Fabricated splicable beam and plate and method thereof
By using precast concrete beams and slabs in a stepped zigzag pattern and connected with tension bolts, combined with the plastic hinge line theory, the problems of long construction period and material waste in prefabricated buildings were solved, achieving an efficient and environmentally friendly construction process.
Patent Information
- Application Number
- CN202410479570.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-22
- Publication Date
- 2025-10-24
AI Technical Summary
The construction period of existing prefabricated buildings is long, they are greatly affected by uncertain factors such as weather, and they also result in serious material waste and environmental pollution.
The standardized production of precast concrete beams and slabs is adopted, and efficient splicing of beams and slabs is achieved through stepped zigzag splicing and tension bolt connection, combined with the plastic hinge line theory to divide the plates.
Shorten construction period, reduce material waste, lower human resource requirements, improve production efficiency, reduce construction waste, and comply with green construction requirements.
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Abstract
Description
BACKGROUND
[0001] The fabricated reinforced concrete structure is one of the important directions of the development of building structures in China, which is beneficial to the development of building industrialization in China, improves production efficiency, saves energy, develops green and environmentally friendly buildings, and is beneficial to improve and ensure the quality of building engineering. Compared with the cast-in-place concrete construction method, the fabricated structure is beneficial to green construction, because the fabricated construction can better meet the requirements of green construction such as land saving, energy saving, material saving, water saving and environmental protection, reduces the negative impact on the environment, including reducing noise, preventing dust, reducing environmental pollution, clean transportation, reducing site interference, saving water, electricity, materials and other resources and energy, and following the principle of sustainable development. SUMMARY
[0002] The purpose of the present application is to provide a fabricated beam and slab and a splicing method of beam and slab, which is convenient for construction by prefabricated components, thereby saving construction period and cost.
[0003] To achieve the above purpose, the present application provides a fabricated beam and slab and a splicing method of beam and slab, specifically: the splicing method of prefabricated concrete floor is divided into two forms of one-way slab and two-way slab. The splicing method of one-way slab is to splice the stepped serrated shape of two splicing slabs at the half length position, and anchor with a pair of bolts. The vertical constraint of the prefabricated concrete beam to the floor is strong, but the rotational constraint is weak. The slab division of the prefabricated concrete floor is divided according to the plastic hinge line position under the action of four-edge simply supported plastic hinge line theory. The connection of the four slabs adopts the same splicing method as the one-way slab. The splicing position of the prefabricated concrete beam is located at the midpoint of the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The connection method between the prefabricated concrete beams is stepped serrated splicing, and is anchored with a pair of bolts. The overlapping joint of the beam and the plate adopts the outer part of the prefabricated concrete floor reserved hole aligning the embedded U-shaped steel of the prefabricated concrete beam, and is fastened and connected with bolts.
[0004] The two forms of the above-mentioned concrete two-way slab and one-way slab are: when the length-to-width size ratio of the floor is less than 2, it is a two-way slab; when the length-to-width size ratio of the floor is between 2 and 3, it is appropriate to consider as a two-way slab; when the length-to-width size ratio of the floor is greater than 3, it is a one-way slab.
[0005] The splicing method of the above-mentioned one-way slab is that the whole one-way slab is spliced from two prefabricated slabs, and the splicing part of the two slabs is provided with an outer structure of a certain size, and the splicing surface is provided with a serrated structure and a reserved bolt hole, so that the outer parts of the slabs are fastened and connected with bolts after splicing.
[0006] The precast concrete beam has a constraint effect on the floor, and the floor and the beam will generate vertical displacement and horizontal displacement under the action of uniform load; the vertical displacement and the horizontal displacement of the floor increase with the increase of the load, but the horizontal displacement under the yield state and the ultimate state of the floor is less than one tenth of the vertical displacement, so the influence of the horizontal displacement on the internal force distribution of the floor can be ignored, and the floor horizontal displacement is positively correlated with the rotational constraint of the beam on the floor, so the influence of the rotational constraint of the beam on the floor can be ignored, therefore, when the floor is analyzed, a simply supported rectangular plate bearing capacity theoretical model can be used for analysis.
