阅读说明：本技术 一种改建地下室新老混凝土交接的施工方法 (Construction method for joining new and old concrete of reconstructed basement ) 是由 王深山 吴宏磊 王毅 戴立军 柴祖尧 易溪 熊明荣 朱亮 刘海东 于 2021-06-28 设计创作，主要内容包括：本发明涉及一种改建地下室新老混凝土交接的施工方法,地下室中设有老钢筋混凝土结构,老钢筋混凝土结构包括老钢筋以及填充在老钢筋四周的老混凝土底板,施工方法具体为：(a)加工老混凝土底板的边界处,使其形成企口形交界面,并暴露出老钢筋；(b)在企口形交界面上布设止水组件；(c)取新钢筋与老钢筋焊接；(d)沿着企口形交界面的长度方向预埋多个注浆管,同时配备止水钢板；(e)在新钢筋、注浆管和止水钢板的四周浇筑混凝土形成新混凝土底板,并与老混凝土底板交接；(f)待新混凝土底板的强度达标后,对注浆管进行注浆,完成施工。与现有技术相比,本发明使得交接部位防水性能佳,且整个施工质量控制好,操作简单,成本低。(The invention relates to a construction method for joining new and old concrete of a reconstructed basement, wherein the basement is provided with an old reinforced concrete structure, the old reinforced concrete structure comprises old reinforcing steel bars and an old concrete bottom plate filled around the old reinforcing steel bars, and the construction method specifically comprises the following steps: (a) processing the boundary of the old concrete bottom plate to form a tongue-and-groove-shaped interface and expose the old reinforcing steel bars; (b) arranging a water stopping component on the tongue-and-groove-shaped interface; (c) welding a new reinforcing steel bar with an old reinforcing steel bar; (d) embedding a plurality of grouting pipes along the length direction of the tongue-and-groove-shaped interface, and simultaneously arranging a water stop steel plate; (e) pouring concrete around the new steel bars, the grouting pipes and the water stop steel plates to form a new concrete bottom plate, and connecting the new concrete bottom plate with the old concrete bottom plate; (f) and after the strength of the new concrete bottom plate reaches the standard, grouting the grouting pipe to complete construction. Compared with the prior art, the invention ensures that the waterproof performance of the joint part is good, the whole construction quality is controlled well, the operation is simple, and the cost is low.)

1. The construction method for reconstructing the new and old concrete handover of the basement is characterized in that an old reinforced concrete structure is arranged in the basement, the old reinforced concrete structure comprises old reinforcing steel bars arranged horizontally and an old concrete bottom plate (101) filled around the old reinforcing steel bars, and the construction method specifically comprises the following steps:

(a) processing the boundary of the old concrete bottom plate (101) to form a tongue-and-groove interface and expose the old reinforcing steel bars;

(b) arranging a water stopping component on the tongue-and-groove-shaped interface;

(c) welding a new reinforcing steel bar with an old reinforcing steel bar;

(d) a plurality of grouting pipes (311) are embedded along the length direction of the tongue-and-groove-shaped interface, and a water stop steel plate (312) is arranged at the same time;

(e) concrete is poured around the new steel bars, the grouting pipes (311) and the water stop steel plates (312) to form a new concrete bottom plate (301), and the new concrete bottom plate is connected with the old concrete bottom plate (101);

(f) and after the strength of the new concrete bottom plate (301) reaches the standard, grouting the grouting pipe (311) to complete construction.

2. The construction method for reconstructing the new and old concrete joint of the basement according to claim 1, wherein the old steel bars comprise old plate-surface steel bars (102) positioned at the upper part in the old concrete bottom plate (101) and old plate-bottom steel bars (103) positioned at the lower part in the old concrete bottom plate (101),

in the step (a), the process of processing the rabbet-shaped interface specifically comprises the following steps: chiseling the concrete (111) positioned in the top range of the old concrete bottom plate to form a tongue-and-groove top surface (121) and exposing the old plate surface reinforcing steel bars (102); then chiseling the concrete (112) positioned in the vertical range of the old concrete bottom plate along the vertical direction to form a rabbet side surface (122); and finally, chiseling the concrete (113) positioned in the bottom range of the old concrete bottom plate along an oblique downward and inward angle to form a tongue-and-groove bottom surface (123) and expose the old plate bottom steel bars (103), wherein the tongue-and-groove top surface (121), the tongue-and-groove side surface (122) and the tongue-and-groove bottom surface (123) are sequentially connected to form a tongue-and-groove-shaped interface.

3. The method as claimed in claim 2, wherein in step (a), the concrete surface is roughened on the whole rabbet-shaped interface after the rabbet-shaped interface is obtained.

