This application relates generally to construction methods and apparatus. More specifically, this application relates to a method and a reusable apparatus for repairing and/or reinforcing pillars and columns and for repairing pipes of any desired diameter on site, using reusable materials.
The drawings, when considered in connection with the following description, are presented for the purpose of facilitating an understanding of the subject matter sought to be protected.
While the present disclosure is described with reference to several illustrative embodiments described herein, it should be clear that the present disclosure should not be limited to such embodiments. Therefore, the description of the embodiments provided herein is illustrative of the present disclosure and should not limit the scope of the disclosure as claimed. In addition, while the following description references using only a few wrapper designs, it will be appreciated that the disclosure includes many more wrapper designs and methods of wrapping the reusable wrapper around the workpiece.
In construction of buildings and bridges, there is often a need to build circular columns. The forming of these columns is not very easy and can be expensive and time-consuming. The current construction practice globally depends on using cardboard tubes that are available in a few sizes. One of the most popular brands in the U.S. is Sonotube®, as shown in
In response to these shortcomings new methods and new articles of manufacture are disclosed for making concrete formworks.
The disclosed method requires using flat or pre-curled, strong, durable and flexible sheets of any materials. One such ideal material is PileMedic® PLG60.60 that is sold by QuakeWrap, Inc., Tucson, Ariz. (www.PileMedic.com). This example product is manufactured from a biaxial glass fabric that is saturated with resin and is cured under pressure and heat. The result is a sheet that is, for example, 4 to 5 feet wide and several hundred feet long. The thickness of the sheet is only about 0.026 inch, making the sheet very light and flexible so it can be coiled around a 4-5 inch diameter core. The sheet may also be manufactured in a curled form. Therefore a 4-ft wide×300-ft long piece of this laminate sheet can be coiled and fit in a box that is merely about 14×14 inch in cross section and about 50 inches long. This compact packaging is one of the advantages of the new system. Other plastic sheets such as HDPE, PVC, vinyl, rubber, etc. can also be used for the same applications.
In some embodiments the laminate sheets are very strong and very durable since they do not absorb water. So, they can be used numerous times. A further property of these laminates is their smooth surface which serves two functions. First, it provides a smooth finished surface for the concrete column that is constructed using this technique. Secondly, the smooth surface prevents bonding of concrete to the form, so the form can be easily removed after each use and be reused. Neither one of these attributes is true about the Sonotubes®.
The assembling of a formwork according to this disclosure in the field is very easy. For example, if it is desirable to build a 5 foot tall and 11 inch diameter column, a 104 inch long segment is cut in the field from a 5-foot width laminate or from a larger width laminate. This will provide for a 3-ply or 3-layer formwork. This piece of laminate is wrapped around itself 3 times to create a tube or a jacket that is 11 inches in diameter and 5-ft tall. Even without any adhesive, the friction between the layers of the laminate prevents it from unraveling and opening up.
It is important to note that the laminate 200 is pre-curled by the manufacturer. One advantage of a pre-curled laminate is its ease of installation and its ability to keep its installed shape without, for example, the need to have a rope tied around it or a frame placed within it, while one of the advantages of a flat fabricated laminate is the ease of storage and transportation. In other embodiments the frames may be totally removed after formation of the formwork. The formwork may also be externally braced to make sure it remains in a plumb position while concrete is being placed. In some embodiments, for example, a reinforcing case of rebars may be utilized as a skeleton around which the laminate sheets are wrapped.
When the concrete is poured inside the formwork the hydrostatic pressure of the fresh concrete pushes the formwork radially and outwardly; however, the friction between multiple layers of the laminate is sufficient to prevent unraveling of the formwork. The adhesive tape, Velcro, strings, or tie wire or shrink-wrap may also help to keep the formwork in its original shape while the concrete cures. When the concrete is set, which may only take a day, the laminate sheet can be removed and wiped cleaned. The laminate is now ready to be used many more times.
For taller columns, either wider laminates (wider than 5-ft) can be used or the 5-ft wide laminates can be longitudinally overlapped by a couple of inches to create an approximately 10-ft tall formwork. In other embodiments adhesive tape, such as duct tape, may be placed over the curved abutting line of the two adjacent stacked forms. In various embodiments laminate bands may be wrapped as many times as necessary to achieve the desired height.
