CN112523517A

CN112523517A - Pre-bent laminated wood-concrete composite beam construction method based on crossbow method

Info

Publication number: CN112523517A
Application number: CN202110063938.8A
Authority: CN
Inventors: 徐云; 王雪娇
Original assignee: North China University of Water Resources and Electric Power
Current assignee: North China University of Water Resources and Electric Power
Priority date: 2021-01-18
Filing date: 2021-01-18
Publication date: 2021-03-19

Abstract

A construction method of a pre-bent laminated wood-concrete composite beam based on a crossbow method comprises the following steps: selecting a bent glued wood beam as an embedded stiff skeleton of the composite beam; drilling holes at two ends of the bent glued wood beam, installing a tensioning bolt, fixing one end of a steel strand on the tensioning bolt, and concentrating the other end on a tool anchor; the curved glued wood beam is arched upwards, a counter-force supporting device is installed at the top of the middle span of the curved glued wood beam, and a tool anchor is arranged on the counter-force supporting device; installing a counterforce device between the counterforce supporting device and the tool anchor; the counterforce device loads counterforce step by step until the glued wood beam reaches zero camber; pouring first-stage concrete; and releasing the pre-bending force after the strength of the first-stage concrete reaches 95%, and pouring second-stage concrete. The invention greatly simplifies the original construction equipment and process and really solves the construction design problem of the I-shaped/rectangular section pre-bent laminated wood-concrete composite beam.

Description

Pre-bent laminated wood-concrete composite beam construction method based on crossbow method

Technical Field

The invention relates to the field of building and bridge engineering, in particular to a construction method of a pre-bent laminated wood-concrete composite beam based on a crossbow method design principle.

Background

The pre-bent composite beam has the advantages of high construction speed, light hoisting weight, good crack resistance and seismic performance and the like, and is a novel composite structure system developed by combining the characteristics of a steel reinforced concrete structure and partial prestressed concrete. Although the technology is widely applied to house construction, ports, bridges and underground engineering in countries such as Europe, America, Japan and the like, the development in China at the initial stage is slow, and through continuous exploration and development for decades, China is mature in the aspects of design, processing and construction technology of the steel-concrete pre-bending combined beam. However, with the continuous emergence of novel engineering materials, the traditional pre-bent composite beam faces a new problem, namely, corresponding research and production practice data are lacked, so that the design and construction process of the pre-bent composite beam constructed based on the new material become a bottleneck problem to be solved urgently in the development of China at present.

Disclosure of Invention

A pre-bending composite beam is called as a pre-bending beam for short, and is a novel prestressed-concrete structure which uses a high-strength steel beam to wrap high-grade concrete when the lower flange of the steel beam is in a tension state so as to store prestress. The novel pre-bent composite beam provided by the invention adopts a novel engineering material (namely, a glued wood beam is used for replacing a steel beam), the glued wood is an engineering composite material with high strength-to-quality ratio, attractive appearance and degradability, and the glued wood is widely applied to the engineering fields of bridges, buildings and the like in European and American countries. As a recyclable green and environment-friendly material, the laminated wood beam has better integral rigidity and fire resistance (after fireproof treatment) compared with a steel beam, and more importantly, the problems of stress concentration and fatigue caused by welding seams in the manufacturing process of the steel beam can be effectively avoided.

The construction process of the traditional steel-concrete pre-bent composite beam mainly comprises seven construction steps of steel beam processing, single steel beam loading and pre-pressing, primary concrete pouring, pre-bending force unloading, web plate concrete pouring, pre-bent composite beam installation, top plate concrete pouring and the like. If I-shaped section glued wood beams/rectangular section glued wood beams are adopted to replace steel beams, the original construction process of pre-bending the composite beam cannot be directly applied in consideration of the mechanical characteristics of materials, and the new process not only meets the construction quality of the composite beam, but also simplifies the construction process and reduces the construction equipment cost.

