CN114953168A - Construction method for solving crack generated by small box girder end tensioning prestress - Google Patents
Construction method for solving crack generated by small box girder end tensioning prestress Download PDFInfo
- Publication number
- CN114953168A CN114953168A CN202210670633.8A CN202210670633A CN114953168A CN 114953168 A CN114953168 A CN 114953168A CN 202210670633 A CN202210670633 A CN 202210670633A CN 114953168 A CN114953168 A CN 114953168A
- Authority
- CN
- China
- Prior art keywords
- box girder
- small box
- tensioning
- rubber plate
- reinforced concrete
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
- B28B23/02—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members
- B28B23/04—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members the elements being stressed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B17/00—Details of, or accessories for, apparatus for shaping the material; Auxiliary measures taken in connection with such shaping
Abstract
The invention discloses a construction method for solving the problem of cracks generated by small box girder end tensioning prestress, which comprises the steps of pouring a reinforced concrete pedestal; installing a rubber plate on the reinforced concrete pedestal to ensure that the upper end surface of the reinforced concrete pedestal is attached to the lower end surface of the rubber plate; installing a small box girder bottom template on the rubber plate, and installing a small box girder side template and a small box girder reinforcing steel bar; pouring small box girder concrete; and (5) curing, namely performing prestress tensioning after the strength of the concrete reaches the design requirement. By adopting the method, the rubber plate has certain rigidity, can bear the weight of the template and the steel bar and the concrete, but has low rigidity, and can generate compression deformation when the rubber plate is subjected to great downward pressure of the end of the small box girder during prestress tensioning, so that the end of the small box girder does not generate cracks, the problem that the end of the small box girder generates cracks due to the prestress tensioning is solved, and the prefabrication quality of the small box girder is ensured.
Description
Technical Field
The invention relates to the field of small box girder construction, in particular to a construction method for solving the problem that a small box girder end head is subjected to tensioning prestress to generate cracks.
Background
The traditional method for prefabricating and constructing the small box girder comprises the following steps: directly installing a bottom template on a concrete production pedestal, hoisting a prefabricated reinforcement framework onto the bottom template, pouring concrete after installing side templates, and performing prestress tensioning after curing until the strength of the concrete meets the design requirement.
The traditional construction method has the following defects:
because the end pulling force is big during prestressing force stretch-draw, the big pressure of little case roof beam end bottom production downwards, and little case roof beam bottom is that the die block follows the concrete pedestal, and rigidity is big, does not have the deformation space, therefore little case roof beam end can appear the crack.
Disclosure of Invention
In order to overcome the defects of the prior art, one of the purposes of the invention is to provide a construction method for solving the problem of cracks generated by the tensioning prestress of the end head of a small box girder, which can solve the problem of cracks generated by the tensioning prestress of the end head of the small box girder.
One of the purposes of the invention is realized by adopting the following technical scheme:
a construction method for solving the problem that a small box girder end head is tensioned and prestressed to generate cracks comprises the following steps:
pouring the reinforced concrete pedestal: pouring a reinforced concrete pedestal;
rubber plate installation: installing a rubber plate on the reinforced concrete pedestal, enabling the upper end surface of the reinforced concrete pedestal to be attached to the lower end surface of the rubber plate, and arranging a bolt type height-adjustable template at a position 100cm away from the end part of the small box girder;
a leveling box mounting step: installing a small box girder bottom template on the rubber plate, and installing a small box girder side template and a small box girder reinforcing steel bar;
secondary pouring: pouring small box girder concrete;
the health preserving step: after pouring concrete for 24-48 h, continuously watering and moisturizing for 2-4 h;
tensioning: and (4) performing prestress tensioning after the strength of the concrete reaches the design requirement.
Furthermore, in the step of pouring the reinforced concrete pedestal, after pouring is completed, the flatness of the upper end face of the reinforced concrete pedestal is corrected.
Further, in the step of pouring the reinforced concrete pedestal, whether the quality standard of the poured reinforced concrete pedestal meets the requirement or not is checked, if yes, the next step is executed, and if not, the reworking treatment is carried out.
Further, in the rubber plate mounting step, a rubber plate with an end surface area smaller than that of the reinforced concrete pedestal is selected.
Further, in the rubber plate mounting step, whether the mounting of the reinforced concrete pedestal and the rubber plate meets the requirements or not is checked, if yes, the leveling box mounting step is executed, and if not, reworking is carried out.
