Vacuum grouting system and vacuum grouting construction method for prestressed bent cap

Abstract

The invention discloses a vacuum grouting system and a vacuum grouting construction method for a prestressed bent cap. The vacuum grouting system comprises a cement paste mixing machine. The feeding end of the grouting pump is communicated with the discharging end of the cement paste mixing machine; a prestress hole channel is formed in the prestress cover beam, and one end of the prestress hole channel communicates with the discharging end of the grouting pump; the feed end of the slurry storage tank is communicated with the other end of the prestressed duct, the slurry storage tank comprises a first discharge end and a second discharge end, and the first discharge end is communicated with the first valve; the feeding end of the vacuum pump is communicated with the second discharging end of the slurry storage tank. According to the method, the vacuum pump is used for extracting air in the prestressed duct, the grouting pump is used for grouting the prestressed duct while the vacuum pump is continuously started, it is ensured that the prestressed duct is filled with cement paste while air at the upper arch curve of the prestressed cover beam is extracted, and the load capacity of the prestressed cover beam is ensured; and the construction quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of the construction of prestressed bent caps, and particularly relates to a vacuum grouting system and a vacuum grouting construction method for prestressed bent caps. Background Art

[0002] A bent cap refers to a cross beam arranged at the top of a row of pile piers to support, distribute, and transfer the loads of the upper structure, also known as a coping beam. A reinforced concrete or under-reinforced concrete cross beam is arranged on a pier (abutment) or on row piles, and its main function is to support the upper structure of the bridge and transfer all loads to the lower structure.

[0003] In the related art, the construction operation of a prestressed bent cap is as follows: construct the positions of prestressed corrugated pipes and steel bars and the tensioning notches, chisel and wash all the floating slurry on the top of the column to ensure firm connection between the pier column and the bent cap; install supports, bottom forms, steel bars, and forms; pour concrete; carry out prestressing construction and duct grouting and carry out anchor sealing treatment to form a prestressed bent cap.

[0004] However, during the process of duct grouting, due to the presence of air in the arched curve part of the bent cap, when performing normal-pressure grouting, the ducts in the bent cap cannot be filled completely, resulting in a reduction in the actual load-bearing capacity of the bent cap and a decrease in the construction quality of the bent cap. Summary of the Invention

[0005] The main purpose of the present invention is to provide a vacuum grouting system and a vacuum grouting construction method for prestressed bent caps, aiming to improve the construction quality of bent caps.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a vacuum grouting system, including:

[0008] A cement slurry mixer;

[0009] A grouting pump, the feeding end of the grouting pump is communicated with the discharging end of the cement slurry mixer;

[0010] A prestressed bent cap, a prestressed duct is formed in the prestressed bent cap, and one end of the prestressed duct is communicated with the discharging end of the grouting pump through a first ball valve;

[0011] A slurry storage tank, the feeding end of the slurry storage tank is communicated with the other end of the prestressed duct through a second ball valve, the slurry storage tank includes a first discharging end and a second discharging end, and the first discharging end is communicated with a first valve;

[0012] A vacuum pump, the feeding end of the vacuum pump is communicated with the second discharging end of the slurry storage tank through a second valve.

[0013] In a second aspect, the present invention provides a vacuum grouting construction method for a prestressed capping beam, which is applied to the above-mentioned vacuum grouting system. The vacuum grouting construction method for the prestressed capping beam includes:

[0014] Construct a steel bar framework of the capping beam and arrange corrugated pipes inside the steel bar framework;

[0015] Construct a formwork along the contour of the steel bar framework and pour to form a capping beam to be tensioned with the prestressed duct;

[0016] Judge whether the concrete strength of the capping beam to be tensioned meets the preset strength;

[0017] If so, perform prestress tensioning on the capping beam to be tensioned to form a capping beam to be grouted;

[0018] Use the vacuum grouting system to perform vacuum grouting on the prestressed duct to form the prestressed capping beam.

