阅读说明：本技术 大跨度缓粘结预应力钢筋混凝土梁及施工方法 (Large-span slow-bonding prestressed reinforced concrete beam and construction method ) 是由 刘洋 石建斌 徐建陇 宋涛 秦鹏 薛德民 郭利红 程秀茹 于 2021-01-07 设计创作，主要内容包括：本发明涉及一种大跨度缓粘结预应力钢筋混凝土梁,包括大跨度缓粘结预应力梁和预应力筋定位装置；所述的大跨度缓粘结预应力梁包括模板体系、支撑结构、预应力张拉端构件、预应力固定端构件、梁钢筋和缓粘结预应力筋；所述的模板体系包括板模板、张拉端浇筑模板、梁模板和柱子模板,所述的板模板、梁模板和柱子模板均通过支撑结构进行支撑固定。本发明的有益效果是：本发明中缓粘结预应力筋的节点布置简单合理,无需预留孔道和压降,并降低了污染物的排放；本发明组成构件简单,方便组装施工,拆卸方便,模板体系可多次重复利用,应用形式灵活；本发明可确保缓粘结预应力筋布筋曲线的顺滑,显著提升现场施工效率。(The invention relates to a large-span slow-bonding prestressed reinforced concrete beam, which comprises a large-span slow-bonding prestressed reinforced concrete beam and a prestressed tendon positioning device; the large-span slow-bonding prestressed beam comprises a template system, a supporting structure, a prestressed tensioning end component, a prestressed fixed end component, beam reinforcing steel bars and slow-bonding prestressed steel bars; the template system comprises a plate template, a tension end pouring template, a beam template and a column template, wherein the plate template, the beam template and the column template are supported and fixed through a supporting structure. The invention has the beneficial effects that: the node arrangement of the slow bonding prestressed tendon is simple and reasonable, a pore passage and pressure drop do not need to be reserved, and the emission of pollutants is reduced; the invention has simple components, convenient assembly and construction, convenient disassembly, reusable template system and flexible application form; the method can ensure the smoothness of the tendon distribution curve of the slow-bonding prestressed tendon and obviously improve the field construction efficiency.)

1. The large-span slow-bonding prestressed reinforced concrete beam is characterized by comprising a large-span slow-bonding prestressed reinforced concrete beam and a prestressed tendon positioning device;

the large-span slow-bonding prestressed beam comprises a template system, a supporting structure (2), a prestressed tensioning end component, a prestressed fixed end component, beam reinforcing steel bars (4) and slow-bonding prestressed tendons (7); the template system comprises a plate template (1), a tension end pouring template (3), a beam template (8) and a column template (9), wherein the plate template (1), the beam template (8) and the column template (9) are supported and fixed through a supporting structure (2), and the supporting structure (2) is formed by erecting steel scaffolds; the tension end pouring template (3) is a steel template and comprises a base plate (10), a rotatable fender (11), two vertical plates (12) and fixed steel bars (13); one end of the rotatable mudguard (11) is connected with the base plate (10) through a hinge, the rotatable mudguard (11) is positioned between two vertical plates (12), and the vertical plates (12) are fixed on the base plate (10); slots (14) are arranged at the top ends of the two vertical plates (12) in parallel, and fixed steel bars (13) are arranged in the slots (14); the tension end pouring template (3) is fixedly arranged on a beam template (8) at one end of the prestressed beam; the prestress tension end component comprises a base plate (10), a square opening cavity die (19), a bearing plate (18) and a spiral rib (17), the prestress fixing end component comprises an extrusion anchorage device (20), the bearing plate (18) and the spiral rib (17), the slow bonding prestress rib (7) vertically penetrates through a preformed hole of the bearing plate (18), the length of the slow bonding prestress rib (7) extending out of the bearing plate (18) is not less than 30cm, and the spiral rib (17) is fixed behind the bearing plate (18); the beam steel bars (4) comprise stress bars (5) and stirrups (6), the beam steel bars (4) are arranged in the concrete beam (32), and the stress bars (5) and the stirrups (6) are connected to form a prestressed beam steel reinforcement cage; the slow-bonding prestressed tendons (7) are fixed through positioning steel bars and penetrate through the whole concrete beam (32);

