Abstract
A buckling resistant spring clad bar (BRSCB) assembly is described. The BRSCB assembly includes a plurality of bars arranged to form a perimeter, each of the plurality of bars having a top end and a bottom end. A plurality of springs are provided, wherein at least one of the plurality of springs is wrapped around each of the plurality of bars. A diameter of the at least one of the plurality of spring is greater than a diameter of the each of the plurality of bars. The at least one of the plurality of springs is wrapped around each of the plurality of bars in close contact to provide buckling resistance against a load applied over each of the plurality of bars.
Claims
1. A buckling resistant spring clad bar (BRSCB) assembly comprising: a plurality of bars arranged to form a perimeter, each of the plurality of bars having a top end and a bottom end; a plurality of lateral restraint elements, each lateral restraint element wound in the shape of a spring; wherein at least one of the plurality of lateral restraint element is wrapped around each of the plurality of bars; wherein a diameter of the at least one of the plurality of lateral restraint element is greater than a diameter of the each of the plurality of bars; and wherein the at least one of the plurality of lateral restraint element is wrapped around each of the plurality of bars in close contact to provide a substantially uniform lateral restraint against buckling along the length of each of the plurality of bars against a load applied over each of the plurality of bars and cause deformation of the plurality of bars with multiple curvatures.
2. The BRSCB assembly of claim 1, further including: a plurality of peripheral ties disposed along a plurality of locations along a length of the plurality of bars, between the top end and the bottom end, the plurality of peripheral ties bounding the perimeter and securely tying the plurality of bars.
3. The BRSCB assembly of claim 1, further including: at least one spring tie disposed along a length of the plurality of bars, between the top end and the bottom end, the at least one spring tie bounding the perimeter and securely tying the plurality bars.
4. The BRSCB assembly of claim 3, further including: a plurality of spring ties disposed along a length of the plurality of bars, between the top end and the bottom end, the plurality of spring tie bounding the perimeter and securely tying the plurality bars.
5. The BRSCB assembly of claim 4, wherein, at least one of the plurality of spring ties is a spring wound in a clockwise direction and at least another one of the plurality of spring ties is a spring would in an anticlockwise direction.
6. The BRSCB assembly of claim 3, wherein, the spring tie is a spring wound in one direction, either clockwise direction or anticlockwise direction.
7. The BRSCB assembly of claim 1, wherein, a plurality of lateral restraint elements are disposed about each of the bars.
8. The BRSCB assembly of claim 7, wherein, the plurality of lateral restraint elements are wound in one direction, either clockwise direction or anticlockwise direction.
9. The BRSCB assembly of claim 7, wherein, at least one of the plurality of lateral restraint elements is wound in a clockwise direction and at least another one of the plurality of lateral constraining element is wound in an anticlockwise direction.
10. The BRSCB assembly of claim 9, wherein, at least one spring tie disposed along a length of the plurality of bars, between the top end and the bottom end, the at least one spring tie bounding the perimeter and securely tying the plurality bars.
11. The BRSCB assembly of claim 9, wherein, the at least one of the plurality of lateral restraint elements wound in the clockwise direction and the at least another one of the plurality of lateral constraining element wound in the anticlockwise direction are interposed with each other.
12. The BRSCB assembly of claim 1, wherein the at least one of the plurality of lateral restraint element wrapped around each of the plurality of bars is held in place without end grips.
13. A buckling resistant spring clad bar (BRSCB) assembly comprising: a bar having a top end and a bottom end; a spring; the spring wrapped around the bar, wherein a diameter of the spring is greater than a diameter of the bar; a sleeve surrounding the bar and the spring, the sleeve spaced apart from the bar and the spring; a first end grip disposed about the top end of the bar and coupled to the bar and the spring, wherein a gap is disposed between the end of the sleeve and the first end grip about the top end of the bar to permit vertical movement of the bar; and a second end grip disposed about the bottom end of the bar and coupled to the bar and the spring, wherein another gap is disposed between another end of the sleeve and the second end grip about the bottom end of the bar to permit vertical movement of the bar.