[0019] Optionally, in the above-mentioned vacuum grouting construction method for the prestressed capping beam, the step of using the vacuum grouting system to perform vacuum grouting on the prestressed duct to form the prestressed capping beam includes:

[0020] Use the vacuum pump to extract the air inside the prestressed duct from one end of the prestressed duct;

[0021] Obtain the current vacuum degree inside the prestressed duct;

[0022] Judge whether the current vacuum degree meets the preset vacuum degree;

[0023] If so, connect the grouting pump to the other end of the prestressed duct;

[0024] Use the grouting pump to pour the cement slurry into the prestressed duct until the prestressed duct is filled with the cement slurry.

[0025] Optionally, in the above-mentioned vacuum grouting construction method for the prestressed capping beam, the preset vacuum degree is A, and -0.06 MPa ≤ A ≤ -0.01 MPa.

[0026] Optionally, in the above-mentioned vacuum grouting construction method for the prestressed capping beam, by mass fraction, the cement slurry includes the following components: 500 parts of water, 1389 parts of cement, and 138.9 parts of grouting agent.

[0027] Optionally, in the above-mentioned vacuum grouting construction method for the prestressed capping beam, the cement is low-alkali ordinary Portland cement with a strength grade not lower than 42.5.

[0028] Optionally, in the above-mentioned vacuum grouting construction method for prestressed capping beams, before the step of using the grouting pump to pour the cement slurry into the prestressed duct until the prestressed duct is filled with the cement slurry, the vacuum grouting construction method for prestressed capping beams further includes:

[0029] Obtain the current slurry temperature of the cement slurry;

[0030] Judge whether the current slurry temperature meets the preset temperature;

[0031] If so, use the grouting pump to pour the cement slurry into the prestressed duct until the prestressed duct is filled with the cement slurry.

[0032] Optionally, in the above-mentioned vacuum grouting construction method for prestressed capping beams, the preset temperature is T, and 5°C ≤ T ≤ 35°C.

[0033] Optionally, in the above-mentioned vacuum grouting construction method for prestressed capping beams, the step of using the grouting pump to pour the cement slurry into the prestressed duct until the prestressed duct is filled with the cement slurry includes:

[0034] While the grouting pump is pouring the cement slurry into the prestressed duct, continuously turn on the vacuum pump to apply a positive pressure to the prestressed duct;

[0035] Obtain the slurry condition of the cement slurry entering the vacuum pump;

[0036] Judge whether the slurry condition meets the preset conditions;

[0037] If so, use the second ball valve and the second valve, and continue to use the grouting pump to pour the cement slurry into the prestressed duct.

[0038] Optionally, in the above-mentioned vacuum grouting construction method for prestressed capping beams, the positive pressure is F, and 0.5 MPa ≤ F ≤ 0.6 MPa.

[0039] One or more of the above technical solutions provided by the present invention may have the following advantages or at least achieve the following technical effects:

[0040] A vacuum grouting system and construction method for post-tensioned prestressed capping beams proposed by the present invention, by using a vacuum pump to extract air from the prestressed duct, while the vacuum pump is continuously turned on, using a grouting pump to grout the prestressed duct, while extracting air from the arch curve part of the capping beam, further ensuring that the prestressed duct is filled with cement slurry, ensuring the actual load-bearing capacity of the capping beam, and improving the construction quality of the capping beam. Description of the Drawings

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these provided drawings.

[0042] Figure 1 It is a schematic structural diagram of the vacuum grouting system of the present invention;

[0043] Figure 2 It is a schematic flow diagram of the vacuum grouting construction method for prestressed capping beams of the present invention;

[0044] Figure 3 For Figure 2 It is a refined flow schematic diagram of step S500 in

[0045] Figure 4 For Figure 3 It is a refined flow schematic diagram before step S550 in

[0046] Figure 5 For Figure 3 It is a refined flow schematic diagram of step S550 in

[0047] Explanation of the reference numerals in the drawings:

[0048] Label Name Label Name 100 Cement slurry mixer 200 Grouting pump 300 Prestressed bent cap 400 Slurry storage tank 500 Vacuum pump 210 First ball valve 310 Second ball valve 410 First valve 420 Second valve

[0049] The realization of the object of the present invention, functional features and advantages will be further described with reference to the embodiments and the drawings. Detailed implementation manners

[0050] To make the object, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0051] It should be noted that in the embodiments of the present invention, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, the directional indications will also change accordingly.

