Post-cast strip structure adopting inflation assembly and process of post-cast strip structure

Abstract

The invention discloses a post-cast strip structure adopting an inflation assembly and a process thereof, and relates to the technical field of building construction, the post-cast strip structure comprises a beam module and a plate module, and the beam module and the plate module are poured into a whole; the beam module comprises post-cast strip beam steel bars connected with beam concrete on the two sides and a beam post-cast strip sealing air bag arranged between the two sets of beam concrete and used for limiting the post-cast strip beam steel bars. The plate module comprises post-cast strip plate steel bars connected with the plate concrete on the two sides, and plate post-cast strip sealing air bags arranged between the two sets of plate concrete and used for limiting the post-cast strip plate steel bars. The post-cast strip has the advantages that the sealing characteristic is directly embodied, component performance damage caused by factors such as steel bar corrosion and accumulated water organification due to long-term exposure of a traditional post-cast strip is fundamentally eradicated, the shaping characteristic is directly embodied, and the shaping high-pressure air bag is used, so that the steel bar position can be accurately positioned through wrapping; and it can be effectively ensured that adjacent concrete does not intrude into the post-cast strip space.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, in particular to a post-cast strip structure using an inflatable component and a process thereof. Background Art

[0002] At present, with the continuous deepening of my country's urbanization process, the size of single building spaces in cities is getting larger and larger. When constructing long reinforced concrete components, different types of post-casting strips need to be set up due to various factors. The usual post-casting strip construction method is: the post-casting strip and the normal pouring area are simultaneously supported, formwork, steel bar binding and other pre-construction processes are carried out, and different types of isolation measures are set up to prevent the concrete in the normal pouring area from entering the post-casting strip. When the post-casting strip reaches the pouring condition, concrete with higher performance (strength, expansion, and shrinkage compensation) than the adjacent concrete is used for pouring. Finally, the post-casting strip formwork and support are removed. The traditional post-casting strip construction method is "open", which leads to many problems and hidden dangers.

[0003] However, this method has the following disadvantages: (1) Traditional open isolation measures are affected by complex environmental conditions, and most isolation effects cannot meet expectations, and most of them need to be chiseled and cleaned. (2) The waiting time for pouring traditional open post-casting strips is long, and problems such as exposed steel bars, rust, and organic water accumulation that seriously affect the performance of components frequently occur. (3) The safety hazard cycle of traditional open post-casting strips is long. Generally, according to the requirements of the specifications, the width needs to be set at 80cm-120cm. Before pouring, the post-casting strips are all key areas for edge protection; when pouring, there is a risk of vertical cross construction. (4) It is difficult to protect the finished steel bars in traditional open post-casting strips, and they need to be rearranged and positioned before pouring. (5) Traditional open post-casting strips are prone to secondary pollution to the completed working surface after pouring, and the level of civilized construction is low. Therefore, a post-casting strip structure and process using inflatable components are now needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a post-cast strip structure and process using an inflatable component, by replacing the open isolation measure installation process with the laying and inflation process of a set high-pressure airbag when setting isolation measures in the traditional post-cast strip, so as to solve the technical problems mentioned in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: a post-cast strip structure using an inflatable component, comprising a beam module and a plate module, wherein the beam module and the plate module are cast into one piece;

[0006] The beam module includes a post-cast strip beam reinforcement connecting the beam concrete on both sides, and a beam post-cast strip closed air bag arranged between the two groups of beam concrete for limiting the post-cast strip beam reinforcement;

[0007] The slab module comprises post-cast strip slab steel bars connecting the slab concrete on both sides, and a slab post-cast strip closing air bag arranged between the two groups of slab concrete for limiting the post-cast strip slab steel bars.

[0008] Preferably, the beam post-casting strip closing airbag and the slab post-casting strip closing airbag are both high-pressure airbags, and the high-pressure airbags include universal wall panel type, customized beam type, and compensation type airbags. The high-pressure airbag has a grouting hole reserved below the post-casting strip, and a grouting pipe is inserted inside the grouting hole. The high-pressure airbag has an air hole reserved above the post-casting strip, and an air pipe is inserted inside the air hole.