[0007] The slab division mode of the bidirectional plate is based on the position of the plastic hinge line in the plastic hinge line theory, which is a commonly used method for ultimate load analysis of reinforced concrete plates, which studies various failure patterns that may occur on the plate and determines the possible displacement field. According to the upper bound theorem of the structural ultimate analysis method, the ultimate load value of the reinforced concrete plate can be obtained. The ultimate load obtained according to the plastic hinge line theory is the upper limit value. The plastic hinge line theory can accurately give the ultimate bearing capacity of the reinforced concrete plate, and the actual failure pattern of the reinforced concrete plate is also consistent with the given failure mechanism. A plurality of plastic hinge lines are formed on the reinforced concrete plate under the ultimate state, and the plastic hinge lines divide the plate into a plurality of plate blocks. All longitudinal steel bars passing through the plastic hinge lines have reached yield, and the resistance bending moment along the plastic hinge line section has reached the ultimate bending moment value. The plastic hinge line bearing positive bending moment is called positive plastic hinge line, and the crack appears on the lower surface of the plate; the plastic hinge line bearing negative bending moment is called negative plastic hinge line, and the crack appears on the upper surface of the plate.
[0008] The lap joint mode between the plate blocks of the bidirectional plate is that the bidirectional plate is divided into four blocks according to the position of the plastic hinge line, and a certain size of the overhanging structure is reserved at the splicing position of the plate blocks, the splicing surface is a zigzag structure and has a reserved bolt hole, so that the overhanging part between the plate blocks after splicing can be fastened and connected by bolts.
[0009] The splicing position of the precast concrete beam is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0), the rotational constraint of the column on the beam and the vertical constraint at the support are strong, so the support form at both ends of the beam is equivalent to a fixed support, the position of the inflection point of the two-end fixed beam under the action of uniform load is (1 / 2-√6 / 6)l away from the end support, l is the length of the beam, and the position of the shear force of the two-end fixed beam under the action of uniform load is located in the middle of the beam, therefore, considering the positions with smaller bending moment and shear force, the midpoint of the two positions is selected as the splicing position of the beam.
[0010] The splicing mode of the precast concrete beam is that a certain size of the overhanging structure is reserved at the splicing position between the precast concrete beams, the splicing surface is a zigzag structure and has a reserved bolt hole, so that the overhanging part after splicing can be fastened and connected by bolts.
[0011] The beam and the plate are spliced at the joint, the U-shaped steel is embedded in the prefabricated concrete beam and extends out of the top of the beam by a certain size, the overlapping joint of the beam and the plate is aligned with the extended part of the embedded U-shaped steel of the prefabricated concrete beam through the reserved hole of the prefabricated concrete floor, and is fastened and connected through bolts.
[0012] Compared with the prior art, the advantages of the present application are that:
[0013] The prefabricated building components can be mass-produced in a standardized manner and are not affected by weather and other uncertain factors, are more reliable in quality, can effectively save human resources, shorten the construction period, increase the artificial control of the construction period, and have a much higher production efficiency than manual operation.
[0014] After the prefabricated components are processed, they are directly transported to the construction site for assembly, this construction process reduces material waste in the construction process, and also greatly reduces the generation of construction waste, saves water, electricity and materials, and is environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 It is a splicing diagram of the prefabricated concrete one-way plate of the present application;
[0016] Figure 2 It is a plate block division diagram of the concrete two-way plate of the present application;
[0017] Figure 3 It is a splicing diagram of the prefabricated concrete two-way plate of the present application;
[0018] Figure 4 It is a stress analysis and splicing diagram of the prefabricated concrete beam of the present application;
[0019] Figure 5 It is a splicing diagram of the concrete beam and plate joint of the present application. DETAILED DESCRIPTION
[0020] Reference Figure 1 The one-way plate is spliced in the manner that the entire one-way plate is spliced from two prefabricated plates, and the splicing part of the two plate blocks is provided with an extended structure of a certain size, the splicing surface is provided with a sawtooth structure and a reserved bolt hole, so as to facilitate the fastening and connection through bolts after splicing.
