and shapes and in prices
range from several cents to several dollars. But how do you make
an intelligent decision on which system to use and how much to spend?
Is more expensive always better - is plastic as effective
as metal and rubber?
Well, it depends. The injection method and the selected material
will help to determine the hardware. Are your cracks actively leaking,
are they dry, do you use epoxy or do you inject polyurethane? How
much pressure will be used, how do you connect your grout line?
There are two types of packer principles available. Insertable packers
(mechanical packers) and surface mounted ports.
Mechanical packers are typically used for polyurethane injection
and high pressure epoxy injection. Since they are not glued
to the surface, they work in wet areas and with decayed concrete.
Mechanical packers come with zerk fittings and button heads
(slide fittings). The zerk type is more commonly used and less costly.
It easily connects and disconnects and works nicely with medium
to high injection pressures. The button head type is only needed
in high volume applications. The opening is larger and material
flows with less resistance.
Injection pressure is the keyword to determine quality. High
pressure separates the packer champs from the lemons. Nobody likes
packers to fail at injection pressures in excess of 2000psi.
A premium packer should be made of metal and an expandable
rubber sleeve to minimize concrete spalls and packer blown outs.
A medium soft, slightly rough rubber provides the best grip.
Many packers made of cheap plastic are inferior by design.
They are not recommended for the following reasons: plastic
sleeves does not grip as securely as a rubber sleeves. The conic
screw-like shape of some packers applies stress to concrete close
to the opening of the drill hole rather than deep inside. The pressure
created can result in concrete spalling and dangerous packer
blow outs. Metal-rubber type packer fit the drill hole more evenly
and expand towards the surrounding concrete deep inside the hole.
A snug and reliable fit is essential for the safety of the technician
and the key factor for successful injection work.
Plastic packers can be a money saving alternative. The so-called
hammer-in or bang-in packers may be safe for use in perfect concrete
and with low injection pressures.
The size of the packer selected whether plastic or metal
depends on the volume to be pumped and the pressures to be applied.
Common diameters are 10mm, 1/2 inch, 5/8 inch and 3/4 inch.
The drill-hole should be kept as small as possible. Therefor the
1/2 inch packer seems to be the best compromise in strength and
size. Long versions and extensions are available.
Price should concern you. Many packers can add up to a substantial
amount. How much is reasonable for a good, regular-sized 1/2" or
5/8" packer? We think a good standard packer should not cost the
end user more than our WEBAC packers.
You might be surprised to learn what we sell
our 1/2" 13-60s packers for. Wwe do encourage you to call us and
request your free sample. Further, you might be surprised
to learn that you might have already used WEBAC packers, although
you have never ordered from us. Well, our competition likes them
too.
The choice of surface ports is less critical since lower
injection pressures are applied. Surface ports are commonly used
for epoxy injection and glued to the surface. A wider base is recommended
for good adhesion. Most surface ports have an unrestricted, and
valve-free opening that can be closed with a cap or a plug after
injection. An outer diameter of 1/4" is common. The grout line can
be attached with a quick-connect system.
In addition, WEBAC provides unique ports for specialty applications
such as a surface port with a zerk fitting to utilize single component
injection systems for small epoxy and polyurethane jobs, and the
IPS injection screw for the WEBAC 2000 Inject Tube System for cold
joints.
The WEBAC product line is system-oriented. WEBAC has been dedicated
to offer you professional, job-tested, innovative injection
technology since 1978.
Detailed information including the comprehensive 'Introduction
to the WEBAC Pressure Injection System' and our product catalog
is available through WEBAC distributors or directly from our California
sales office.
WEBAC - Our formula is your solution.
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When building water tight structures such as a tank or a
below grade structure, the concrete serves two purposes: it provides
the structural support and it seals against water, either in a way
to keep it in the structure or to keep it out. In either situation,
special attention must be paid to the construction of " cold" joints.
The WEBAC 2000 Inject Tube System is a practical method for making
cold joints watertight.
A well known characteristic of concrete is shrinkage while
curing. Stress caused during this time and temperature changes provoke
the development of small cracks and fissures. Several design and
reinforcement techniques help to control this effect, but cannot
control them completely. Fine cracks of sometimes less than 0.1mm
are inevitable. These cracks are considered normal and generally
do not cause any problems. However, at cold joints, the tendency
to form larger cracks cannot be reduced. Since old and new concrete
do not bond together homogeneously and do not form a monolithic
concrete body, stress cracks concentrate mainly in these areas.
They easily conduct water and may cause severe damage.
The WEBAC 2000 Injection Tube System for sealing cold joints utilizes
the natural tendency of concrete to form cracks. A special tube
system is installed at the joint where leaks are most likely to
occur. The system allows resin injection directly into the joint
through a protected porous tube after completion of the structure.
The resin penetrates through the perforation of the tube and fills
the cracks and voids of the cold joint area thereby sealing the
structure.
To be effective, the system must have certain properties.
The tube must be sturdy enough to withstand the high pressure of
placed concrete and it must resist concrete slurry penetration.
On the other hand the injection resin must be able to penetrate
the hose at a moderate injection pressure. The installation and
injection process must be suitable for construction sites.The Injection
Tube System is designed to meet these requirements:
o A sturdy PVC hose withstands pressures of at least 60 ft
of poured concrete.
o A layer of tightly woven fabric (filter) prevents concrete particles
from entering the Inject Tube.
o A large number of holes in the hose allows the resin to penetrate
the tube with little loss of pressure.
o A top layer of tough plastic fabric protects the filter fabric
against mechanical damage during the installation on the rough concrete
surface.
o Special Inject Sleeves and Inject Screws provide for easy installation
and resin injection.
Before pouring the new concrete the tube shall be attached to the
existing surface as tight as possible and usually towards the middle
of the future cold joint using suitable clips or by attaching it
to the existing rebars. It is crucial that the hose is tightly fixed
in the center of the joint area so that it can neither move nor
lift during the concrete placement. Six to twelve inches between
clips are typically recommended.
The hose must be placed in a manner that it will not touch
the outside surface of the structure at any point. To allow sufficient
injection pressures, the maximum length of injection tube should
not exceed 30 ft.
Special Inject Sleeves have to be attached to both ends of the
Inject Tube prior to installation. The Inject Sleeves are solid
and cannot be penetrated by the resin. Two thirds of the sleeves
must be poured into the concrete to allow a successful injection
procedure. Injection Screws fitted with an injection zerk attach
to the sleeves prior to injection. For detailed information, please
refer to our product data sheet.
The concrete should set for as long as necessary to allow shrinkage.
WEBAC polyurethane resin is then injected by attaching a WEBAC packer
and pumping resin into the tube. Electrical or hand pumps may be
used for the resin injection. To ensure that the tube is filled,
resin shall be pumped until it emerges from the other end of the
hose at the packer, which is then plugged with a zerk fitting. The
resin shall be pumped slowly and steadily. High pressure forces
the resin out of the hose and into the fine cracks and voids. Injection
shall be continued until resin emerges from the joint. Typically
the applied pressure should not exceed 1500 psi. It is recommended
to make several injections while the resin is still workable. The
typical working time is 20 minutes at 68 F. The concrete temperature
and presence of water will effect this time. The cured product will
permanently seal against penetrating water.
When used appropriately, the WEBAC 2000 Injection Tube System
is the most convenient and effective way to seal construction joints.
The non-invasive application through the pre-installed system minimizes
the risk of damage. Compared to the injection method through mechanical
packers that have to be installed by drilling holes into the concrete,
the WEBAC 2000 System reduces the amount of labor and material drastically.
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