Efficient construction method for concrete expansion joint

Abstract

The application discloses a high-efficiency construction method of concrete expansion joints, which comprises the following steps: manufacturing a rigid fixed frame; installing the rigid fixed frame at multiple expansion joints; and continuously pouring concrete with a certain length. The high-efficiency construction method of concrete expansion joints is characterized in that the rigid fixed frame is arranged to firmly fix the expansion joint filling material, continuously pour the concrete structure, and solve the problems of expansion joint deformation and displacement.

Description

Technical Field

[0001] This invention relates to the field of cast-in-place concrete construction technology for reserved expansion joints in building engineering, specifically to an efficient construction method for concrete expansion joints, applicable to the construction of expansion joints in linear concrete structures in transportation, waterway, water conservancy, municipal and other engineering projects, such as expansion joint construction scenarios for linear concrete components like track beams, retaining walls, wharf yard trenches, and water conveyance channels. Background Technology

[0002] In the construction of transportation, water conservancy, and municipal engineering projects, linear concrete structures, due to their long length, are affected by factors such as temperature changes, concrete shrinkage, and foundation settlement. Therefore, expansion joints are necessary to release structural deformation stress and prevent cracking and damage. Currently, the filling materials for expansion joints in linear concrete structures are mostly extruded polystyrene foam boards (XPS) and expandable polystyrene boards (EPS). These materials are lightweight and have low rigidity, making them susceptible to deformation and displacement during concrete pouring due to material flow impact and lateral pressure. This can lead to misalignment of the expansion joint, uneven joint width, and compromised structural expansion and contraction capabilities and waterproofing.

[0003] To avoid the above problems, the industry generally adopts the skip-pour method for intermittent segmented pouring of linear concrete structures. However, this construction method has many technical defects, as follows: 1. Complex procedures and high construction costs: The skip-worksite construction method is limited by on-site personnel, equipment, formwork and other resources. Construction equipment and materials need to be transferred to the next work site repeatedly, which not only directly increases the cost of machinery shifts and manual handling, but also significantly increases the difficulty of construction organization. At the same time, the frequent transfer of equipment aggravates wear and tear, and the increased turnover of formwork makes it easy for the edges and corners to wear out and deform, requiring additional investment in repair or replacement, which indirectly increases the overall construction cost.

[0004] 2. Long construction period and low construction efficiency: The skip-pour method requires that after each section of concrete is poured, the formwork (the formwork on the outside of the linear concrete) must be removed before the concrete reaches the design strength and the construction preparation for the adjacent section can be carried out. The curing period significantly extends the construction time. In addition, the formwork, support system, vibration equipment, etc. need to be repeatedly disassembled and reassembled according to the position of the section, which further consumes construction time and reduces the overall construction efficiency.

[0005] 3. Large deviations in structural alignment and poor construction quality: The characteristics of the skip-pour method for segmented pouring lead to differences in pouring time, temperature conditions, and curing environment between adjacent concrete sections, resulting in inconsistent concrete shrinkage and deformation, which can easily cause deviations in the overall structural alignment. At the same time, during the formwork closing process, the splicing of the formwork between the newly poured section and the already completed section is prone to deformation, further affecting the smoothness of the structural alignment. Moreover, the misalignment of expansion joints can easily lead to a decrease in the waterproof sealing of the structure, shortening the service life of the project.

[0006] To address the aforementioned shortcomings of the skip-pour method, the industry has attempted to use the continuous pouring method for constructing linear concrete structures. However, this method is difficult to effectively fix the expansion joint foam board and cannot solve the core problems of expansion joint displacement and deformation. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing methods for intermittently pouring linear concrete structures, such as cumbersome procedures, long construction periods, and large deviations in structural alignment, as well as the technical problem that continuous pouring methods cannot solve the issue of expansion joint displacement. This invention provides a highly efficient construction method for concrete expansion joints. This method uses a rigid fixing frame to firmly secure the expansion joint filler material, enabling continuous pouring of the concrete structure, solving the problems of expansion joint deformation and displacement, and achieving the goals of improving construction efficiency, shortening the construction period, reducing construction costs, and ensuring project construction quality.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An efficient construction method for concrete expansion joints includes the following steps: Step 1: Construct a rigid, fixed frame; Step 2: Install rigid fixing frames at the corresponding expansion joints; Step 3: Pour concrete continuously for a certain length.

[0009] The rigid fixing frame in step one is made of rigid material.