Further, in the leveling box mounting step, the small box girder bottom template adopts a bolt type height-adjustable template.
Further, in the leveling box mounting step, whether the mounting positions of the bottom template, the side template and the steel bars of the small box girder meet the requirements or not is checked, if yes, the secondary pouring step is executed, and if not, the reworking treatment is carried out.
Further, in the secondary pouring step, when the small box girder concrete is poured, pouring is carried out along the middle part to the periphery.
Further, in the tensioning step, more than 10 test points at different positions are selected to measure the concrete strength.
Further, in the tensioning step, when the concrete strength of all the measuring points reaches the design requirement, prestress tensioning is carried out.
Compared with the prior art, the invention has the beneficial effects that:
pouring a reinforced concrete pedestal; installing a rubber plate on the reinforced concrete pedestal to ensure that the upper end surface of the reinforced concrete pedestal is attached to the lower end surface of the rubber plate; installing a small box girder bottom template on the rubber plate, and installing a small box girder side template and a small box girder reinforcing steel bar; pouring small box girder concrete; and (5) curing, namely performing prestress tensioning after the strength of the concrete reaches the design requirement. By adopting the method, the rubber plate has certain rigidity, can bear the weight of the template and the steel bar and the concrete, but has low rigidity, and can generate compression deformation when the rubber plate is subjected to great downward pressure of the end of the small box girder during prestress tensioning, so that the end of the small box girder does not generate cracks, the problem that the end of the small box girder generates cracks due to the prestress tensioning is solved, and the prefabrication quality of the small box girder is ensured.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.
Drawings
FIG. 1 is a flow chart of a construction method for solving the problem of cracks generated by small box girder end tensioning prestress;
FIG. 2 is a schematic structural diagram of rubber plate installation in the construction method for solving the problem of cracks generated by small box girder end tensioning prestress shown in FIG. 1;
fig. 3 is a cross-sectional view of the schematic structure shown in fig. 2.
In the figure: 1. a bottom template of the small box girder; 2. a rubber plate; 3. reinforced concrete pedestal.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Referring to fig. 1, a construction method for solving the problem of cracks generated by the small box girder end tensioning prestress includes the following steps:
pouring the reinforced concrete pedestal: pouring a reinforced concrete pedestal; preferably, in the reinforced concrete pedestal pouring step, pour the back, rectify the roughness of reinforced concrete pedestal up end, specifically, adopt to strike off the mode of arch, the recast leak and rectify. And (3) checking whether the quality standard of the poured reinforced concrete pedestal meets the requirement, if so, executing the next step, and if not, performing rework treatment.
Rubber plate installation: installing a rubber plate on the reinforced concrete pedestal, enabling the upper end surface of the reinforced concrete pedestal to be attached to the lower end surface of the rubber plate, and adopting a bolt type height-adjustable template as a bottom template at a position 100cm away from the end part of the small box girder; preferably, in the rubber plate mounting step, a rubber plate with an end surface area smaller than that of the reinforced concrete pedestal is selected. Whether the installation of inspection reinforced concrete pedestal and rubber slab satisfies the requirement, if yes, carry out leveling box installation step, if no, the processing of doing over again, the concrete standard of "whether the installation of inspection reinforced concrete pedestal and rubber slab satisfies the requirement" means: whether the laminating degree of inspection reinforced concrete pedestal and rubber slab meets the requirements, whether the deviation appears in inspection reinforced concrete pedestal and rubber slab mounted position.
A leveling box mounting step: installing a small box girder bottom template on the rubber plate, and installing a small box girder side template and a small box girder reinforcing steel bar; preferably, in the leveling box mounting step, the bottom template of the small box girder adopts a bolt-type height-adjustable template. Specifically, after the bottom formwork at a position 100cm away from the end part of the small box girder is subjected to bolt type formwork small box girder concrete pouring with adjustable height and before the prestress is tensioned, the bottom formwork is separated from the bottom of the small box girder by 3cm through adjusting a bolt supported by the bottom of the formwork, and the problem that the end of the small box girder is cracked due to the prestress is tensioned can be solved. In this embodiment, the bolt-type height-adjustable template or rubber pad is used for double adjustment, first, bolt adjustment is an estimated amount, and when the actual deformation is greater than the estimated amount, the deformation can be borne by the rubber pad.
