Steel-concrete i-beam composite beam and bridge structure

Abstract

The present application relates to the technical fields of bridge engineering, and provides a steel-concrete I-beam combined beam and a bridge structure, the steel-concrete I-beam combined beam comprising a combined beam, an I-beam and a concrete panel, the combined beam being arranged on a fulcrum, the I-beam being connected to two sides of the combined beam, and the concrete panel covering the upper surfaces of the combined beam and the I-beam.The present application sets the combined beam in the steel-concrete I-beam combined beam to replace the existing steel beam, and the combined beam is subjected to overall stress to significantly enhance the lateral connection stiffness, and the combined beam can be industrially produced, has small construction difficulty and short construction period.In the process of old bridge reconstruction, the combined beam arranges the traditional multiple support systems on the pier, and is improved to only need to set the support at the position with good stress of the bridge pier, so that the upper and lower force transmission paths of the bridge are more explicit, the stress of the old bridge pier can be effectively relieved, the construction is convenient, and the construction cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge engineering, and in particular to a steel-concrete I-shaped composite beam and bridge structure. BACKGROUND

[0002] The steel-concrete composite structure is a structure that connects concrete and steel materials into a whole through connecting members such as shear studs, so that the two materials can bear force together, and can fully exert the respective advantages of the two materials. The I-shaped composite beam is widely used in small and medium span bridges due to its simplicity, agility and high efficiency.

[0003] The existing steel-concrete composite structure applied in bridges uses a steel cross beam as a main support connected with a steel longitudinal beam. A support needs to be arranged on the steel cross beam and at the bottom of each steel longitudinal beam, and the steel-concrete composite structure is arranged on a pier through the support.

[0004] Although this structure can be well applied in new bridges, if old bridge reconstruction is needed, the existing technology is difficult to improve the main beam bearing capacity without increasing the lower load; and in order to improve the stress of the lower structure of the old bridge, the lower structure of the old bridge needs to be reinforced, which has a high construction cost. SUMMARY

[0005] The present application provides a steel-concrete I-shaped composite beam and bridge structure to solve the above technical problems in the prior art, so as to achieve the purposes of high rigidity, good bearing capacity, short construction period, high production efficiency, low manufacturing cost, etc.

[0006] In order to achieve the above purposes, the first aspect of the present application provides a steel-concrete I-shaped composite beam, comprising:

[0007] A composite cross beam is arranged on the fulcrum;

[0008] An I-shaped longitudinal beam is connected on both sides of the composite cross beam;

[0009] A concrete panel covers the upper surfaces of the composite cross beam and the I-shaped longitudinal beam.

[0010] According to the steel-concrete I-shaped composite beam provided by the present application, the composite cross beam comprises a slot-shaped structure arranged at an angle and a I-shaped connecting joint;

[0011] The interior of the slot-shaped structure is provided with a partition, a shear stud and a steel reinforcement cage;

[0012] The two ends of the I-shaped connecting joint are connected with the I-shaped longitudinal beam, and the upper surface of the I-shaped connecting joint is provided with a shear stud.

[0013] According to the steel-concrete I-shaped composite beam provided by the present application, the interior of the slot-shaped structure is further provided with a stiffening rib.

[0014] The steel-concrete I-shaped composite beam provided by the present application is characterized in that the inner part of the groove-shaped structure is filled with micro-expansion concrete or shrinkage-compensating concrete.

[0015] The steel-concrete I-shaped composite beam provided by the present application is characterized in that the partition plate is provided with a plurality of holes and openings.

[0016] The steel reinforcement framework is arranged through the holes.

[0017] The openings are used for pouring and compacting the micro-expansion concrete or shrinkage-compensating concrete filled in the inner part of the groove-shaped structure.

[0018] The steel-concrete I-shaped composite beam provided by the present application is characterized in that the steel reinforcement framework comprises first steel bars and second steel bars.

[0019] The first steel bars are arranged through the partition plate.

[0020] The second steel bars are arranged around the first steel bars and extend out of the groove-shaped structure to be connected with the steel bars in the concrete panel.