14. The BRSCB assembly of claim 13, wherein, a plurality of springs are disposed about the bar.
15. The BRSCB assembly of claim 14, wherein, the plurality of springs are wound in one direction, either clockwise direction or anticlockwise direction.
16. The BRSCB assembly of claim 14, wherein, at least one of the plurality of springs is wound in a clockwise direction and at least another one of the plurality of springs is wound in an anticlockwise direction.
17. The BRSCB assembly of claim 13, wherein, the sleeve includes a plurality of perforations along a length of the sleeve, to permit concrete or grout to flow into the sleeve.
18. The BRSCB assembly of claim 13, wherein, a plurality of bars with at least one spring wrapped around each of the bar is disposed inside the sleeve.
19. The BRSCB assembly of claim 18, wherein, a plurality of springs are wrapped around each of the bar.
20. The BRSCB assembly of claim 19, wherein, the plurality of springs are wound in one direction, either clockwise direction or anticlockwise direction.
21. The BRSCB assembly of claim 19, wherein, at least one of the plurality of springs is wound in a clockwise direction and at least another one of the plurality of springs is wound in an anticlockwise direction.
22. A buckling resistant spring clad bar (BRSCB) assembly comprising: a plurality of bars arranged to form a perimeter, each of the plurality of bars having a top end and a bottom end; and a plurality of spring ties disposed along a length of the plurality of bars, between the top end and the bottom end, the plurality of spring ties bounding the perimeter and securely tying the plurality bars, wherein the plurality of spring ties are wound in the shape of a spring, wherein, at least one of the plurality of spring ties is a spring wound in a clockwise direction and at least another one of the plurality of spring ties is another spring wound in an anticlockwise direction.
23. The BRSCB assembly of claim 22, further including: a plurality of lateral restraint elements, each lateral restraint element wound in the shape of a spring; wherein, a plurality of the lateral restraint elements are disposed about each of the plurality of bars; and wherein, at least one of the plurality of lateral restraint element is wound in a clockwise direction and at least another one of the plurality of lateral restraint element is wound in an anticlockwise direction.
24. The BRSCB assembly of claim 22, wherein the plurality of bars and the plurality of spring ties together are substantially surrounded by concrete.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
(2) FIG. 1a illustrates a single element having one-way spring in a BRSCB with grips at end, according to an embodiment herein;
(3) FIG. 1b illustrates a cage assembly of a one-way spring in a BRSCB with grips at end, according to an embodiment herein;
(4) FIG. 1c illustrates a single element having one-way spring in a BRSCB without grips at end, according to an embodiment herein;
(5) FIG. 1d illustrates a cage assembly of a one-way spring in a BRSCB without grips at end, according to an embodiment herein;
(6) FIG. 2a illustrates a concrete structure of a one-way spring in a BRSCB with grips at end, according to an embodiment herein;
(7) FIG. 2b illustrates a concrete structure of a one-way spring in a BRSCB without grips at end, according to an embodiment herein;
(8) FIG. 3a illustrates a single element having an opposing spring in a BRSCB, with grips at end, according to another embodiment herein;
(9) FIG. 3b illustrates a cage assembly of an opposing spring in a BRSCB with grips at end, according to another embodiment herein;
(10) FIG. 3c illustrates a single element having an opposing spring in a BRSCB, without grips at end, according to another embodiment herein;
(11) FIG. 4a illustrates a concrete structure of an opposing spring in a BRSCB without grips at end, according to another embodiment herein;
(12) FIG. 4b illustrates a concrete structure of an opposing spring in a BRSCB with grips at end, according to another embodiment herein;
(13) FIG. 4c illustrates a cage assembly of an opposing spring in a BRSCB, according to an embodiment herein;
(14) FIG. 5a illustrates a single element having one-way spring with sleeve in a BRSCB, according to an embodiment herein;
(15) FIG. 5b illustrates a single element having one-way spring with perforated sleeve in a BRSCB, according to an embodiment herein;
(16) FIG. 6a illustrates a single element having opposing spring with sleeve in a BRSCB, according to another embodiment herein;
(17) FIG. 6b illustrates a single element having opposing spring placed in a perforated sleeve, according to another embodiment herein;
(18) FIG. 7a illustrates perspective view of a single core having opposing spring placed in a sleeve, according to another embodiment herein;
(19) FIG. 7b illustrates perspective view of a multiple core having opposing spring placed in a sleeve, according to another embodiment herein;
