Method and apparatus for restoring piling

The system for the restoring and reconditioning structural pile provides an outer form which is attachable to a portion of a piling which has been eroded or corroded and has lost some of its thickness and thus its overall strength. A diameter building filler is placed into an intraform space between the form and the piling, the filler providing a protective and structural coating to that portion of the piling where corrosion or damage has taken place. In the preferred embodiment the filler is a setting material such as a suitable epoxy.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to the reconditioning and restoration of 
posts and piling, and more particularly relates to a method in apparatus 
for the reconditioning of marine piling, especially at the water level. 
2. General Background and Prior Art 
In the marine environment, posts, piling, and like structural members 
frequently become eroded or corroded especially at the water line area. 
The area far beneath the water line is usually protected by cathodic 
protection, while that portion of the pile well above the water line is 
easily painted for protection and seldom comes in contact with water which 
can cause corrosion or erosion. 
At the water line however, the piling can be attacked by wave action, tidal 
fluctuations, marine growth, oxidation, and the like. Steel pipes which 
are used as piling, as well as wooden posts such as creosote posts all 
suffer extensively from corrosion and/or mechanical erosion in this area 
adjacent the water surface. Wooden piling and creosote piling can become 
rotten as they are attacked by worms. 
Concrete piling also suffer at the water line, as the water can seep into 
the pores of the concrete. Air and water in the pores of a concrete piling 
can cause it to expand and produce cracks due to stress. Once cracks have 
allowed water to seep into the inner portion of a concrete pile member, 
the steel or metal reinforcement is exposed and can quickly corrode with 
the reinforcing steel of the concrete piling loosing much if not all of 
its tensile strength. 
From the above, it can be seen that when corrosion or erosion of such 
piling becomes severe, the piling itself must be demolished or replaced, 
or at least structurally reinforced. The repairing and reinforcing of such 
piling has usually involved the construction of a wall, cofferdam, or like 
around the piling with the subsequent removal of water to give workmen a 
dry space in which to work. 
The necessity of creating a dry environment around a marine piling is quite 
costly and can often be impossible in for example severe marine 
environment such as the North Sea. 
Even if some type of protective coating were to be added to a piling 
member, it must be a coating which is substantially water resistent so 
that subsequent attack will not rekindle an old problem. 
GENERAL DISCUSSION OF THE PRESENT INVENTION 
An object of the present invention is to provide a simple and effective 
method of repairing a partially corroded pipe or pile and protecting it 
against further corrosion or mechanical erosion. 
The invention provides an apparatus which is comprised of an outer 
circumferential form which is attachable to that portion of the piling 
which needs to be reconditioned or restored. In the preferred embodiment, 
the form is a flexible sheet of material which is circumferentially 
attached about the piling with spaces being provided to hold it off the 
pile itself, thus providing an intraform space into which a suitable 
filler is placed. The filler in the preferred embodiment forms a 
protective and structural coating to that portion of the piling to which 
the form is attached, which portion of the piling has been corroded, 
eroded, or otherwise "eaten away". The filler is preferably heavier than 
water and substantially water impenetrable. The filler in the preferred 
embodiment is initially a fluid, but eventually sets to form a structural, 
integral bond with the piling itself. 
The form is provided at its lower end portion with a seal which prevents 
the escape of the filler from the bottom of the form at its connection to 
the piling itself. The intraform space is filled with the suitable filler, 
the intraform space being occupied by the filler as is desirable. Since 
the filler is heavier than water and initially flowable it displaces the 
water within the intraform space as it is added thereto. From the above it 
can be seen that the problem of providing a dry environment is solved, 
since the filter material is initially flowable and is both water 
impenetrable and heavier than water negating the need for a dry 
environment for its application. The filler merely enters the intraform 
space (by pouring for example) and fills it, displacing the sea water 
upward and out of the intraform space as is desirable (See FIG. 5). 
In the preferred embodiment, the filler material is a suitable epoxy which 
is water impenetrable, and which initially is a pumpable flowable fluid 
which can be added to the intraform space by means of, for example, a 
suitable flexible conduit, or hose. The flowable filler flows into all the 
crevices, holes, gaps, and like corroded and/or eroded imperfections of 
the pile member as it is added to the intraform space in its initial 
liquid form. After the liquid filler is added to the intraform space in 
this manner, it subsequently sets and hardens providing a structural and 
integral bond with the worn piling, reconditioning it and giving it added 
protection and structural integrity. 
