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Publication numberUS20020194808 A1
Publication typeApplication
Application numberUS 09/887,598
Publication dateDec 26, 2002
Filing dateJun 22, 2001
Priority dateJun 22, 2001
Publication number09887598, 887598, US 2002/0194808 A1, US 2002/194808 A1, US 20020194808 A1, US 20020194808A1, US 2002194808 A1, US 2002194808A1, US-A1-20020194808, US-A1-2002194808, US2002/0194808A1, US2002/194808A1, US20020194808 A1, US20020194808A1, US2002194808 A1, US2002194808A1
InventorsFrank Ratliff
Original AssigneeRatliff Frank W.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Lightweight high load capacity reinforced beam and method of making same
US 20020194808 A1
Abstract
The present invention relates to a lightweight reinforced beam which utilizes a tendon system to provide tension on a rigid panel structural frame made from wood, wood composite, plastic or other material. An alternative embodiment uses a tendon system to provide tension on a precast form made from a castable material such as concrete by post tensioning a shielded tendon. This tendon, made from steel, carbon fiber or similar materials, will resist a load imposed on the reinforced beam and will support a large load relative to the weight of the tendon. Such a configuration would reduce the manpower and equipment necessary for placement and handling and transporting of such a beam, be easy and inexpensive to manufacture from a variety of materials and in a variety of lengths and sizes so as to be useful in a number of different load bearing situations, allow for post-tensioning of a shielded tendon thus shortening the length of time required for manufacture of the structure, and which would bear an equal or greater load than conventional solid beams at the point of greatest load demand thus providing for a safe, economical alternative to conventional solid beams for construction purposes.
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Claims(29)
What is claimed is:
1. A lightweight high capacity reinforced beam assembly comprising:
(a) at least two side beam member means;
(b) central spacer means and end spacer means for the purpose of spacing apart said side beam member means;
(c) fastening means for the purpose of securely attaching and holding in place said central spacer means, end spacer means, and side member means;
(d) tendon means having two ends configured for secure anchoring; and
(e) bearing plate means for the purpose of securely attaching and anchoring said tendon means ends to said end spacer means and side member means.
2. The lightweight high capacity reinforced beam assembly according to claim 1, wherein said side beam member means, central spacer means and end spacer means are constructed of natural materials.
3. The lightweight high capacity reinforced beam assembly according to claim 2 wherein said natural materials includes wood.
4. The lightweight high capacity reinforced beam assembly according to claim 1, wherein said side beam member means, central spacer means and end spacer means are constructed of non-natural materials.
5. The lightweight high capacity reinforced beam assembly according to claim 4, wherein said non-natural materials includes steel.
6. The lightweight high capacity reinforced beam assembly according to claim 1, wherein said tendon means having two ends configured for secure anchoring, is a steel cable.
7. The lightweight high capacity reinforced beam assembly according to claim 6, wherein said steel cable includes ends that are threaded.
8. The lightweight high capacity reinforced beam assembly according to claim 7, wherein said threaded ends are anchored to said bearing plates by passing said threaded end through an aperture in said bearing plate and securing a nut to said threaded end.
9. The lightweight high capacity reinforced beam assembly according to claim 1, wherein said bearing plate means are located in the upper one half portion of said end spacer means.
10. A lightweight high capacity reinforced beam assembly comprising:
(a) at least two side beam member means;
(b) central floating beam member means for bearing a load, and lower triangular end spacer means for the purpose of spacing apart said side beam member means;
(c) fastening means for the purpose of securely attaching and holding in place said lower triangular end member means and sandwiching said central floating beam member means between said side beam member means such that said central floating beam member is allowed to move downwardly toward said triangular end member means;
(d) tendon means having two ends configured for secure anchoring; and
(e) cross bolt means for the purpose of securely attaching and anchoring said tendon means ends to said side beam member means, whereby when a load force is applied to said beam assembly, said central floating beam member moves downwardly to contact said tendon means and thereby transfers the load force onto said tendon means.
11. The lightweight high capacity reinforced beam assembly according to claim 10, wherein said side beam member means, central floating beam member, and lower triangular end spacer means are constructed of natural materials.
12. The lightweight high capacity reinforced beam assembly according to claim 11, wherein said natural materials includes wood.
13. The lightweight high capacity reinforced beam assembly according to claim 10, wherein said side beam member means, central floating beam member, and lower triangular end spacer means are constructed of non-natural materials.
14. The lightweight high capacity reinforced beam assembly according to claim 13, wherein said non-natural materials includes steel.