(20) FIG. 8a illustrates a top view of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, according to another embodiment herein;
(21) FIG. 8b illustrates a side view of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, according to another embodiment herein;
(22) FIG. 9a illustrates a top view of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with one-way spring, according to another embodiment herein;
(23) FIG. 9b illustrates a side view of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with one-way spring, according to another embodiment herein;
(24) FIG. 10a illustrates a top view of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with opposing spring, according to another embodiment herein;
(25) FIG. 10b illustrates a side view of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with opposing spring, according to another embodiment herein; and
(26) FIG. 11 illustrates a comparison graph between conventional concrete and a BRSCB, according to an embodiment herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(27) The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
(28) As mentioned above, there is a need for a system to improve lateral confinement of compression system uniformly to withstand both compression and tension. Further, there is a need for a structure to improve ductility when embedded in reinforced concrete structure. The embodiments herein achieve this by providing a Buckling Resistant Spring Clad Bar (BRSCB) with either one-way spring or opposing spring on a bar. Referring now to the drawings, and more particularly to FIGS. 1 through 9, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
(29) According to an embodiment, a sleeve-spring clad core system (herein after BRSCB) to improve lateral confinement of compression system uniformly to withstand both compression and tension. The BRSCB comprises, a plurality of bar, a plurality of one-way spring, and a plurality of peripheral ties; wherein the bar is a confinable bar of any material; wherein the one-way spring wrapped around the bar; wherein the diameter of the one-way spring is greater than diameter of the bar; The BRSCB further comprises of a plurality of grips; wherein the grips are provided at least at both the end of the bar to hold the assembly firmly and to avoid end slippage of the one-way spring.
(30) According to an embodiment, the multiple BRSCB can be assembled as a cage of square or circular or any shaped column according to a structure requirement; wherein the structure comprises multiple bars, each cladded with one-way spring with or without grips placed on the circumference and in the body as desired for a given shape of column, securely tied with peripheral ties. Further, the BRSCB can be placed centrally to a sleeve with at least a gap between one-way spring and the sleeve of suitable material; wherein the gap is grouted to get the performance. Further, the sleeve can be either perforated sleeve or plain sleeve. The BRSCB formed with multiple bars and each wrapped with the one-way springs are housed in the sleeve with at least a gap.
(31) According to another embodiment, a BRSCB to improve lateral confinement of compression system uniformly to withstand both compression and tension. Further, the system is designed in such a way so as to improve ductility of the structure when embedded in reinforced concrete. The BRSCB comprises, a plurality of bar, a plurality of counter springs of same coil diameter, a plurality of grips, and a plurality of peripheral ties; wherein the bar is a confinable bar of any material; wherein the counter springs wrapped around bar; wherein the coil diameter of the spring is greater than diameter of the bar; wherein the grips are provided at least at both the end of the bar to hold the assembly firmly and to avoid slippage of the opposing springs; and wherein the bars are securely tied by the peripheral ties at multiple locations to maintain stability of the system.
(32) According to another embodiment, the BRSCB can be placed central to a sleeve with a gap between the opposing spring and the sleeve; wherein the gap is grouted to get the desired performance. Further, the BRSCB can also be formed with multiple bars and each wrapped with clockwise and anticlockwise opposing springs housed in the sleeve with at least gap.
(33) FIG. 1a illustrates a single element having one-way spring 100a in a BRSCB with grips at end, according to an embodiment. The single element of the BRSCB comprises a bar 103, a one-way spring 102 and an end grip 101; wherein the bar 103 is confinable bar of any material and is cladded with the one-way spring 102. The end grips 101 are provided at both ends of the bar 103, to hold assembly firmly to avoid end slippage. Optionally, intermediate grips are provided to connect the one-way spring and the bar to improve stiffness of the one-way spring.