Preferably, in the leveling box mounting step, whether the mounting positions of the small box girder bottom template, the small box girder side template and the small box girder reinforcing steel bar meet the requirements is checked, if so, the secondary pouring step is executed, and if not, the reworking treatment is carried out. Specifically, the "checking whether the installation positions of the bottom template, the side template and the steel bar of the small box girder meet the requirements" means that: and whether the small box girder bottom template, the small box girder side template and the small box girder reinforcing steel bar have installation deviation or not is inconsistent with an installation drawing.
Secondary pouring: pouring small box girder concrete; preferably, in the secondary pouring step, when the small box girder concrete is poured, the small box girder concrete is poured from the middle part to the periphery.
The health preserving step: after pouring concrete for 24-48 h, continuously watering and moisturizing for 2-4 h; tensioning: and (4) performing prestress tensioning after the strength of the concrete reaches the design requirement. Preferably, in the tensioning step, more than 10 test points at different positions are selected to measure the concrete strength. And (5) when the concrete strength of all the measuring points reaches the design requirement, performing prestress tensioning. By adopting the method, the rubber plate has certain rigidity, can bear the weight of the template and the steel bar and the concrete, but has low rigidity, and can generate compression deformation when the rubber plate is subjected to great downward pressure of the end of the small box girder during prestress tensioning, so that the end of the small box girder does not generate cracks, the problem that the end of the small box girder generates cracks due to the prestress tensioning is solved, and the prefabrication quality of the small box girder is ensured.
Referring to fig. 2-3, it is a schematic view of the installation of the bottom form 1, the rubber plate 2 and the reinforced concrete platform 3 of the small box girder, in this embodiment, the bottom form 1 of the small box girder is an installation part of the leveling box, the rubber plate 2 is a rubber plate 150cm × 84cm × 5cm, and the reinforced concrete platform 3 is a rectangular parallelepiped.
The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.
Claims (10)
1. A construction method for solving the problem that a small box girder end head is tensioned and prestressed to generate cracks is characterized by comprising the following steps:
pouring the reinforced concrete pedestal: pouring a reinforced concrete pedestal;
rubber plate installation: installing a rubber plate on the reinforced concrete pedestal, enabling the upper end surface of the reinforced concrete pedestal to be attached to the lower end surface of the rubber plate, and arranging a bolt type height-adjustable template at a position 100cm away from the end part of the small box girder;
a leveling box mounting step: installing a small box girder bottom template on the rubber plate, and installing a small box girder side template and a small box girder reinforcing steel bar;
secondary pouring: pouring small box girder concrete;
the health preserving step: after pouring concrete for 24-48 h, continuously watering and moisturizing for 2-4 h;
tensioning: and (4) performing prestress tensioning after the strength of the concrete reaches the design requirement.
2. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: in the step of pouring the reinforced concrete pedestal, after pouring is finished, the flatness of the upper end face of the reinforced concrete pedestal is corrected.
3. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: in the step of pouring the reinforced concrete pedestal, whether the quality standard of the poured reinforced concrete pedestal meets the requirement or not is checked, if yes, the next step is executed, and if not, the reworking treatment is carried out.
4. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: in the rubber plate mounting step, a rubber plate with an end surface area smaller than that of the reinforced concrete pedestal is selected.
5. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: and in the rubber plate mounting step, whether the mounting of the reinforced concrete pedestal and the rubber plate meets the requirements is checked, if so, the leveling box mounting step is executed, and if not, the reworking treatment is carried out.
6. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: in the leveling box mounting step, the small box girder bottom template adopts a bolt type height-adjustable template.
7. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: in the leveling box mounting step, whether the mounting positions of the small box girder bottom template, the small box girder side template and the small box girder reinforcing steel bar meet the requirements or not is checked, if yes, the secondary pouring step is executed, and if not, the reworking treatment is carried out.
8. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 1, is characterized in that: in the secondary pouring step, when the small box girder concrete is poured, the small box girder concrete is poured from the middle part to the periphery.
9. The construction method for solving the problem of the crack generated by the tensioning prestress of the end head of the small box girder as claimed in claim 1, wherein in the tensioning step, more than 10 test points at different positions are selected to measure the concrete strength.