In the method of the present invention, the piling member is first cleaned 
of extraneous matter, such as marine growth, scum, rust, and the like, 
with a suitable cleansing unit such as a sand blasting, water blasting, or 
like apparatus. 
The second step in the method of the present invention involves the 
attachment of a circumferential form about the corroded or damaged section 
of piling, the form providing a substantially fluid tight envelope about 
the corroded section of the piling. A suitable spacer which can be, for 
example, a strip of sealing material is placed between the pile and the 
outer form member. At the lowermost portion of the form, the spacer is 
continuous and provides a bottom seal creating a dam for the prevention of 
downward travel of the filler material from the form and the corroded 
area. At the upper portion of the form, spaced seal members are provided 
so that filler material can be added. The form is thus spaced a distance 
from the piling, providing an intraform space between the pile and the 
outer form. Into this space will be added a suitable filler material which 
is at first a pumpable fluid, and thereafter sets to form a structural 
integral connection with the damaged pile. The form can be held in a 
secured type position about the pile, with the inner filler being likewise 
supported there within by a plurality of tensile fastener or straps. 
If desired, the form can be removed after the epoxy or like filler has 
hardened, although the removal of the form is not necessary.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
FIGS. 1-5 illustrate broadly the method of the present invention used on a 
pile 12 mounted in a marine environment to the ocean floor 16. 
FIGS. 3, 4 & 5, illustrate broadly the preferred embodiment of the 
apparatus of the present invention, while FIGS. 6, 6A & 7, illustrate 
structural connections of the outer form. 
In FIG. 1, there can be seen a typical pile 12 which in FIG. 1 is being 
cleaned by means of a suitable cleaning device such as a sand blasting rig 
13. Pile 12 could be a timber pile such as a creosote timber pile, steel 
pile, or like structural support member as is known and used in the 
structural engineering and construction art. It should be understood that 
any suitable mechanical means of cleaning pile 12 could be employed, such 
as sand blasting, water blasting, scraping, and the like. 
The pile 12 illustrated in FIG. 1 is shown in a marine environment, with 
the water line 14 being schematically illustrated. Note further in FIG. 1 
that a corroded, eroded, or otherwise damaged recess 18 is shown. This 
circumferential eroded area 18 is the problem to which the present 
invention is addressed. 
Note in FIG. 1 that arrows 15 indicate the vertical movement of the 
cleaning apparatus or sand blasting rig 13, while curved arrow 17 
illustrate its circumferential movement. Arrows 15, 17, illustrate that a 
suitable sand blasting rig or a like cleaning apparatus will be utilized 
to clean the entire circumferential eroded area 18 of extraneous 
barnicles, marine growth, corrosion, rust, and the like, to provide a good 
surface to which a suitable structural bond can be made with the filler 
portion of the present invention as we will discuss more fully 
hereinafter. 
Sand blasting rig 13 can be supplied through line 11 with a suitable supply 
of blasting materials, such as sand or water as is known. 
In FIG. 2, there can be seen the placement of a lower strap seal 22 and a 
plurality of upper strap seals 20. Note that lower strap seal 22 is 
continuous circumferentially about pile 12. Lower strap seal 22 could be 
attached to piling 12 by any suitable means as fastener 24. Suitable 
fasteners such as, nails, bolts, screws, or the like could be employed. 
Further, lower seal 22 and upper seals 20 could be applied directly to 
form 30 by glue or like means if desirable an "MEK" (methyl ethyl keytone) 
glue would be suitable. 
Note that upper and lower seals 20, 22 are placed above and below 
circumferentially eroded area 18, which area is indicated to be of a 
height "H" of piling 12 in FIG. 2. 
In FIG. 3, there can be seen a form 30 which is a sheet of flexible 
material and is circumferentially attached about piling 12 and adhered in 
a sealable fashion to seals 20, 24. Note that seal 24 is continuous in its 
lowermost position. When form 30 is fully attached to pile 12, its 
attachment against lower seal 24 will form a lowermost "dam", which will 
prevent the lower or downward escape of filler from the space created 
between piling 12 and form 30, which could be called an "intraform" space. 
Each seal 20, 22 has a certain thickness which will hold form 30 in a 
spaced orientation from pile 12. This creates an intraform space to which 
a suitable filler will be added as we will described more fully 
hereinafter. By providing such a spacing of form 30 from pile 12, added 
thickness at the corroded area 18 can be achieved. Thus, the pile will be 
in fact, as strong as, if not more strong than it was prior to the repair 
and reconditioning as is taught by the present invention. 
In FIG. 3, arrows 29 indicate schematically the circumferential attachment 
of form 30 to pile 12. 
The final connection of form 30 about piling 12 is perfected when the 
tongue and groove connection 26 is made. In FIG. 3, there can be seen a 
leading edge 32 portion of form 30 which interlocks with the tongue and 
groove 26 portion thereof. (See in detail--FIGS. 6A and 6B). 
In FIG. 4, the tongue and groove connection 26 of form 30 has been 
completed. A plurality of tensile strap fasteners is seen which hold the 
form 30 about pile 12 and against seal members 20, 22, as is desirable. 
Tensile fasteners 34 would be set at a fixed diameter so as to prevent the 
bulging or expansion of form 30 after the filler material is added. Straps 
34 could be subsequently added to form 30 as filler is pumped into the 
intraform space as will be described more fully hereinafter with respect 
to FIG. 5. 
Note in FIGS. 6 and 6A the attachment of form 30 about pile 12 by means of 
the tongue and groove 26 connection. The form 30 provides two end 
portions. One end portion 32 provides a male connection, the other end 
portion 27, 28 consists of a pair of flaps 27, 28, which are attached by 
gluing, for example, to form 30. The connection of end portion 32 of form 
30 to the tongue and groove 26 connection completes a substantially fluid 
tight seal of form 30 about piling 12 as is desirable. This completed 
connection is illustrated in FIGS. 6A and 6B, as well as FIG. 5. 
In FIG. 2, upper and lower seals 20, 22 are shown as first attached to 
piling 12. 
In FIG. 7, a form 30 of length "L" is shown. It should be understood that 
lower seal 22 can be utilized to "measure" the circumference of pile 12 at 
the point of attachment of seal 22 thereto. Thus, when so attached and 
used to measure pile 12, seal 22 likewise could be used to gauge the 
necessary length "L" required for form 30. With such a measuring by lower 
seal 22, it could be glued directly to form 30 by using a suitable glue 
prior to the attachment of form 30 to pile 12. Upper seals 20 could 
likewise be glued to form 30 if desired. 
In FIG. 5, there can be seen a conduit 36 or like fluid conveying tube 
which is used to add a suitable filler 41 such as epoxy to the intraform 
space (that space between the pile 12 and form 30). The intraform space is 
shown in FIG. 5 to contain the lower tip portion 37 of conduit 36. Arrows 
38 schematically illustrate the flow of epoxy or like filler 41 from 
conduit 36 into the intraform space. 
Note that upper seal 20 is comprised of a plurality of seal members 20 
which leaves a plurality of gaps 45 between the pile 12 and form 30. This 
gap 45 provides a space through which conduit 36 can be placed so that it 
can enter the intraform space and fill the space with epoxy or like filler 
40. 
If desirable, conduit 36 can be withdrawn (See arrow 39, FIG. 5) as the 
level 41 of epoxy or like filler 40 rises. 
A suitable epoxy or like filler 40 would be utilized which would be heavier 
than water. Thus, as the filler 40 is added to the intraform space, the 
water would be displaced upwardly spilling out through gaps 45 and 
expelled to the outside of form 30. Further, a suitable epoxy or like 
filler 40 would be selected which would be water impenetrable, negating 
the chance for the mixture of water and filler 40. 
From the above, it can be seen that a "dry" environment is not necessary 
for the practice of the present invention. The present invention provides 
a method for reconditioning piles which can be performed at the water line 
or in a marine environment with no extra construction or cofferdam 
required. The method of the present invention works substantially equally 
well in both "wet" and "dry" environments. 
Indeed, the present invention could be practiced by two individuals by one 
overseeing a pump to feed epoxy or like filler 40 through conduit 36 to 
the intraform sspace. A second individual such as a diver (in a marine 
installation) could oversee the proper placement of the tip portion of 
conduit 36 during the actual filling operation. 
An alternative form of attachment of conduit 36 is seen at the lowermost 
portion of FIG. 5. There is provided a conduit 48 having a valve 50 which 
attaches at its distal end portion 52 to an opening 54 in form 30. Thus, a 
continuous injection of filler material 40 could be made through conduit 
48, valve 50, into the intraform space as is indicated schematically by 
arrows 56 in FIG. 5. With such an apparatus, the valve could be merely 
closed after the filling operation and if desired, removed once the epoxy 
or like setting filler 40 had hardened somewhat. 