[0009] A post-cast strip sealing construction process for an inflatable component comprises the following steps:

[0010] S1. Construction preparation: Build a 3D model of the post-casting strip based on BIM technology, reserve a standard width post-casting strip, and maintain the traditional support formwork system;

[0011] S2. High-pressure airbag preparation: Prefabricate the high-pressure airbag system in sections based on the three-dimensional model. The system includes universal airbags for walls and panels, nested airbags for beams, and compensating airbags. Each airbag has a grouting hole at the bottom and an air hole at the top.

[0012] S3. Install and position the high-pressure airbags in sequence according to the parts: install them according to the beam module and plate module respectively;

[0013] Beam module: When tying the beam stirrups to the post-casting zone, insert the nested airbags into the gaps between the main reinforcements to make the ABS board surface fit the stirrups and secure them;

[0014] Plate formwork: After the reinforcement is tied, insert the wall and plate universal airbags into the post-casting zone in sections to make the ABS plate surface close to the formwork;

[0015] S4. Gradual aeration molding: Inflate the walls, beams, and slabs in order from bottom to top. Inflate the wall and beam airbags to 0.25MPa, and the slab airbags to 0.11MPa. Maintain the pressure until the adjacent concrete begins to set.

[0016] S5. Pour the expansive mortar in sequence: After the settlement of the structure stabilizes, grout the walls, beams, and slabs from bottom to top in sequence. The grouting pressure is 0.3-0.5MPa, and the slurry expansion is ≥600mm.

[0017] Preferably, in step S1, first familiarize yourself with the drawings, give workers detailed instructions on the plan, drawings, construction process, etc., check construction materials and equipment to ensure that they can be put into use, reserve a 10 cm width post-casting strip, and do not need to implement isolation measures. The support and formwork of the post-casting strip are constructed according to traditional construction methods. BIM technology is used to construct a three-dimensional structure of the enclosed space of the post-casting strip. The chemical fiber textile processing plant produces high-pressure airbags in sections and models according to on-site needs.

[0018] Preferably, in step S2, the airbag is made of aramid polyester composite material, wherein the universal airbag for walls and panels adopts a composite structure of a single-layer aramid polyester composite layer and a 3mm ABS board, the nested type for beams includes peripheral airbags and internal airbags, the periphery of the nested type for beams adopts a single-layer aramid polyester composite + ABS board, the interior of the nested type for beams adopts a double-layer aramid + butyl rubber flexible structure, and the compensatory airbag adopts a double-layer aramid + butyl rubber flexible structure.

[0019] Preferably, when the airbag is installed in the beam in step S3, the airbag is installed synchronously during the process of tying the stirrups at the post-casting strip position, the grouting holes are drawn out from the bottom of the beam template, and the air holes are drawn out from the top;

[0020] The segment length of wall and board airbags is ≤2m, and the installation spacing is ≤800mm;

[0021] When tying the beam stirrups, once the stirrups have reached the designated location in the post-casting strip, a custom nested airbag is placed through the beam's main reinforcement and positioned in the designated location in the post-casting strip. Ensure the airbag's plastic panel fits the beam stirrups and secures them. Continue tying the remaining stirrups until the entire beam is tied. When closing the formwork, the grouting holes are drawn out from the bottom of the beam formwork and sealed, while the air holes are drawn out from the top and sealed.

[0022] After the wall and slab reinforcement is tied, the universal air bags for walls and slabs are inserted into the predetermined positions of the post-pouring strips in sections from the reinforcement spacing to ensure that the plastic board surface of the air bags fits the casting formwork and is tied and fixed. When closing the casting formwork, the grouting holes are led out from the bottom of the formwork and closed, and the air holes are led out from the top and closed.

[0023] Preferably, in step S4, air is inflated into the airbags from bottom to top using an inflation device in the order of first the wall post-casting strip, then the beam post-casting strip, and finally the slab post-casting strip. After inflation, the pressure is maintained until the concrete reaches initial setting.