[0052] In the present invention, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or system comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "comprising..." does not preclude the existence of additional identical elements in the process, method, article or system comprising that element. Additionally, the meaning of "and / or" appearing throughout the text includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously.

[0053] In the present invention, unless otherwise clearly defined and limited, terms such as "connect" and "fix" shall be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the communication inside two components or the interaction relationship between two components.

[0054] In the present invention, if there are descriptions involving "first", "second", etc., such descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0055] In the present invention, suffixes such as "module", "component", "part", "member" or "unit" used to denote elements are only for the convenience of describing the present invention and have no specific meaning in themselves. Therefore, "module", "member" or "unit" can be used interchangeably.

[0056] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Additionally, the technical solutions of each embodiment can be combined with each other, provided that it is based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] Currently, in modern bridge construction, prestressed bent caps, as an important structural element, undertake the key task of transferring and distributing the loads of the superstructure while ensuring the stability and safety of the overall structure. The quality and performance of prestressed bent caps directly affect the load-bearing capacity and durability of the bridge.

[0058] However, a major technical problem during construction is the presence of air in the duct, which can cause the duct to not be fully filled during the grouting process, thereby affecting the prestressing effect and the overall quality of the capping beam. The existence of this problem not only reduces the actual load-bearing capacity of the capping beam but also lowers the safety and reliability of the overall structure.

[0059] The inventive concept of the present invention will be further elaborated below in conjunction with some specific embodiments.

[0060] The present invention provides a vacuum grouting system and a vacuum grouting construction method for a prestressed capping beam 300.

[0061] Referring to Figure 1 , Figure 1 is a schematic structural diagram of the vacuum grouting system of the present invention.

[0062] In an embodiment of the present invention, as Figure 1 shown, a vacuum grouting system includes: a cement slurry mixer 100, a grouting pump 200, a prestressed capping beam 300, a slurry storage tank 400, and a vacuum pump 500. The feeding end of the grouting pump 200 is communicated with the discharging end of the cement slurry mixer 100; a prestressing duct is formed in the prestressed capping beam 300, and one end of the prestressing duct is communicated with the discharging end of the grouting pump 200 through a first ball valve 210; the feeding end of the slurry storage tank 400 is communicated with the other end of the prestressing duct through a second ball valve 310. The slurry storage tank 400 includes a first discharging end and a second discharging end, and the first discharging end is communicated with a first valve 410; the feeding end of the vacuum pump 500 is communicated with the second discharging end of the slurry storage tank 400 through a second valve 420.

[0063] It can be understood that the cement slurry mixer 100 is used for mixing cement slurry; the grouting pump 200 includes a slurry suction pipe. The grouting pump 200 is used to suck the cement slurry mixed by the cement slurry mixer 100 into the pump body through the slurry suction pipe and press the cement slurry into the prestressing duct; when the grouting pump 200 continuously grouts the prestressing duct in the prestressed capping beam 300, the slurry storage tank 400 is used to store the cement slurry overflowing from the prestressing duct, that is, the excess cement slurry; the vacuum pump 500 is used to extract the air in the prestressing duct to make the prestressing duct in a vacuum state.

[0064] In one embodiment, the grouting end (i.e., the output end) of the grouting pump 200 is connected to one end of a prestressed duct, and a first ball valve 210 is provided at the grouting end of the grouting pump 200. The first ball valve 210 is used to block or connect the grouting end of the grouting pump 200 and the prestressed duct communicated therewith. At the other end of the prestressed duct, the prestressed duct is connected to the slurry storage tank 400 by a pipeline. Moreover, a second ball valve 310 is provided on the pipeline connecting the slurry storage tank 400 and the prestressed duct. The second ball valve 310 is used to block or connect the feeding end of the slurry storage tank 400 and the prestressed duct communicated therewith. Two discharging ends, namely a first discharging end and a second discharging end, are provided on the slurry storage tank 400. A first valve 410 is provided on the pipeline connected to the first discharging end, and a second valve 420 is provided on the pipeline connected to the second discharging end. The pipeline connected to the second discharging end is used to connect the second discharging end to the feeding end of the vacuum pump 500. The first valve 410 is used to discharge the slurry or air in the storage tank to the end not connected to the vacuum pump 500, and the second valve 420 is used to block or connect the second discharging end of the storage tank and the vacuum pump 500 communicated therewith.