(34) According to an embodiment, when compression load is applied on cage, each bar can receive a load that is proportional to its capacity. Under axial compression, spring can compress ahead of the bar and increase its capacity for confinement. As the pitch reduces, the capacity of the spring can restrain bar from lateral movement/buckling. Accordingly, the bar assumes multiple curvatures instead of a single profile. As a result, vertical capacity of bar increases, consequently its ability to sustain load increases. This feature results in improved ductility of the structure.
(35) FIG. 1b illustrates a cage assembly 100b of a one-way spring in a BRSCB with grips at end, according to an embodiment. The cage assembly comprises of multiple bars 103 that are connected together by a plurality of peripheral ties 104 at multiple locations to maintain stability of the system. The peripheral ties can securely tie the bars 103 to form the desired shape that includes but is not limited to circular column, square, rectangular and so on. Further, the multiple bars 103 can be placed on the circumference and in the cage body as desired for a given shape of column; wherein each bar 103 is wrapped/cladded with the one-way spring 102 using springs of diameter marginally more than the bar 103.
(36) FIG. 1c illustrates a single element having one-way spring 100c in a BRSCB without grips at end, according to an embodiment. The single element having one-way spring in the BRSCB can be assembled without grips at end. In this example, the diameter D of the one-way spring 102 is marginally larger than the diameter of the bar 103.
(37) FIG. 1d illustrates a cage assembly of a one-way spring 100d in a BRSCB without grips at end, according to an embodiment. The cage assembly of a one-way spring in the BRSCB can be assembled without grips at end.
(38) FIG. 2a illustrates a concrete structure of a one-way spring 200a in a BRSCB with grips at end, according to an embodiment. The concrete structure of a one-way spring in a BRSCB can be assembled with end grips 101. The cage assembly can be embedded in the reinforced concrete to improve the ductility and stability of the structure.
(39) FIG. 2b illustrates a concrete structure of a one-way spring in a BRSCB without grips at end, according to an embodiment. The concrete structure of a one-way spring in a BRSCB can be assembled without grips at end.
(40) FIG. 3a illustrates a single element having opposing spring 300a in a BRSCB with grips at end, according to another embodiment. The single element of the counter spring cladded compression system comprises a bar 103, an opposing spring and an end grip 101. The opposing spring comprises clockwise spring 301 and anticlockwise spring 302. One set of clockwise spring 301 and anticlockwise spring 302 is inserted from opposite sides and then the bar 103 is passed through to lock the springs. The springs are of same core diameter and pitch. This arrangement of inserting the bar avoids staggered arrangement. The end grips 101 are provided at both ends of the bar, to hold assembly firmly to avoid end slippage. Optionally, intermediate grips are provided to connect the opposing spring and the bar to improve stiffness of the opposing spring.
(41) FIG. 3b illustrates a cage assembly of an opposing spring 300b in a BRSCB with grips at end, according to another embodiment. The cage assembly comprises of multiple bars 103 that are connected together by a plurality of peripheral ties 104 at multiple locations to maintain stability of the system. The peripheral ties 104 are spaced apart and disposed at multiple locations along a length of the plurality of bars 103. Adjacent peripheral ties 104 in one example, are spaced apart by a distance “P”. In one example, the distance P may be of the order of about 3 inches to about 18 inches. The peripheral ties can securely tie the bars 103 to form the desired shape that includes but is not limited to circular column, square, rectangular and so on. In one example, the peripheral ties 104 may be formed using either a strip, cable, or a rod made of a metal or an alloy of metal. In one example, the peripheral ties may be formed using mild steel rod or high strength steel rod, based on the application. In some examples, high strength steel rod may have deformation patterns on the external surface to promote better bonding with concrete. In one example, the deformation patterns may be in the form of ribs over the surface of the rod. In one example, the peripheral ties 104 are wrapped around the bars 103. Further, the multiple bars 103 can be placed on the circumference and in the cage body as desired for a given shape of column; wherein each bar 103 is wrapped/cladded with the opposing spring (clockwise spring 301 and anti-clockwise spring 302) using springs of diameter marginally more than the bar 103.