[0024] Preferably, the test pressure of the wall and beam airbags is 0.25 MPa, the test pressure of the plate airbags is 0.11 MPa, the inflation pressure fluctuation value is ≤5%, and after inflation is completed, the density of the contact surface between the airbag and the concrete is detected by ultrasonic wave, and the deviation value is ≤3 mm.

[0025] Preferably, in step S5, after the conditions for pouring the post-casting strip are met, the grouting holes and air holes of each air bag are opened, and grouting equipment is used to inject grout from the grouting holes of each air bag from bottom to top in the overall order of first the wall post-casting strip, then the beam post-casting strip, and finally the slab post-casting strip. The slurry used for grouting meets the general performance requirements for post-casting strip concrete in the specifications.

[0026] Preferably, the grouting in step S5 needs to meet the following conditions: the structural settlement stabilization period is ≥60d, the ambient temperature is ≤25°C, the air holes are opened synchronously during grouting as exhaust channels, the expansion rate of the expansive mortar is controlled at 1.5-2%, and the grouting fullness is verified by ultrasound after the grouting is completed, and the void rate is ≤0.3%.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The post-casting strip construction method of this process is "closed", which avoids the open operation of traditional post-casting strip construction, greatly reduces or eliminates the occurrence of hidden problems, thereby solving the problem. It has the advantage of being directly reflected by the closed characteristics, and fundamentally eliminates the damage to component performance caused by factors such as steel bar corrosion and organic water accumulation caused by long-term exposure of traditional post-casting strips.

[0029] 2. This process also has the advantage of being directly reflected in the shaping characteristics. The use of shaped high-pressure airbags can not only accurately locate the position of the steel bars by wrapping them, but also effectively ensure that the adjacent concrete does not invade the post-casting zone space, reducing the probability of adjacent concrete leakage problems. The shaped airbags fully wrap and accurately position the steel bars after inflation, reducing the need to reposition the steel bars.

[0030] 3. It indirectly reduces the difficulty of safety control in the pouring condition waiting stage and the pouring implementation stage. Since the post-casting strip is closed in advance, the strict safety control working condition of the edge of the post-casting strip is indirectly changed to a general safety supervision working condition; since the bladder-type pouring bag is used for zoned high-pressure grouting during pouring, the strict safety control working condition of vertical cross construction is indirectly changed to a general safety supervision working condition, and the installation and dismantling process of the post-casting strip isolation measures is eliminated, the cleaning and chiseling process is eliminated, the amount of concrete is reduced, the safety and quality risks are reduced, the level of civilized construction is improved, etc., which indirectly reduces the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the bottom structure of the positioning frame body of the present invention;

[0033] Figure 3 This is a schematic diagram of the installation structure of the engraving module of the present invention;

[0034] Figure 4 It is a construction process flow chart of the present invention.

[0035] In the figure: 1. Post-cast beam reinforcement; 2. Post-cast slab reinforcement; 3. Beam concrete; 4. Slab concrete; 5. Grouting pipe; 6. Air pipe; 7. Beam post-cast strip closed air bag; 8. Slab post-cast strip closed air bag. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] like Figure 1-Figure 3 As shown, the present invention provides a post-cast strip structure using an inflatable component, including a beam module and a plate module, and the beam module and the plate module are cast into one body.

[0039] The beam module includes a post-cast strip beam reinforcement 1 connecting the beam concrete 3 on both sides, and a beam post-cast strip closed air bag 7 arranged between the two groups of beam concrete 3 for limiting the post-cast strip beam reinforcement 1.

[0040] The slab module includes post-cast strip slab steel bars 2 connecting the slab concrete 4 on both sides, and a slab post-cast strip closing air bag 8 arranged between the two groups of slab concrete 4 for limiting the post-cast strip slab steel bars 2.

[0041] The closed airbag 7 of the beam post-casting strip and the closed airbag 8 of the slab post-casting strip are both high-pressure airbags, and the high-pressure airbags include universal airbags for wall panels, customized airbags for beams, and compensation airbags. The high-pressure airbag has a grouting hole reserved below the post-casting strip, and a grouting pipe 5 is inserted inside the grouting hole. The high-pressure airbag has an air hole reserved above the post-casting strip, and an air pipe 6 is inserted inside the air hole.