[0021] The steel-concrete I-shaped composite beam provided by the present application is characterized in that the I-shaped connecting joint comprises an equal-width section and an outer widened section.

[0022] The outer widened section is fixedly connected with the I-shaped longitudinal beam.

[0023] The cross-sectional dimension of the outer widened section close to the equal-width section is greater than the cross-sectional dimension of the outer widened section close to the I-shaped longitudinal beam.

[0024] The steel-concrete I-shaped composite beam provided by the present application is characterized in that the I-shaped connecting joint comprises any one of the following forms.

[0025] The I-shaped connecting joint is an I-shaped steel.

[0026] The I-shaped connecting joint comprises upper flange plates and lower flange plates arranged in alignment, the upper flange plates and the lower flange plates being arranged on the upper and lower sides of the groove-shaped structure respectively, a web plate being arranged between the upper flange plates and the lower flange plates, and the web plate being arranged in alignment with the partition plate.

[0027] The steel-concrete I-shaped composite beam provided by the present application is characterized in that the composite cross beam is welded by a plurality of segments.

[0028] To achieve the above-mentioned purpose, the second aspect of the present application provides a bridge structure comprising the steel-concrete I-shaped composite beam according to any one of the above-mentioned aspects.

[0029] The steel-concrete I-shaped composite beam provided by the application has the advantages that the composite cross beam is arranged in the steel-concrete I-shaped composite beam to replace the existing steel cross beam, the lateral connecting stiffness of the composite cross beam is significantly enhanced by the overall stress of the composite cross beam, the composite cross beam can be industrially manufactured, the construction difficulty is small, and the construction period is short.

[0030] In the process of old bridge reconstruction, the composite cross beam arranges the traditional multiple support system on the pier, and is improved to only need to set the support at the position where the bridge pier is better in stress, so that the upper and lower force transmission paths of the bridge are more explicit, the bending shear stress of the old bridge pier can be effectively relieved, the construction is convenient, and the construction cost is low.

[0031] In the process of new bridge construction, the number and sectional size of the I-shaped longitudinal beam in the steel-concrete I-shaped composite beam are adjusted to improve the sectional bearing capacity, the stress of the lower structure of the bridge can be effectively improved, especially the case that the beam height is limited and the main beam bearing capacity needs to be improved can be effectively relieved, in addition, the composite cross beam can not be provided with a formwork when the micro-expansion concrete is internally poured, the construction is convenient, and the efficiency is high.

[0032] Further, the bridge structure provided by the application has all the advantages of the steel-concrete I-shaped composite beam. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is a structural schematic view of the steel-concrete I-shaped composite beam provided by the application;

[0035] Figure 2 is a planar layout view of the composite cross beam in the steel-concrete I-shaped composite beam provided by the application;

[0036] Figure 3 is Figure 2 is a sectional view along the C-C line in the figure;

[0037] Figure 4 is Figure 2 is a sectional view along the D-D line in the figure;

[0038] Figure 5 is a side view of the composite cross beam in the steel-concrete I-shaped composite beam provided by the application;

[0039] Figure 6 is Figure 5 is a sectional view along the B-B line in the figure;

[0040] Figure 7 is a cross-sectional view of a channel-shaped steel in a steel-concrete composite I-beam provided by the present application;

[0041] Figure 8 is a schematic view of a steel reinforcement arrangement in a steel-concrete composite I-beam provided by the present application;

[0042] Figure 9 is a schematic view of a bridge structure provided by the present application;

[0043] Figure 10 is Figure 9 is a cross-sectional view along line A-A.