(42) FIG. 3c illustrates a single element having opposing spring 300c in a BRSCB, without grips at end according to another embodiment. The single element having opposing spring in the BRSCB can be assembled without end grips. In this example, the diameter D1 of the clockwise spring 301 is marginally larger than the diameter of the bar 103. Also, the diameter D2 of the anticlockwise spring 302 is marginally larger than the diameter of the bar 103. In one example, the diameter D1 and D2 may be same. In another example, the diameter D1 and D2 may be different.
(43) FIG. 4a illustrates a concrete structure of an opposing spring 400a in a BRSCB without grips at end, according to another embodiment. The cage assembly can be embedded in the reinforced concrete to improve the ductility and stability of the structure.
(44) FIG. 4b illustrates a concrete structure of an opposing spring 400b in a BRSCB with grips at end, according to another embodiment. The concrete structure of an opposing spring in a BRSCB can be assembled with end grips 101.
(45) FIG. 4c illustrates a cage assembly 400c of an opposing spring in a BRSCB with a perforated sleeve, according to another embodiment. The single element of the bar 103 that is wrapped with the opposing spring (clockwise 301 and anticlockwise spring 302) can be embedded in a perforated sleeve 503. The perforated sleeve 503 may be of any material having hoop resistance according to the requirement. In one example, the perforated sleeve 503 may include a plurality of perforations 503a. The perforations 503a permit flow of concrete or grout into the sleeve 503. In one example, the perforations 503a may be of suitable shape and dimension to permit flow of concrete or grout into the sleeve. In some examples, the perforations 503a may be shaped as a circles or an ovals. In some examples, the perforations 503a may be a shaped as a rectangle opening or as an elongated slot. In some examples, the perforations 503a may be dimensioned with an opening area of about 0.1 square inches to about 6 square inches.
(46) The cage assembly 400c comprises of multiple bars 103 with sleeve 503 that are connected together by a plurality of peripheral ties 104 at multiple locations to maintain stability of the system. The peripheral ties 104 can securely tie the bars 103 with the sleeve 503 to form the desired shape that includes but is not limited to circular column, square, rectangular and so on. Further the multiple bars 103 with sleeve 503 can be placed on the circumference and in the cage body as desired for a given shape of column. As previously described, each bar 103 is wrapped/cladded with the opposing springs (301 & 302) using springs of diameter marginally more than the bar 103. As one skilled in the art appreciates, the cage assembly 400c can be embedded in the reinforced concrete to improve the ductility and stability of the structure.
(47) FIG. 5a illustrates a single element having one-way spring with sleeve 500a in a BRSCB, according to an embodiment. The single element of the bar 103 that is wrapped with the one-way spring 102 (either clockwise or anticlockwise spring) can be embedded in a sleeve 502 to improve the lateral restraining of bar. The sleeve may have a circular, square or rectangular cross-section. An allowable displacement 501 between end grip 101 and the sleeve 502 is also provided about the top end 503 of the bar 103, to permit vertical movement of the bar 103, along its length, in either direction. Another end grip 101 is disposed about a bottom end 504 of the bar 103. In one example, another allowable displacement 505 may be provided between the sleeve 502 and the end grip 101 disposed about the bottom end 504 of the bar 103. The end grip 101 is coupled to the spring 102 and the bar 103 about the top end 503 and the bottom end 504 of the bar 103.
(48) FIG. 5b illustrates a single element having one-way spring with perforated sleeve 500b in a BRSCB, according to an embodiment. The single element of the bar 103 that is wrapped with the one-way spring 102 can be embedded in a perforated sleeve 503. The perforated sleeve 503 may be of any material having hoop resistance according to the requirement. In one example, the perforated sleeve 503 may include a plurality of perforations 503a. The perforations 503a permit flow of concrete or grout into the sleeve 503. In one example, the perforations 503a may be of suitable shape and dimension to permit flow of concrete or grout into the sleeve. In some examples, the perforations 503a may be shaped as a circles or an ovals. In some examples, the perforations 503a may be a shaped as a rectangle opening or as an elongated slot. In some examples, the perforations 503a may be dimensioned with an opening area of about 0.1 square inches to about 6 square inches.