[0042] like Figure 4 As shown, the present invention also provides a post-casting strip sealing construction process for an inflatable component, comprising the following steps:

[0043] S1. Construction Preparation: Build a 3D model of the post-casting strip based on BIM technology, reserve a standard width post-casting strip, and maintain the traditional support formwork system. First, familiarize yourself with the drawings, and provide detailed instructions to workers on the plan, drawings, and construction process. Inspect construction materials and equipment to ensure they are ready for use. Reserve a 10cm width post-casting strip. No isolation measures are required. The support and formwork of the post-casting strip are constructed using traditional construction methods. Use BIM technology to construct the 3D structure of the enclosed space of the post-casting strip. The chemical fiber textile processing plant will produce high-pressure airbags in sections and models according to on-site needs.

[0044] S2. High-pressure airbag preparation: A high-pressure airbag system is prefabricated in sections based on the three-dimensional model. The system includes universal airbags for walls and panels, nested airbags for beams, and compensatory airbags. Each airbag has a grouting hole at the bottom and an air hole at the top. The airbags are made of aramid polyester composite material. Universal airbags for walls and panels use a single-layer aramid polyester composite layer and a 3mm ABS board composite structure. Nested airbags for beams include peripheral airbags and internal airbags. The perimeter of the nested airbag for beams is made of a single-layer aramid polyester composite + ABS board, while the interior of the nested airbag for beams uses a double-layer aramid + butyl rubber flexible structure. The compensatory airbag uses a double-layer aramid + butyl rubber flexible structure.

[0045] S3. Install and position the high-pressure airbags in sequence according to the parts: install them according to the beam module and plate module respectively;

[0046] Beam module: When tying the beam stirrups to the post-casting zone, insert the nested airbags into the main reinforcement gaps to make the ABS board surface fit the stirrups and secure them. Plate module: After the reinforcement is tied, insert the wall and plate universal airbags in sections into the post-casting zone to make the ABS board surface fit closely to the formwork.

[0047] When installing airbags for beams, the airbags are installed simultaneously during the process of tying the stirrups at the post-casting strip position. The grouting holes are led out from the bottom of the beam formwork, and the air holes are led out from the top. The segmented length of the wall and slab airbags is ≤2m, and the installation spacing is ≤800mm. When tying the stirrups of the beams, when the stirrups are tied to the predetermined position of the post-casting strip, the customized nested airbags for the beams are passed through the main reinforcement of the beams and arranged at the predetermined position of the post-casting strip. Ensure that the plastic surface of the airbags fits the beam stirrups and is placed and tied securely. Continue to tie the remaining stirrups of the beams until the entire beam is tied. When closing the formwork, the grouting holes are led out from under the beam formwork and closed, and the air holes are led out from above and closed. After the wall and slab reinforcement is tied, the universal wall and slab airbags are inserted into the predetermined position of the post-casting strip in sections from the reinforcement spacing. Ensure that the plastic surface of the airbags fits the casting formwork and is tied securely. When closing the casting formwork, the grouting holes are led out from under the formwork and closed, and the air holes are led out from above and closed.

[0048] S4. Graded aeration molding: Inflate from bottom to top in the order of walls, beams, and slabs. Inflate the wall and beam airbags to 0.25 MPa, and the slab airbags to 0.11 MPa. Maintain pressure until the adjacent concrete begins to set. Use an aeration device to inflate air from the air holes of each airbag from bottom to top in the order of first the wall post-casting strip, then the beam post-casting strip, and finally the slab post-casting strip. After inflation, maintain pressure until the adjacent concrete reaches initial setting. The test pressure of the wall and beam airbags is 0.25 MPa, and the test pressure of the slab airbags is 0.11 MPa. The inflation pressure fluctuation value is ≤5%. After inflation, the density of the contact surface between the airbag and the concrete is tested by ultrasonic testing, and the deviation value is ≤3 mm.