[0010] The rigid fixing frame is made of steel bars, angle steel or flat steel. Multiple sets of densified support structures are fixed horizontally or longitudinally within the rigid fixing frame, and the rigid fixing frame and densified support structures form a grid structure.

[0011] The outer edge dimensions of the rigid fixed frame match the cross-sectional dimensions of the structural steel reinforcement in the concrete structure, and the outer edge dimensions of the rigid fixed frame are not less than the outer contour dimensions of the inner plate of the expansion joint by 1cm-2cm.

[0012] In step two, the rigid fixing frame is installed after the structural reinforcement of the concrete structure is tied and before the formwork is installed.

[0013] Step two includes the following steps: 2.1. Install the expansion joint panels according to the design location, and initially correct the position of the panels to ensure that the width of the expansion joint meets the design requirements; 2.2. Rigid fixing frames are symmetrically placed on both sides of the expansion joint slab. The planar position and verticality of the slab and rigid fixing frames are accurately checked by measurement and layout to ensure that the axis of the expansion joint is perpendicular to the axis of the concrete structure. 2.3. The rigid fixing frame is welded and fixed to the structural steel bars of the concrete structure by using extended steel bars to achieve a rigid fixing frame in both horizontal and vertical directions.

[0014] Step three includes the following steps: 3.1 Determine the continuous pouring length: Determine the length based on the on-site concrete mixing capacity, transportation efficiency, pouring speed, and formwork storage conditions to maximize the construction efficiency advantages of continuous pouring; 3.2 Symmetrical unloading: Concrete material is unloaded synchronously and evenly on both sides of the expansion joint slab, so that the concrete height on both sides rises synchronously. 3.3 Control the unloading speed: The unloading speed of concrete in the left and right areas near the expansion joint should be appropriately reduced, and the unloading speed should not exceed 3m³ / h; 3.4 Layered vibration: The concrete pouring adopts a layered vibration process, and the vibrator avoids direct contact with the rigid fixed frame and expansion joint of the slab.

[0015] In section 3.1, the continuous pouring length is generally taken as 3 to 5 spans of the designed segment length of the concrete structure. For example, if an expansion joint is set every 10m in the design length of a linear concrete structure, these 10m are usually considered as one span.

[0016] In section 3.2, the height difference between the two sides of the concrete shall not exceed 5cm.

[0017] The panels inside the expansion joints are made of XPS or EPS boards.

[0018] This invention provides an efficient construction method for concrete expansion joints, which has the following technical advantages: 1) Significantly improved construction efficiency and shortened construction period: This invention enables continuous pouring of linear concrete structures, eliminating the need for intermittent segmented construction and multiple transfers of pouring surfaces using the skip-pour method. It saves time spent waiting for concrete curing and repeatedly disassembling and reassembling formwork / equipment. The continuous pouring length can reach 3 to 5 spans of the designed segment length, improving overall construction efficiency by more than 50% and shortening the construction period by 30% to 40%. It is suitable for linear concrete engineering construction with tight schedule requirements.

[0019] 2) Existing technologies using continuous casting for linear concrete structures suffer from limitations in effectively securing expansion joint foam boards, failing to address displacement and deformation issues. This application employs a rigid fixing frame, directly limiting left and right movement at each expansion joint to achieve the desired effect. The rigid fixing frame is mesh-like, allowing the flowing concrete slurry to circumferentially flow through the mesh during casting, ensuring rapid equalization of concrete pressure on both sides of the foam board (expansion joint filler), preventing one-sided high-pressure pushing of the foam board. The rigid mesh frame itself possesses sufficient overall rigidity to firmly hold the XPS / EPS foam board in place, restricting its floating, lateral movement, and tilting. The mesh structure provides unobstructed access, allowing unimpeded concrete pouring, vibration, and self-compaction (preventing air bubbles). The force exerted on the foam board is a uniform and gentle enveloping pressure, rather than concentrated compression, preventing any denting, twisting, or displacement of the foam board.

[0020] 2) Simplified procedures and significantly reduced construction costs: On the one hand, continuous pouring reduces the number of times construction equipment and materials are transferred, reducing machinery operating costs, manual handling costs and equipment wear and tear. The number of formwork turnovers is also reduced, lowering the cost of formwork maintenance and replacement. On the other hand, the rigid fixed frame is easy to manufacture and can be processed using conventional materials such as steel bars and angle steel on the construction site. There is no need to purchase special equipment, resulting in high material utilization. Furthermore, the construction procedure of welding and fixing the rigid fixed frame to the structural steel bars is simple and does not require additional professional construction personnel, thus reducing the overall construction cost by 20% to 30%.

[0021] 3) Precise construction quality of expansion joints and smooth structural lines: The rigid fixed frame achieves precise positioning of the foam plastic board through bidirectional rigid fixing, resisting the impact and lateral pressure of concrete pouring, effectively avoiding deformation and displacement of the grout material, ensuring accurate position and uniform joint width of the expansion joint, and improving the structural expansion function and waterproof sealing performance; at the same time, continuous pouring eliminates the problem of inconsistent concrete shrinkage deformation caused by the segmented construction method, and the overall structural line deviation is controlled within the design allowable range, greatly improving the appearance quality and structural smoothness of the project.

[0022] 4) The construction process is highly versatile and easy to operate: The rigid fixing frame of this invention can be flexibly processed according to the cross-sectional dimensions and expansion joint design parameters of different linear concrete structures (track beams, retaining walls, road panels, etc.). The material is a conventional material used on the construction site, and the processing and installation process is simple. Construction personnel can operate it after a simple briefing. At the same time, the pouring process is seamlessly connected with conventional cast-in-place concrete construction without changing the existing construction process. It is suitable for the construction of linear concrete expansion joints in various projects such as transportation, waterway, water conservancy, and municipal engineering, and has a wide range of engineering application value.

[0023] 5) Improved overall structural reliability and extended service life: This invention ensures the construction quality of expansion joints, avoids stress concentration caused by expansion joint misalignment or uneven joint width, and effectively prevents cracking and damage to concrete structures; at the same time, the waterproof sealing of expansion joints is guaranteed, preventing groundwater and rainwater from seeping into the structure and causing steel corrosion, thus improving the overall reliability and durability of linear concrete structures and extending the service life of the project by more than 10 years. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a construction diagram of the expansion joint of the linear concrete structure in this invention.

[0025] Figure 2 This is a schematic diagram of the rigid frame structure in this invention.

[0026] In the diagram: 1. Extended reinforcing bar; 2. Expansion joint; 3. Rigid fixed frame; 4. Horizontal reinforcing bar; 5. Concrete structure; 6. Dense support structure; h represents the thickness of the protective layer. Detailed Implementation

[0027] like Figure 1 As shown, Figure 1 The connection between the rigid fixed frame 3 and the horizontal steel bar 4 of the concrete structure 5 (linear) is shown. The rigid fixed frame is symmetrically set on both sides of the foam plastic board of the expansion joint 2 and is fixed by welding the extended steel bar 1 to the horizontal steel bar 4 to form an overall limiting structure.

[0028] A highly efficient construction method for concrete expansion joints involves using a rigid fixing frame 3 to provide bidirectional rigid restraint for the foam plastic board (XPS board / EPS board) installed within the expansion joint 2, combined with a symmetrical and uniform continuous concrete pouring process, to prevent deformation and displacement of the joint filler material. The method specifically includes the following steps: Step 1: Construct a rigid fixed frame 1) Function of rigid fixing frame 3: The rigid fixing frame 3 is used to limit the foam plastic board in the expansion joint 2, providing sufficient rigidity and load-bearing capacity to resist the impact of material flow and lateral pressure during the concrete pouring process, prevent the foam plastic board from deforming or shifting, and ensure the accurate position and width of the expansion joint 2.

[0029] 2) Material selection: The rigid fixed frame 3 uses rigid materials such as steel bars, angle steel, and flat steel, which are processed and formed by welding. The strength of the materials must match the impact load and lateral pressure requirements of the concrete pouring. HRB400 threaded steel bars are preferred to balance rigidity and weldability.

[0030] 3) Dimensional Design: The outer dimensions of the rigid fixing frame 3 are consistent with the cross-sectional dimensions of the structural reinforcement of the concrete structure 5, and the outer dimensions of the rigid fixing frame 3 shall not be less than 2cm of the outer contour dimension of the foam plastic board to ensure complete coverage of the sealant. A transverse or longitudinal reinforced support structure 6 is installed inside the rigid fixing frame 3, with a spacing of no more than 10cm. The rigid fixing frame 3 and the reinforced support structure 6 form a grid structure, ensuring the overall rigidity and stability of the rigid fixing frame 3. The purpose of the grid structure is to ensure the concrete filling.

[0031] 4) Connection structure: Prepare extended steel bar 1. The diameter of extended steel bar 1 is not greater than the diameter of horizontal steel bar 4 in concrete structure 5. It is used to weld the rigid fixed frame 3 to the horizontal steel bar 4 to ensure that the rigid fixed frame 3 and the horizontal steel bar 4 form a whole and avoid the rigid fixed frame 3 from shifting during the pouring process.

[0032] Step 2: Install the rigid fixing frame The installation of the rigid fixed frame 3 must be carried out after the horizontal reinforcement 4 is tied and before the formwork is installed to ensure installation accuracy and connection firmness. Specific operation: 1) Install the foam plastic board for expansion joint 2 according to the design position, and initially correct the position of the board to ensure that the width of expansion joint 2 meets the design requirements; 2) Two sets of rigid fixing frames 3 are symmetrically placed on both sides of the foam plastic board. The planar position and verticality of the foam plastic board and the rigid fixing frame 3 are accurately checked by measurement and layout to ensure that the axis of the expansion joint 2 is perpendicular to the axis of the concrete structure 5.

[0033] 3) Use extended steel bars 1 to weld and fix the rigid fixing frame 3 to the horizontal steel bars 4 and the bottom main bars to achieve a two-way rigid fixation of the rigid fixing frame 3 in both horizontal and vertical directions. The welding points must be full and without incomplete welding to ensure that the rigid fixing frame 3 and the horizontal steel bars 4 become one, thus restricting the left and right displacement of the rigid fixing frame 3 and the foam plastic board.

[0034] Step 3: Pouring concrete After the rigid fixed frame 3 is installed and passes inspection, the continuous pouring of concrete structure 5 will commence. Strict control of unloading and vibration processes is required during the pouring process. Specific requirements are as follows: 1. Continuous pouring length: Determined based on on-site concrete mixing capacity, transportation efficiency, pouring speed, and formwork storage conditions. Generally, it is taken as 3 to 5 spans of the 5 design segment lengths of the concrete structure to maximize the construction efficiency advantages of continuous pouring. 2. Symmetrical unloading: Simultaneously and evenly unload concrete material on both sides of the expansion joint 2 foam board to ensure that the concrete height on both sides rises synchronously and the height difference between the two sides should not exceed 5cm to avoid excessive pressure on one side causing deformation of the foam board. 3. Control the unloading speed: The unloading speed of concrete in the areas near the expansion joints should be appropriately reduced, and the unloading speed should not exceed 3m³ / h to reduce the direct impact of the material flow on the foam board; Layered vibration: The concrete pouring adopts a layered vibration process. The vibrator avoids direct contact with the rigid fixed frame 3 and the foam plastic board to prevent the vibration force from causing the rigid fixed frame 3 to shift or the board to deform, ensuring the compactness of the concrete while protecting the expansion joint structure.

[0035] Example 1 Construction of concrete expansion joints for track beams in transportation and waterway engineering wharf storage yards Project Overview This example illustrates the concrete construction of a wharf yard track beam in a waterway engineering project. A single track beam is 400m long, 80cm wide, and 160cm high. The design requires expansion joint 2 to be installed every 10m, with a joint width of 2cm. The joint filling material is extruded polystyrene foam board (XPS), which is a typical construction scenario for expansion joints in long-distance linear concrete structures.

[0036] Construction steps 1. Fabrication of a rigid fixed frame 1.1 Dimension Calculation: The concrete protective layer thickness of the track beam is 5cm. Subtracting the protective layer thickness from the cross-sectional dimensions of the track beam (160cm×80cm) yields a cross-sectional dimension of 150cm×70cm for the track beam reinforcement. Therefore, the outer edge dimension of the rigid fixed frame is designed to be 150cm×70cm, and the frame dimension is 2cm larger than the outer contour of the XPS board to achieve complete enclosure. 1.2 Material and Structure: Both the rigid fixed frame 3 and the reinforced support structure 6 are made of HRB400 12mm diameter threaded steel bars welded together. The reinforced support structure 6 has horizontal steel bars arranged horizontally with a spacing of 10cm to form a uniform grid structure, which strengthens the rigidity of the frame. 1.3 Preparation of connecting bars: Select 10mm diameter extended steel bars (smaller than the diameter of the horizontal steel bars of the track beam) for welding connection between the rigid fixed frame 3 and the horizontal steel bars 4 of the concrete structure 5.