the prestressed tendon positioning device comprises a positioning steel bar, a positioning steel plate (21) and an end positioning device (36); the positioning steel bars comprise vertical steel bars (25), transverse steel bars (24) and concrete cushion blocks (26), wherein one ends of the vertical steel bars (25) are provided with threads (27), two ends of the transverse steel bars (24) are provided with threads (27), and the concrete cushion blocks (26) are provided with screw holes (28); the upper end and the lower end of the vertical steel bar (25) respectively penetrate through the insertion holes (22) of the positioning steel plate (21), and one end, with threads (27), of the vertical steel bar (25) is screwed into a screw hole (28) of the concrete cushion block (26); two ends of the transverse steel bar (24) are screwed into screw holes (28) of the concrete cushion block (26), the transverse steel bar (24) is horizontally arranged in a prestressed beam reinforcement cage, and the transverse steel bar (24) and the vertical steel bar (25) are fixed through steel wires (33); two parallel long-strip notches (23) are formed in two sides of the positioning steel plate (21), a plurality of insertion holes (22) are formed in the length direction of the positioning steel plate (21), and a steel wire (33) penetrates through the long-strip notches (23) to fixedly connect the positioning steel plate (21) and the stirrups (6); the end positioning device (36) comprises a bearing plate (18), a lower sleeve (29) and an anchor plate (30), wherein the lower sleeve (29) and the anchor plate (30) are respectively provided with an anchor backing plate (38), the lower sleeve (29) is connected with the bearing plate (18) through a high-strength bolt (37), and the bearing plate (18) is fixedly connected with the anchor plate (30) through the high-strength bolt (37); the anchor plate (30) is provided with a plurality of prestressed tendon insertion holes (31), prestressed tendon bundles (39) are inserted into the prestressed tendon insertion holes (31), and the slow-bonding prestressed tendons (7) penetrate through the bearing plate (18) and the lower sleeve (29).

2. The large-span prestressed reinforcement concrete beam of claim 1, characterized in that said slab form (1), beam form (8) and column form (9) are made of wood, steel plate or aluminum plate.

3. The large-span slow-bonded prestressed reinforced concrete beam according to claim 1, wherein the fixing steel bars (13) in the tension-end casting formwork (3) are fixed by bolts (15).

4. The large-span prestressed reinforcement concrete beam of claim 1, wherein said square open cavity form (19) is disposed at the center of the base plate (10) of the tension end casting form (3).

5. The large-span slow-bonded prestressed reinforced concrete beam according to claim 1, wherein said extrusion anchors (20) are located in front of the bearing plate (18).

6. The large-span prestressed reinforcement concrete beam that slowly bonds of claim 1, characterized in that, the position of the horizontal reinforcing bar (24) and vertical reinforcing bar (25) junction corresponds to the arrangement curve of slowly-bonded prestressed reinforcement (7).

7. The large-span prestressed reinforced concrete beam slowly-bonded according to claim 1, wherein said positioning steel plates (21) are arranged in parallel on the upper and lower surfaces of the prestressed beam reinforcement cage, a plurality of insertion holes (22) are reserved on the positioning steel plates (21) at equal intervals, and the diameter of the insertion holes (22) is the same as that of the vertical reinforcement (25).

8. The large-span prestressed reinforcement concrete beam slowly-bonded according to claim 1, characterized in that a spiral reinforcement (17) is arranged outside the slowly-bonded prestressed reinforcement (7), and a steering device (40) is further arranged at the end part of the slowly-bonded prestressed reinforcement (7).