[0044] Reference signs:

[0045] 1, composite beam; 11, channel-shaped structure; 111, notch; 12, I-shaped connecting joint; 121, equal-width section; 122, outer widened section; 13, partition plate; 131, hole; 132, first opening; 133, second opening; 14, first shear pin; 15, second shear pin; 16, section weld; 17, first steel reinforcement; 18, second steel reinforcement; 19, micro-expansive concrete; 2, I-shaped longitudinal beam; 3, concrete panel; 4, support; 5, pier; 6, bridge pier. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0047] In the description of the application, it should be noted that, unless explicitly defined and limited, the terms "mounting", "connection", "linking" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal connection of two elements. "First", "second", "third", "fourth" do not represent any sequence relationship, but only distinguish for convenience of description. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] Please refer to Figures 1 to 10 The embodiments of the present application are described. It should be understood that the following description is only a schematic embodiment of the present application, and does not constitute any limitation on the present application.

[0049] Please refer to Figure 1The steel-concrete I-beam combination provided by the present application comprises a combination beam 1, an I-beam 2 and a concrete panel 3, the combination beam 1 is arranged at a support point such as a pier 6 or an abutment, the I-beam 2 is connected to the combination beam 1 as a main beam, and the concrete panel 3 covers the upper surfaces of the combination beam 1 and the I-beam 2 to form an integral stress structure.

[0050] It can be understood that the present application arranges the combination beam 1 in the steel-concrete I-beam combination to replace the existing steel beam, and the combination beam 1 has significantly enhanced lateral connection stiffness through integral stress, and the combination beam can be industrially manufactured, has small construction difficulty and short construction period.

[0051] As shown in Figure 2 , specifically, the combination beam 1 comprises a groove structure 11 arranged at an angle and a I-shaped connecting joint 12, and the groove structure 11 and the I-shaped connecting joint 12 can be welded and fixed; in order to facilitate construction, the groove structure 11 and the I-shaped connecting joint 12 can also be integrally formed. The groove structure 11 mainly plays a supporting role as a main beam, and the I-shaped connecting joint 12 can act as a connecting joint for connecting the I-beam 2, and the I-beam 2 and the I-shaped connecting joint 12 can be fixed by welding or bolt connection.

[0052] Since the piers 6 are not arranged along a straight line, the angle between the groove structure 11 and the I-shaped connecting joint 12 can be between 0° and 90°, and the specific angle is determined according to the arrangement form of the piers 6 in the bridge, for example, if two adjacent piers 6 are arranged in parallel on the same straight line, the angle between the groove structure 11 and the I-shaped connecting joint 12 can be 90°, that is, the groove structure 11 and the I-shaped connecting joint 12 can be arranged perpendicularly.

[0053] In some embodiments, the groove structure 11 can be a groove-shaped steel, and the groove structure 11 can also be composed of two steel plates arranged in parallel.

[0054] A partition plate 13, a first shear pin 14 and a steel reinforcement framework are arranged in the groove structure 11. The I-shaped connecting joints 12 are arranged at intervals on the groove structure 11 to form a groove 111 on the groove structure 11 between two adjacent I-shaped connecting joints 12, as shown in Figure 2 .

[0055] As shown in Figure 3 and Figure 4 , the partition plate 13 is arranged at the position where the groove structure 11 and the I-shaped connecting joint 12 meet, that is, the position of the partition plate 13 is aligned with the web position of the I-beam 2 to realize continuous transmission of force of the combination beam 1 near the pier top to the I-beam 2.

[0056] A plurality of holes 131 are formed in the partition plate 13 for the steel reinforcement to pass through, and openings are formed in the partition plate 13 to connect the spaces on both sides of the partition plate 13, so as to fill the micro-expansion concrete 19 or the shrinkage-compensating concrete in the groove structure 11. The positions of the openings can include the following cases:

[0057] One case is that the openings are formed at the bottom of the partition plate 13, and are formed by chamfering the partition plate 13, which are denoted as first openings 132.

[0058] Another case is that the openings are formed at the center of the partition plate 13, which are denoted as second openings 133. The sizes of the second openings 133 and the first openings 132 are selected according to actual conditions and are not specifically limited.

[0059] As shown in Figure 3 , Figure 4 and Figure 6 , the first shear nails 14 are fixedly welded to the inner side walls of the groove structure 11.