[0021] Reference Figure 2, the slab division of the two-way slab is based on the location of plastic hinge line. Plastic hinge line theory is a common method for ultimate load analysis of reinforced concrete slab. It studies the possible failure patterns of the slab and determines the possible kinematically admissible displacement field. According to the upper bound theorem of the structural ultimate analysis method, the ultimate load value of the reinforced concrete slab can be obtained. The ultimate load obtained by the plastic hinge line theory is the upper limit value. The plastic hinge line theory can accurately give the ultimate bearing capacity of the reinforced concrete slab, and the actual failure pattern of the reinforced concrete slab is also consistent with the given failure mechanism. A number of plastic hinge lines are formed in the reinforced concrete slab under the ultimate state, and the plastic hinge lines divide the slab into several slabs. All longitudinal steel bars along the plastic hinge line have reached yield, and the resistance bending moment along the plastic hinge section has reached the ultimate bending moment value. The plastic hinge line that bears positive bending moment is called positive plastic hinge line, and the crack appears on the lower surface of the slab. The plastic hinge line that bears negative bending moment is called negative plastic hinge line, and the crack appears on the upper surface of the slab. Among them, Figure 2 wherein n represents the position parameter of the two-way slab; μ is the orthogonal parameter, i.e. the yield bending moment ratio of the two directions of the two-way slab; M x is the yield bending moment value of the slab along the long side direction; M y is the yield bending moment value of the slab along the short side direction.
[0022]
[0023] Reference Figure 3 , the lap joint mode of the two-way slab is divided into four blocks according to the location of the plastic hinge line. The lap joint part between the blocks is provided with an overhanging structure with a certain size, the joint surface is provided with a zigzag structure and a reserved bolt hole, and the bolt is used for fastening connection after the joint is completed.
[0024] Reference Figure 4 , the joint position of the prefabricated concrete beam is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The rotation constraint of the column to the beam and the vertical constraint at the support are strong, so the support form at both ends of the beam is equivalent to a fixed support. The inflection point position of the two-end fixed beam under the action of uniform load is (1 / 2-√6 / 6)l away from the end support, l is the length of the beam, and the shear force of the two-end fixed beam under the action of uniform load is located at the mid-span of the beam. Therefore, considering the positions with smaller bending moment and shear force, the midpoint of the two positions is selected as the joint position of the beam. Meanwhile, the joint part between the prefabricated concrete beams is provided with an overhanging structure with a certain size, the joint surface is provided with a zigzag structure and a reserved bolt hole, and the bolt is used for fastening connection after the joint is completed.
[0025] Reference Figure 5The above-mentioned jointing mode of the beam and the slab, the U-shaped steel is pre-buried in the prefabricated concrete beam and extends out of the beam top by a certain size, the jointing of the beam and the slab is overlapped and connected by aligning the extended part of the pre-buried U-shaped steel of the prefabricated concrete beam with the reserved hole of the prefabricated concrete slab, and fastening and connecting by the bolt.
Claims
1. A fabricated beam and slab and a method of splicing thereof, characterized by: The splicing mode of precast concrete floor is divided into two forms of single-way plate and double-way plate. The splicing mode of single-way plate is that the two splicing plates are spliced in a stepped zigzag shape at the position of half of the total length, and are anchored by a pair of bolts. The vertical constraint of precast concrete beam to the floor is strong, but the rotational constraint is weak. The division of precast concrete floor slab is divided according to the plastic hinge line position of plastic hinge line theory under four-edge simply supported action. The connection of four slabs adopts the same splicing mode as the single-way plate. The splicing position of precast concrete beam is located at the midpoint of the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The connection mode between precast concrete beams is a stepped zigzag splicing, and is anchored by a pair of bolts. The overlapping junction of beam and plate adopts the outer part of the precast concrete floor reserved hole aligned with the pre-buried U-shaped steel of the precast concrete beam, and is fastened and connected by bolts.