[0049] S5. Pour the expansive mortar in sequence: after the settlement of the structure is stable, grout the wall, beam and slab in the order from bottom to top with a grouting pressure of 0.3-0.5MPa and a slurry expansion of ≥600mm. After the conditions for pouring the post-casting strip are met, open the grouting holes and air holes of each air bag. Use the grouting equipment to grout the grouting holes from each air bag from bottom to top in the order of first the wall post-casting strip, then the beam post-casting strip and finally the slab post-casting strip. The slurry used for grouting must meet the general performance requirements of the post-casting strip concrete in the specification. The grouting must meet the following conditions: the structural settlement stabilization period is ≥60d, the ambient temperature is ≤25℃, the air holes are opened simultaneously during grouting as exhaust channels, the expansion rate of the expansive mortar is controlled at 1.5-2%, and ultrasonic verification of the grouting fullness is used after the grouting is completed. The void rate is ≤0.3%.

[0050] Specifically, by replacing the open isolation measure installation process with the process of laying and inflating the set high-pressure airbags during the process of setting isolation measures in the traditional post-casting joint, and by replacing the open pouring process with the closed high-pressure grouting process during the open pouring process of the traditional post-casting joint, and by using new materials, breaking through the traditional open pouring technology of the post-casting joint, and innovatively using the technology of high-pressure grouting of the bag-type closed post-casting joint, a series of quality problems of open construction are eliminated, the difficulty of safety management and control is reduced, the accuracy of steel bar positioning is ensured, and the integrity of the post-casting components and the pre-casting components is improved, while also improving the level of civilized construction on the construction site.

[0051] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A post-casting strip structure using an inflatable component, characterized in that: It includes a beam module and a plate module, and the beam module and the plate module are cast into one piece; The beam module comprises a post-cast strip beam reinforcement (1) connecting the beam concrete (3) on both sides, and a beam post-cast strip closed air bag (7) arranged between the two groups of beam concrete (3) for limiting the post-cast strip beam reinforcement (1); The slab formwork comprises post-cast strip slab steel bars (2) connecting slab concrete (4) on both sides, and a slab post-cast strip closing air bag (8) arranged between the two groups of slab concrete (4) for limiting the post-cast strip slab steel bars (2).

2. The post-casting strip structure using aerated grouting holes according to claim 1, characterized in that: The beam post-casting strip sealing airbag (7) and the slab post-casting strip sealing airbag (8) are both high-pressure airbags, and the high-pressure airbags include universal wall panel type, customized beam type, and compensation type airbags. The high-pressure airbags have grouting holes reserved below the post-casting strip, and grouting pipes (5) are inserted into the grouting holes. The high-pressure airbags have air holes reserved above the post-casting strip, and air pipes (6) are inserted into the air holes.

3. A post-casting strip sealing construction process for the inflatable assembly according to any one of claims 1-2, characterized in that: The following steps are involved: S1. Construction preparation: Build a 3D model of the post-casting strip based on BIM technology, reserve a standard width post-casting strip, and maintain the traditional support formwork system; S2. High-pressure airbag preparation: Prefabricate the high-pressure airbag system in sections based on the three-dimensional model. The system includes universal airbags for walls and panels, nested airbags for beams, and compensating airbags. Each airbag has a grouting hole at the bottom and an air hole at the top. S3. Install and position the high-pressure airbags in sequence according to the parts: install them according to the beam module and plate module respectively; Beam module: When tying the beam stirrups to the post-casting zone, insert the nested airbags into the gaps between the main reinforcements to make the ABS board surface fit the stirrups and secure them; Plate formwork: After the reinforcement is tied, insert the wall and plate universal airbags into the post-casting zone in sections to make the ABS plate surface close to the formwork; S4. Gradual aeration molding: Inflate the walls, beams, and slabs in order from bottom to top. Inflate the wall and beam airbags to 0.25MPa, and the slab airbags to 0.11MPa. Maintain the pressure until the adjacent concrete begins to set. S5. Pour the expansive mortar in sequence: After the settlement of the structure stabilizes, grout the walls, beams, and slabs from bottom to top in sequence. The grouting pressure is 0.3-0.5MPa, and the slurry expansion is ≥600mm.