15. The lightweight high capacity reinforced beam assembly according to claim 10, wherein said tendon means having two ends configured for secure anchoring, is a steel cable or carbon fiber tendon.
16. The lightweight high capacity reinforced beam assembly according to claim 15, wherein said steel cable includes ends that are looped.
17. The lightweight high capacity reinforced beam assembly according to claim 16, wherein said looped ends are anchored to said side beam member means by said cross bolt means.
18. The lightweight high capacity reinforced beam assembly according to claim 10, wherein said cross bolt means for the purpose of securely attaching and anchoring said tendon means ends to said side beam member means are located in the upper one half portion of said side beam member means.
19. A method for making a lightweight high capacity reinforced beam assembly comprising the steps of:
(a) providing at least two side beam members;
(b) providing central spacer means and end spacer means for the purpose of spacing apart said side beam member means;
(c) providing fastening means for the purpose of securely attaching and holding in place said central spacer means, end spacer means, and side member means;
(d) providing tendon means having two ends configured for secure anchoring; and
(e) providing bearing plate means for the purpose of securely attaching and anchoring said tendon means ends to said end spacer means and side member means;
(f) passing said tendon means through said bearing plate means;
(g) anchoring said tendon means to said bearing plate means; and
(h) assembling said side beam member means, said central spacer means, said end spacer means, said tendon means and said bearing plate means, whereby when a load force is applied to said central spacer means that load force is transferred to said tendon means which is in turn supported by said end spacer means and said bearing plate means.
20. The method for making a lightweight high capacity reinforced beam assembly according to claim 19, wherein said step of providing tendon means having two ends configured for secure anchoring includes providing a steel cable with at least one threaded end.
21. The method for making a lightweight high capacity reinforced beam assembly according to claim 19, wherein said step of providing tendon means having two ends configured for secure anchoring includes providing a steel cable with looped ends.
22. The method for making a lightweight high capacity reinforced beam assembly according to claim 21, wherein said step of providing bearing plate means for the purpose of securely attaching and anchoring said tendon means ends to said end spacer means and side member means is omitted and replaced with the step of providing cross bolt means for the purpose of securely attaching and anchoring said tendon means ends to said side member means only.
23. The method for making a lightweight high capacity reinforced beam assembly according to claim 22, wherein said step of providing central spacer means and end spacer means for the purpose of spacing apart said side beam member means is omitted and is replaced by the step of providing a central floating beam member means and triangular end spacer means for the purpose of supporting a load force and spacing apart said side beam member means.
24. A solid precast high capacity reinforced beam assembly comprising:
(a) a solid beam member means;
(b) a centrally located curved hollow sheath means located within said solid beam member means;
(c) tendon means having two ends configured for secure anchoring; and
(e) bearing plate means located on the ends of said beam member means, located in the upper one-half portion of the end of said beam member means, for the purpose of securely attaching and anchoring said tendon means, whereby said tendon is placed within said sheath and curved downward to about the lower one-third of said beam member and securely anchored to said bearing plates such that said beam member may be post-tensioned and thereby capable of more rapid manufacture.
25. The solid precast high capacity reinforced beam assembly according to claim 24, wherein said solid beam member is constructed of precast concrete.
26. The solid precast high capacity reinforced beam assembly according to claim 24, wherein said hollow sheath means includes a corrosion inhibitor material.
27. The solid precast high capacity reinforced beam assembly according to claim 24, wherein the ends of said tendon are anchored and secured to said bearing plates by tendon anchoring means.
29. The solid precast high capacity reinforced beam assembly according to claim 24, wherein said tendon means includes a steel cable or carbon fiber tendon.
30. The solid precast high capacity reinforced beam assembly according to claim 27, wherein said tendo n ancho r means includes conventional cable grippers and anchor end plates or barrels.
Description
BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a new and improved lightweight high load capacity reinforced beam and method of making it. More particularly, the present invention relates to a lightweight reinforced beam which would utilize a tendon system to provide tension on a rigid panel structural frame made from wood, wood composite, plastic or other material. An alternative embodiment uses a post tensioning tendon system to provide tension on a precast form made from a castable material such as concrete. This shielded tendon, made from steel, carbon fiber or similar materials, will resist a load imposed on the reinforced beam and will support a large load relative to the weight of the tendon and beam.