9. The construction method of the large-span slow-bonding prestressed reinforced concrete beam as claimed in any one of claims 1 to 8, characterized by comprising the following steps:

s1: construction preparation: raw materials enter a field and are checked and accepted, and a template system, a slow bonding prestressed reinforcement (7), a non-prestressed reinforcement and a prestressed anchorage device required by construction are prepared;

s2: bottom die laying: laying a prestressed reinforced concrete beam bottom die, presetting bottom die reverse arch according to a reverse arch value provided by design, and properly adjusting the reverse arch value according to construction practice and the tensioning condition of the beam;

s3: mounting a non-prestressed reinforcement framework: before binding the steel bars, cleaning the bottom die, coating a layer of isolating agent, installing and binding the steel bars, and reasonably placing cushion blocks;

s4: mounting a prestressed tendon positioning support: installing positioning steel plates (21) on the upper surface and the lower surface of a prestressed beam reinforcement cage, and determining the position of a fixed connection point of a transverse reinforcement (24) and a vertical reinforcement (25) in a positioning reinforcement according to a reinforcement distribution curve function of a slowly-bonded prestressed reinforcement (7);

s5: laying a slow bonding prestressed tendon: the slow-bonding prestressed tendons (7) are laid according to a conventional method, and the slow-bonding prestressed tendons (7) are positioned and fixed by adopting a prestressed tendon positioning support;

s6: and (3) mounting prestressed tendon nodes: mounting a prestress tensioning end component and a prestress fixing end component, and fixing the slow bonding prestressed tendon (7) by penetrating through an end positioning device (36);

s7: and (3) side die installation: installing a prestressed beam side mold on the periphery above the bottom mold, reserving a reinforcing steel bar hole on the side mold, enabling a main reinforcing bar to penetrate through the reinforcing steel bar hole and extend out of the side mold, and fixing the whole prestressed beam reinforcing steel bar and the side mold;

s8: pouring and maintaining concrete: after confirming that the side mold is closed, pouring concrete, adopting a method of mutually combining a high-frequency attached vibrator as a main part and an inserted vibrator as an auxiliary part for vibration, and after pouring, taking corresponding maintenance measures for normal maintenance according to seasons, and removing the mold after the strength reaches the designed strength;

s9: tensioning the prestressed tendons: pretensioning the slow-bonding prestressed tendons when the strength of concrete reaches 80% of the designed strength, finishing final tensioning when the strength reaches 100% of the designed strength, tensioning at the beam, the column side or the end part of the haunched end of the beam, and symmetrically tensioning the prestressed tendons of the same beam section;

s10: cutting and sealing the end part of the prestressed tendon: cutting redundant steel strand wires in the working length after the slow bonding prestressed tendons (7) are tensioned, wherein the length of the steel strand wires exposed out of the anchorage device is not less than 30 mm; and finally, sealing the prestressed reinforcement by using fine aggregate concrete, wherein the thickness of the concrete protective layer outside the prestressed reinforcement is larger than 25 mm.

Technical Field

The invention belongs to the technical field of building construction, and particularly relates to a large-span slow-bonding prestressed reinforced concrete beam and a construction method.

Background

Along with the great improvement of the engineering technology level and the increasing of the personalized demand in recent years, the demand of the domestic building market for open space is increased; the prestressed beam technology has the characteristics of small self weight, high rigidity, cracking resistance, strong deformation resistance and the like, and has good adaptability to large-span and large-load structures.

The traditional prestressed beam uses unbonded prestressed tendons or bonded prestressed tendons, the unbonded prestressed tendons have the defect of insufficient structural performance, pore channels and pressure drop need to be arranged in the bonded prestressed tendon construction, the process is complex, and a large amount of pollutants are generated. Meanwhile, due to the characteristic of large span, the arrangement of the slow bonding prestressed tendons in the beam is often bent, and a device capable of accurately positioning the prestressed tendons in the slow bonding prestressed beam is needed.