4. The post-casting strip sealing construction process of an inflatable component according to claim 3 is characterized in that: In step S1, workers are first familiar with the drawings, and detailed explanations of the scheme, drawings, and construction process are given to the workers. Construction materials and equipment are checked to ensure that they can be put into use. A 10 cm width post-casting strip is reserved, and isolation measures do not need to be implemented. The support and formwork of the post-casting strip are constructed using traditional construction methods. BIM technology is used to construct a three-dimensional structure of the enclosed space of the post-casting strip. The chemical fiber textile processing plant produces high-pressure airbags in sections and models according to on-site needs.

5. The post-casting strip sealing construction process of an inflatable component according to claim 4 is characterized in that: In step S2, the airbag is made of aramid polyester composite material, wherein the universal airbag for walls and panels adopts a composite structure of a single-layer aramid polyester composite layer and a 3mm ABS board. The nested type for beams includes peripheral airbags and internal airbags. The periphery of the nested type for beams adopts a single-layer aramid polyester composite + ABS board, and the interior of the nested type for beams adopts a double-layer aramid + butyl rubber flexible structure. The compensatory airbag adopts a double-layer aramid + butyl rubber flexible structure.

6. The post-casting strip sealing construction process of an inflatable component according to claim 5, characterized in that: When installing the airbags for the beam in step S3, the airbags are installed simultaneously with the process of tying the stirrups at the post-casting strip position, with the grouting holes drawn out from the bottom of the beam formwork and the air holes drawn out from the top; The segment length of wall and board airbags is ≤2m, and the installation spacing is ≤800mm; When tying the beam stirrups, once the stirrups have reached the designated location in the post-casting strip, a custom nested airbag is placed through the beam's main reinforcement and positioned in the designated location in the post-casting strip. Ensure the airbag's plastic panel fits the beam stirrups and secures them. Continue tying the remaining stirrups until the entire beam is tied. When closing the formwork, the grouting holes are drawn out from the bottom of the beam formwork and sealed, while the air holes are drawn out from the top and sealed. After the wall and slab reinforcement is tied, the universal air bags for walls and slabs are inserted into the predetermined positions of the post-pouring strips in sections from the reinforcement spacing to ensure that the plastic board surface of the air bags fits the casting formwork and is tied and fixed. When closing the casting formwork, the grouting holes are led out from the bottom of the formwork and closed, and the air holes are led out from the top and closed.

7. The post-casting strip sealing construction process of an inflatable component according to claim 6, characterized in that: In step S4, air is inflated into the airbags from bottom to top using an inflation device in the order of first the wall post-casting strip, then the beam post-casting strip, and finally the slab post-casting strip. After inflation, the pressure is maintained until the concrete reaches initial setting.

8. The post-casting strip sealing construction process of an inflatable component according to claim 7, characterized in that: The test pressure of the wall and beam airbags is 0.25 MPa, the test pressure of the plate airbags is 0.11 MPa, the inflation pressure fluctuation value is ≤5%, and the density of the contact surface between the airbag and the concrete is tested by ultrasonic wave after inflation, and the deviation value is ≤3 mm.

9. The post-casting strip sealing construction process of an inflatable component according to claim 8, characterized in that: In step S5, after the conditions for pouring the post-casting strip are met, the grouting holes and air holes of each air bag are opened, and grouting equipment is used to inject grout from the grouting holes of each air bag from bottom to top in the overall order of first the wall post-casting strip, then the beam post-casting strip, and finally the slab post-casting strip. The slurry used for grouting meets the general performance requirements for post-casting strip concrete in the specifications.

10. The post-casting strip sealing construction process of an inflatable component according to claim 9, characterized in that: The grouting in step S5 must meet the following conditions: the structural settlement stabilization period is ≥ 60 days, the ambient temperature is ≤ 25°C, the air holes are opened simultaneously during grouting as exhaust channels, the expansion rate of the expansive mortar is controlled at 1.5-2%, and the grouting fullness is verified by ultrasound after the grouting is completed, and the void rate is ≤ 0.3%.

Images