(49) FIG. 6a illustrates a single element having opposing springs with sleeve 600a in a BRSCB, according to an embodiment. The single element of the bar 103 that is wrapped with the opposing spring (clock-wise spring 301 and anticlockwise spring 302) can be embedded in a sleeve 502 to improve the structure stability. An allowable displacement 501 between end grip 101 and the sleeve is also provided.
(50) FIG. 6b illustrates a single element having opposing springs placed in a perforated sleeve 600b, according to another embodiment. The single element of the bar 103 that is wrapped with the opposing springs (clock-wise spring 301 and anticlockwise spring 302) can be embedded in a perforated sleeve 503. The perforated sleeve 503 may be of any material having hoop resistance according to the requirement. In one example, the perforated sleeve 503 may include a plurality of perforations 503a. The perforations 503a permit flow of concrete or grout into the sleeve 503. In one example, the perforations 503a may be of suitable shape and dimension to permit flow of concrete or grout into the sleeve. In some examples, the perforations 503a may be shaped as a circles or an ovals. In some examples, the perforations 503a may be a shaped as a rectangle opening or as an elongated slot. In some examples, the perforations 503a may be dimensioned with an opening area of about 0.1 square inches to about 6 square inches.
(51) FIG. 7a illustrates perspective view of a single element having opposing springs placed in a sleeve 700a, according to an embodiment. In between the sleeve and the single bar an allowable gap is provided. Each bar 102 is wrapped with the opposing springs (clock-wise spring 301 and anticlockwise spring 302). The gap is grouted to get the desired performance and reduce friction. In some cases, there may not be any requirement for the gap.
(52) FIG. 7b illustrates perspective view of a single rebar having opposing springs placed in a sleeve 700b, according to another embodiment. The multiple bars 103, each wrapped with the opposing springs (301 and 302) are also housed in the sleeve 502 for higher load carrying capacity and ductility improvement. The same can be implemented for the bar 103 each wrapped with one-way spring.
(53) FIG. 8a illustrates a top view 800a of a circular shape concrete structure of an opposing spring in a BRSCB, according to an embodiment. The top view of the circular shape concrete structure of an opposing spring in the BRSCB shows the bars 103. The bars are arranged in such a way to obtain the circular shape for the concrete structure.
(54) FIG. 8b illustrates a side view 800b of a circular shape concrete structure of an opposing spring in a BRSCB, according to an embodiment. In the circular shape concrete structure, the bars 103 are collectively wrapped with opposing (clockwise spring tie 301a and anticlockwise spring tie 302a) spring ties that are inserted into each other and placed at the periphery or the circumference of the cage assembly. The cage assembly is surrounded by concrete 105 of suitable strength, based on the application. In one example, no peripheral ties are used to confine the bars 103, as the opposing spring ties 301a and 302a provide the confinement for the bars 103. In one example, the bars 103 may be collectively wrapped with one of the spring tie (either clockwise spring tie 301a or anticlockwise spring tie 302a) placed at the periphery or circumference of the cage assembly. In one example, the spring tie may have a variable diameter, (for example, a tapered shaped spring tie), which may be used to configure a tapered column, varying in diameter, along the length of the bars.
(55) FIG. 9a illustrates a top view 900a of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with one-way spring 102, according to an embodiment. FIG. 9b illustrates a side view 900b of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with one-way spring 102, according to an embodiment. In the circular shape concrete structure, bar wrapped with one-way spiral spring 102, the bars 103 that are wrapped with opposing (clockwise spring tie 301a and anticlockwise spring tie 302a) spring ties are inserted into each other and placed at the periphery or the circumference of the cage assembly. In one example, no peripheral ties are used to confine the bars 103, as the opposing spring ties 301a and 302a provide the confinement for the bars 103.
(56) FIG. 10a illustrates a top view 1000a of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod wrapped with opposing spring, according to an embodiment. The top view of a concrete cage structure of an opposing spring in a BRSCB with multiple bars, with each bar 103 wrapped with opposing (clockwise 301 and anticlockwise 302) springs is shown. The bars 103 are collectively wrapped with opposing (clockwise spring tie 301a and anticlockwise spring tie 302a) spring ties arranged in such a way to obtain the circular shape for the concrete structure.