The invention aims to provide a novel construction method of a pre-bent laminated wood-concrete composite beam based on a crossbow method. The invention relates to a combined structural beam with a brand-new concept and a construction technical process derived based on the construction process of two combined structural beams and the manufacturing principle of a traditional crossbow, wherein the construction process of the two combined structural beams comprises the concrete pouring process of the traditional I-shaped section steel beam/rectangular section steel beam-concrete pre-bending combined beam and the prestressed tension process of prestressed concrete construction; in view of the manufacturing principle of the traditional crossbow in China, the pre-bent glued wood beam is equivalent to a bow body in a novel combined structure beam, the construction platform is equivalent to a crossbow arm, the steel strand is equivalent to a bow string, and the pre-bending force is applied to the steel strand through the jack when the steel strand is tensioned. By organically combining the three processes with the pre-bending I-shaped section laminated wood beam/rectangular section laminated wood beam, the original construction equipment and process are greatly simplified, and the construction design problem of the I-shaped/rectangular section pre-bending laminated wood-concrete composite beam is really solved.

The purpose of the invention is realized by the following technical scheme:

a construction method of a pre-bent laminated wood-concrete composite beam based on a crossbow method comprises the following steps:

a. selecting a bent glued wood beam as an embedded stiff skeleton of the composite beam;

b. drilling holes at two ends of the bent glued wood beam, installing tension bolts in the drilled holes, and fixing one ends of the steel strands on the tension bolts;

c. the curved glued wood beam is arched upwards, a counter-force supporting device is installed at the top of the middle span of the curved glued wood beam, and a tool anchor is arranged on the counter-force supporting device;

d. c, concentrating the other ends of the steel strands at the two ends of the bent glued wood beam on the tool anchor;

e. installing a counterforce device between the counterforce supporting device and the tool anchor;

f. formally pre-bending, namely loading counter force step by step through a counter force device until the glued wood beam reaches a horizontal state without camber and deflection;

g. pouring first-stage concrete, installing a concrete template, then pouring the concrete, and embedding the glued wood beam part and the tensioning bolts at the bottom in the first-stage concrete;

h. and releasing the pre-bending force after the strength of the first-stage concrete reaches 95%, shearing the steel strand at the upper part of the laminated wood beam, pouring second-stage concrete, and maintaining to finally obtain the pre-bent laminated wood-concrete combined beam based on the crossbow method.

In the construction method of the pre-bent laminated wood-concrete composite beam based on the crossbow method, the bent laminated wood beam selected in the step a is an I-shaped section laminated wood beam/rectangular section laminated wood beam.

According to the construction method of the pre-bent laminated wood-concrete composite beam based on the crossbow method, the water content of the bent I-shaped section laminated wood beam/rectangular section laminated wood beam is less than 12%, the outer layer of the bent I-shaped section laminated wood beam/rectangular section laminated wood beam is coated with waterproof paint, and carbon fiber cloth is pasted on the upper surface and the lower surface of the bent I-shaped section laminated wood beam/rectangular section laminated wood beam.

In the construction method of the pre-bent laminated timber-concrete composite beam based on the crossbow method, the drilling positions in the bent laminated timber beam are distributed at 1/10 and 9/10 of the span of the bent laminated timber beam in the step b.

In the construction method of the pre-bent laminated wood-concrete composite beam based on the crossbow method, in the step b, after the hole is drilled in the bent laminated wood beam, the adhesive is coated around the drilled hole.

In the step h, after the strength of the first-stage concrete reaches 95%, fastening a tension bolt at the upper part of the glued wood beam, cutting off a steel strand, removing a template, installing a second-stage concrete template, and pouring second-stage concrete to complete the construction of the pre-bent glued wood-concrete composite beam.

By adopting the technical scheme, the invention has the beneficial effects that:

the invention relates to a combined structural beam with a brand-new concept and a construction technical process derived based on the construction process of two combined structural beams and the manufacturing principle of a traditional crossbow, wherein the construction process of the two combined structural beams comprises the concrete pouring process of the traditional I-shaped section steel beam/rectangular section steel beam-concrete pre-bending combined beam and the prestressed tension process of prestressed concrete construction; in view of the manufacturing principle of the traditional crossbow in China, the pre-bending glued wood beam is equivalent to a bow body in a novel combined structure, the construction platform is equivalent to a crossbow arm, the steel strand is equivalent to a bow string, and the pre-bending force is applied to the steel strand through the jack when the steel strand is tensioned. By organically combining the three processes with the pre-bending I-shaped section laminated wood beam/rectangular section laminated wood beam, the original construction equipment and process are greatly simplified, and the construction design problem of the I-shaped/rectangular section pre-bending laminated wood-concrete composite beam is really solved.