In view of this, in order to solve the existing engineering problems, a long-span slow-bonding prestressed reinforced concrete beam and a construction method thereof are urgently needed to accelerate the construction efficiency, improve the positioning accuracy of the prestressed tendons in the slow-bonding prestressed concrete beam and reduce the environmental pollution.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a large-span slow-bonding prestressed reinforced concrete beam and a construction method thereof, wherein the large-span slow-bonding prestressed reinforced concrete beam is simple to implement, high in positioning accuracy, good in construction quality and environment-friendly, and the technical problems that the structural performance of the beam is insufficient due to unbonded prestressed ribs and bonded prestressed ribs, the prestressed ribs in the large-span slow-bonding prestressed beam are difficult to position, and the environment pollution is easily caused in construction in the background technology are solved.

The large-span slow-bonding prestressed reinforced concrete beam comprises a large-span slow-bonding prestressed beam and a prestressed tendon positioning device;

the large-span slow-bonding prestressed beam comprises a template system, a supporting structure, a prestressed tensioning end component, a prestressed fixed end component, beam reinforcing steel bars and slow-bonding prestressed steel bars; the template system comprises a plate template, a tension end pouring template, a beam template and a column template, wherein the plate template, the beam template and the column template are supported and fixed through a support structure, and the support structure is formed by erecting steel scaffolds; the tension end pouring template is a steel template and comprises a base plate, a rotatable fender, two vertical plates and fixed steel bars; one end of the rotatable mudguard is connected with the base plate through a hinge, the rotatable mudguard is positioned between two vertical plates, and the vertical plates are fixed on the base plate; slots are formed in the top ends of the two vertical plates in parallel, and fixing steel bars are installed in the slots; the tension end pouring template is fixedly arranged on a beam template at one end of the prestressed beam; the prestress tension end component comprises a base plate, a square opening cavity die, a bearing plate and a spiral rib, the prestress fixing end component comprises an extrusion anchorage device, the bearing plate and the spiral rib, the slow bonding prestress rib vertically penetrates through a preformed hole of the bearing plate, the length of the slow bonding prestress rib extending out of the bearing plate is not less than 30cm, and the spiral rib is fixed behind the bearing plate; the beam reinforcing steel bars comprise stress bars and stirrups, the beam reinforcing steel bars are arranged in the concrete beam, and the stress bars and the stirrups are connected to form a prestressed beam reinforcing cage; the slow-bonding prestressed tendons are fixed through the positioning steel bars and penetrate through the whole concrete beam;

the prestressed reinforcement positioning device comprises a positioning reinforcement, a positioning steel plate and an end positioning device; the positioning steel bars comprise vertical steel bars, transverse steel bars and concrete cushion blocks, wherein one ends of the vertical steel bars are provided with threads, two ends of the transverse steel bars are provided with threads, and the concrete cushion blocks are provided with screw holes; the upper end and the lower end of the vertical steel bar respectively penetrate through the jacks of the positioning steel plate, and the threaded end of the vertical steel bar is screwed into the screw hole of the concrete cushion block; the two ends of the transverse steel bar are screwed into screw holes of the concrete cushion block, the transverse steel bar is horizontally arranged in a prestressed beam reinforcement cage, and the transverse steel bar and the vertical steel bar are fixed through steel wires; two parallel strip notches are formed in two sides of the positioning steel plate, a plurality of insertion holes are formed in the length direction of the positioning steel plate, and a steel wire penetrates through the strip notches to fixedly connect the positioning steel plate and the stirrups; the end positioning device comprises a bearing plate, a lower sleeve and an anchor plate, wherein the lower sleeve and the anchor plate are respectively provided with an anchor backing plate, the lower sleeve is connected with the bearing plate through a high-strength bolt, and the bearing plate is fixedly connected with the anchor plate through the high-strength bolt; the anchor plate is provided with a plurality of prestressed tendon inserting holes, prestressed tendon bundles are inserted into the prestressed tendon inserting holes, and the slowly-bonded prestressed tendons penetrate through the bearing plate and the lower sleeve.

Preferably, the method comprises the following steps: the plate templates, the beam templates and the column templates are made of wood, steel plates or aluminum plates.

Preferably, the method comprises the following steps: and the fixed steel bar in the tension end pouring template is fixed through a bolt.