4. The construction method for reconstructing the joint of the new and old concrete of the basement according to claim 2, wherein in the step (b), the water stop assembly comprises a water-swelling rubber water stop (201) and an interface adhesive (202), and the laying process comprises: installing a water-swelling rubber water stop belt (201) on the tongue-and-groove top surface (121) and the tongue-and-groove side surface (122), coating interface glue (202) on the rest parts of the tongue-and-groove interface without the water-swelling rubber water stop belt (201), and polishing and cleaning the surfaces of the rest parts of the tongue-and-groove interface before coating.

5. The construction method for joining new and old concrete for reconstructing the basement according to claim 1, wherein the steel bar welding mode adopted in the step (c) is as follows: the arc welding machine is adopted to generate high-temperature electric arc between the welding rod and the weldment, so that the welding rod and the weldment melt and weld one side.

6. The construction method for improving the joining of the new and old concrete of the basement according to claim 1, wherein in the step (c), the welding length of the old steel bars and the new steel bars is 10 times the diameter of the old steel bars and the new steel bars with the larger diameter;

in the step (c), the space between the adjacent new reinforcing steel bars is consistent with the space between the adjacent old reinforcing steel bars.

7. The construction method for reconstructing the new and old concrete joint of the basement according to claim 1, wherein the old reinforced concrete structure further comprises an old concrete bottom slab cushion layer (104) arranged at the bottom of the old concrete bottom slab (101),

in the step (d), the grouting pipe (311) is inserted downwards in an inclined manner towards the direction of the old reinforced concrete structure and is inserted into the old concrete bottom plate cushion layer (104), and when grouting is not performed, the openings at two ends of the grouting pipe (311) are plugged for protection.

8. The construction method for joining new and old concrete of a reconstructed basement according to claim 1, wherein in the step (d), the grouting pipes (311) are arranged at intervals of 1 m;

in the step (d), the size of the water stop steel plate (312) is as follows: 300mm on a side and 4mm in thickness.

9. The construction method for improving the joining of the new and old concrete of the basement according to claim 1, wherein in the step (e), the new concrete is poured before the water-swelling rubber water stop (201) is not swelled.

10. The construction method for joining new and old concrete of a reconstructed basement according to claim 1, wherein in the step (f), cement-water glass double hydraulic pressure sealing grouting is performed on the grouting pipe (311);

the cement is ordinary 425 portland cement, and the water-cement ratio in the cement slurry is 1: 1;

the modulus of the water glass is 2.4, the concentration is 400 Be, and the ratio of the water glass slurry to the cement slurry is 0.3: 1;

the grouting adopts a double-liquid grouting machine, the grouting pressure is not less than 1.5MPa, and the final pressure reaches the grouting pressure and is maintained.

Technical Field

The invention relates to the technical field of concrete structure waterproofing, in particular to a construction method for joining new and old concrete of a reconstructed basement.

Background

In recent years, along with the increasingly scarce phenomenon of land resources in the core area of a first-line city, the reconstruction, upgrading and reutilization of an existing building become an industrial hotspot, and the problem of connection between a new bottom plate and an old basement reinforced concrete bottom plate is often encountered in the process of reconstructing a basement of the existing building. Because new and old structure exists structural construction seam, and because the building waterproof material of new and old at the bottom of the board is difficult to form effectual connection, lead to having very big infiltration hidden danger in handing-over region, influence the normal use of building.

In order to ensure that the structure at the concrete junction of the new basement and the old basement has self-waterproof performance, the main method at present is to vertically cut the old basement to a reserved boundary and chisel the old basement, then adopt interface treatment modes of arranging a water swelling water stop strip on the interface, brushing an inorganic interface agent, arranging a water stop steel plate in a groove and the like, and implant the reinforcing steel bars of the new basement into the old basement in a bar planting mode. The method has a certain waterproof effect, the construction mode is simple, but due to the fact that flat-end cutting is adopted, the water seepage path is transparent, certain water seepage risks still exist, meanwhile, the steel bar planting amount of the bottom plate is too large, the quality of planted steel bars is difficult to guarantee, risks of collision between newly-planted steel bars and original steel bars exist, and the situation that the waterproof performance of the structure of the joint is poor is caused at a high probability.

Disclosure of Invention

The invention aims to provide a construction method for joining new and old concrete of a reconstructed basement, which ensures that the joining part has good waterproof performance, the whole construction quality is well controlled, the operation is simple and the cost is low.