Drawings

Fig. 1 is a schematic pre-bending view of an i-section curved laminated timber beam according to the present invention.

Fig. 2 is a left side view of fig. 1.

Fig. 3 is a schematic structural view of a pre-bent glued wood beam with an I-shaped section.

Fig. 4 is a left side view of fig. 3.

Fig. 5 is a schematic view of a first-stage concrete pouring position of the I-shaped section laminated wood beam.

Fig. 6 is a left side view of fig. 5.

Fig. 7 is a schematic view of a laminated wood beam-concrete composite beam of i-shaped section pre-bent after first-stage concrete.

Fig. 8 is a left side view of fig. 7.

Fig. 9 is a schematic view of a second-stage concrete post-preflex laminated wood-concrete beam with an i-section.

Fig. 10 is a left side view of fig. 9.

Fig. 11 is a schematic pre-bending view of a rectangular cross-section curved laminated wood beam of the present invention.

Fig. 12 is a left side view of fig. 11.

Fig. 13 is a schematic view of a pre-bent rectangular cross-section laminated wood beam structure.

Fig. 14 is a left side view of fig. 13.

Fig. 15 is a schematic view of a rectangular-section laminated wood beam in concrete pouring in one stage.

Fig. 16 is a left side view of fig. 15.

Fig. 17 is a schematic view of a rectangular-section laminated wood beam-concrete composite beam pre-bent after first-stage concrete.

Fig. 18 is a left side view of fig. 17.

Fig. 19 is a schematic view of a post-secondary concrete pre-bent rectangular-section laminated wood-concrete composite beam.

Fig. 20 is a left side view of fig. 19.

Fig. 21 is a view of construction equipment for a pre-bent laminated wood-concrete composite beam according to the present invention.

Fig. 22 is a left side view of fig. 21.

Detailed Description

The structure and operation of the present invention will be described in detail with reference to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, fig. 7, fig. 8, fig. 9, fig. 10, fig. 11, fig. 12, fig. 13, fig. 14, fig. 15, fig. 16, fig. 17, fig. 18, fig. 19, fig. 20, and fig. 21.

Example 1

As shown in fig. 1 to 10, a method for constructing a pre-bent laminated wood-concrete composite beam based on a crossbow method, which is a method for constructing a pre-bent laminated wood-concrete composite beam with an i-shaped cross section, includes the following steps:

a. selecting a bent I-shaped section laminated wood beam 16 as an embedded stiffened framework of the composite beam;

for the processing of the wood beam, for the steel beam with the I-shaped section, the technical problems of stress concentration and fatigue damage caused by welding seams, large steel consumption, high single-span manufacturing cost, complex construction process and the like always restrict the development of the steel-concrete pre-bent combined beam to be a gap which is difficult to exceed. The glued wood beam with the I-shaped section has simpler manufacturing process and cost in the aspects of design, material taking, processing and the like, replaces the traditional welding mode with a gluing mode, and avoids the problem of structural defects generated in the manufacturing process of the pre-bent beam. Considering the span design of the laminated wood beam and the prestress and bearing functions of the wood beam in the whole composite beam, the web plate and the wing plate of the laminated wood beam with the I-shaped section are made of structural composite materials LVL (laminated veneer lumber) with higher strength. Considering that the concrete needs about 20 days to reach the target strength, and the tensile side of the wood beam is subjected to potential tensile fracture in the process, the carbon fiber cloth 17 needs to be adhered to the upper side and the lower side of the wood beam in the tensile process so as to enhance the tensile strength of the whole wood beam. The water content is an important factor directly influencing the bending strength of the wood beam, and the original water content of the wood beam can be greatly changed by pouring concrete, so that the water content of wood is strictly controlled below 12% in the whole processing process of the glued wood beam, and 3 layers of waterproof paint are coated to block the invasion of water.