10. The construction method for solving the problem of cracks generated by tensioning prestress of the end head of the small box girder as claimed in claim 9, is characterized in that: in the tensioning step, when the concrete strength of all the measuring points reaches the design requirement, prestress tensioning is carried out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210670633.8A CN114953168A (en) | 2022-06-14 | 2022-06-14 | Construction method for solving crack generated by small box girder end tensioning prestress |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210670633.8A CN114953168A (en) | 2022-06-14 | 2022-06-14 | Construction method for solving crack generated by small box girder end tensioning prestress |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114953168A true CN114953168A (en) | 2022-08-30 |
Family
ID=82961556
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210670633.8A Pending CN114953168A (en) | 2022-06-14 | 2022-06-14 | Construction method for solving crack generated by small box girder end tensioning prestress |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114953168A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103774561A (en) * | 2014-02-11 | 2014-05-07 | 湖北高路江南高速公路有限公司 | Streamline operation construction method of precast small box girders for highway in assembling mode |
| CN108638324A (en) * | 2018-05-28 | 2018-10-12 | 中交路桥北方工程有限公司 | A kind of construction method of prefabricated case beam |
| CN111469253A (en) * | 2020-04-09 | 2020-07-31 | 中铁十四局集团第一工程发展有限公司 | Assembled multifunctional steel structure box girder pedestal |
| CN213137167U (en) * | 2020-04-23 | 2021-05-07 | 广西长长路桥建设有限公司 | Box girder steel ground child |
-
2022
- 2022-06-14 CN CN202210670633.8A patent/CN114953168A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103774561A (en) * | 2014-02-11 | 2014-05-07 | 湖北高路江南高速公路有限公司 | Streamline operation construction method of precast small box girders for highway in assembling mode |
| CN108638324A (en) * | 2018-05-28 | 2018-10-12 | 中交路桥北方工程有限公司 | A kind of construction method of prefabricated case beam |
| CN111469253A (en) * | 2020-04-09 | 2020-07-31 | 中铁十四局集团第一工程发展有限公司 | Assembled multifunctional steel structure box girder pedestal |
| CN213137167U (en) * | 2020-04-23 | 2021-05-07 | 广西长长路桥建设有限公司 | Box girder steel ground child |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8522507B2 (en) | Concrete platform production process, concrete platform, and connecting member | |
| CN109707173B (en) | Construction method of assembly type laminated beam plate installation auxiliary device | |
| CN108035594A (en) | The prefabricated decompression cone construction method of concrete silo structure | |
| CN112647597A (en) | Construction method of high-altitude large-cantilever concrete beam plate structure | |
| CN107143076A (en) | A kind of Prefabricated stacking floor with side flanging and its construction method for being used to drop plate region | |
| CN110318490A (en) | A kind of construction method that superimposed sheet is connect with secondary beam and node connecting structure | |
| CN111550036A (en) | Aluminum-wood mixed template structure and construction method thereof | |
| CN106592867A (en) | Construction method of reinforced concrete beam | |
| CN102777044A (en) | Hoisting method of steel-structured spraying layer of urea prilling tower | |
| CN114953168A (en) | Construction method for solving crack generated by small box girder end tensioning prestress | |
| CN209759902U (en) | 8-shaped prefabricated track slab suitable for urban rail transit construction requirements | |
| CN211278938U (en) | Bottom paving device, precast beam bottom die and precast beam construction device | |
| CN107152112A (en) | A kind of modularization Prefabricated stacking floor and its construction method for being used to drop plate region | |
| CN115573597B (en) | Fully-assembled concrete canopy and construction method thereof | |
| CN207244961U (en) | A kind of Prefabricated stacking floor with side flanging for being used to drop plate region | |
| CN212096869U (en) | Precast beam processingequipment | |
| CN214696077U (en) | High-altitude large-cantilever concrete beam plate structure | |
| CN110598250B (en) | Method and system for optimizing bending moment distribution of continuous rigid frame bridge | |
| CN213926977U (en) | Prefabricated bottom plate with hidden beam and folded plate type laminated slab comprising prefabricated bottom plate | |
| CN112140290B (en) | Pouring method for prefabricated bridge deck | |
| CN113172754A (en) | Method for manufacturing prefabricated pedestal of pipe gallery | |
| CN114319103A (en) | Steel shell concrete combined cable tower structure | |
| CN101219559B (en) | Method for casting prestressed concrete T beam without shutter vibrator | |
| CN212836176U (en) | Composite prefabricated floor slab with roughened surface | |
| CN219690578U (en) | Independent column pier type double-layer plate construction elevator concrete foundation structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |