Ultra-high performance concrete beam and production method thereof

Abstract

The invention provides an ultra-high-performance concrete beam and a production method thereof, the ultra-high-performance concrete beam comprises an embedded framework and ultra-high-performance concrete, the ultra-high-performance concrete is poured into the embedded framework, and the embedded framework is embedded in the ultra-high-performance concrete; the embedded framework comprises a steel bar frame and prestressed steel strands penetrating through the steel bar frame, the steel bar frame comprises first steel bars and a steel bar assembly, the steel bar assembly comprises stirrups and is provided with constraint matching rings, the prestressed steel strands and the first steel bars extend in the X direction, and the steel bar assembly is arranged in the second direction. The second direction is perpendicular to the first direction, and at least part of the prestressed steel strand penetrates through the constraint matching ring. The bearing capacity and durability of the ultra-high-performance concrete beam structure are improved, and the advantages of high environment adaptability and good corrosion resistance of the ultra-high-performance concrete structure are fully exerted.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction engineering, and in particular to an ultra-high performance concrete beam and a production method thereof. Background Art

[0002] In the field of bridge construction engineering technology, trestles are usually used to meet the passage of construction machinery, materials and construction personnel. At present, the longitudinal beams on the trestles are mainly designed with Bailey plates, and their types include 321 Bailey plates and 421 Bailey plates. As the main load-bearing structure in the trestles, Bailey plates must consider whether the materials used have excellent mechanical properties, durability and corrosion resistance. Generally speaking, Bailey plates are welded from channel steel. Although they have the characteristics of simple structure, convenient transportation, fast erection and easy disassembly, they often suffer from severe rust during use, which leads to a serious lack of durability and bearing capacity, which will cause great safety hazards to the built trestles. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an ultra-high performance concrete beam and a production method thereof, wherein the bearing capacity and durability of the beam are improved.

[0004] To solve the above technical problems, the present invention provides: an ultra-high performance concrete beam, comprising an embedded frame and ultra-high performance concrete, the ultra-high performance concrete is cast in the embedded frame and the embedded frame is embedded in the ultra-high performance concrete; the embedded frame comprises a steel bar frame and a prestressed steel strand passing through the steel bar frame, the steel bar frame comprises a first steel bar and a steel bar assembly, the steel bar assembly comprises stirrups, the steel bar assembly forms a constraint fitting ring, the prestressed steel strand and the first steel bar extend along a first direction, the steel bar assembly is arranged along a second direction, the second direction is arranged perpendicular to the first direction, and at least part of the prestressed steel strand is passed through the constraint fitting ring.

[0005] In one embodiment: the steel bar assembly has two side ends, both sides of the side ends are expanded outward, at least part of the prestressed steel strands are passed through the side ends, and after the ultra-high performance concrete is poured, horseshoe-shaped structures are formed on both side ends of the ultra-high performance concrete beam.

[0006] In one embodiment: the first steel bar and the steel bar assembly are connected together.

[0007] In one embodiment: the steel bar assembly further includes a second steel bar, the second steel bar is connected to the stirrup and the stirrup forms the above-mentioned constraint fitting ring, and the second steel bar is extended along the second direction.

[0008] In one embodiment: the steel bar assembly includes two second steel bars arranged at intervals along a third direction, the third direction is perpendicular to the first direction and the second direction, the stirrup and the two second steel bars are connected together, and the constraint matching ring has a middle area located between the two second steel bars and two side areas located on both sides of the middle area, and the side areas are located outside the two second steel bars; the stirrup has a first straight line segment, two second straight line segments respectively fixed at both ends of the first straight line segment, and two third straight line segments respectively fixed at the ends of the second straight line segment, the two third straight line segments are cross-arranged, and the first straight line segment is fixed at the end of the second steel bar.

[0009] In one embodiment: ends of the two third straight line segments are fixed to the two second steel bars respectively.

[0010] In one embodiment: the prestressed steel strand is passed through a middle region of the constraint fitting ring, and a plurality of first steel bars are passed through the side region.

[0011] In one embodiment: prestressed steel strands are inserted into the middle region and the side regions of the constraint fitting ring, and a plurality of first steel bars are also inserted into the middle region of the constraint fitting ring.

[0012] In one embodiment: the stirrup is formed with the above-mentioned constraint fitting ring, and the stirrup is extended along the second direction.

[0013] In one embodiment: the restraining matching ring of the stirrup is a dumbbell-shaped closed structure with large ends at both ends and a small middle. The dumbbell-shaped closed structure has two head parts and a radial part connected between the two head parts and extending along the second direction. The two head parts constitute the two side ends of the steel bar assembly. The head parts are arranged to expand outward relative to the radial part. At least part of the prestressed steel strands are passed through the head parts. After the ultra-high performance concrete is poured, a horseshoe-shaped structure is formed at the two side ends of the ultra-high performance concrete beam.

[0014] In one embodiment: the head includes a fourth straight line segment extending along a third direction, and a fifth straight line segment formed by vertically extending from the end of the fourth straight line segment, the third direction is perpendicular to the first direction and the second direction, the end of the fifth straight line segment is bent toward another fifth straight line segment to form an inclined sixth straight line segment, and the radial portion includes two seventh straight line segments, and the seventh straight line segment connects the ends of the sixth straight line segments of the two heads.

[0015] In one embodiment: the steel bar assembly further includes a second steel bar, the second steel bar is connected to the stirrups, the second steel bar and the stirrups connected together cooperate to form the above-mentioned constraint fitting ring, and the second steel bar is extended along the second direction.

[0016] In one embodiment: it also includes a protective member, which is arranged on the outer surface of the ultra-high performance concrete, and the outer surface of the protective member is flush with the outer surface of the ultra-high performance concrete.

[0017] In one embodiment: it also includes a mounting hole for cooperating with external construction equipment, and the mounting hole is set in the ultra-high performance concrete.

[0018] In order to solve the above technical problems, the present invention further provides: a method for producing the ultra-high performance concrete beam, comprising:

[0019] Step 1, a bottom mold is set on the pedestal, a steel bar frame is installed on the bottom mold, and a side mold is installed. The side mold and the bottom mold cooperate to form a casting mold. The steel bar frame is located in the casting mold, and the prestressed steel strand is passed through and tensioned.

[0020] Step 2: After the prestressed steel strands are tensioned in place, ultra-high performance concrete is poured into the casting mold, and the ultra-high performance concrete buries the embedded structure therein;

[0021] Step 3, after pouring, curing is performed. After the ultra-high performance concrete solidifies to a specified strength, the casting mold is disassembled, and the prestressed steel strands are tensioned. After tensioning is completed, the prestressed steel strands are cut off.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0023] Provide ultra-high performance concrete beams, by setting prestressed steel strands in ultra-high performance concrete, and the steel bar components form a constraint matching ring, forming a strong and closed frame, the prestressed steel strands are passed through the constraint matching ring, so as to improve the bearing capacity and durability of the ultra-high performance concrete beam structure, give full play to the advantages of ultra-high performance concrete structure with strong environmental adaptability and good corrosion resistance, and provide an additional safety guarantee for the production operations of the pier construction project. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of an ultra-high performance concrete beam according to Example 1 of the present invention;

[0025] Figure 2 It is a partial side schematic diagram of an ultra-high performance concrete beam according to Example 1 of the present invention;

[0026] Figure 3 This is a schematic structural diagram of a steel bar assembly according to Embodiment 1 of the present invention;

[0027] Figure 4 It is a side schematic diagram of a steel bar assembly according to Embodiment 1 of the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the stirrups of Example 1 of the present invention;

[0029] Figure 6 This is a partial schematic diagram of the internal structural connection relationship of the ultra-high performance concrete beam of Example 1 of the present invention.

[0030] Figure 7 A schematic diagram of the structure of the stirrups of Example 2 of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "installed / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0034] Example 1

[0035] refer to Figure 1-Figure 6This embodiment provides a prestressed ultra-high performance concrete beam, including an embedded frame and ultra-high performance concrete 3, the ultra-high performance concrete 3 is cast in the embedded frame and the embedded frame is fixedly embedded in the ultra-high performance concrete 3; the embedded frame includes a steel frame 2 and a prestressed steel strand 1 passing through the steel frame 2. The steel bar frame 2 includes a first steel bar and a steel bar assembly 23. The first steel bar is divided into an N1 steel bar 21 and an N2 steel bar 22. The diameter of the N1 steel bar 21 is larger than that of the N2 steel bar 22. The steel bar assembly 23 is used to connect the first steel bars (N1 steel bars 21, 22) and includes a second steel bar 231 and a stirrup 232. The prestressed steel strand 1, the N1 steel bar 21, and the N2 steel bar 22 are extended along the X direction. The second steel bar 231 is extended along the Y direction. The stirrup 232 is located at the side end of the ultra-high performance concrete 3 in the Y direction. The second steel bar 231 and the stirrup 232 are connected together and the stirrup 232 forms a constraint matching ring to form a strong and closed frame. The prestressed steel strand 1 is inserted into the constraint matching ring. The two ends of the second steel bar 231 are connected to stirrups 232, so the upper and lower ends of the ultra-high performance concrete beam are provided with prestressed steel strands 1. After the ultra-high performance concrete 3 is poured, a horseshoe structure is formed at both ends of the ultra-high performance concrete beam. The prestressed steel strand 1 can arch after being released to enhance the bearing capacity of the ultra-high performance concrete beam. The steel frame 2 is used to improve the bearing capacity of the prestressed ultra-high performance concrete beam; the above-mentioned X direction is such as the length direction of the ultra-high performance concrete beam, the Y direction is such as the height direction, and the Z direction is such as the thickness direction.

[0036] The steel bar assembly 23 includes two second steel bars 231 arranged at intervals along the Z direction. The constraint matching ring of the stirrup 232 has a first straight line segment, two second straight line segments respectively fixed at both ends of the first straight line segment and two third straight line segments respectively fixed at the ends of the second straight line segment. The two third straight line segments are arranged crosswise, the first straight line segment is fixed at the ends of the second steel bars 231, and the intersection of the two third straight line segments is welded or tied or simply overlapped. The ends of the two crosswise arranged third straight line segments are respectively fixed at the two second steel bars 231. The stirrup 232 and the two second steel bars 231 are connected together, and the constraint matching ring has a middle area 2321 located between the two second steel bars 231 and two side areas 2322 located at both sides of the middle area 2321. The side area 2322 is located outside the two second steel bars 231 and between the second straight line segment and the second steel bars 231. A triangular enclosed area 2323 is formed between the two crosswise arranged third straight line segments and the second steel bars. The second steel bar 231 and the stirrup 232 are connected together to form a constrained fit. The connection can be welded, tied or overlapped as needed. The connection is conducive to the N1 steel bar 21 and the N2 steel bar 22 being welded inside the steel bar assembly 23, which plays a binding and restricting role for the longitudinally placed N1 steel bar 21 and N2 steel bar 22. The steel bar assembly 23 in this embodiment takes two second steel bars 231 as an example, but it is not limited to this. There can be more than two as needed. In this case, the two second steel bars are the two second steel bars located on the outermost side. The second steel bar 231 and the stirrup 232 are preferably 8mm round steel.

[0037] Both ends of the second steel bar 231 are connected with stirrups 232, wherein:

[0038] In the stirrups 232 at the upper end: the prestressed steel strand 1 is inserted into the middle area 2321 of the constraint fitting ring, and a plurality of first steel bars, such as N1 steel bars 21, are inserted into the side area 2322; if two prestressed steel strands 1 are provided, the two prestressed steel strands 1 are spaced apart along the Y direction, and if three N1 steel bars 21 are provided in each side area 2322, the three N1 steel bars 21 are spaced apart along the Y direction, one prestressed steel strand 1 is adjacent to the first straight line segment, one N1 steel bar 21 in each side area 2322 is connected to the first straight line segment, and the N1 steel bar 21 in each side area 2322 is connected to the second straight line segment, and the connection is such as welding, tying or overlapping; the N1 steel bar 21 serves as the main force-bearing steel bar to assist the prestressed steel strand 1 at the upper end of the ultra-high performance concrete 3 in resisting the downward bending moment.

[0039] In the stirrups 232 at the lower end: prestressed steel strands 1 are inserted in the middle area 2321 and the side area 2322 of the constraint matching ring, and a plurality of first steel bars, such as N2 steel bars 22, are also inserted in the middle area 2321 of the constraint matching ring; two prestressed steel strands 1 are respectively arranged in the middle area 2321 and the side area 2322, and the two prestressed steel strands 1 are arranged at intervals along the Y direction, and the prestressed steel strands 1 in the middle area 2321 and the side area 2322 are arranged at the same height, and two rows of first steel bars, such as four N2 steel bars 22, are arranged in the middle area 2321, and the two rows of N2 steel bars 22 are respectively connected to the two second steel bars 231 at intervals along the Y direction, and the connection is such as welding, binding or overlapping;

[0040] A first steel bar, such as an N2 steel bar 22 of a first steel bar, is provided in the enclosed area 2323, and the N2 steel bar 22 is connected at a fork angle between the second steel bar and the third straight line segment.

[0041] The first steel bar is divided into a first part located between the two second steel bars and a second part located outside the two second steel bars. The first steel bar of the first part is an N2 steel bar 22, and the first steel bar of the second part is an N1 steel bar 21. The N2 steel bar 22 and the second steel bar 231 are connected together. The connection can be welded or tied. The N2 steel bar 22 and the second steel bar 231 are connected to form a steel mesh. The N2 steel bar 22 serves as a secondary force-bearing steel bar to assist the N1 steel bar 21 and the prestressed steel strand 1 in resisting the downward bending moment. At the same time, it also serves as a stand bar to stand up the steel bar assembly 23 to form a regular steel cage. The N1 steel bars 21 and the N2 steel bars 22 are equidistantly spaced and parallel to each other. In this embodiment, the N1 steel bar 21 is preferably a 14mm threaded steel bar, and the N2 steel bar 22 is preferably an 8mm round steel bar.

[0042] In this embodiment, the steel frame 2 includes a plurality of steel bar assemblies 23, and the steel bar assemblies 23 are arranged at equal intervals along the X direction, and the spacing distance between two adjacent steel bar assemblies 23 is preferably 150 mm. In this embodiment, the stirrup 232 is shaped as a closed polygon formed by steel bars and cross-connected at the head and tail. Considering the relationship between the production cost and the use effect of the ultra-high performance concrete beam, welding is the preferred connection between the steel bars. The connection between the second steel bar 231 and the stirrup 232, between the N1 steel bar 21 and the stirrup 232, and between the N2 steel bar 22 and the second steel bar 231 and the stirrup 232 are all welded. In detail, there are 3 welding points corresponding to one second steel bar 231 welding one stirrup 232. As a common replacement of this embodiment, it can be understood that at least one welding point is provided between the second steel bar 231 and the stirrup 232. Further, the N1 steel bar 21 is welded to the stirrup 232, and the N2 steel bar 22 is welded to the second steel bar 231. Specifically, the N1 steel bar 21 is welded to the inner side of the stirrup 232, and the N2 steel bar 22 is welded to the area between the two second steel bars 231. In this embodiment, the N2 steel bar 22 placed at the top of the steel bar frame 2 is welded to the enclosed area 2323 formed between the stirrup 232 and the second steel bar 231.