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

a construction method for reconstructing new and old concrete handover of a basement is provided, wherein an old reinforced concrete structure is arranged in the basement, the old reinforced concrete structure comprises old reinforcing steel bars arranged horizontally and an old concrete bottom plate filled around the old reinforcing steel bars, and the construction method specifically comprises the following steps:

(a) processing the boundary of the old concrete bottom plate to form a tongue-and-groove-shaped interface and expose the old reinforcing steel bars;

(b) arranging a water stopping component on the tongue-and-groove-shaped interface;

(c) welding a new reinforcing steel bar with an old reinforcing steel bar;

(d) embedding a plurality of grouting pipes along the length direction of the tongue-and-groove-shaped interface, and simultaneously arranging a water stop steel plate;

(e) pouring concrete around the new steel bars, the grouting pipes and the water stop steel plates to form a new concrete bottom plate, and connecting the new concrete bottom plate with the old concrete bottom plate;

(f) and after the strength of the new concrete bottom plate reaches the standard, grouting the grouting pipe to complete construction.

The old reinforcing steel bars comprise old plate reinforcing steel bars positioned at the upper part in the old concrete bottom plate and old plate bottom reinforcing steel bars positioned at the lower part in the old concrete bottom plate,

in the step (a), the process of processing the rabbet-shaped interface specifically comprises the following steps: chiseling the concrete at the top range of the old concrete bottom plate to form a tongue-and-groove top surface and expose the reinforcing steel bars of the old concrete bottom plate; chiseling the concrete in the vertical range of the old concrete bottom plate along the vertical direction to form a rabbet side face; and finally chiseling the concrete at the bottom range of the old concrete bottom plate along an oblique downward and inward angle to form a tongue-and-groove bottom surface and expose reinforcing steel bars at the bottom of the old concrete, wherein the tongue-and-groove top surface, the tongue-and-groove side surface and the tongue-and-groove bottom surface are sequentially connected to form a tongue-and-groove-shaped interface. The whole processing adopts a static cutting mode, the three cutting procedures all adopt protective dismantling, the integrity of the rabbet shape is ensured, a pneumatic pick, a high-power electric pick or a heavy hammer and other machines are not required to be adopted for destructive dismantling, and simultaneously, in the concrete chiseling process, the concrete at the whole rabbet-shaped interface is ensured to expose a new surface of the aggregate after chiseling. Compared with the up-down through flat-mouth interface, the rabbet-shaped interface in the shape has the advantages that the underground water positioned below the plate bottom can be infiltrated to the plate surface by a longer infiltration path, so that a first structural waterproof measure is formed.

In the step (a), after the tongue-and-groove-shaped interface is obtained, a flower hammer, a grinder or high-pressure water jet is adopted to roughen the concrete surface of the whole tongue-and-groove-shaped interface, so that the whole tongue-and-groove-shaped interface can be conveniently connected with a subsequent new concrete bottom plate.

In the step (b), the water stopping assembly comprises a water-swelling rubber water stopping belt and interface glue.

In the step (b), the layout process specifically comprises: installing water swelling rubber water stop belts on the top surface and the side surface of the rabbet, coating interface glue on the rest parts of the rabbet-shaped interface without the water swelling rubber water stop belts, and polishing and cleaning the surfaces of the rest parts of the rabbet-shaped interface before coating.

In the step (b), the water-swelling rubber waterstop is made of rectangular product type water-swelling rubber, the volume expansion rate is not less than 400%, the width is 30mm, and the thickness is 20 mm. The water-swelling rubber water stop is a rubber water stop product, can gradually swell after meeting water, and finally can slowly block capillary pores which are distributed all over, so that the contact of a concrete interface which is contacted with the water-swelling rubber water stop is tighter, and a larger water-resisting pressure is generated to play a water stopping role. The waterproof material is bonded on the top surface and the side surface of the rabbet through waterproof glue, so that a second structural waterproof measure can be formed.

In the step (b), the interface adhesive is an A-grade adhesive, and the compression shear strength of concrete-to-concrete bonding and the qualification of test results need to be determined according to the requirements of appendix N in GB50728-2011 'engineering structure reinforcing material application safety identification Specification'. The interface glue is structural glue based on concrete, can enhance the cohesive force of the surfaces of new and old concrete, and is integrally coated on the parts of the interface except the tongue-and-groove shape, which are stuck with the water stop belt and comprise a tongue-and-groove top surface, a tongue-and-groove side surface and a tongue-and-groove bottom surface to form a third structural waterproof measure.

In the step (c), the new steel bars comprise new plate surface steel bars and new plate bottom steel bars, the new plate surface steel bars and old plate surface steel bars are matched and positioned below the old plate surface steel bars, and the new plate bottom steel bars and the old plate bottom steel bars are matched and positioned above the old plate bottom steel bars.

In the step (c), the adopted steel bar welding mode is as follows: the arc welding machine is adopted to generate high-temperature electric arc between the welding rod and the weldment, so that the welding rod and the weldment melt and weld one side.

In the step (c), the welding length of the old steel bars and the new steel bars is 10 times of the diameter of the old steel bars and the new steel bars with the larger diameter. When the diameter of the old steel bar is larger than that of the new steel bar, the welding length of the old steel bar and the new steel bar is 10 times of the diameter of the old steel bar; when the diameter of the old steel bar is smaller than that of the new steel bar, the welding length of the old steel bar and the new steel bar is 10 times of the diameter of the new steel bar.

In the step (c), the space between the adjacent new reinforcing steel bars is consistent with the space between the adjacent old reinforcing steel bars. The novel steel bar and the old steel bar are comprehensively and effectively connected, and the two steel bars which form a whole can effectively bear bending moment.

The old reinforced concrete structure also comprises an old concrete bottom plate cushion layer arranged at the bottom of the old concrete bottom plate,

in the step (d), the grouting pipe is inserted downwards in a slant direction towards the old reinforced concrete structure and is inserted into the cushion layer of the old concrete bottom plate (generally extending out 300mm below the bottom of the old concrete bottom plate), and when grouting is not performed, the openings at two ends of the grouting pipe are plugged for protection.

In the step (d), the grouting pipes are arranged at intervals of 1 m.

In the step (d), the diameter of the grouting pipe is 50 mm.

In the step (d), the size of the water stop steel plate is as follows: 300mm on a side and 4mm in thickness.

And (e) pouring new concrete before the water-swelling rubber water stop band is not swelled.

And (e) adopting impervious concrete with a corresponding impervious grade according to the actual pouring depth.

In the step (f), performing cement-water glass double-hydraulic-pressure close grouting on the grouting pipe;

the cement is ordinary 425 portland cement, and the water-cement ratio in the cement slurry is 1: 1;

the modulus of the water glass is 2.4, the concentration is 400 Be, and the ratio of the water glass slurry to the cement slurry is 0.3: 1;

the grouting adopts a double-liquid grouting machine, the grouting pressure is not less than 1.5MPa, and the final pressure reaches the grouting pressure and is maintained. The grouting pipe after grouting can block the leakage of underground water below the bottom of the plate to the concrete joint, and a fourth structural waterproof measure is formed.

Considering that underground water possibly exists at the bottom of the basement and is easy to permeate into the basement, the invention adopts four waterproof measures of the structure, which are respectively as follows: the water-swelling rubber waterstop and the interface glue fill up a structural construction joint gap at the joint of a new reinforced concrete structure and an old reinforced concrete structure, and the grouting pipe injects cement and water glass into an old concrete bottom plate cushion layer to form a waterproof barrier, so that the self-waterproof effect of the basement new and old concrete bottom plate structure is optimal, the operability of the whole construction process is good, the building waterproof treatment cost can be reduced, and the water-swelling rubber waterstop and the interface glue have great popularization and application values.

Drawings

FIG. 1 is a schematic structural view of a tongue-and-groove interface formed by processing an old reinforced concrete structure;

FIG. 2 is a schematic structural diagram of a water-swellable rubber water stop and an interface adhesive provided on a tongue-and-groove interface;

FIG. 3 is a schematic view of a new and old reinforced concrete hybrid structure after completion of construction;

FIG. 4 is a schematic view of the construction process of the present invention.

In the figure: 101-old concrete bottom plate; 102-boss face steel bars; 103-boss bottom steel bars; 104-old concrete bottom plate cushion layer; 111-concrete at the top extent of the old concrete floor slab; 112-concrete located at the vertical extent of the old concrete floor; 113-concrete at the slab bottom range of the old concrete floor; 121-tongue and groove top surface; 122-tongue and groove side; 123-tongue-and-groove bottom surface; 201-water swelling rubber waterstop; 202-interface glue, 301-new concrete bottom plate; 302-new plate surface reinforcing steel bars; 303-new slab bottom steel bars; 311-grouting pipes; 312-Water stop Steel plate.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Examples

As shown in fig. 1, 2, 3 and 4, a construction method for changing over old and new concrete of a basement is provided, wherein the basement is provided with an old reinforced concrete structure, the old reinforced concrete structure comprises old reinforcing steel bars which are horizontally arranged, an old concrete bottom plate 101 which is filled around the old reinforcing steel bars and an old concrete bottom plate cushion layer 104 which is arranged at the bottom of the old concrete bottom plate 101, the old reinforcing steel bars comprise old slab surface reinforcing steel bars 102 which are positioned at the upper part in the old concrete bottom plate 101 and old slab bottom reinforcing steel bars 103 which are positioned at the lower part in the old concrete bottom plate 101,

the construction method specifically comprises the following steps:

(a) as shown in fig. 1, the processing of the boundary of the old concrete bottom plate 101 to form a tongue-and-groove interface and expose the old steel bars includes the following specific steps: chiseling the concrete 111 positioned in the top range of the old concrete bottom plate to form a rabbet top surface 121 (which is a rectangular-section notch, the size of the notch can be determined according to the diameter of the old concrete bottom plate reinforcing steel bar and the required welding length) and expose the old concrete surface reinforcing steel bar 102; then chiseling the concrete 112 positioned in the vertical range of the old concrete bottom plate along the vertical direction to form a rabbet side surface 122; chiseling the concrete 113 positioned in the bottom range of the old concrete bottom plate along an oblique downward and inward angle to form a rabbet bottom surface 123 (a notch with a triangular section, and the length size of the bottom edge of the notch can be the same as that of a top notch of the old concrete bottom plate), exposing the old plate bottom steel bars 103, sequentially connecting a rabbet top surface 121, a rabbet side surface 122 and the rabbet bottom surface 123 to form a rabbet-shaped interface, and roughening the surface of the concrete on the whole rabbet-shaped interface by adopting a flower hammer, a grinding wheel machine or high-pressure water jet after obtaining the rabbet-shaped interface;

(b) as shown in fig. 2, a water-swelling rubber water stop 201 and an interface adhesive 202 are used as water stop components and are arranged on a rabbet-shaped interface, the water-swelling rubber water stop 201 is arranged on the rabbet top surface 121 and the rabbet side surface 122, the interface adhesive 202 is coated on the rest parts of the rabbet-shaped interface where the water-swelling rubber water stop 201 is not arranged, before coating, the surfaces of the rest parts of the rabbet-shaped interface are polished to be flat and cleaned, the water-swelling rubber water stop 201 is made of rectangular product type water-swelling rubber, the volume expansion rate is not less than 400%, the width is 30mm, the thickness is 20mm, and the interface adhesive 202 is made of class a adhesive;

(c) as shown in fig. 3, new steel bars and old steel bars are taken to be subjected to single-side lap welding, the distance between the adjacent new steel bars is kept consistent with the distance between the adjacent old steel bars, the new steel bars comprise new slab-face steel bars 302 and new slab-bottom steel bars 303, the new slab-face steel bars 302 are matched with the old slab-face steel bars 102 and are positioned below the old slab-face steel bars 102, the new slab-bottom steel bars 303 are matched with the old slab-bottom steel bars 103 and are positioned above the old slab-bottom steel bars 103, and the welding length of the old steel bars and the new steel bars is 10 times the diameter of the old steel bars and the new steel bars with the larger diameter;

(d) as shown in fig. 3, a plurality of grouting pipes 311 with the diameter of 50mm are pre-embedded along the length direction of the tongue-and-groove shaped interface at intervals of 1m, the grouting pipes 311 are inserted obliquely downwards towards the direction of the old reinforced concrete structure and are inserted into the old concrete bottom plate cushion layer 104, generally extending below 300mm of the old concrete bottom plate 101, when grouting is not performed, the orifices at the two ends of the grouting pipes (311) are plugged for protection, and a water stop steel plate 312 is provided, wherein the size of the water stop steel plate 312 is as follows: 300mm on a side and 300mm on a side, and 4mm in thickness;

(e) adopting impervious concrete with a corresponding impervious grade according to the actual pouring depth, pouring concrete around the new steel bar, the grouting pipe 311 and the water-stop steel plate 312 to form a new concrete bottom plate 301 before the water-swelling rubber water-stop belt 201 is not swelled, and connecting the new concrete bottom plate with the old concrete bottom plate 101;

(f) and after the strength of the new concrete bottom plate 301 reaches the standard (generally after 28 days), performing cement-water glass double-hydraulic-compaction grouting on the grouting pipe 311, wherein the cement is ordinary 425 portland cement, the water cement ratio in the cement grout is 1:1, the modulus of the water glass is 2.4, the concentration is 400 Be, the ratio of the water glass grout to the cement grout is 0.3:1, the grouting is performed by adopting a double-liquid grouting machine, the grouting pressure is not less than 1.5MPa, and the final pressure reaches the grouting pressure and is maintained, so that the construction is completed, and the new and old reinforced concrete mixed structure is obtained.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.