Form 30 could be manufactured of any suitable preferably flexible plastic 
material such as "ABS" plastic, "PVC" plastic, or fiberglass. Upper and 
lower seal members 20, 22 could be provided of a resilient material such 
as a fairly stiff foam or rubber. 
A suitable resilient material such as that sold by Union Carbide Co. under 
the name "Evazote" would suffice as seal members 20, 22. 
A plurality of spacer blocks as is shown in seal 20 could be positioned 
wherever desirable within the intraform space to prevent the form 30 from 
touching pipe 12. Such blocks could be provided of a resilient material 
such as Evazote or any other type material to which the filler 40 could 
bond. 
Filler 40 would preferably be a thermo-plastic type material such as epoxy. 
A suitable epoxy material would be comprised for example of forty to sixty 
percent by weight of (40%-60%) Shell Oil Companies resin No. 828 and forty 
to sixty percent by weight (40%-60%) of Pacific Anchor Chemical Companies 
hardener "SUR-WET-R". 
In order to aide the pumping of these epoxy materials prior to their 
filling into the intraform space as illustrated in FIG. 5, the epoxy or 
like filler 40 could be warmed sufficiently, with a temperature of ninety 
degrees Fahrenheit (90.degree. F.) being exemplary. 
If the piling member were of wood or concrete, a sand or like granular 
solid could be added to the thermo-plastic filler material 40. The sand 
occupies some volume, with the more expensive epoxy lasting longer. 
When the pile 12 is of metal, the quantity of Ciba Geigy No. 508 resin, 
being less than 10% by weight of the epoxy material or filler 40 is added 
to the filler 40. Thus, such an epoxy material or filler 40 would be 
comprised as follows: 50% by weight of SUR-WET-R hardener, 45-49.5% by 
weight of Shell's No. 828 resin, and 0.5-5% by weight of Ciba Geigy's 508 
resin. 
Alternatively, the epoxy material 40 could comprise approximately 65% by 
weight of Ciba Geigy's resin No. 502 or 507 and approximately 35% by 
weight of a mixture of Ciba Geigy's hardener No. 830 and 850. 
In a second aspect the present invention broadly consists in a method of 
positioning a form, comprising a sleeve or jacket around a pipe or pile, 
injecting epoxy material into the form, the epoxy material comprising a 
mixture of 40 to 60% by weight of Shell Oil Company's No. 828 resin and 40 
to 60% by weight of Pacific Anchor Chemical Company's hardener SUR-WET-R, 
and allowing the epoxy material to set. 
Preferably, the resin comprises 50% by weight of Shell Oil Company's No. 
828 and 50% by weight of Pacific Anchor Company's SUR-WET-R. 
Alternatively, the resin comprises 45 to 49.5% by weight of Shell resin No. 
828, 50% by weight of SUR-WET-R and Ciba Geigy resin No. 508. 
The form 30 preferably is made of ABS plastics, coated with an acrylic 
paint if desired, although other plastics materials such as PVC may be 
suitable as may also fiberglass. It is important that the material will be 
such as not to deteriorate or crack when it is exposed to the marine 
environment. Around the top and bottom edge of the form there is a strip 
of resilient material to seal off the space within the form. The resilient 
material may be foam plastics and is preferably the material sold by Union 
Carbide Company under the name EVAZOTE. The sealing strip at the top end 
has one or more gaps in it so that material can be injected into the form 
through the gap and so that any water enclosed within the form can be 
expelled through the gap. 
The plastics form preferably has a groove formation along each longitudinal 
side so that when the form is wrapped around the pile or pipe and these 
edges are brought together to close the form the two grooves can slot into 
each other to provide an effective seal. (See FIGS. 6A and 6B.) Each 
groove is in the form of a double flap of material along the edge of the 
sheet so that in cross-section the edge of the sheet has a "Y" formation. 
One arm of each "Y" can then fit into the space between the arms of the 
other "Y" and the flaps are laid together to provide the seal. However, 
instead of providing a tongue and groove seal, it is possible simply to 
wrap a flexible sheet around the pipe or pile a couple of times and secure 
it so that it neither leaks nor collapses onto the pipe or pile. 
Reinforcing tensile fastener bands 36 typically of stainless steel are 
positioned around the form along the length of it and are secured tightly 
so that the seal along the form cannot comp apart. (See FIG. 4.) They are, 
however, not so tight that the form is either buckled in or touching 
against the pipe or pile itself. 
