A precast-cast-in-place joint uhpc zoned and graded self-adaptive perfusion method

Abstract

This invention discloses a zoned and graded adaptive grouting method for precast-cast-in-place UHPC joints, belonging to the field of prefabricated building and bridge engineering construction technology. This method divides the connection area into zones based on the geometry of the connection cavity formed by the precast component and the cast-in-place structure, the grouting path, and the venting location, and establishes a graded grouting sequence according to the grouting position and height. By collecting grouting volume, grouting time, grout flow state, and grout discharge status from observation holes at each grouting stage, the filling status of the corresponding area is determined. Based on the determination results, the opening and closing sequence of grouting holes, grouting speed, and grouting method are dynamically adjusted, and abnormal areas are supplemented and rechecked until each area meets the dense grouting requirements. This invention can improve the filling uniformity and density of UHPC in complex and narrow connection cavities, reduce the risk of missed grouting, under-grouting, and local cavities, and improve the connection quality between precast components and cast-in-place structures.

Description

Technical Field

[0001] This invention relates to the field of prefabricated building and bridge engineering construction technology, specifically to a method for zoning, grading and adaptive grouting construction of UHPC connection cavities at the junction of prefabricated components and cast-in-place structures. Background Technology

[0002] Precast-cast-in-place composite structures offer advantages such as rapid construction, easy control of component quality, minimal on-site wet work, and ease of assembly-based construction. They have been widely applied in prefabricated buildings, bridge engineering, and precast component connection structures. Precast components and cast-in-place structures are typically connected as a whole through connecting cavities, embedded reinforcing bars, and the pouring of UHPC (Used High-Pressure Polymer). UHPC possesses high strength, high fluidity, high toughness, and good durability. It can fill the narrow connection space between precast components and cast-in-place structures and, through synergistic stress distribution with embedded reinforcing bars and existing concrete interfaces, improve the overall load-bearing capacity and durability of the joint.

[0003] Currently, the construction of precast-cast-in-place UHPC joints typically involves pre-reserved injection holes, observation holes, or vent holes. UHPC grout is injected into the connection cavity via pumping or manual methods, gradually increasing the filling depth from low to high. Existing construction methods rely heavily on workers to determine the compactness of the connection cavity based on injection time, grout flow, injection volume, and whether grout is observed through the observation holes. When the connection cavity is large, long, or contains embedded reinforcing bars or connectors, the UHPC grout is easily obstructed during flow, leading to localized stagnation, flow around the grout, or gas accumulation. This results in variations in filling speed and degree of filling in different areas.

[0004] Meanwhile, most existing grouting construction follows a predetermined grouting sequence and fixed construction parameters, often lacking a dynamic adjustment mechanism for the actual filling status of different areas. When an area experiences insufficient grouting volume, poor venting, discontinuous grout flow, or localized abnormal filling, construction personnel often need to suspend grouting and address the issue through tamping, auxiliary vibration, or reselecting grouting holes. The grouting process relies heavily on manual experience. Especially for narrow, segmented, or connecting cavities with elevation differences, a uniform grouting sequence is difficult to adapt to the actual flow conditions of different areas, easily resulting in some areas being fully filled while others remain under-grown or insufficiently vented.

[0005] Furthermore, current construction quality control primarily relies on final visual inspection, grout volume verification, and observation of grout discharge from observation holes. It lacks a construction mechanism that correlates and controls the spatial zoning of the connection cavity, grouting level, grouting state, and subsequent grouting path. When the actual grouting state deviates from the predetermined state, construction personnel typically have to adjust the grouting plan temporarily, making it difficult to establish a standardized and repeatable grouting control process. Therefore, while ensuring good flowability of UHPC, the key issues for improving the grouting quality and construction reliability of UHPC joints are: how to establish reasonable grouting areas and grouting levels based on the spatial characteristics of the precast-cast-in-place connection cavity, and how to dynamically adjust the opening and closing sequence of grouting holes, grouting speed, and supplementary grouting path according to the actual filling state during the grouting process to achieve coordinated filling of different areas.