[0043] Due to the presence of the stirrups 232, the cross-sectional area of ​​the ends of the ultra-high performance concrete 3 is larger than the cross-sectional area of ​​the middle of the ultra-high performance concrete 3. In this embodiment, the upper and lower ends of the ultra-high performance concrete 3 are designed to be horseshoe-shaped, with the upper and lower ends being wider and the middle being narrower. This reasonably optimizes the external shape of the ultra-high performance concrete 3 while also saving the use of concrete materials. Furthermore, the ultra-high performance concrete beam can be stable and will not fall over during storage, transportation and placement.

[0044] The ultra-high performance concrete beam also includes a protective member 4 for preventing the ultra-high performance concrete beam from being damaged by collision, and the protective member 4 is arranged on the outer surface of the ultra-high performance concrete 3. The protective member 4 is fixed to the outer surfaces of both ends of the ultra-high performance concrete 3, and the outer surfaces of the protective member 4 are flush with the outer surfaces of both ends of the ultra-high performance concrete 3. In this example, the protective member 4 is preferably an angle steel. The angle steel is arranged on the outer surface of the ultra-high performance concrete beam to prevent the ultra-high performance concrete beam from colliding with other objects during the transportation, hoisting and turnover process, thereby avoiding damage to its edges and corners.

[0045] The ultra-high performance concrete beam also includes a mounting hole 5 for cooperating with external construction equipment, such as a flower stand for construction. The mounting hole 5 is provided on the ultra-high performance concrete 3, and the mounting hole 5 is distributed between the stirrups 232 near the middle of the ultra-high performance concrete 3. The mounting hole 5 includes at least one hole at the same position on the ultra-high performance concrete 3. The hole shape is circular, rectangular, or other polygonal. The mounting holes 5 are arranged at intervals along the length direction of the ultra-high performance concrete 3. The mounting hole 5 runs through the ultra-high performance concrete 3, and the opening direction of the mounting hole 5 is perpendicular to the length direction of the ultra-high performance concrete 3.

[0046] The prestressed steel strand 1 is a twisted steel cable or steel bar composed of 2, 3, 7 or 19 high-strength steel wires. The twisted steel cable or steel bar is subjected to stress relief treatment (stabilization treatment) and is suitable for prestressed concrete and similar purposes. The main characteristics of the prestressed steel strand 1 are high strength and good relaxation performance. In addition, it is relatively straight when unfolded. The common tensile strength grade is 1860 MPa, and there are strength grades such as 1720, 1770, and 1960 MPa. The yield strength of this steel is also very high. In this embodiment, the prestressed steel strand 1 is arranged along the length direction of the ultra-high performance concrete 3. In this embodiment, the prestressed steel strand 1 uses a 15.2mm steel strand and a high-strength low-relaxation steel strand. The prestressed steel strand 1 can improve the durability of the ultra-high performance concrete beam structure, and even based on the shrinkage and arching of the prestressed steel strand 1, the bearing capacity of the ultra-high performance concrete beam structure is enhanced, and the bearing capacity required for cracking is delayed. The prestressed steel strand 1 has the mechanical property of high tensile strength and can effectively prevent concrete cracking or control the cracks to a harmless level.

[0047] To elaborate, in this embodiment, the prestressed steel strand 1 is tensioned by the pre-tensioning method, with one end (fixed end) fixed and the other end (tensioning end) tensioned symmetrically. During the concrete construction process, the prestressed steel bar or steel bundle is first fixed at one end and tensioned at the other end. "Single-strand symmetrical tensioning" means that when a single prestressed tendon is tensioned, a symmetrical time sequence is adopted. For example, the middle steel bar is tensioned first each time, and then tensioned to both sides in turn. In this way, the force during the tensioning process will be evenly distributed, the structure will be balanced, and cracks caused by excessive local force will be avoided. The bending moment caused by uneven gravity is also reduced, ensuring uniform distribution of prestress and preventing structural deformation problems caused by uneven distribution of prestress. The staff can more accurately control the size and direction of the prestress, thereby improving construction accuracy and component quality. The production process of this embodiment is as follows: Step 1, assemble the steel frame 2, the prestressed steel strand 1 is passed through the steel frame 2 and the prestressed steel strand 1 is tensioned; Step 2, pour the ultra-high performance concrete; Step 3, after the ultra-high performance concrete solidifies, the prestressed steel strand 1 is tensioned, such as gradually tensioning, and after the tensioning is completed, the part of the prestressed steel strand 1 outside the concrete is cut off. According to the needs, it can also be adopted: one end is fixed, the other end is tensioned as a whole, or both ends are tensioned; mechanical jacks or hydraulic jacks are used for tensioning.

[0048] Ultra-high performance concrete, referred to as UHPC, is a new type of high-strength, high-durability and high-toughness concrete material. UHPC uses cement aggregate, ultrafine cement and silica fume with optimized mix ratios, and some special materials such as high elastic modulus fibers are also used for reinforcement to achieve better engineering performance. Compared with ordinary concrete, UHPC's unique rheological properties and self-compacting properties give it good mold filling performance, and it can produce prefabricated components with complex shapes and high precision. In addition, the compressive strength, flexural strength and other mechanical properties of UHPC concrete materials are significantly better than ordinary concrete, and it also has better durability and erosion resistance, and can maintain a long service life even in harsh environments. Moreover, UHPC has extremely high fire resistance and impact resistance, and can maintain a certain bearing capacity after encountering fire or impact. In the present embodiment, the ultra-high performance concrete beam has excellent mechanical properties, durability and anti-corrosion performance, and has strong bearing capacity and good anti-corrosion performance. Moreover, the production cost of the ultra-high performance concrete beam is controllable, the structure is simple, and it is easy to turn around and transport. It also has strong adaptability to the environment and excellent casting and molding performance. It is more economical in material consumption than other concrete materials, can reduce the deadweight of components, and reduce carbon dioxide emissions. The excellent durability reduces component maintenance and repair, and is more green and energy-saving. In some trestle construction projects, the ultra-high performance concrete beam can be used to replace Bailey sheets to improve the problems exposed by Bailey sheets in trestle construction projects, further ensure the safe production operation of construction projects, and improve construction efficiency. Compared with Bailey sheets, the ultra-high performance concrete beam of the present embodiment reduces the weight of its own components, reduces the large-scale use of steel and steel, reduces carbon dioxide emissions, and achieves energy conservation and emission reduction.

[0049] A method for producing a prefabricated ultra-high performance concrete beam, comprising:

[0050] Step 1, a bottom mold is set on the pedestal, the bottom mold is such as a plastic patterned plate, a steel frame 2 is mounted on the bottom mold, a side mold is installed, the side mold and the bottom mold cooperate to form a casting mold, the steel frame 2 is located in the casting mold, a prestressed steel strand 1 is passed through, and the prestressed steel strand 1 is tensioned, such as by a single symmetrical tensioning method or other tensioning methods;

[0051] Step 2, after the prestressed steel strand 1 is tensioned in place, ultra-high performance concrete is poured into the casting mold, and vibration is performed during the pouring process, so that the ultra-high performance concrete fixes the embedded frame therein;

[0052] Step 3, curing after pouring, after the ultra-high performance concrete solidifies to the specified strength (such as final setting), dismantle the casting mold, and then release the prestressed steel strand 1, and cut off the prestressed steel strand 1 after the release. Among them: the prestressed steel strand 1 is released in a multiple step-by-step manner so that the prestressed steel strand 1 has a good arching effect after release. The order of releasing multiple prestressed steel strands 1 is to release them one by one from the middle first and then from the middle to the outside, and release them symmetrically from the middle to the outside, which can improve the arching stability; after cutting, fill the hole with ultra-high performance concrete. After cutting, move the concrete beam to the storage position, seal the ends, and continue to cure the concrete.