[0037] 2. Rigid fixed frame installation 2.1 Place 2cm thick XPS plates at the designed positions after the track beam reinforcement is tied, with a design spacing of 10m, and preliminarily correct the position of the plates; 2.2. The completed rigid fixing frames 3 are symmetrically placed on both sides of the XPS board. The planar positions of the rigid fixing frames 3 and the XPS board are checked by measuring and setting out with a total station to ensure that the axis of the expansion joint 2 coincides with the axis of the track beam. 2.3. The rigid fixing frame 3 is welded and fixed to the horizontal main reinforcement and bottom main reinforcement of the track beam by using extended steel bars 1 to achieve rigid fixation in both directions, thereby limiting the horizontal and vertical displacement of the XPS plate (the figure shows the left and right limit, which can achieve the effect). The welding points are full and there are no false welds.

[0038] 3. Continuous concrete pouring 3.1 In this embodiment, the concrete mixing and transportation capacity meets the requirements for continuous pouring, and the continuous pouring length is determined to be 5 spans (50m), so as to realize the long-segment continuous pouring of the track beam; 3.2 During pouring, unload the XPS board symmetrically and synchronously on both sides, strictly controlling the height difference of the concrete on both sides to not exceed 5cm. The purpose of requiring uniform and synchronous unloading height on both sides is to prevent deformation, displacement, or to prevent the joint filler material (XPS board) from being crushed. The unloading speed in the area near the expansion joint should be controlled at 2.5m³ / h, which is lower than the design limit of 3m³ / h, to reduce the impact of material flow. 3.3. Adopt a layered vibration process, with the vibrator at least 5cm away from the frame and XPS board to avoid direct contact that could cause deformation and ensure concrete compaction.

[0039] Construction effect After construction in this embodiment, the positional deviation of the track beam expansion joint is controlled within ±1mm, the joint width is uniform, and there is no deformation or displacement of XPS board; the overall alignment of the track beam is smooth, and the concrete surface is free of cracks and damage; compared with the traditional skip-pour method, this embodiment improves construction efficiency by 60%, shortens construction period by 40%, and reduces overall construction cost by 25%, meeting the engineering design and usage requirements.

[0040] Example 2 Construction of concrete expansion joints for retaining walls in municipal engineering projects Project Overview This example illustrates the construction of a concrete retaining wall in a municipal engineering project. The concrete retaining wall is 1000m long, with a right-angled trapezoidal cross-section, an upper base width of 80cm, a lower base width of 120cm, and a height of 100cm. The design requires an expansion joint to be installed every 15m (one expansion joint is installed transversely every 15m along the length of the concrete retaining wall), with a joint width of 2cm. Expandable polystyrene (EPS) boards are used as the joint filling material. This is a construction scenario for expansion joints in a large-span linear concrete structure in a municipal engineering project.

[0041] Construction steps 1. Fabrication of a rigid fixed frame 1.1 Dimension Calculation: The concrete protective layer thickness of the retaining wall is 4cm. Subtracting the protective layer thickness from the cross-sectional dimensions of the retaining wall, the cross-sectional dimensions of the retaining wall reinforcement are 72cm (top) × 112cm (bottom) × 92cm (height). Therefore, the outer edge dimensions of the rigid fixed frame are designed to be 72cm × 112cm × 92cm. The frame dimensions are 2cm larger than the outer contour of the EPS board. 1.2 Material and Structure: The main frame and the reinforced support structure are both made of HRB400 10mm diameter threaded steel bars welded together. The reinforced support uses horizontal steel bars arranged laterally with a spacing of 8cm (less than the design limit of 10cm) to form a grid structure. 1.3 Preparation of connecting bars: 8mm diameter extended steel bars 1 are selected for welding connection between the rigid fixing frame 3 and the horizontal steel bars 4 of the retaining wall.

[0042] 2. Rigid fixed frame installation 2.1. Place 2cm thick EPS boards at the designed positions after the reinforcement of the retaining wall is tied at a spacing of 15m according to the design, and preliminarily correct the verticality and planar position of the boards. 2.2. Rigid fixing frames 3 are symmetrically placed on both sides of the EPS board. The positions of the rigid fixing frames 3 and the EPS board are checked by a level and a total station to ensure that the axis of the expansion joint 2 coincides with the axis of the retaining wall. 2.3. The rigid fixing frame 3 is welded and fixed to the horizontal main reinforcement and bottom main reinforcement (both horizontal main reinforcement and bottom main reinforcement are horizontal steel bars 4) of the retaining wall by using extended steel bars 1 to achieve bidirectional rigid limiting and prevent the EPS board from shifting or deforming.

[0043] 3. Continuous concrete pouring 3.1 Based on the site construction conditions, the continuous pouring length is determined to be 4 spans (60m) to achieve continuous pouring of the retaining wall; 3.2 During pouring, unload the EPS board simultaneously and evenly on both sides, controlling the height difference of the concrete on both sides to not exceed 5cm. The unloading speed in the areas near the expansion joints should be controlled at 2.8m³ / h to reduce the impact of the material flow on the EPS board. 3.3. Vibrate the concrete in layers, avoiding contact between the vibrator and the rigid fixed frame 3 and EPS board to ensure the concrete is dense and to protect the expansion joint structure.

[0044] Construction effect After construction using the method of this invention in this embodiment, the expansion joints of the retaining wall are accurately positioned, with uniform joint width, and there is no deformation or displacement of the EPS board. The overall shape of the retaining wall is smooth, and the waterproof sealing is good. Compared with the traditional skip-pile method, the construction efficiency is increased by 55%, the construction period is shortened by 35%, and the overall construction cost is reduced by 28%, meeting the design and use requirements of municipal engineering.

Claims

1. A high-efficiency construction method for concrete expansion joints, characterized in that, Includes the following steps: Step 1: Construct a rigid fixed frame (3); Step 2: Install rigid fixing frames at the corresponding locations of multiple expansion joints (2); Step 3: Pour concrete continuously for a certain length.

2. The efficient construction method for concrete expansion joints according to claim 1, characterized in that: The rigid fixed frame (3) in step one is made of rigid material.

3. The efficient construction method for concrete expansion joints according to claim 2, characterized in that: The rigid fixed frame (3) is made of steel bars, angle steel or flat steel. Multiple sets of densified support structures (6) are fixed horizontally or longitudinally inside the rigid fixed frame (3). The rigid fixed frame (3) and the densified support structures (6) form a grid structure.

4. The efficient construction method for concrete expansion joints according to claim 1, characterized in that: The outer edge dimensions of the rigid fixed frame (3) match the cross-sectional dimensions of the structural steel bars of the concrete structure (5), and the outer edge dimensions of the rigid fixed frame (3) are not less than the outer contour dimensions of the inner plate of the expansion joint (2) by 1cm-2cm.

5. The efficient construction method for concrete expansion joints according to claim 1, characterized in that: In step two, the rigid fixed frame (3) is installed after the structural steel reinforcement of the concrete structure (5) is tied and before the formwork is installed.

6. The efficient construction method for concrete expansion joints according to claim 1, characterized in that: Step two includes the following steps: 2.

1. Place the expansion joint (2) plate according to the design position, and preliminarily correct the position of the plate to ensure that the width of the expansion joint (2) meets the design requirements; 2.

2. Rigid fixing frames (3) are symmetrically placed on both sides of the expansion joint (2). The planar position and verticality of the plate and the rigid fixing frame (3) are accurately checked by measurement and layout to ensure that the axis of the expansion joint (2) is perpendicular to the axis of the concrete structure (5). 2.

3. The rigid fixed frame (3) and the structural steel bars of the concrete structure (5) are welded and fixed together by using extended steel bars (1) to achieve horizontal and vertical bidirectional rigid fixation of the rigid fixed frame (3).

7. The efficient construction method for concrete expansion joints according to claim 1, characterized in that: Step three includes the following steps: 3.1 Determine the continuous pouring length: Determine the length based on the on-site concrete mixing capacity, transportation efficiency, pouring speed, and formwork storage conditions to maximize the construction efficiency advantages of continuous pouring; 3.2 Symmetrical unloading: Concrete material is unloaded synchronously and evenly on both sides of the expansion joint (2) to achieve synchronous rise of concrete height on both sides; 3.3 Control the unloading speed: The unloading speed of concrete in the areas near the expansion joints should be appropriately reduced, and the unloading speed should not exceed 3m³ / h; 3.4 Layered vibration: The concrete pouring adopts a layered vibration process, and the vibrator avoids direct contact with the rigid fixed frame (3) and the expansion joint (2) of the slab.

8. The efficient construction method for concrete expansion joints according to claim 7, characterized in that: In 3.1, the continuous pouring length is generally taken as 3 to 5 spans of the design segment length of the concrete structure (5).

9. The efficient construction method for concrete expansion joints according to claim 7, characterized in that: In section 3.2, the height difference between the two sides of the concrete shall not exceed 5cm.

10. The efficient construction method for concrete expansion joints according to claim 7, characterized in that: The board inside the expansion joint (2) is made of XPS board or EPS board.

Images