Preferably, the method comprises the following steps: the square opening cavity die is arranged at the center of the base plate of the stretch-draw end pouring template.

Preferably, the method comprises the following steps: the extrusion anchorage device is positioned at the front part of the bearing plate.

Preferably, the method comprises the following steps: the position of the connecting point of the transverse steel bar and the vertical steel bar corresponds to the reinforcement distribution curve of the slow bonding prestressed reinforcement.

Preferably, the method comprises the following steps: the positioning steel plates are arranged on the upper surface and the lower surface of the prestressed beam reinforcement cage in parallel, a plurality of jacks are reserved on the positioning steel plates at equal intervals, and the aperture of each jack is the same as the diameter of the vertical reinforcement.

Preferably, the method comprises the following steps: the outer side of the slow bonding prestressed tendon is provided with a spiral tendon, and the end part of the slow bonding prestressed tendon is also provided with a steering device.

The construction method of the large-span slow-bonding prestressed reinforced concrete beam comprises the following steps:

s1: construction preparation: raw materials enter a field and are checked and accepted, and a template system, a slow bonding prestressed reinforcement, a non-prestressed reinforcement and a prestressed anchorage device required by construction are prepared;

s2: bottom die laying: laying a prestressed reinforced concrete beam bottom die, presetting bottom die reverse arch according to a reverse arch value provided by design, and properly adjusting the reverse arch value according to construction practice and the tensioning condition of the beam;

s3: mounting a non-prestressed reinforcement framework: before binding the steel bars, cleaning the bottom die, coating a layer of isolating agent, installing and binding the steel bars, and reasonably placing cushion blocks;

s4: mounting a prestressed tendon positioning support: installing positioning steel plates on the upper surface and the lower surface of a prestressed beam reinforcement cage, and determining the position of a fixed connection point of a transverse reinforcement and a vertical reinforcement in a positioning reinforcement according to a reinforcement distribution curve function of a slowly-bonded prestressed reinforcement;

s5: laying a slow bonding prestressed tendon: laying the slow-bonding prestressed tendons according to a conventional method, and positioning and fixing the slow-bonding prestressed tendons by adopting a prestressed tendon positioning support;

s6: and (3) mounting prestressed tendon nodes: mounting a prestress tensioning end component and a prestress fixing end component, and fixing the slow bonding prestressed tendon through an end positioning device;

s7: and (3) side die installation: installing a prestressed beam side mold on the periphery above the bottom mold, reserving a reinforcing steel bar hole on the side mold, enabling a main reinforcing bar to penetrate through the reinforcing steel bar hole and extend out of the side mold, and fixing the whole prestressed beam reinforcing steel bar and the side mold;

s8: pouring and maintaining concrete: after confirming that the side mold is closed, pouring concrete, adopting a method of mutually combining a high-frequency attached vibrator as a main part and an inserted vibrator as an auxiliary part for vibration, and after pouring, taking corresponding maintenance measures for normal maintenance according to seasons, and removing the mold after the strength reaches the designed strength;

s9: tensioning the prestressed tendons: pretensioning the slow-bonding prestressed tendons when the strength of concrete reaches 80% of the designed strength, finishing final tensioning when the strength reaches 100% of the designed strength, tensioning at the beam, the column side or the end part of the haunched end of the beam, and symmetrically tensioning the prestressed tendons of the same beam section;

s10: cutting and sealing the end part of the prestressed tendon: cutting redundant steel strand wires in the working length after the tension of the slow bonding prestressed tendon is finished, wherein the length of the steel strand wires exposed out of the anchorage device is not less than 30 mm; and finally, sealing the prestressed reinforcement by using fine aggregate concrete, wherein the thickness of the concrete protective layer outside the prestressed reinforcement is larger than 25 mm.

The invention has the beneficial effects that:

(1) the node arrangement of the slow-bonding prestressed tendon is simple and reasonable, pore channels and pressure drop do not need to be reserved, the construction is convenient, the purchase of equipment is reduced, the emission of pollutants (mortar) is reduced, and the environment protection is facilitated.

(2) The invention has simple components, convenient assembly and construction, convenient disassembly, reusable template system and flexible application form.

(3) The positioning steel bar, the positioning steel plate and the end positioning device are combined for use, so that the prestressed tendons in the slow bonding prestressed beam are accurately positioned, the smooth tendon distribution curve of the slow bonding prestressed tendons can be ensured, and the field construction efficiency is obviously improved.

Drawings

FIG. 1 is a schematic view of a large-span slow-bonding prestressed beam according to the present invention;

FIG. 2 is a structural diagram of a casting template at a tensioning end of the invention;

FIG. 3 is a schematic view of a pre-stressed tension end member according to the present invention;

FIG. 4 is a schematic view of a prestressed anchor end member of the present invention;

FIG. 5 is a schematic view of a prestressed tendon positioning device for a large-span slow-bonding prestressed beam according to the present invention;

FIG. 6 is a schematic view of the structure of the positioning bar according to the present invention;

FIG. 7 is a schematic view of the structure of the positioning steel plate according to the present invention;

FIG. 8 is a perspective view of the end positioning device of the present invention;

FIG. 9 is a side view of the end positioning device of the present invention;

fig. 10 is a layout diagram of prestressed tendons of a large-span slow-bonding prestressed beam in the beam.

Description of reference numerals: 1-slab form, 2-support structure, 3-tension end casting form, 4-beam reinforcement, 5-stress bar, 6-stirrup, 7-slow bond prestressing bar, 8-beam form, 9-column form, 10-base plate, 11-rotatable fender, 12-riser, 13-fixing reinforcement, 14-slot, 15-bolt, 16-concrete, 17-spiral bar, 18-bearing plate, 19-square opening cave form, 20-extrusion anchorage, 21-positioning steel plate, 22-jack, 23-strip notch, 24-transverse reinforcement, 25-vertical reinforcement, 26-concrete pad, 27-screw thread, 28-screw hole, 29-lower sleeve, 30-anchor plate, 31-prestressing bar jack, 32-concrete beam, 33-steel wire, 34-upper stressed steel bar, 35-lower stressed steel bar, 36-end positioning device, 37-high-strength bolt, 38-anchor backing plate, 39-prestressed reinforcement bundle and 40-steering device.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Example one

As shown in fig. 1-10, the large-span slow-bonding prestressed reinforced concrete beam comprises a large-span slow-bonding prestressed beam and a prestressed tendon positioning device.

The large-span slow-bonding prestressed beam comprises a template system, a supporting structure 2, a prestressed tensioning end component, a prestressed fixing end component, beam steel bars 4 and slow-bonding prestressed tendons 7; the template system comprises a plate template 1, a tension end pouring template 3, a beam template 8 and a column template 9, wherein the beam template 8 is arranged on the side part of the prestressed beam, the plate template 1 is arranged on the upper part of the prestressed beam, and the column template 9 is arranged below the prestressed beam; the plate formwork 1, the beam formwork 8 and the column formwork 9 are supported and fixed through a support structure 2, and the support structure 2 is formed by erecting a steel scaffold; the tension end pouring template 3 is a steel template and comprises a base plate 10, a rotatable fender 11, two vertical plates 12 and fixed steel bars 13; one end of the rotatable mudguard 11 is connected with the base plate 10 through a hinge, the rotatable mudguard 11 is positioned between two vertical plates 12, and the vertical plates 12 are fixed on the base plate 10; the top ends of the two vertical plates 12 are provided with slots 14 in parallel, fixing steel bars 13 are arranged in the slots 14, and the fixing steel bars 13 can move in the slots 14 by screwing or unscrewing the fixing steel bars 13; when the prestressed beam tensioning end seal is poured, the tensioning end pouring template 3 is fixedly arranged on a beam template 8 at one end of the prestressed beam, the fixed steel bar 13 is moved to enable the rotatable fender 11 to be in an inclined state, the fixed steel bar 13 is fixed to pour concrete 16, after the concrete 16 is poured, the fixed steel bar 13 is unscrewed to enable the rotatable fender 11 to be vertically attached to the base plate 10, the fixed steel bar 13 is screwed tightly, and the concrete 16 is cured; the prestress tension end component comprises a base plate 10, a square opening cavity die 19, a bearing plate 18 and a spiral rib 17, the prestress fixing end component comprises an extrusion anchorage device 20, the bearing plate 18 and the spiral rib 17, the slow bonding prestress rib 7 vertically penetrates through a preformed hole of the bearing plate 18, the length of the slow bonding prestress rib 7 extending out of the bearing plate 18 is not less than 30cm, and the spiral rib 17 is fixed behind the bearing plate 18; the beam reinforcing steel bars 4 comprise stress bars 5 and stirrups 6, the stress bars 5 and the stirrups 6 are arranged in the concrete beam 32 according to a drawing, and the stress bars 5 and the stirrups 6 are connected to form a prestressed beam reinforcing steel cage, wherein the stress bars 5 comprise upper stress reinforcing steel bars 34 and lower stress reinforcing steel bars 35; the slow-bonding prestressed tendons 7 are fixed through the positioning steel bars and penetrate through the whole concrete beam 32.