[0053] Example 2

[0054] refer to Figure 7 , which is different from the first embodiment in that: the stirrup 232 is formed with a constraint matching ring, the stirrup is extended along the second direction of 232, the second direction and the first direction are arranged perpendicularly, the constraint matching ring of the stirrup 232 is a dumbbell-shaped closed structure with large ends at both ends and a small middle, the dumbbell-shaped closed structure has two heads 2324 and a radial portion 2325 connecting the two heads 2324, at least part of the prestressed steel strands are inserted in the head 2324, and the radial portion 2325 is extended along the second direction. The two heads constitute the two side ends of the steel bar assembly, the heads are arranged outward relative to the radial portion, and the horseshoe structure is formed at the two side ends of the ultra-high performance concrete beam after the ultra-high performance concrete is poured. The head 2324 includes a fourth straight line segment extending along the third direction, a fifth straight line segment formed by the vertical extension of the end of the fourth straight line segment, the end of the fifth straight line segment is bent toward another fifth straight line segment to form an inclinedly arranged sixth straight line segment, and the radial portion includes two seventh straight line segments, and the seventh straight line segment is connected between the ends of the sixth straight line segments of the two heads. The dumbbell-shaped closed structure is as follows: (1) a single steel bar is bent, and the ends are welded, tied or overlapped together after bending to form a closed structure; (2) two steel bars are bent to form the same structure, and the two ends of the two same bent parts are welded, tied or overlapped together after bending to form a closed structure; (3) or other structures are used to form a closed structure.

[0055] Example 3

[0056] The difference between the embodiment 1 and the embodiment 1 is that the constraint matching ring of the stirrup is a dumbbell-shaped closed structure with large ends and a small middle.

[0057] Example 4

[0058] The difference between the embodiment 1 and the embodiment 1 is that the constraint matching ring is formed by the above-mentioned stirrups and the second steel bar.

[0059] The above is only a preferred specific implementation of the present invention, but the design concept of the present invention is not limited to this. Any technician familiar with the technical field who uses this concept to make non-substantial changes to the present invention within the technical scope disclosed by the present invention shall be deemed to infringe the protection scope of the present invention.

Claims

1. Ultra-high performance concrete beam, characterized in that: It includes an embedded frame and ultra-high performance concrete, the ultra-high performance concrete is cast in the embedded frame and the embedded frame is embedded in the ultra-high performance concrete; the embedded frame includes a steel bar frame and a prestressed steel strand passing through the steel bar frame, the steel bar frame includes a first steel bar and a steel bar assembly, the steel bar assembly includes stirrups, the steel bar assembly forms a constraint matching ring, the prestressed steel strand and the first steel bar are extended along a first direction, the steel bar assembly is arranged along a second direction, the second direction is arranged perpendicular to the first direction, and at least part of the prestressed steel strand is passed through the constraint matching ring.

2. The ultra-high performance concrete beam according to claim 1, characterized in that: The steel bar assembly has two side ends, the two sides of the side ends are expanded outward, at least part of the prestressed steel strands are passed through the side ends, and after the ultra-high performance concrete is poured, horseshoe-shaped structures are formed on the two side ends of the ultra-high performance concrete beam.

3. The ultra-high performance concrete beam according to claim 1, characterized in that: The first rebar and the rebar assembly are connected together.

4. The ultra-high performance concrete beam according to claim 1, 2 or 3, characterized in that: The steel bar assembly also includes a second steel bar, the second steel bar is connected to the stirrup and the stirrup is formed with the above-mentioned constraint matching ring, and the second steel bar is extended along the second direction.