[0003] 2. Description of the Related Art

[0004] Increased pressure on natural resources, environmental concerns over the depletion of forests, high energy and labor costs, and an increasing demand for affordable housing and other buildings are requiring more efficient means for providing structurally sound building materials utilizing less material from natural resources such as trees and less manpower for construction. In many instances, utilizing lightweight, high load bearing reinforced beams in place of conventional solid beams would reduce man-hours and equipment demands for use in construction.

[0005] Conventional solid beams, when simply supported, utilize only a small percentage of the beam's material to resist the imposed load resting upon it. Most of the load rests on the center of the beam, where the beam is most likely to fail under the imposed load.

[0006] A high load capacity reinforced beam utilizing a pre-stressed tendon to bear the load at the point of greatest demand would allow for reinforcement of the beam at that point most likely to fail under the imposed load.

[0007] Such an invention could be easily adapted to components consisting of a number of different materials readily available in any given region without the need for expensive or customized adaptors or high transportation costs. In addition, the components of reinforced beams could be specifically manufactured for building codes in regions where likelihood of earthquakes or other natural disasters may dictate a specific requirement of building materials.

[0008] Prestressed and reinforced beams in industry have been in use for a wide variety of applications, and is well known. The most commonly used prestressed, reinforced beams are made from concrete using steel cables or strands. Essentially, a cable is used to stress a concrete beam which adds strength to the beam. The cable may be tensioned prior to the casting operation or a shielded cable may be tensioned after the casting operation.

[0009] The benefits of reinforced beams designed for use construction are well known. Examples of different types and kinds of arrangements and techniques for manufacturing reinforced beams are disclosed in U.S. Pat. Nos. 6,158,184, 5,934,835, 5,509,759, and 4,307,550.

[0010] Reinforced structures for building purposes are generally known in the prior art. Such a device is described in U.S. Pat. No. 6,158,184. The claimed device comprises a lateral force resisting system which is held together by a rigid structural panel. The addition of the internal system reinforces the structure of wooden buildings against lateral force.

[0011] This novel invention, is meant to resist lateral forces placed on wooden building structures from such occurrences as earthquakes and high winds which generate lateral forces upon those wooden structures. It does not, however, provide reinforcement for vertical forces such as gravity placed upon the structure.

[0012] Furthermore, this inventive device utilizes wood for construction of the internal reinforcement system to supplement shear wall construction and is not intended to reduce beam weight or consumption of materials in construction.

[0013] Therefore, it would be highly desirable to have a new and improved lightweight high load capacity reinforced beam and method of making same which would reduce the weight of conventional solid beams used to resist vertical forces and allow reduced manpower and equipment necessary for the placement of such beams during construction.

[0014] Moreover, it would be highly desirable to have a lightweight high load capacity reinforced beam that would reduce the demand on trees, be economical to manufacture and transport and be readily adapted to a variety of sizes, materials and uses.

[0015] The device described in U.S. Pat. No. 5,934,835 addresses the problem of providing for vertical stress in a prestressed beam. This unique invention uses a solid pre-cast prestressed concrete foundation pile. The device utilizes a single prestressing strand located on the longitudinal center axis. The prestressing strand is tensioned prior to casting the cement pile around the prestressed strand.

[0016] The use of a pre-tensioned strand incorporated into the structure during the pouring of the cement into the mold requires that the cement must be fully cured before the prestressed strand is released. The process from pouring to complete curing slows the manufacturing time.

[0017] Therefore, it would be highly desirable to have a new and improved device and method for making same for a high load capacity reinforced beam which would allow post-tensioning of a shielded cable allowing for removal of the forming mold in a shorter period of time thus shortening manufacture time.

[0018] U.S. Pat. No. 4,307,550 also describes a device that utilizes a pre-tensioned strand incorporated into the structure prior to molding of the cement structure around the strand. Again, the process is lengthened due to the necessity of waiting for complete curing of the cement prior to release of the pre-tensioned strand.

[0019] Therefore, it would be highly desirable to have a new and improved device and method for making same for a high load capacity reinforced beam which would allow post-tensioning of a shielded cable allowing for removal of the forming mold in a shorter period of time thus shortening manufacture time.