[0065] When performing vacuum grouting on the prestressed duct, first, close the first ball valve 210 and the first valve 410, open the second ball valve 310 and the second valve 420, and start the vacuum pump 500 to evacuate the prestressed duct.

[0066] After the vacuum degree of the prestressed duct meets the requirements, open the first ball valve 210, and start the grouting pump 200 to pump out the cement slurry prepared in the cement slurry mixer 100 and pour it into the prestressed duct. During this process, the vacuum pump 500 continuously evacuates the prestressed duct to prevent the air in the cement slurry from affecting the filling saturation of the cement slurry in the prestressed duct again. After the cement slurry in the prestressed duct is saturated, close the first ball valve 210, and then close the second ball valve 310 after a certain period of time to make the prestressed duct filled with the saturated cement slurry.

[0067] The technical solution of the present invention utilizes the vacuum pump 500 to extract the air in the prestressed duct. While the vacuum pump 500 is continuously turned on, the grouting pump 200 is used to grout the prestressed duct. While extracting the air in the upward arch curve part of the capping beam, it further ensures that the prestressed duct is filled with cement slurry completely, ensures the actual load-bearing capacity of the capping beam, and improves the construction quality of the capping beam.

[0068] Continue to refer to Figure 1 and refer to Figure 2 Figure 2 is a schematic flow chart of the vacuum grouting construction method for the prestressed capping beam 300 of the present invention.

[0069] In addition, based on the same inventive concept, as Figure 1 and Figure 2 ​As shown in the figure, the present invention further provides a vacuum grouting construction method for a prestressed capping beam 300, which is applied to the above-mentioned vacuum grouting system. The vacuum grouting construction method for the prestressed capping beam 300 includes the following steps:

[0070] Step S100: Build the steel bar framework of the capping beam and set bellows inside the steel bar framework; the bellows are used for threading steel strands during the tensioning construction of the capping beam. Multiple bellows are set in the same capping beam to form multiple prestressed ducts.

[0071] Step S200: Build a formwork along the contour of the steel bar framework and pour to form a capping beam to be tensioned with prestressed ducts.

[0072] Step S300: Determine whether the concrete strength of the capping beam to be tensioned meets the preset strength.

[0073] Step S400: If so, perform prestress tensioning on the capping beam to be tensioned to form a capping beam to be grouted; after tensioning the capping beam using each prestressed duct, cut off the steel strands exposed from the prestressed ducts (the exposed length of the steel strands should not be less than 30 mm), and perform anchor sealing. The anchor sealing is carried out using non-shrinking cement mortar. When sealing the anchor, the anchor plate and clamping pieces under the anchor and the exposed steel strands must be completely wrapped, and the thickness of the covering layer is greater than 15 mm. Grouting is carried out within 24 to 48 hours after anchor sealing, and the grouting holes on the anchor plate under the anchor are cleaned to ensure the smoothness of the grouting channel.

[0074] Step S500: Use the vacuum grouting system to perform vacuum grouting on the prestressed ducts to form the prestressed capping beam 300; use the vacuum grouting system to perform vacuum grouting on each prestressed duct one by one.

[0075] For the specific structure of the vacuum grouting system, refer to the above-mentioned embodiment. Since the vacuum grouting construction method for the prestressed capping beam 300 adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0076] Continue to refer to Figure 1 and Figure 2 and refer to Figure 3 , Figure 3 For Figure 2 is a detailed process schematic diagram of step S500 in

[0077] In an embodiment, as Figures 1 to 3 shown, the steps of using the vacuum grouting system to perform vacuum grouting on the prestressed ducts to form the prestressed capping beam 300 include:

[0078] Step S510: Start the vacuum pump 500 to pump vacuum, and use the vacuum pump 500 to extract the air inside the prestressed ducts from one end of the prestressed ducts.