5. The ultra-high performance concrete beam according to claim 4, characterized in that: The steel bar assembly includes two second steel bars arranged at intervals along a third direction, the third direction is perpendicular to the first direction and the second direction, the stirrup and the two second steel bars are connected together, and the constraint matching ring has a middle area located between the two second steel bars and two side areas located on both sides of the middle area, and the side areas are located outside the two second steel bars; the stirrup has a first straight line segment, two second straight line segments respectively fixed at both ends of the first straight line segment, and two third straight line segments respectively fixed at the ends of the second straight line segment, the two third straight line segments are cross-arranged, and the first straight line segment is fixed at the end of the second steel bar.

6. The ultra-high performance concrete beam according to claim 5, characterized in that: The ends of the two third straight line segments are respectively fixed to the two second steel bars.

7. The ultra-high performance concrete beam according to claim 5, characterized in that: The prestressed steel strand is passed through a middle area of ​​the constraint matching ring, and a plurality of first steel bars are passed through the side area.

8. The ultra-high performance concrete beam according to claim 5, characterized in that: Prestressed steel strands are inserted into the middle region and the side regions of the constraint fitting ring, and a plurality of first steel bars are also inserted into the middle region of the constraint fitting ring.

9. The ultra-high performance concrete beam according to claim 1, characterized in that: The stirrup is formed with the above-mentioned constraint matching ring, and the stirrup is extended along the second direction.

10. The ultra-high performance concrete beam according to claim 9, characterized in that: The restraining matching ring of the stirrup is a dumbbell-shaped closed structure with large ends at both ends and a small middle. The dumbbell-shaped closed structure has two head parts and a radial part connected between the two head parts and extending along the second direction. The two head parts constitute the two side ends of the steel bar assembly. The head parts are arranged to expand outward relative to the radial part. At least part of the prestressed steel strands are passed through the head parts. After the ultra-high performance concrete is poured, horseshoe-shaped structures are formed at the two side ends of the ultra-high performance concrete beam.

11. The ultra-high performance concrete beam according to claim 10, characterized in that: The head includes a fourth straight line segment extending along a third direction, and a fifth straight line segment formed by vertically extending from the end of the fourth straight line segment, wherein the third direction is perpendicular to the first direction and the second direction, the end of the fifth straight line segment is bent toward another fifth straight line segment to form an inclined sixth straight line segment, and the radial portion includes two seventh straight line segments, and the seventh straight line segment connects the ends of the sixth straight line segments of the two heads.

12. The ultra-high performance concrete beam according to claim 1, 2 or 3, characterized in that: The steel bar assembly also includes a second steel bar, which is connected to the stirrups. The second steel bar and stirrups connected together cooperate to form the above-mentioned constraint matching ring, and the second steel bar is extended along the second direction.

13. The ultra-high performance concrete beam according to claim 1, characterized in that: It also includes a protective member, which is arranged on the outer surface of the ultra-high performance concrete, and the outer surface of the protective member is flush with the outer surface of the ultra-high performance concrete.

14. The ultra-high performance concrete beam according to claim 1, characterized in that: Also included are mounting holes for engaging external building construction equipment, the mounting holes being provided in the ultra-high performance concrete.

15. The method for producing ultra-high performance concrete beams according to claim 1, characterized in that: include: Step 1, a bottom mold is set on the pedestal, a steel bar frame is installed on the bottom mold, and a side mold is installed. The side mold and the bottom mold cooperate to form a casting mold, the steel bar frame is located in the casting mold, and the prestressed steel strand is passed through and tensioned; Step 2: After the prestressed steel strands are tensioned in place, ultra-high performance concrete is poured into the casting mold, and the ultra-high performance concrete buries the embedded structure therein; Step 3, after pouring, curing is performed. After the ultra-high performance concrete solidifies to a specified strength, the casting mold is disassembled, and the prestressed steel strands are tensioned. After tensioning is completed, the prestressed steel strands are cut off.

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