SUMMARY OF THE INVENTION

[0020] Therefore, the present invention relates to a lightweight reinforced beam which would utilize a tendon system to provide tension on a rigid panel structural frame made from wood, wood composite, plastic or other material. An alternative embodiment uses a tendon system to provide tension on a precast form made from a castable material such as concrete by post tensioning a shielded tendon. This tendon, made from steel, carbon fiber or similar materials, will resist a load imposed on the reinforced beam and will support a large load relative to the weight of the tendon.

[0021] It is a further object of the present invention to provide such a new and improved device and method for making same, for a lightweight reinforced beam that would reduce the manpower and equipment necessary for placement and handling and transporting of such a beam.

[0022] It is a further object of the present invention to provide such a new and improved device and method for making same, for a lightweight reinforced beam, which could be made in such a manner as to be easy and inexpensive to manufacture from a variety of materials and in a variety of lengths and sizes so as to be useful in a number of different load bearing situations.

[0023] It is yet a further object of the present invention to provide such a new and improved device and method for making same, for a lightweight reinforced beam, which would also allow for post-tensioning of a shielded tendon thus shortening the length of time required for manufacture of the structure.

[0024] It is yet a further object of the present invention to provide such a new and improved device and method for making same, for a lightweight reinforced beam, which would bear an equal or greater load than conventional solid beams at the point of greatest load demand thus providing for a safe, economical alternative to conventional solid beams for construction purposes.

[0025] Briefly, the above and further objects of the present invention are realized by providing a new and improved lightweight reinforced beam and method of making it. More particularly, the present invention relates to a lightweight reinforced beam system which uses standard commonly available materials to construct a rigid panel structural frame and an internal tendon which is post-tensioned. This post-tensioned tendon resists a load imposed in the center of the tendon. This allows a large load to be supported in comparison to the physical weight of that cable.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above mentioned and other objects and features of this invention and the manner of attaining them will become apparent, and the invention itself will be best understood by reference to the following description of the embodiment of the invention in conjunction with the accompanying drawings, wherein:

[0027]FIG. 1 is a side elevational view of a conventional prior art solid beam;

[0028]FIG. 2a is a longitudinal cross-sectional view of one embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0029]FIG. 2b is a bottom view of one embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0030]FIG. 2c is a vertical cross-sectional view of one embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0031]FIG. 2d is a top view of one embodiment of the lightweight high load capacity reinforced beam constructed in accordance with the present invention;

[0032]FIG. 2e is a side elevational view of one embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0033]FIG. 3a is a longitudinal cross-sectional view of a second embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0034]FIG. 3b is a bottom view of a second embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0035]FIG. 3c is a top view of a second embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0036]FIG. 3d is a side elevational view of a second embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0037]FIG. 4a is a longitudinal cross-sectional view of a third embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0038]FIG. 4b is a bottom view of a third embodiment of the lightweight high load capacity reinforced beam constructed in accordance with the present invention;

[0039]FIG. 4c is a vertical cross-sectional view of a third embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0040]FIG. 4d is a side elevational view of a third embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0041]FIG. 4e is a top view of a third embodiment of the lightweight high load capacity reinforced beam, constructed in accordance with the present invention;

[0042]FIG. 5a is a longitudinal cross-sectional view of a conventional prior art solid cement beam with pretensioned strand;

[0043]FIG. 5b is a vertical cross-sectional view of a conventional prior art solid cement beam with pretensioned strand;

[0044]FIG. 6a is a longitudinal cross sectional view of another embodiment of the high load capacity reinforced beam, constructed in accordance with the present invention utilizing a shielded, post tensioned tendon;

[0045]FIG. 6b is a vertical cross-sectional view of another embodiment of the high load capacity reinforced beam, constructed in accordance with the present invention utilizing a shielded, post tensioned tendon;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Referring now to the drawings, and more particularly to FIG. 1 thereof, there is shown a typical prior art conventional solid beamlO composed of standard metal or wood with simple supports 12 and 14 at either end of the beam. This conventional solid beam10 is shown with a load F on the beam's center. As the load is applied, point A is in tension and point B is being compressed. As the load F is increased, failure of the beam will occur at point A or B or both depending upon the composition of the material.