in order to construct a crossbow tension structure system, the I-shaped section bending laminated wood beam is required to be arranged at the positions which are separated from the ends 1/10 and 9/10 of the bent laminated wood beam, the I-shaped section bending laminated wood beam is composed of a laminated wood beam web 15, a laminated wood upper flange 14 at the upper end of the web and a lower flange 18 at the lower end of the laminated wood beam web, and holes are pre-drilled in the center lines of the laminated wood upper flanges and the laminated wood lower flanges on the two sides of the web at the two ends of the I-shaped section bending laminated wood beam body. And (3) installing 1 set of tensioning bolts 8 on the drilled holes on two sides of the web plate at one end of the bent glued wood beam, and respectively fastening 2 tensioning steel strands 1 in the tensioning bolts on two sides of the web plate. And drilling holes at the other end of the bent glued wood beam, installing tension bolts and fastening steel strands. The transverse instability caused by the eccentric stress of the beam body is a key problem in the construction stage of manufacturing the pre-bent combined beam, so that in order to ensure the accurate stress positions of 3 points of the central line of the beam and two ends of the bent glued wood beam, the glued wood beam on site needs to be retested before pre-bending, and the method mainly measures the positions of the central lines of 3 control sections and the positions of holes, and allows deviation: the mid-span midline position deviation is less than 0.1mm, and the two ends open the holes with the position deviation less than 0.1mm (as shown in figures 1 and 2).

c. The curved glued wooden beam is arched upwards, a counter-force supporting device is installed at the top of the middle span of the curved glued wooden beam, and a tool anchor is arranged on the counter-force supporting device;

considering the balance of the anchoring end, the midspan counterforce supporting device and the force system of the opening points at the two ends, the opening on the glued wood beam can cause the local stress redistribution of the flange part, so that an adhesive needs to be coated at the junction of the tension steel strand and the opening of the flange to improve the engagement degree of the tension steel strand and the opening of the flange, and further the stress loss caused by the opening is compensated. After the pre-bending force is gradually applied, the applied external force and the supporting force of the cross counterforce supporting frame are uniformly transmitted by utilizing 4 balance points at two ends of the bent glued wood beam, so that the preliminary positioning and fixing of the glued wood beam are completed (as shown in figures 1 and 2).

d. C, concentrating the other ends of the 4 steel strands at the two ends of the bent glued wood beam on the tool anchor;

f. formally pre-bending, namely loading counter force step by step through a counter force device until the glued wood beam reaches a horizontal state without camber and deflection, as shown in figures 3 and 4;

residual deformation exists in the glued wood beam, the final upwarping amplitude of the cross section of the beam end is used as a control value, pressure testing is carried out on the glued wood beam, and meanwhile, the actual pre-bending force is checked. After the connection condition among the tensioning bolts, the tensioning steel strands and the jacks, the positions of the central line of the span of the wooden beam and the openings at two ends and the application condition of the acting force are carefully checked to confirm that no installation quality problem exists, the glued wooden beam is subjected to step-by-step pressure test, the actual pre-bending force is checked at the same time, and the final upwarp amplitude of the section at the beam end is used as a control value.

The actual pre-bending force takes the magnitude of external force applied when the upwarp amplitude of two ends reaches a design value as a design value, and the pre-bending force is unloaded step by step after the pre-bending beam reaches no camber, so as to obtain the residual upwarp value of the beam end.

After the bending test is finished and the glued wood beam is ensured not to have any cracking and other adverse problems, the glued wood beam is loaded step by step until the glued wood beam reaches the horizontal state without camber and deflection, and the glued wood beam is continuously kept in the state until the poured concrete reaches the target strength. The pre-bending force loading is carried out by taking the deflection amplitude of the beam end of the laminated wood beam as a control value, and reloading when the difference between the design value of the deflection amplitude and the actual value is more than 5%. (as shown in fig. 3 and 4).