[0079] Step S520: Obtain the current vacuum degree inside the prestressed duct;

[0080] Step S530: Determine whether the current vacuum degree meets the preset vacuum degree;

[0081] Step S540: If so, connect the grouting pump 200 to the other end of the prestressed duct;

[0082] Step S550: Start the grouting pump 200. When the slurry output by the grouting pump 200 reaches the required consistency, open the conveying pipe valve on the grouting pump 200 and open the first ball valve 210. The grouting pump 200 sucks the cement slurry from the cement slurry mixer 100. The cement slurry flows into the prestressed duct from one end of the prestressed duct through the first ball valve 210 to start grouting. Use the grouting pump 200 to inject the cement slurry into the prestressed duct until the prestressed duct is filled with the cement slurry.

[0083] In one embodiment, to ensure that the cement slurry in the prestressed duct can be fully filled and in a saturated state, the preset vacuum degree is A, and -0.06 MPa ≤ A ≤ -0.01 MPa.

[0084] It should be understood that during the process of applying prestress, the injection of cement slurry is one of the key steps. The cement slurry needs to fully fill the duct to ensure that the protective layer around the steel strand is uniform and dense, thereby improving the durability and bearing capacity of the prestressed member. The uniformity and density of the cement slurry filling directly affect the performance of the prestressed member. Therefore, by setting a predetermined vacuum degree range (-0.06 MPa to -0.01 MPa), the full filling and densification of the cement slurry in the duct can be promoted. The vacuum degree helps to extract the air inside the duct, reduce the formation of bubbles, and make the cement slurry form a relatively uniform and dense protective layer inside the duct. It can effectively avoid the prestress loss and durability reduction caused by internal cavities or non-uniformity in the duct.

[0085] In one embodiment, by mass fraction, the cement slurry includes the following components: 500 parts of water, 1389 parts of cement, and 138.9 parts of grouting agent.

[0086] In one embodiment, the cement is low-alkali ordinary Portland cement with a strength grade not lower than 42.5.

[0087] To ensure that the water-cement ratio, fluidity, and bleeding property of the cement paste meet the technical requirement indicators, so that the cement paste has a certain fluidity and will not quickly leave the prestressed duct due to the adsorption of the vacuum pump 500, resulting in the failure of the vacuum grouting construction. The cement is low-alkali ordinary Portland cement with a strength grade not lower than 42.5, and a water reducer and a rust inhibitor are added. The water-binder ratio does not exceed 0.34, there is no bleeding, the fluidity should be 14 - 22 s, and it should not be greater than 30 s after 30 min; the initial setting time is not less than 4 hours, and the final setting time is not greater than 24 hours.

[0088] Continue to refer to Figures 1 to 3 and refer to Figure 4 , Figure 4 For Figure 3 the detailed process schematic diagram before step S550 in

[0089] In one embodiment, as Figures 1 to 4 shown, before the step of using the grouting pump 200 to fill the prestressed duct with cement paste until the cement paste fills the prestressed duct, the vacuum grouting construction method for the prestressed capping beam 300 further includes:

[0090] Step A100: Obtain the current temperature of the cement paste;

[0091] Step A200: Determine whether the current temperature of the cement paste meets the preset temperature;

[0092] Step A300: If so, use the grouting pump 200 to fill the prestressed duct with cement paste until the cement paste fills the prestressed duct.

[0093] It should be understood that the temperature of the cement paste directly affects its fluidity, setting time, and final strength. At a suitable temperature, the cement paste can maintain good fluidity, be easy to pour, and at the same time ensure the normal progress of the setting and hardening process, thus ensuring the quality and durability of the structure; an unsuitable temperature will cause the cement paste to set prematurely or have poor fluidity, affecting the grouting quality and structural performance. In this embodiment, by setting the suitable pouring temperature range of the cement paste, it can be ensured that the paste maintains suitable fluidity during the pouring process and the quality of later hardening. Sufficient and uniform filling of the cement paste is crucial for ensuring the effective binding of the prestressed steel strands and the durability of the entire structure. The use of the grouting pump 200 can precisely control the filling amount and speed of the cement paste, ensuring that the cement paste fully fills the prestressed duct and avoiding the generation of voids or uneven density in the duct.