[0047]FIG. 2a depicts a longitudinal cross sectional view of one embodiment of the novel lightweight high load capacity reinforced beam constructed in accordance with the present invention. As shown, the frame of the beam assembly 20 is comprised of a top spacer member 22, a center spacer member 24 with center bearing plate 48 and end spacer members 26 and 28. The frame of the beam assembly 20 may be composed of any number of different materials which may include but are not limited to wood, wood composite, plastic or other material. A reinforcement assembly 30 is comprised of a tendon 32 that may be made from any number of materials including but not limited to a steel, carbon fiber or similar materials. Swaged threaded stud ends 34 and 36 are mounted to either end of the tendon 32. The threaded portions 38 and 42 of the swaged threaded stud ends 34 and 36 extend through the end bearing plates 44 and 46 on the distal ends of the beam assembly 20 and are secured by means of retaining adjusting nuts 52 and 54. The end bearing plates 44 and 46 are shown as protruding from the ends of the beam assembly 20, however, the end bearing plates 44 and 46 can be embedded flush in the beam assembly 20. Increased tension on the retaining adjusting nuts 52 and 54 allow for prestressing the beam assembly 20 against an imposed load F. This prestressing of the beam assembly 20 improves the load capability of the beam assembly 20 and decreases deflection of the beam assembly 20 when loaded. Internal diagonal spacer members 56 and 58 are positioned below the tendon 32. These internal diagonal spacer members 56 and 58 serve to maintain the structural integrity of the beam assembly 20 and help direct the compressive forces of the load F to the center of the tendon 32. A cross-sectional view 2C of the beam assembly 20 is further illustrated in FIG. 2c.

[0048] Referring now to FIG. 2b, there is shown a bottom view of the beam assembly 20 constructed in accordance with the present invention. This view clearly illustrates the center bearing plate 48 and end spacer members 26 and 28. The exposed tendon 32 may be seen between the internal diagonal spacer members 56 and 58. The side beam elements 62 and 64 are located at either end of the beam assembly 20. The threaded portions 38 and 42 extend through the end bearing plates 44 and 46 on the distal ends of the beam assembly 20 and are secured by means of retaining adjusting nuts 52 and 54.

[0049]FIG. 2c is a vertical cross sectional view of one embodiment of the novel lightweight high load capacity reinforced beam constructed in accordance with the present invention. The top spacer member 22 and the internal diagonal spacer member 56 are seen located between the side beam elements 62 and 64. The cross section of the tendon 32 is located just above the internal diagonal spacer member 56.

[0050] Referring to FIG. 2d, a top view of one embodiment of the novel lightweight high load capacity reinforced beam constructed in accordance with the present invention is illustrated. The end spacer members 26 and 28 of the beam assembly 20 are located at either end of the top spacer member 22. The threaded portions 38 and 42 extend through the end bearing plates 44 and 46 on the distal ends of the side beam elements 62 and 64 and are secured by means of retaining adjusting nuts 52 and 54.

[0051]FIG. 2e is a side elevational view of one embodiment of the novel lightweight high load capacity reinforced beam constructed in accordance with the present invention. A multiplicity of flush or recessed fasteners is represented by one flush or recessed fasteners 66 which secure the side beam element 64 to the beam assembly 20. The threaded portions 38 and 42 extend through the end bearing plates 44 and 46 on the distal ends of the beam assembly 20 and are secured by means of retaining adjusting nuts 52 and 54.

[0052]FIG. 3a depicts a longitudinal cross sectional view of an alternative embodiment beam assembly 80 constructed in accordance with the present invention. As shown, the frame of the beam assembly 80 is comprised of a top spacer member 82, a center spacer member 84 with center bearing plate 108 and end spacer members 86 and 88. A reinforcement assembly 90 is comprised of a tendon 92 with looped end portions 95 and 97. Threaded portions 98 and 102 are mounted to either end of the tendon 92 by means of turn buckle jaw ends 94 and 96 which are attached to the looped end portions 95 and 97 of the tendon 92. The looped end portions 95 and 97 are secured by means of collars 99 and 103. The threaded portions 98 and 102 extend through the end bearing plates 104 and 106 on the distal ends of the alternative embodiment of the beam assembly 80 and are secured by means of retaining adjusting nuts 112 and 114. Again, increased tension on the retaining adjusting nuts 112 and 114 allow for prestressing the alternative embodiment of the beam assembly 80 against an imposed load F. Internal diagonal spacer members 116 and 118 are positioned below the tendon 92. These internal diagonal spacer members 116 and 118 serve to maintain the structural integrity of the alternative embodiment of the beam assembly 80 and help direct the compressive forces of the load F to the center of the tendon 92.