g. Pouring first-stage concrete 19, installing a concrete template, then pouring the concrete, and embedding the lower flange 18 of the glued wood beam, part of the web 15 and the lower tension bolt in the first-stage concrete;

after determining that the wooden beam has no cracking, transverse instability and the like again, a concrete template can be installed on the glued wooden beam, then concrete above C40 is poured on the lower flange part, and the concrete pouring position is shown in figures 5 and 6. It should be noted that before and during the casting process, the stress conditions of the tension steel strand and the tension bolt need to be checked repeatedly to avoid the problems of damage to the tension steel strand and the opening of the wood beam caused by the construction (see fig. 5-8).

h. After the strength of the first-stage concrete reaches 95%, the first-stage concrete is subjected to graded unloading, the lower flange concrete generates larger forward bending prestress through the resilience of the wood beam, the prestress is balanced with the compressive stress of the lower flange concrete, the whole wood beam is changed into a stiff wood-concrete beam, the beam recovers part of camber after unloading and is in a slightly convex shape (as shown in figures 7 and 8), and the first-stage glued wood-concrete combined beam 20 is obtained.

i. Pouring concrete in the second stage: after the hoisting of the glued wood-concrete composite beam 20 in the first period is completed and the tension steel strand and the concrete template are removed, after the whole broken beam is installed, the mid-span camber is measured again, a support is erected, a shear connector is installed at the center line position of the upper beam of the wood beam, templates are installed on the upper part of the lower flange and part of the web plate, and reinforcing steel bars are bound; installing a template on a partial web plate at the lower part of the lower upper flange of the upper flange, and binding reinforcing steel bars; and simultaneously pouring secondary concrete 21 on the two parts to enable the composite beam to form a whole span, and further completing construction of the I-shaped section laminated wood-concrete pre-bent composite beam based on the crossbow method (as shown in figures 9 and 10).

The I-shaped section pre-bent laminated wood-concrete composite beam is formed by embedding an I-shaped section laminated wood beam in concrete, pouring concrete in the first stage to completely wrap a lower wing plate of the I-shaped section laminated wood beam in the concrete in the first stage, then performing second-stage concrete pouring on the rest exposed I-shaped web plate and an upper wing plate external mold, and completely wrapping the I-shaped section laminated wood beam in the concrete.

Example 2

As shown in fig. 11 to 20, a method for constructing a pre-bent laminated wood-concrete composite beam based on a crossbow method in this embodiment is a method for constructing a pre-bent laminated wood-concrete composite beam with a rectangular cross section, and includes the following steps:

a. the curved rectangular section laminated wood beam 22 is selected as the embedded stiff skeleton of the composite beam: compared with an I-shaped section steel beam, the rectangular section laminated wood beam can effectively reduce the production process complexity of the traditional steel beam from the aspects of camber, span, size and the like from the aspect of materials, and effectively reduce the problems of stress concentration, fatigue damage and the like caused by welding seams in the manufacturing engineering of the I-shaped section steel beam from the aspect of construction quality. In consideration of the pre-stress and the external load bearing effect of the pre-bent laminated wood beam in the composite beam, the laminated wood beam is usually made of engineering composite wood such as structural composite materials LVL (laminated veneer lumber), PSL (parallel strand lumber), LSL (laminated strand lumber) and laminated wood. The pre-bent glued wood beam needs to be manufactured into a parabolic upward-arched wood beam according to design requirements. The water content of the wood can directly influence the bending strength and the anti-arching effect of the laminated wood beam, in order to avoid the change of the original water content of the laminated wood beam caused by the pouring of the concrete, the water content of the raw materials and the finished laminated wood beam is strictly controlled below 12%, and 3 layers of waterproof paint are coated to isolate water. The manufacturing cycle of the pre-bent composite beam is generally about 20 days, and in order to prevent the middle part of the glued wood beam from being broken by stretching during the period, carbon fiber cloth needs to be adhered to the upper side and the lower side of the glued wood beam in a stretching mode so as to enhance the tensile strength of the whole glued wood beam.