[0060] As shown in Figure 8 , the steel reinforcement includes first steel bars 17 and second steel bars 18. The first steel bars 17 pass through the holes 131 in the partition plate 13 and are arranged along the length direction of the groove structure 11. The second steel bars 18 extend into the groove bottom from one side of the groove opening 111 and extend out from the other side of the groove opening 111 by bypassing the first steel bars 17. The first steel bars 17 and the second steel bars 18 are fixedly bound to each other.

[0061] In addition, as shown in Figure 6 , the groove structure 11 is also filled with micro-expansion concrete 19 or shrinkage-compensating concrete in the interior of the groove opening 111. As shown in Figure 6 , the micro-expansion concrete 19 embeds the partition plate 13, the first shear nails 14 and the steel reinforcement, so that the groove structure 11 forms an integral structure with the partition plate 13, the first shear nails 14, the steel reinforcement and the micro-expansion concrete 19 to bear stress.

[0062] In addition, a stiffening rib (not shown in the figure) is arranged in the interior of the groove structure 11 to improve the rigidity and support strength of the groove structure 11.

[0063] In some embodiments, as shown in Figure 2 and Figure 6 , the I-shaped connecting joint 12 includes an equal-width section 121 and an outer widened section 122. The equal-width section 121 is fixedly connected to the groove structure 11. The outer widened section 122 is symmetrically arranged at both ends of the equal-width section 121 and is used to connect the I-shaped longitudinal beam 2.

[0064] The cross-sectional dimension of the outer variable-width section 122 close to one end of the equal-width section 121 is greater than the cross-sectional dimension of the outer variable-width section 122 close to one end of the I-shaped longitudinal beam 2, which corresponds to the transition of the outer variable-width section 122 from the equal-width section 121 to the I-shaped longitudinal beam 2, and the cross-sectional dimension gradually decreases to meet the force requirement at the connection between the I-shaped longitudinal beam 2 and the I-shaped connecting joint 12.

[0065] As shown in the drawings, the second shear stud 15 is fixedly arranged on the upper surface of the I-shaped connecting joint 12, and the composite beam 1 and the concrete slab 3 form an integral structure through the second shear stud 15 to bear force together. Figure 5

[0066] In some embodiments, the I-shaped connecting joint 12 can be an I-shaped steel, and can include a lower flange plate (not numbered in the drawings) and an upper flange plate (not numbered in the drawings) arranged in alignment. The structures of the two beam plates correspond, and the cross-sectional dimension of the middle is greater than that of the two ends. The lower flange plate can be welded and fixed to the bottom of the channel-shaped structure 11, and the upper flange plate can be welded and fixed to the top of the channel-shaped structure 11.

[0067] In addition, if the I-shaped connecting joint 12 adopts the lower flange plate and the upper flange plate arranged in correspondence, a web plate is arranged between the lower flange plate and the upper flange plate, and the web plate is arranged in alignment with the partition plate, so that the cross-sectional shape of the I-shaped connecting joint 12 is in the shape of an “I”, which corresponds to the shape of the I-shaped longitudinal beam 2, facilitating continuous force transmission.

[0068] In some embodiments, the concrete slab 3 is a reinforced concrete structure, which can be cast-in-place or partially prefabricated and partially cast-in-place, and the specific construction method is selected according to the actual use.

[0069] The concrete slab 3 is connected with the composite beam 1 to form an integral structure through the second steel bar 18 extending to the outside of the channel-shaped structure 11 and the second shear stud 15 to bear force together.

[0070] In some embodiments, as shown in the drawings, the I-shaped longitudinal beam 2 can be an I-shaped steel, and the number and cross-sectional dimension thereof can be increased or decreased according to the force requirement and the beam height limit. Figure 1

[0071] It should be noted that the channel-shaped steel, the I-shaped steel, and the steel plate described above are all made of weathering steel, so that the bridge structure (bridge) forms a paint-free weathering bridge. Even if it is “exposed” to the natural environment, the outer surface of the paint-free weathering bridge will automatically form an oxidation protective layer that is beautiful and maintenance-free, which can have a long-term corrosion prevention effect. Not only is the life cycle and maintenance cost low, but also no painting is required, which saves costs and meets the environmental protection concept.

[0072] ​​In some embodiments, in order to make the steel-concrete I-beam convenient to transport and simple to assemble, the composite beam 1 is provided in multiple segments, and two adjacent segments are welded together.

[0073] Each segment includes a channel structure 11 and an I-shaped connecting joint 12, and the I-shaped connecting joint 12 in each segment is connected with the I-shaped longitudinal beam 2 to form a bridge pier, and multiple bridge piers are combined to form the skeleton of the steel-concrete I-beam.

[0074] Another aspect of the present application provides a bridge structure including the above-described steel-concrete I-beam.

[0075] The present application provides a preparation method of the steel-concrete I-beam, which can include the following steps:

[0076] Step S10: According to the arrangement of the piers, the channel structure 11 and the I-shaped connecting joint 12 are welded together at a certain angle to form the composite beam 1.

[0077] Step S20: The I-shaped longitudinal beam 2 is connected with the I-shaped connecting joint 12; the first shear stud 14 and the partition plate 13 are welded inside the channel structure 11, the first steel bar 17 is passed through the partition plate 13, the second steel bar 18 is fixed with the first steel bar 17, the second steel bar 18 extends out of the channel structure 11, and the second shear stud 15 is welded on the upper surface of the I-shaped connecting joint 12.

[0078] Step S30: The micro-expanding concrete 19 is poured inside the channel structure 11; and after the micro-expanding concrete 19 reaches a certain strength, the reinforced concrete structure is arranged on the upper surfaces of the composite beam 1 and the I-shaped longitudinal beam 2 to form the concrete panel 3.

[0079] That is, when a complete bridge pier is welded, the micro-expanding concrete 19 is poured inside the channel structure 11; when the micro-expanding concrete 19 reaches a certain strength, the remaining bridge piers can be continuously constructed by the same method until all the bridge piers in the bridge are completely constructed, and then the concrete panel 3 of the concrete structure is constructed.

[0080] This step can make the channel structure 11 and the micro-expanding concrete 19 form an integral structure to bear stress together through the first steel bar 17 and the first shear stud 14, and can make the composite beam 1 and the concrete panel 3 form an integral structure to bear stress together through the second steel bar 18 and the second shear stud 15, and at the same time, the concrete panel 3 and the I-shaped longitudinal beam 2 form an integral structure to bear stress, so that the steel-concrete I-beam has higher structural rigidity and stronger support.

[0081] The steel-concrete I-beam realized by the above structure and preparation method has the advantages of Figure 1As shown, in actual use, the steel-concrete I-beam composite beam uses 10 I-beams 2, with 10 corresponding I-shaped connection joints 12. The concrete panel 3 is a cast-in-place reinforced concrete structure. Practice has proven that the on-site construction time for this structure is only three months, a shorter construction period. Compared to related steel-concrete I-beam composite beams, the construction period is reduced by 3-6 months, resulting in less traffic closure pressure. Furthermore, the steel-concrete I-beam composite beam provided by this invention has a self-weight of approximately 140t, which is about 40t less than that of existing steel-concrete I-beam composite beams, a reduction of approximately 22%. It has a compact structure, good rigidity, and lighter weight.

[0082] Furthermore, the steel-concrete composite I-beams provided by this invention can be modularly produced in a factory, resulting in lower construction difficulty and a shorter construction period. After construction, they are erected on piers 5, and supports 4 are simply installed at locations on piers 5 where they bear good stress, avoiding the use of a multi-support system. Figure 10 As shown, two supports 4 can be installed, each located at the axial center of the pier 6. This allows the forces of the bridge superstructure to be directly transmitted to the pier 6 through the supports 4, without passing through the abutment 5. This effectively alleviates the problem of insufficient strength of the abutment 5 during the renovation of old bridges. Figure 9 and Figure 10 As shown.