[0053] Referring now to FIG. 3b, there is shown a bottom view of the alternative embodiment beam assembly 80 constructed in accordance with the present invention. This view clearly illustrates the center bearing plate 108 and end spacer members 86 and 88. The exposed tendon 92 may be seen between the internal diagonal spacer members 116 and 118 located between the side beam elements 122 and 124 of the alternative embodiment of the beam assembly 80. The threaded portions 98 and 102 extend through the end bearing plates 104 and 106 on the distal ends of the alternative embodiment of the beam assembly 80 and are secured by means of retaining adjusting nuts 112 and 114.

[0054] Referring to FIG. 3c, a top view of an alternative embodiment beam assembly 80 constructed in accordance with the present invention is illustrated. The side beam elements 122 and 124 of the alternative embodiment of the beam assembly 80 are located on either side of the either side of the center spacer member 84 and the end spacer members 86 and 88. The threaded portions 98 and 102 extend through the end bearing plates 104 and 106 on the distal ends of the beam assembly 80 and are secured by means of retaining adjusting nuts 112 and 114.

[0055]FIG. 3d is a side elevational view of the alternative embodiment beam assembly 80 constructed in accordance with the present invention. A multiplicity of flush or recessed fasteners as represented by one flush or recessed fastener 126 secure the side beam element 124. The threaded portions 98 and 102 extend through the end bearing plates 104 and 106 on the distal ends of the alternative embodiment beam assembly 80 and are secured by means of retaining adjusting nuts 112 and 114.

[0056] While FIG. 2 and FIG. 3 depict beam assemblies constructed in accordance with the present invention, and both of these embodiments show tendons which are adjustable at both ends, additionally, it should be noted that in both the beam assemblies of FIG. 2 and FIG. 3, the user or maker of the beam assembly needs to only have one end of the tendon to be adjustable. Therefore, alternatively, in both of the embodiments depicted in FIGS. 2 and 3, one end of the tendon could be fixed and the opposite end of the same tendon would be adjustable.

[0057]FIG. 4a depicts a longitudinal cross sectional view of an alternative embodiment beam assembly 140 constructed in accordance with the present invention. The alternative embodiment beam assembly 140 consists of two lower diagonal beam elements 144 and 146 that are attached to side beam element 148. Looped portions 156 and 158 of the tendon 154 are secured by means of collars 162 and 164. The looped portions 156 and 158 are attached to the alternative embodiment beam assembly 140 by means of cross-bolts 166 and 168. A floating top beam member 142 rests on the tendon 154. Increased load F on the floating top beam member 142 increases the tension on the tendon 154 thus placing increased stress on the alternative embodiment of the beam assembly 140 as the imposed load F increases. Internal diagonal spacer members 144 and 146 are positioned below the tendon 152. A cross section of the alternative embodiment beam assembly 140 is illustrated by FIG. 4c.

[0058] Referring now to FIG. 4b, there is shown a bottom view of the alternative embodiment beam assembly 140 constructed in accordance with the present invention. This view clearly illustrates the lower diagonal beam elements 144 and 146. The exposed tendon 154 as well as a portion of the floating top beam member 142 may be seen between the lower diagonal beam elements 144 and 146 and the side beam elements 148 and 152.

[0059]FIG. 4c is a vertical cross sectional view of the alternative embodiment beam assembly 140 constructed in accordance with the present invention. The floating top beam member 142 is seen as it rests on the tendon 154. The lower diagonal beam element 146 is located between the side beam elements 148 and 152.

[0060]FIG. 4d is a side elevational view of the alternative embodiment beam assembly 140 constructed in accordance with the present invention. A multiplicity of flush or recessed fasteners as represented by one flush or recessed fastener 172 secure the side beam element 152. The top portion of the floating top beam member 142 is seen above the side beam element 152 where load F is imposed. In all cases it should be understood that load F could also be a distributed load, rather than a point load as shown here in all examples, embodiments and figures.