The prestressed tendon positioning device comprises a positioning steel bar, a positioning steel plate 21 and an end part positioning device 36; the positioning steel bars comprise vertical steel bars 25, transverse steel bars 24 and concrete cushion blocks 26, wherein one ends of the vertical steel bars 25 are provided with threads 27, two ends of the transverse steel bars 24 are provided with threads 27, and the concrete cushion blocks 26 are provided with screw holes 28; the upper end and the lower end of the vertical steel bar 25 respectively penetrate through the jacks 22 of the positioning steel plate 21, and one end of the vertical steel bar 25 with threads 27 is screwed downwards into the screw hole 28 of the concrete cushion block 26; the two ends of the transverse steel bar 24 are screwed into screw holes 28 of the concrete cushion block 26, the transverse steel bar 24 is horizontally arranged in a prestressed beam reinforcement cage, and the transverse steel bar 24 and the vertical steel bar 25 are fixed through steel wires 33; two parallel strip notches 23 are formed in two sides of the positioning steel plate 21, a plurality of insertion holes 22 are formed in the length direction of the positioning steel plate 21, and the positioning steel plate 21 is fixedly connected with the stirrups 6 by enabling steel wires 33 to penetrate through the strip notches 23; the end positioning device 36 comprises a bearing plate 18, a lower sleeve 29 and an anchor plate 30, wherein the lower sleeve 29 and the anchor plate 30 are provided with anchor backing plates 38, the lower sleeve 29 is connected with the bearing plate 18 through a high-strength bolt 37, and the bearing plate 18 is fixedly connected with the anchor plate 30 through the high-strength bolt 37; the anchor plate 30 is provided with a plurality of prestressed tendon insertion holes 31, so that prestressed tendon bundles 39 can be conveniently inserted to stretch the slow-bonding prestressed tendon 7, and the slow-bonding prestressed tendon 7 passes through the bearing plate 18 and the lower sleeve 29.

The plate templates 1, the beam templates 8 and the column templates 9 can be made of wood, steel plates, aluminum plates and other materials.

And the fixed steel bars 13 in the tension end pouring template 3 are fixed through bolts 15.

The square opening cavity mold 19 is arranged at the center of the base plate 10 of the tensioning end pouring template 3, and the square opening cavity mold 19 needs to be detached after the concrete beam 32 is poured and before the slow bonding prestressed tendons 7 are tensioned. The extrusion anchorage device 20 is located in front of the bearing plate 18.

The prestress tensioning end component achieves the strength requirement after the concrete beam 32 is poured, and tensioning end sealing construction is carried out through the tensioning end pouring template 3 after the slow bonding prestressed tendon 7 is tensioned.