[0083] like Figure 5 As shown, for convenient transportation and quick connection, in actual use, the trough structure 11 can be divided into five segments along the bridge width direction. Adjacent segments are welded and fixed. Two I-shaped connecting joints 12 are welded on the trough structure 11 of each segment. I-beams 2 are welded on each I-shaped connecting joint 12 to form bridge span segments. By adjusting the number of crossbeam segments and bridge span segments, different bridge conditions can be adapted.

[0084] The innovation of this invention lies in the fact that by setting a composite beam 1 in the steel-concrete I-beam composite beam to replace the existing steel beam, the lateral connection stiffness is significantly enhanced by the overall stress of the composite beam 1, and the composite beam can be industrially manufactured, with low construction difficulty and short construction period.

[0085] During the renovation of the old bridge, the composite beam 1 improves the traditional system of multiple supports 4 on the pier 5 by only setting supports 4 at the position where the pier 6 is under good stress. This makes the force transmission path of the upper and lower parts of the bridge clearer, effectively alleviates the bending and shear stress of the old bridge pier 5, and is convenient to construct and has low construction cost.

[0086] In the process of building a new bridge, by adjusting the number and cross-sectional size of the I-beams 2 in the steel-concrete I-beam combination beam, the cross-sectional bearing capacity is improved, the stress of the bridge substructure is effectively improved, and the height limitation of the beam is effectively alleviated, and the bearing capacity of the main beam is improved; in addition, the combination beam 1 can be cast without formwork when the micro-expansion concrete 19 is cast inside, which is convenient and efficient.

[0087] The application is mainly used in old bridge reconstruction, and the upper structure of the new bridge is built by using the original bridge substructure, which effectively alleviates the height limitation of the main beam and the bearing capacity deficiency of the original bridge substructure.

[0088] It should be noted that the technical solutions in each embodiment of the application can be combined with each other, but the basis for the combination is that it can be realized by a person skilled in the art; when the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, i.e. it is not within the protection scope of the application.

[0089] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the application.

Claims

1. A steel-concrete composite I-beam, characterized in that, include: A composite beam, mounted on a support point, comprises a channel-shaped structure and an I-shaped connecting joint arranged at an angle; the channel-shaped structure has internal partitions, shear studs, and a reinforcing steel skeleton; the interior of the channel-shaped structure is filled with micro-expansion concrete or shrinkage-compensating concrete; the partitions have multiple holes and openings; the reinforcing steel skeleton passes through the holes; the openings are used to ensure that the micro-expansion concrete or shrinkage-compensating concrete filling the interior of the channel-shaped structure is poured densely. An I-beam is connected to both sides of the combined crossbeam; both ends of the I-shaped connecting joint are connected to the I-beam, and shear studs are provided on the upper surface of the I-shaped connecting joint; the I-shaped connecting joint includes a constant width section and an outer variable width section; the outer variable width section is fixedly connected to the I-beam; the cross-sectional dimension of the outer variable width section near the constant width section is larger than the cross-sectional dimension of the outer variable width section near the I-beam. A concrete panel covers the upper surface of the combined crossbeam and the I-beam.

2. The steel-concrete composite I-beam according to claim 1, characterized in that, The groove structure is also equipped with stiffening ribs inside.

3. The steel-concrete composite I-beam according to claim 1, characterized in that, The steel reinforcement cage includes a first steel bar and a second steel bar; The first reinforcing bar is installed through the partition plate; The second reinforcing bar is arranged around the first reinforcing bar and extends out of the groove structure to connect with the reinforcing bar in the concrete panel.

4. The steel-concrete composite I-beam according to claim 1, characterized in that, The I-shaped connector includes any of the following forms; The I-shaped connection joint is an I-beam; The I-shaped connecting joint includes an upper flange plate and a lower flange plate aligned together, the upper flange plate and the lower flange plate being respectively disposed on the upper and lower sides of the groove structure; a web plate is disposed between the upper flange plate and the lower flange plate; the web plate is aligned with the partition plate.

5. The steel-concrete composite I-beam according to claim 1, characterized in that, The composite beam is welded together from multiple segments.

6. A bridge structure, characterized in that, Includes the steel-concrete I-beam composite beam as described in any one of claims 1 to 5.

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