If the pipe or pile is not vertical it may be necessary to have spacing 
blocks within the form so that the form does not collapse onto the pipe or 
pile. These blocks may also be desired even when the pipe or pile is 
vertical. They may be small pieces of EVAZOTE form, or they may be blocks 
of resin material with wooden piling, nails or bolts could be driven into 
the pile leaving a small length of each nail or bolt exposed to act as a 
"spacer". A plurality of such nails or bolts substantially equally spaced 
over the eroded area would be desirable. 
Once this material is set, it is hard and strong and adheres firmly to the 
wood or concrete and also to the ABS form. The stainless steel fastener 
bands 36 may be removed if desired but this is not necessary. Thus all the 
corroded material which has been removed from the pile has been replaced 
by the epoxy resin which is strong to give a reinforcing strength to the 
pile so that it is now stronger than it was when new and also provides a 
protective surface at the water level of the pile which will not be 
corroded by water and not easily corroded by wave action. 
If the method is being applied to a steel pile or pipe then it is necessary 
that the epoxy be slightly flexible once set so that it will not come away 
from the steel when the steel flexes or expands and contracts with 
variations in temperature. Thus, instead of 50% by weight of No. 828 resin 
of the Shell Chemical Company, a resin mixture of 45% by weight of Shell's 
No. 828 resin and 5% by weight of Ciba Geigy's No. 508 Resin is used. 
These quantities can be varied so that the percentage of the Ciba Geigy 
resin can vary from 0.5 to 10% by weight. However, once the proportion of 
the Ciba Geigy resin exceeds 10%, then the final epoxy becomes too soft, 
and also subject to water corrosion. The ratio of hardener to resin or 
resin mixture is preferably 50/50 but may vary between 40/60 and 60/40. 
The materials are preferably warmed to 90.degree. F. before mixing. If they 
are not, then bubbles may form in the resin and the material is not as 
strong. However, the result can still be quite satisfactory. The epoxy 
material comprising 50% by weight of Shell's No. 828 resin and 50% by 
weight of Pacific Anchor Chemical's SUR-WET-R hardener, is three to five 
times stronger than a typical concrete mixture. For example, concrete is 
typically of 3000-5000 PSI compressive strengths, whereas the epoxy 
material has a compressive strength of 10,000-15,000 PSI. The addition of 
the Ciba Geigy resin required for metal pipes and piles does not make the 
resin material weaker but not so weak that it does not still provide 
reinforcing strength for steel pipe or pile. 
This epoxy material also bonds very securely to a surface which has been 
immersed in fresh or salt water. The epoxy is water resistant so that 
water which is adhering to the surface of the piles or pipes is repelled 
by the epoxy and the epoxy grips firmly to the surface. It also bonds 
reasonably securely to the ASB plastics of the form, especially if the 
epoxy is warm as it is injected into the form. It has been found that 
fresh water can be pumped into the intraform space in a salt water 
environment, as the resin bonds somewhat better (to metal piling 
especially) in the fresh water environment. 
An alternative epoxy material consists of approximately 65% by weight of 
Ciba Geigy's resin 502 or 507 and approximately 35% by weight of a mixture 
of Ciba Geigy hardeners Nos. 830 and 850. The mixture of hardeners 
preferably comprises equal quantities of each hardener, but this ratio may 
be varied. It is possible to use only one of the hardeners with none of 
the other hardener mixed into it. The Ciba Geigy resin 502 will give a 
stronger epoxy material than the resin 507 will, but resin 507 is less 
viscous and easier to handle and will give a satisfactory result. 
This material bonds well, although not as well as the Shell resin mixture, 
but it is stronger. It is good for use on wooden and concrete piles and 
quite satisfactory for metal ones. 
The process of injecting the epoxy material into a form to strengthen a 
pipe or pile need not be restricted to the water line. It can be done to 
any post or pipe or pile above or below the water surface and may, for 
example, be applied to telegraph poles also. Also, the method need not be 
restricted to the repair and rehabilitation of corroded posts, pipes and 
piles but it may also be used to provide a protective sheathing to a new 
or substantially uncorroded post, pipe or pile to prevent any corrosion 
which might affect it in the future. 
References in this specification to materials by their trade references 
should be construed as including the equivalent material when made or sold 
under any other name. 
Because many varying and different embodiments may be made within the scope 
of the inventive concept herein taught, and because many modifications may 
be made in the embodiments herein detailed in accordance with the 
descriptive requirement of the law, it is to be understood that the 
details herein are to be interpreted as illustrative and not in a limiting 
sense.