b. Drilling holes at two ends of the bent glued wood beam with the rectangular cross section, installing tensioning bolts 8 in the drilled holes, and fixing one end of each steel strand 1 on each tensioning bolt;

due to the adoption of the design principle of a crossbow, holes need to be pre-drilled at the central lines of the beam bodies at the positions which are separated from 1/10 and 9/10 span positions of the beam ends of the glued wood beam with the rectangular section, 2 sets of tensioning bolts are installed, and 2 tensioning steel strands are respectively fastened in the tensioning bolts at 1/10 and 9/10. In order to ensure accurate stress positions of the 3 points of the beam center line and the beam end and prevent transverse instability of the glued wood beam caused by eccentric stress, re-measurement needs to be performed on the glued wood beam on site before pre-bending, the positions of the center lines of 3 control sections and the positions of holes are mainly measured, and the allowable deviation is as follows: the mid-span midline position deviation is less than 0.1mm and the two ends open the holes with a positional deviation of less than 0.1mm (as shown in figures 11 and 12).

the rectangular-section glued wood beam is fixed in place, the tensioning bolt is installed at an opening at the beam end of the glued wood beam, in order to enhance the bonding force between the bolt and the glued wood beam, an adhesive needs to be coated on the contact part of the bolt and the glued wood beam in advance, and 2 tensioning steel strands are gathered at a pre-bending force applying device, namely a counterforce device. After initial pre-bending force is applied step by step, the steel strands at the positions of the holes at the two ends and the mid-span counter-force supporting device of the construction platform form a three-point balance force system, and the initial positioning and fixing of the glued wood beam are completed after the tensioning steel strands are straightened (as shown in fig. 11 and 12).

d. C, concentrating the other ends of the 2 steel stranded wires at the two ends of the bent glued wood beam in the step b on a tool anchor;

and (3) bending test of the glued wood beam, wherein before bending test, the connection condition among the tensioning bolt, the tensioning steel strand and the jack, the position of the center line of the span of the glued wood beam and the openings at two ends of the glued wood beam and the acting force application condition are carefully checked. Residual deformation exists in the glued wood beam, the final upwarping amplitude of the cross section of the beam end is used as a control standard, pressure testing is carried out on the glued wood beam, and meanwhile, the actual pre-bending force is checked. And when the upwarp amplitudes at the two ends reach the design value, taking the force as the actual design value of the pre-bending force, and unloading the pre-bending force step by step to further obtain the residual upwarp value of the beam end.

And (3) formally pre-bending the glued wood beam, gradually loading pre-bending force, taking the bending amplitude at the beam end of the glued wood beam as a control value, and reloading when the difference between the design value of the bending amplitude and the actual value is more than 5%. As shown in fig. 13 and 14, the loading of the pre-bending force may be stopped until the laminated wood beam reaches a level of no camber and no deflection.

g. Pouring first-stage concrete, installing a concrete template, then pouring the concrete, and embedding the glued wood beam part and the tensioning bolts at the bottom in the first-stage concrete 19;

the method comprises the following specific operations: after confirming that the pre-bending of the wood beam has no crack, transverse instability, beam end opening and no damage to the tension steel stranded wires, a concrete template can be installed, and then concrete is poured into high-performance concrete with the concrete content of more than C40 (as shown in figures 15 and 16).

h. When the strength and the elastic modulus of the first-stage concrete reach 95% of the design values, the pre-bending force can be gradually released, the first-stage concrete obtains the pre-stress by means of the elastic recovery of the pre-bent steel beam, the camber of the restored part of the glued wood beam at the moment, namely the pre-bent rectangular section glued wood- (first-stage) concrete composite beam 24, and the anti-camber of the pre-bent glued wood beam is smaller than the original pre-camber value due to the constraint action of the concrete (as shown in figures 17 and 18).

i. Pouring concrete in the second stage: after the reverse camber of the pre-bent rectangular section laminated wood- (first-stage) concrete composite beam reaches the design requirement, the tension steel strand and the concrete template can be removed, after the beam is transported to the corresponding beam span erection position, the mid-span camber is measured again, the support is erected, the template is installed, the reinforcing steel bars are bound, the shear connector is installed on the upper portion of the laminated wood beam, the second-stage concrete is poured, and the construction of the pre-bent composite beam is completed (as shown in fig. 19 and 20).

The laminated wood-concrete composite beam obtained after the whole construction can be embodied from fig. 19 and 20, and the laminated wood beam with the rectangular section is completely wrapped in the concrete.