[0094] In one embodiment, the preset temperature is T, 5°C ≤ T ≤ 35°C.

[0095] During grouting, the temperature of the cement paste does not exceed 35°C and is not lower than 5°C, otherwise corresponding measures should be taken for treatment. The paste has no corrosive effect on the steel strands.

[0096] It should be understood that obtaining the current temperature of the cement slurry is to ensure that it is within a suitable temperature range, namely 5°C to 35°C. This temperature range ensures that the cement slurry has good fluidity, neither having poor fluidity due to too low a temperature, which makes it difficult to pour, nor setting quickly due to too high a temperature, which affects the pouring effect and the subsequent setting process. In this embodiment, by judging whether the actual temperature of the cement slurry is within the preset temperature range, it can be ensured that the cement slurry maintains the best construction state during the grouting process. If the temperature exceeds this range, measures need to be taken to adjust the temperature, such as heating or cooling the cement slurry, to avoid affecting the safety and durability of the structure. After confirming that the temperature of the cement slurry meets the preset conditions, using the grouting pump 200 for grouting can ensure that the cement slurry is poured into the prestressed duct at a suitable speed and pressure, thus avoiding the generation of voids or unevenness. The suitable temperature range also helps the cement slurry to be evenly distributed in the duct, avoiding inconsistent setting times caused by temperature differences, and ensuring the formation of a uniform and dense protective layer around the prestressed steel strand.

[0097] Continue to refer to Figures 1 to 4 and refer to Figure 5 , Figure 5 is Figure 3 a detailed process schematic diagram of step S550 in

[0098] In one embodiment, as Figures 1 to 5 shown, the steps of using the grouting pump 200 to pour the cement slurry into the prestressed duct until the prestressed duct is filled with the cement slurry include:

[0099] Step S551: While the grouting pump 200 is pouring the cement slurry into the prestressed duct, continuously turn on the vacuum pump 500 to apply a positive pressure to the prestressed duct;

[0100] Step S552: Obtain the slurry condition of the cement slurry entering the vacuum pump 500;

[0101] Step S553: Judge whether the slurry condition meets the preset conditions;

[0102] Step S554: If so, use the second ball valve 310 and the second valve 420, and continue to use the grouting pump 200 to pour the cement slurry into the prestressed duct.

[0103] In one embodiment, the positive pressure is F, and 0.5 MPa ≤ F ≤ 0.6 MPa.

[0104] To ensure the grouting effect of vacuum grouting and the construction quality of the prestressed capping beam 300, during the grouting process, the vacuum pump 500 keeps working continuously. When there is grout passing through the air filter at the vacuum pump 500 end, close the valve (the second valve 420) at the front end of the air filter. Then open the exhaust valve later. When the cement grout flows smoothly out of the exhaust valve and the consistency is the same as that of the grout poured in, close all the valves at the vacuum extraction end (the second ball valve 310 and the second valve 420). The grouting pump 200 continues to work until the pressure reaches 0.5 - 0.6 Mpa and holds the pressure for no less than 2 minutes.

[0105] Close the grouting pump 200 and all the valves at the grouting end (the first ball valve 210) to complete the grouting.

[0106] Disassemble the external pipelines and accessories, and clean the air filter and valves, etc., to conduct vacuum grouting for the next prestressed duct.

[0107] It should be noted that to enable the vacuum grouting system to have the condition of being recycled and prevent the cement grout from blocking the pipelines and various valves in the vacuum grouting system, after completing the grouting of the day, all the equipment stained with cement grout must be cleaned thoroughly. The ball valves (the first ball valve 210) installed at the grouting end and the slurry outlet end should be removed and cleaned within one hour after grouting.