(57) FIG. 10b illustrates a side view 1000b of a concrete cage structure of an opposing spring in a BRSCB with multiple bar, each rod 103 wrapped with opposing spring (clockwise spring 301 and anticlockwise spring 302), according to an embodiment. In the circular shape concrete structure, each bar 103 wrapped with opposing spiral (clockwise spring 301 and anticlockwise spring 302) springs are collectively inserted into opposing spiral springs (clockwise spring tie 301a and anticlockwise spring tie 302a). The opposing spiral spring ties 301a and 302a are inserted into each other and placed at the periphery or the circumference of the cage assembly. In one example, no peripheral ties are used to confine the bars 103, as the opposing spring ties 301a and 302a provide the confinement for the bars 103.
(58) FIG. 11 illustrates a comparison graph 1100 between conventional concrete and a BRSCB according to an embodiment. The comparison graph between conventional concrete with bars and peripheral ties passively embedded in concrete and a Buckling Resistant Spring Clad Bar (BRSCB) with bar wrapped with opposing springs, passively embedded in concrete. A graphical representation between load and axial displacement can clearly shows the improvement in ductility of the structure. The load applied is in Kilo Newton and axial displacement that is measured is in mm. When the load is applied on the specimen, the axial displacement for a conventional reinforced concrete specimen with circular hoops/peripheral ties 901 increases and at one point onwards, it starts loosing capacity rapidly indicating reduced ductility. However, when the load is applied on the specimen, the axial displacement for a reinforced concrete specimen with opposing spring cladded bar & ties 902 shows stable increase in axial displacement without appreciable loss of capacity indicating appreciable improvement in ductility.
(59) In various examples described above, peripheral ties 104 are used. The peripheral ties 104 may be spaced apart and disposed at multiple locations along a length of the plurality of bars 103. Adjacent peripheral ties 104 in one example, are spaced apart by a distance “P”. In one example, the distance P may be of the order of about 3 inches to about 18 inches. The peripheral ties can securely tie the bars 103 (with or without a sleeve surrounding the bars 103) to form the desired shape that includes but is not limited to circular column, square, rectangular and so on. In one example, the peripheral ties 104 may be formed using either a strip, cable, or a rod made of high strength metal or an alloy of metal. In one example, the peripheral ties may be formed using high strength steel rod. In some examples, high strength steel rod may have deformation patterns on the external surface to promote better bonding with concrete. In one example, the peripheral ties 104 are wrapped around the bars 103.
(60) In some examples, the end grips described in one or more examples above may be formed of a metal or alloy of metal. In one example, the end grips may be a plate selectively welded to the bars so as to prevent slippage of the spring relative to the bar. In some examples, the end grips may be formed in the shape of a cylindrical ring, with a diameter greater than the diameter of the spring and selectively welded to the ends of the bars so as to prevent slippage of the spring relative to the bar. In some examples, the end grips may be made of metal or an alloy of metal that is crimped inside and configured to receive and clamp the bar and the spring at the ends of the bar. In some examples, ends of the spring may also be welded to the end grips. In some examples, ends of the spring may be welded to the bars. In some examples where the ends of the spring is welded to the bars, there may not be a need for an end grip at the end of the bars.
(61) In some examples, a plurality of one-way springs may be used to wrap around the bars 103, which are spaced apart (or phased apart) from each other along a length of the bars 103. For example, these one-way springs may all be either clockwise springs or anti-clockwise springs. In one example, the one-way springs may have different diameters, varying the gap between the bar and the spring, along the length of the bar.
(62) In some examples, a plurality of opposing springs may be used to wrap around the bars 103, which are spaced apart (or phased apart) from each other along a length of the bars 103. For example, these opposing springs may be a combination of a plurality of clockwise springs and a plurality of anti-clockwise springs. In one example, the opposing springs may have different diameters.
(63) In some examples, an implicit system may refer to an application where various example implementations of BRSCB described above is embedded in concrete. In some examples, an explicit system may refer to an application where various example implementations of BRSCB described above is not embedded in concrete. In some examples, the BRSCB described above wherein the springs wrapped around the bar will constrain the lateral buckling of the bar, for example, due to a seismic or earthquake event.
(64) The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