A further advantage of this method is that it is able to construct a cylindrical or a non-cylindrical formwork/form around an existing column. For example, as in
It is important to mention that the more the layers of the laminate 540, the less the need for using any kinds of strap, rope, or tape around the framework since the friction between the layers will not permit the laminate 540 to unwrap, especially if the laminate 540 is pre-curled. Even if an insignificant strap, rope, or tape is used around the wrapped laminate, it is merely for creating an initial friction between the layers of the laminate which increases by the internal pressures of the fresh concrete. The tension in the strap, rope, or tape is not the reason for creating resistance against unwrapping. Almost all the resistance against unwrapping is caused by the friction between the layers of the laminate. In some embodiments the inner surface of the laminate 540 may be slightly wetted to increase the friction between the layers. Concrete is then placed in the annular space 520 between the shell (i.e. formwork) and the column 500. Once the concrete is cured, the laminate 540 is unwrapped and removed or peeled off. The laminate 540 can be wiped clean and used over and over again. In some embodiments the outer surface of the laminate 540 may be slightly wetted to add to the friction between the laminate layers. In various embodiments surface(s) of the laminate sheet may not be very smooth by design to increase the friction between the laminate layers.
In various applications and embodiments the friction between the layers of the laminate 540 is nearly sufficient to hold the formwork/shell 510 together even when any filler material is poured in the annular space between the shell (i.e. formwork) and the column. Actually the pressure created by the filler material on the shell increases the pressure between the shell layers which in turn increases the friction between the shell layers. And in many cases, just a small piece of duct tape or the like is sufficient to hold the end of the laminate in place to prevent its unraveling. The use of the ratchet straps is often an “overkill”.
In some embodiments, shell 510 can be left in place in which case the laminate 540 can serve as a reinforcing or a protective “skin” element for the newly cast column. The laminate 540 will also prevent moisture ingress and thus delay or stop corrosion of the column inside the concrete casting.
A further advantage of the disclosed system and method is in repair of columns that have a tapering geometry and/or a non-circular cross-section. These are very commonly used as cell phone towers or utility poles. If one wishes to increase the diameter of a tapering tube by 2 inches, for example, the present disclosed methods may be adopted. In this case for example, six 1-inch diameter PVC pipes are tied around the tube at 60 degrees apart. Then the laminate sheet is wrapped around these PVC pipes; this results in a tapering formwork that is radially offset by 1 inch from the original column (or tube) along the whole length. Both the original pole and the new casting will have the same exact taper.
This disclosure also relates to the repair and strengthening of columns and piles that may be submerged in water. Such structures are subjected to loads such as those induced by gravity, traffic, earthquakes, blast and explosion, strong winds, flow-induced forces from water and the like. These structures often corrode and require repair and reinforcement.
One method for reinforcing a weakened column or pile is to encase it in a slightly larger plastic or FRP and fill the annular space with filler materials such as resin or grout. Fiber Reinforced Polymer (FRP) is made of fibers such as glass, carbon, basalt, aramid and the like saturated with a resin such as epoxy, polyester, vinyl ester and the like and then allowed to cure. If such jackets are installed to include a continuous wrap around the column in the hoop direction, the resulting confining pressure on the pile or column adds significant strength to the structure. Strengthening a pipe from the outside is very similar to reinforcing a concrete column, for example, as described below.
Hoops 614 are mainly used as guides to wrap the sheets 611 around them and ensure a uniform diameter form. These disks 612 may have openings to allow passage of concrete through them. These disks 612, as will be described in more details, may also contain holes for placement of longitudinal steel reinforcing bars that are often used in construction of columns. The disks 612 or hoops 614 can be secured together at a desired distance along the height of the column to create a skeleton or a frame around which the laminate sheets 611 are wrapped.
In yet other embodiments, for ease of transportation, each of the hoops 614 may initially be a straight strap of material to be curved on site to produce a hoop of any desired diameter. The Individual hoops 614 may be configured to be opened after each use and revert to reusable straight straps. As is obvious to anyone skilled in the art, each strap provides several choices of desired diameters. To have a conical column, each neighboring hoop 614 may be adjusted to be slightly larger or smaller.