[0108] It should be explained that the serial numbers of the above embodiments of the present invention are only for description and do not represent the superiority or inferiority of the embodiments. The above embodiments are only optional embodiments of the present invention and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the description and drawings of the present invention under the inventive concept of the present invention, or directly or indirectly applied to other related technical fields, are all included in the patent protection scope of the present invention.

Claims

1. A vacuum grouting system, characterized in that: include: Cement slurry mixer; A grouting pump, wherein the feed end of the grouting pump is connected to the discharge end of the cement slurry mixer; A prestressed cap beam, wherein a prestressed channel is formed in the prestressed cap beam, and one end of the prestressed channel is connected to the discharge end of the grouting pump through a first ball valve; A slurry storage tank, wherein a feed end of the slurry storage tank is connected to the other end of the prestressed channel via a second ball valve, the slurry storage tank comprises a first discharge end and a second discharge end, and the first discharge end is connected to a first valve; A vacuum pump, wherein a feed end of the vacuum pump is connected to a second discharge end of the slurry storage tank via a second valve.

2. A vacuum grouting construction method for prestressed cap beam, characterized in that: Applied to the vacuum grouting system as claimed in claim 1, the vacuum grouting construction method for the prestressed cap beam comprises: Building a steel frame of the cap beam, and arranging a corrugated pipe in the steel frame; Building a template along the outline of the steel frame, and casting to form a cap beam to be tensioned with the prestressed duct; Determining whether the concrete strength of the to-be-tensioned cap beam meets a preset strength; If yes, prestressing is performed on the cap beam to be tensioned to form a cap beam to be grouted; The vacuum grouting system is used to perform vacuum grouting on the prestressed duct to form the prestressed cap beam.

3. The vacuum grouting construction method for prestressed cap beam according to claim 2, characterized in that: The step of performing vacuum grouting on the prestressed duct by using the vacuum grouting system to form the prestressed cap beam comprises: Using the vacuum pump to extract air in the prestressed channel from one end of the prestressed channel; Obtaining the current vacuum degree in the prestressed duct; Determining whether the current vacuum degree meets a preset vacuum degree; If yes, connect the grouting pump to the other end of the prestressed channel; The grouting pump is used to inject cement slurry into the prestressed pores until the cement slurry fills the prestressed pores.

4. The vacuum grouting construction method for prestressed cap beam according to claim 3, characterized in that: The preset vacuum degree is A, -0.06MPa≤A≤-0.01MPa.

5. The vacuum grouting construction method for prestressed cap beam according to claim 4, characterized in that: Calculated by weight, the cement slurry includes the following components: 500 parts of water, 1389 parts of cement, and 138.9 parts of grouting agent.

6. The vacuum grouting construction method for prestressed cap beam according to claim 5, characterized in that: The cement is low-alkali ordinary Portland cement with a strength grade of not less than 42.

5.

7. The vacuum grouting construction method for prestressed cap beam according to claim 6, characterized in that: Before the step of using the grouting pump to inject cement slurry into the prestressed hole until the cement slurry fills the prestressed hole, the vacuum grouting construction method for the prestressed cap beam further includes: Obtaining the current slurry temperature of the cement slurry; Determining whether the current slurry temperature meets a preset temperature; If so, the cement slurry is poured into the prestressed pores by using the grouting pump until the cement slurry fills the prestressed pores.

8. The vacuum grouting construction method for prestressed cap beam according to claim 7, characterized in that: The preset temperature is T, 5°C≤T≤35°C.

9. The vacuum grouting construction method for prestressed cap beam according to claim 8, characterized in that: The step of using the grouting pump to inject cement slurry into the prestressed pores until the cement slurry fills the prestressed pores comprises: While the grouting pump is pouring the cement slurry into the prestressed duct, the vacuum pump is continuously turned on to apply positive pressure into the prestressed duct; Obtaining the slurry condition of the cement slurry entering the vacuum pump; Determine whether the slurry condition meets the preset conditions; If yes, the second ball valve and the second valve are used, and the grouting pump is continued to be used to inject the cement slurry into the prestressed hole.

10. The vacuum grouting construction method for prestressed cap beam according to claim 9, characterized in that: The positive pressure is F, 0.5MPa≤F≤0.6MPa.

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