2. Concrete two-way and one-way slabs according to claim 1, characterized in that: When the length-to-width ratio of the floor is less than 2, it is a double-way plate. When the length-to-width ratio of the floor is between 2 and 3, it is appropriate to consider it as a double-way plate. When the length-to-width ratio of the floor is greater than 3, it is a single-way plate.
3. The splicing method of the unidirectional sheet according to claim 1, wherein: The entire single-way plate is spliced from two precast plates, and the splicing part of the two plates is provided with an extended structure of a certain size. The splicing surface is in a zigzag shape and has a reserved bolt hole, which facilitates the fastening and connection of the plates after splicing.
4. The restraining action of a precast concrete beam on a floor slab as claimed in claim 1, wherein: Under uniform load, the floor and beam will produce vertical displacement and horizontal displacement. The vertical displacement and horizontal displacement of the floor increase with the increase of the load, but the horizontal displacement under the yield state and ultimate state of the plate is less than one tenth of the vertical displacement, so the influence of the horizontal displacement on the internal force distribution of the floor can be ignored. The horizontal displacement of the floor and the rotational constraint of the beam to the plate are positively correlated, so the influence of the rotational constraint of the beam to the plate can be ignored. Therefore, the floor can be analyzed as a four-edge simply supported rectangular plate model.
5. The method of claim 1, wherein the plastic hinge locations are based on a plastic hinge theory. The plastic hinge line theory is a commonly used method for ultimate load analysis of reinforced concrete slabs. It studies various failure patterns that may occur in the slab and determines the possible displacement field that can be allowed. According to the upper bound theorem of the structure ultimate analysis method, the ultimate load value of the reinforced concrete slab can be obtained. The ultimate load obtained by the plastic hinge line theory is the upper limit value. The plastic hinge line theory can accurately give the ultimate bearing capacity of the reinforced concrete slab, and the actual failure pattern of the reinforced concrete slab is also consistent with the given failure mechanism. At the ultimate state, the reinforced concrete slab forms several plastic hinge lines, which divide the slab into several slabs. All longitudinal steel bars along the plastic hinge line have reached yield, and the resistance moment of the cross section along the plastic hinge line has reached the ultimate bending moment value. The plastic hinge line under positive bending moment is called positive plastic hinge line, and the crack occurs on the lower surface of the plate. The plastic hinge line under negative bending moment is called negative plastic hinge line, and the crack occurs on the upper surface of the plate.
6. The method according to claim 1, wherein the two-way plate is connected by the lap joint between the plate pieces. The double-way plate is divided into four blocks according to the position of the plastic hinge line. The splicing part between the slabs is provided with an extended structure of a certain size. The splicing surface is in a zigzag shape and has a reserved bolt hole, which facilitates the fastening and connection of the plates after splicing.
7. The precast concrete beam of claim 1, wherein the splice location is at the midpoint between the point of contraflexure (moment = 0) and the mid-span location (shear = 0), and wherein: The rotation constraint of the column to the beam and the vertical constraint at the support are strong, so the support form at the two ends of the beam is equivalent to a fixed support. The position of the inflection point of the two-end fixed beam under the action of the uniform load is (1 / 2-√6 / 6)l from the end support, l is the length of the beam, and the position of the zero shear of the two-end fixed beam under the action of the uniform load is located in the middle of the beam span. Therefore, the midpoint of the two positions with smaller bending moment and shear is selected as the splicing position of the beam.
8. The method of splicing precast concrete beams according to claim 1, wherein: The splicing part between the precast concrete beams is provided with an overhanging structure with a certain size, the splicing surface is provided with a zigzag structure and a reserved bolt hole, so that the bolt fastening connection after the splicing is facilitated.
9. The beam and slab interface joint of claim 1, wherein: The U-shaped steel is embedded in the precast concrete beam and overhanging out of the top of the beam by a certain size, the overlapping joint between the beam and the plate is connected by the overhanging part of the U-shaped steel embedded in the precast concrete beam through the reserved hole of the precast concrete floor and the bolt fastening.