The positions of the connecting points of the transverse steel bars 24 and the vertical steel bars 25 are adjusted according to the rib distribution curve function of the slow bonding prestressed tendons 7, so that the rise accuracy and the smooth curve of the slow bonding prestressed tendons 7 are ensured.

The positioning steel plates 21 are arranged on the upper surface and the lower surface of the prestressed beam reinforcement cage in parallel, a plurality of insertion holes 22 are reserved on the positioning steel plates 21 at equal intervals, and the diameter of each insertion hole 22 is the same as that of the vertical reinforcement.

The outside of the slow bonding prestressed tendon 7 is provided with a spiral tendon 17, and the end part of the slow bonding prestressed tendon 7 is also provided with a steering device 40 for changing the steering of the slow bonding prestressed tendon 7 and ensuring that the slow bonding prestressed tendon 7 vertically passes through the bearing plate 18.

Example two

The construction method of the large-span slow-bonding prestressed reinforced concrete beam mainly comprises the following steps:

s1: construction preparation: raw materials enter a field, are checked and accepted, and a template system, a slow bonding prestressed reinforcement 7, a non-prestressed reinforcement, a prestressed anchorage device and the like required by construction are prepared;

s2: bottom die laying: laying a prestressed reinforced concrete beam bottom die, presetting bottom die reverse arch according to a reverse arch value provided by design, and properly adjusting the reverse arch value according to construction practice and the beam tensioning condition;

s3: mounting a non-prestressed reinforcement framework: before binding the steel bars, cleaning the bottom die and coating a layer of isolating agent, installing and binding the steel bars in a certain sequence strictly according to a construction drawing, and reasonably placing cushion blocks to ensure the thickness of a protective layer;

s4: mounting a prestressed tendon positioning support: installing positioning steel plates 21 on the upper surface and the lower surface of a prestressed beam reinforcement cage, and determining the position of a fixed connection point of a transverse reinforcement 24 and a vertical reinforcement 25 in a positioning reinforcement according to a reinforcement distribution curve function of a slowly-bonded prestressed reinforcement 7;

s5: laying a slow bonding prestressed tendon: the slow-bonding prestressed tendon 7 is laid according to the design requirements by a conventional method, the prestressed tendon must rise accurately and curve smoothly during laying, and the slow-bonding prestressed tendon 7 is positioned and fixed by a prestressed tendon positioning bracket;

s6: and (3) mounting prestressed tendon nodes: mounting a prestress tensioning end component and a prestress fixing end component, and fixing the slow bonding prestressed tendon 7 by passing through an end positioning device 36;

s7: and (3) side die installation: installing a prestressed beam side mold on the periphery above the bottom mold, reserving a reinforcing steel bar hole on the side mold, enabling a main reinforcing bar to penetrate through the reinforcing steel bar hole and extend out of the side mold, and fixing the whole prestressed beam reinforcing steel bar and the side mold;

s8: pouring and maintaining concrete: after confirming that the side mold is closed, pouring concrete, wherein the vibration adopts a method of mutually combining a high-frequency attached vibrator as a main part and an inserted vibrator as an auxiliary part, the pouring is finished in time, corresponding maintenance measures are taken according to seasons for normal maintenance, and the mold is removed after the strength reaches the designed strength;

s9: tensioning the prestressed tendons: pretensioning the slow-bonding prestressed tendons when the strength of concrete reaches 80% of the designed strength, completing final tensioning when the strength reaches 100% of the designed strength, tensioning at the beam, column side or haunched end of the beam, and symmetrically tensioning the prestressed tendons of the same beam section;

s10: cutting and sealing the end part of the prestressed tendon: after the slow-bonding prestressed tendons 7 are tensioned, redundant steel strand wires in the working length can be cut, and the length of the steel strand wires exposed out of the anchorage device is not less than 30 mm. And finally, sealing by using fine aggregate concrete, wherein the thickness of the concrete protective layer outside the prestressed tendon is more than 25 mm.