[0061] Referring to FIG. 4e, a top view of an alternative embodiment beam assembly 140 constructed in accordance with the present invention is illustrated. The top of the floating top beam member 142 is located between the side beam elements 148 and 152. A portion of the looped portions of tendon 156 and 158 are illustrated on either end of the floating top beam member 142. These looped portions of tendon 156 and 158 are secured to the side beam elements 148 and 152 by means of cross-bolts 166 and 168.

[0062] Referring now to FIG. 5a, there is shown a typical prior art conventional solid beam 200 composed of precast, pre-tensioned concrete. This conventional solid beam 200 is shown with a slight crown of the beam member 202 caused by release of the tension on a prestressed cable 204. The cable is secured on each end of the beam member 202 by means of tendon anchors 210 and 212 after the cable is threaded through bearing plates 206 and 208. A corrosion inhibitor system may be used to protect the cable and is common practice in the industry. This prior art may also be constructed with a shielded cable which is then post-stressed. During loading of this prior art conventional solid beam 200, the beam deflects downward, removing the crowning effect. A cross-sectional view of the conventional solid beam 200 is illustrated by FIG. 5b.

[0063]FIG. 5b is a vertical cross sectional view of a cement beam member 202 with pretensioned cable strand 204.

[0064] Referring to FIG. 6a, a longitudinal cross sectional view of an alternative embodiment of a solid reinforced beam 220 constructed in accordance with the present invention which illustrates the tendon 224 shielded by a tendon sheath or tendon channel bore 225. The ends of the tendon 224 are held in place by tendon anchors 230 and 232 after the tendon 224 is threaded through bearing plates 226 and 228 after post-tensioning of the tendon 224. Although the illustration indicates that the bearing plates 226 and 228 are protruding from the ends of the solid reinforced beam 220, they may be imbedded flush in the ends of the beam member 222. This beam member 222 may be composed of any number of castable materials which may include but is not limited to concrete.

[0065] During the post tensioning of the tendon 224, the beam member 222 is crowned upward as illustrated in FIG. 6a. During loading of the beam, the beam member 222 deflects downward, removing the “crowning effect”. As the load is applied, the tendon 224 increases the prestress load and compensates for the increase beam loading by increasing the prestress in the bottom area of the beam member 222.

[0066]FIG. 6b is a vertical cross sectional view of a beam member 222 with posttensioned tendon 224 shielded by a tendon sheath or tendon channel bore 225.

[0067] This novel alternative embodiment of a solid reinforced beam 220 can be posttensioned, which allows removal from the form sooner than a pretensioned beam. The novel alternative embodiment of a solid reinforced beam 220 also compensates for additional load by increasing the tension to the cable as the load is applied to the beam. This allows a flatter installation of the alternative embodiment of a solid reinforced beam 220 and less deflection of the alternative embodiment of a solid reinforced beam 220 during loading.

[0068] It should be understood, however, that even though these numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, chemistry and arrangement of parts within the principal of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7748180 *Jun 23, 2006Jul 6, 2010Plavidal Richard WJoist stiffening system
US8443572Jun 23, 2010May 21, 2013S2 Holdings Pty LimitedBuilding methods
US8607528 *Jun 23, 2010Dec 17, 2013Murray EllenBuilding methods
US20100257813 *Jun 23, 2010Oct 14, 2010Murray EllenBuilding Methods
US20110232216 *Feb 22, 2011Sep 29, 2011Pacific Bearing CompanyBeam having internal tensioning and methods
US20120180407 *Aug 18, 2011Jul 19, 2012Rees Kyle JRoof truss kit to enable support of solar panels on roof structures
Classifications
U.S. Classification52/633, 52/650.1, 52/223.8, 52/638, 52/745.19
International ClassificationE04C5/08, E04C3/02, E04C3/18, E04C3/28
Cooperative ClassificationE04C3/18, E04C3/02, E04C5/085, E04C2003/023, E04C3/185, E04C3/28
European ClassificationE04C5/08A, E04C3/28, E04C3/02, E04C3/18, E04C3/18B
Legal Events
DateCodeEventDescription
Aug 29, 2001ASAssignment
Owner name: MECHANICAL SOLUTIONS, INC., CALIFORNIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:RATLIFF, FRANK W.;REEL/FRAME:012115/0903
Effective date: 20010819