Straps 640 and 650 and perimeter elements 647 and 648 may be made from semi-flexible, semi-rigid, and/or rigid materials as desired, such as plastic. In practice, shells may be constructed while frames are horizontally laid on the ground and be erected after the formation of the shells. One of the advantages of making the rings with open and uncoiled straps is that even for repairing a damaged column that is located between a floor and a ceiling, unlike the Sonotube®, the frame can be easily formed around the column and later be removed along with the shell.
In various embodiments straps 640 and 650 may also have protrusions 649 to make sure that hoops 640 and 650 and perimeter elements 647 and 648 remain concealed and fully encased in the cured concrete and not exposed to the outside of the structure/column.
In some embodiments, such as in
Please note that the roughness of the surface(s) of the laminates can be designed to have any coefficient of friction as desired, without bonding to the inside concrete.
In recent years a technique has been developed for repair of pipelines that uses Spiral-Wound Bands (SWB). SWBs are typically made of plastics such as HDPE, PVC and the like that can be easily molded to any shape. While a SWB is being wrapped, the edges of the adjacent turns are overlapped and are interlocked together by a male and a female strip/band that are manufactured as a part of the SWB. This locking mechanism is very similar to the mechanism of Ziploc® plastic bags.
It is important to note that the above described methods of repair or construction may be also performed by spirally wound laminate bands instead of non-spirally wound laminate sheets.
In some embodiments the exterior surface of the shell or jacket can be coated with a coating that protects the jacket against ultraviolet rays. In other embodiments coatings of various texture and color can be applied to the exterior of the jacket to achieve the desired architectural appearance.
In this specification a method, a system, and an article of manufacture are disclosed for reinforcing various structures, such as pipes, ducts, vessels, tanks, silos, beams, columns, walls, slabs and the like, constructed from various materials including, but not limited to steel, concrete, masonry, wood, plastics, and the like, where the article of manufacture is reusable. The same or very similar article of manufacture may also be used to temporarily or permanently build a pipe of any desired diameter
In some embodiments the wrappers are in the shape of long bands of reusable materials and are wound helically around the workpiece and in other embodiments the wrappers are large sheets of bendable, flexible, or semi-rigid materials and are wrapped non-helically around the workpiece. Those skilled in the art recognize that additional reinforcement material such as still rebars or carbon strips may be placed inside the spaces between the wrapped materials and the workpieces.
In various embodiments, a layer of 3D fabric is impregnated or saturated with a resin and is used as a sheet of laminate material. A 3D fabric is a special type of fabric made, for example, with glass, carbon, or Kevlar reinforcing fibers. The 3D fabric is woven as two X-Y fabric layers that are connected with short fibers of glass, carbon or Kevlar fibers, substantially in Z direction. (X, Y, and Z create a Cartesian coordinate system.) During application of 3D fabrics, both layers of the fabric can be saturated with a resin such as epoxy, polyester or vinyl ester at the same time. During the curing process, the short fibers in Z-Direction will rise causing further separation between the two layers of the fabric to form a 3D structure—a thick sheet of laminate. This process results in a cured three-dimensional structure with a certain thickness and stiffness that is more than the thickness and stiffness of the 3D fabric before the application of the resin.
Changes can be made to the claimed invention in light of the above Detailed Description. While the above description details certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the claimed invention can be practiced in many ways. Details of the system may vary considerably in its implementation details, while still being encompassed by the claimed invention disclosed herein.
Particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the claimed invention to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the claimed invention encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the claimed invention.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B,” and also the phrase “A and/or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. It is further understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
While the present disclosure has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
This application, under 35 U.S.C. § 119, claims the benefit of the filing date of the U.S. Provisional Patent Application 62/551,397, entitled “Spiral-Wound Jackets for Repair of Piles,” filed on 1 Jan. 2017; and of the U.S. Provisional Patent Application 62/355,775, entitled “Reusable Construction Formwork,” filed on 28 Jun. 2016; and of the U.S. Provisional Patent Application 62/441,992, entitled “Spiral-Wound Reusable Concrete Form,” filed on 4 Jan. 2017, the specifications of which are incorporated herein in their entirety by reference.