The present invention is implemented by a pre-bent laminated wood-concrete composite beam construction apparatus based on the crossbow method, as shown in fig. 21 and 22, wherein the counter force supporting device is a longitudinal supporting beam of the pre-bent laminated wood-concrete composite beam construction apparatus based on the crossbow method, and the others are the same as the apparatus.

The utility model provides a pre-bending glued wood-concrete composite beam construction equipment based on crossbow method, includes the stretch-draw bolt 8 that sets up respectively at crooked glued wood roof beam 9 both ends to and set up the vertical supporting beam 7 at crooked glued wood roof beam middle part, vertical supporting beam top is provided with instrument anchor 3, still sets up counterforce device 2 between vertical supporting beam top and instrument anchor, fixes steel strand wires 1 on the stretch-draw bolt at crooked glued wood roof beam both ends, and the tip of two steel strand wires passes instrument anchor and concentrates the fixing on the instrument anchor.

The invention relates to pre-bent laminated wood-concrete composite beam construction equipment based on a crossbow method, wherein a limiting plate 4 is arranged at the top of a longitudinal supporting beam, a counterforce device is arranged between the limiting plate and a tool anchor, and the limiting plate is used as a supporting platform of the counterforce device.

The pre-bent laminated wood-concrete composite beam construction equipment based on the crossbow method also comprises a transverse supporting beam 5 arranged on one side of two ends of a longitudinal supporting beam for facilitating construction damage, one end of the longitudinal supporting beam corresponding to a counterforce device is fixed on the transverse supporting beam through a counterforce supporting frame 13, one end of the longitudinal supporting beam corresponding to a bent laminated wood beam is fixed on the transverse supporting beam through a midspan counterforce support 10, and the two beams are fixedly connected to the supporting beam through a transverse support 12, so that the effect of supporting stability is achieved. And foundation bolts 6 are arranged at the bottoms of the two transverse supporting beams and are fixed on the construction site through the foundation bolts.

A pre-bent laminated wood-concrete combined beam construction device based on a crossbow method is characterized in that a wood beam stabilizing support 11 is arranged on a midspan counter-force support.

The counter-force device of the invention adopts a jack, and can also adopt other counter-force loading devices.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the overall concept of the invention, and these should be considered as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicability of the patent.

Claims

1. A construction method of a pre-bent laminated wood-concrete composite beam based on a crossbow method comprises the following steps:

h. and releasing the pre-bending force after the strength of the first-stage concrete reaches 95%, shearing the steel strand at the upper part of the laminated wood beam, pouring second-stage concrete, and curing to obtain the pre-bent laminated wood-concrete composite beam.

2. The pre-bent laminated wood-concrete composite beam construction method based on the crossbow method of claim 1, wherein: the bent glued wood beam selected in the step a is an I-shaped section glued wood beam/rectangular section glued wood beam.

3. The pre-bent laminated wood-concrete composite beam construction method based on the crossbow method of claim 3, wherein: the water content of the bent I-shaped section laminated wood beam/rectangular section laminated wood beam is less than 12%, waterproof paint is coated on the outer layer of the bent I-shaped section laminated wood beam/rectangular section laminated wood beam, and carbon fiber cloth is pasted on the upper surface and the lower surface of the bent I-shaped section laminated wood beam/rectangular section laminated wood beam.

4. The pre-bent laminated wood-concrete composite beam construction method based on the crossbow method of claim 1, wherein: the drilling locations on the curved glulam beam are distributed at 1/10 and 9/10 of the curved glulam beam span.

5. The pre-bent laminated wood-concrete composite beam construction method based on the crossbow method of claim 1, wherein: and b, after drilling holes in the bent glued wood beam, coating adhesive around the drilled holes.

6. The pre-bent laminated wood-concrete composite beam construction method based on the crossbow method of claim 1, wherein: and h, after the strength of the first-stage concrete reaches 95%, fastening a tension bolt at the upper part of the bent glued wood beam, shearing a steel strand, dismantling the template, then installing a second-stage concrete template, pouring second-stage concrete, and completing construction of the pre-bent glued wood-concrete composite beam.