[0006] Therefore, it is necessary to propose a zoned and graded adaptive grouting method for precast-cast-in-place UHPC joints. This method involves spatially partitioning the connection cavity and classifying the grouting levels. It also involves dynamically judging the grouting process based on the actual grouting volume, grouting time, grout flow state, and grout discharge status from the observation holes. Furthermore, it involves adjusting the grouting sequence and grouting parameters according to the filling status of different areas and implementing targeted supplementary grouting for abnormal areas. This approach aims to improve the overall filling uniformity and compactness of the UHPC connection cavity and reduce the risk of under-grouting, leakage, and the formation of local cavities. Summary of the Invention

[0007] The purpose of this invention is to provide a zoned and graded adaptive grouting method for precast-cast-in-place UHPC joints, which solves the problems of complex internal space of the connecting cavity, fixed grouting path, large differences in filling state of different areas, and reliance on manual experience to judge the grouting state during the existing precast-cast-in-place UHPC grouting process, which is prone to problems such as under-grouting, leakage, poor air venting, and local cavities. The invention realizes zoned organization, graded grouting, state judgment and dynamic adjustment of UHPC connecting cavities, thereby improving the filling uniformity and grouting density of UHPC in precast-cast-in-place joints.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for adaptive grouting of precast-cast-in-place UHPC joints, characterized in that it includes:

[0009] S1. Based on the length, height, width, spatial shape, internal embedded connectors and flow-blocking structure of the UHPC connection cavity formed between the precast component and the cast-in-place structure, the connection cavity is divided into multiple injection areas, and corresponding injection holes are set in each injection area. Exhaust observation holes are set in positions where gas accumulation is likely to occur or in the upper part of the injection area.

[0010] S2. Based on the spatial location, elevation, connectivity between adjacent areas, and expected flow path of UHPC slurry in each grouting area, the grouting levels of multiple grouting areas are divided, the initial opening and closing states of each grouting hole and the grouting sequence of each grouting area are determined, so that UHPC slurry can gradually diffuse and fill from the low-level area to the high-level area according to the predetermined path.

[0011] S3. Prepare UHPC grout according to the predetermined construction requirements, check the flow properties of the prepared UHPC grout, and inject it into the connection cavity according to the graded injection sequence after the injection requirements are met, and record the actual injection volume and injection duration corresponding to each injection area.

[0012] S4. During the grouting process, the filling status of each grouting area is judged by observing the grout discharge status, grout flow status and actual grouting volume changes of the corresponding venting observation hole in each grouting area, and the grouting area is divided into normal filling status, insufficient filling status, abnormal venting status or local stagnation status.

[0013] S5. Based on the identified grouting status, adjust the opening and closing sequence of subsequent grouting holes, the switching sequence of grouting holes, the grouting speed, and the continuous grouting time; reduce or stop the corresponding grouting path for normal filling areas; for areas with insufficient filling, abnormal venting, or local stagnation, open the grouting holes connected to the abnormal areas or adjust the grouting sequence so that the UHPC slurry changes its original flow path and replenishes the abnormal areas.

[0014] S6. For areas identified by dynamic identification as having insufficient filling, abnormal venting, or local stagnation, targeted replenishment shall be carried out, and the replenishment effect shall be verified by observing the slurry discharge status of adjacent venting observation holes and injection holes and the actual injection volume changes; if the corresponding area still does not reach the predetermined filling state, the injection path shall be adjusted and replenishment shall be carried out until the dense injection requirements are met.

[0015] S7. After completing the graded grouting of each grouting area and the supplementary grouting of abnormal areas, make a comprehensive judgment on the actual grouting volume of each area, the grouting status of the venting observation hole and the final filling status. After confirming that the connecting cavity has met the requirements for dense grouting, stop grouting, seal the grouting hole and observation hole and carry out curing.

[0016] In a preferred embodiment of the present invention, the grouting area is divided according to the spatial length, height, cross-sectional changes of the UHPC connection cavity, and the internal pre-embedded steel bars, connectors and other structures, so that different grouting areas correspond to relatively independent grout flow paths, and maintain a continuous grout diffusion relationship between adjacent grouting areas.

[0017] In a preferred embodiment of the present invention, the injection areas are graded according to their spatial elevation, and the lower injection areas are injected first. After the lower areas reach the preset filling state, the injection holes of the adjacent higher areas are gradually opened, so that the UHPC slurry forms a continuous filling process from low to high in the connecting cavity.

[0018] In a preferred embodiment of the present invention, the exhaust observation hole is located at the upper part, local high point or position where air is likely to accumulate in each injection area, so that air inside the connecting cavity can be discharged through the exhaust observation hole during the injection process, and the discharge state of the exhaust observation hole is used as the basis for judging the filling state of the corresponding injection area.

[0019] In a preferred embodiment of the present invention, the dynamic identification of the injection status is based primarily on the actual injection volume, injection duration, and slurry discharge status from the venting observation hole. When the actual injection volume reaches the predetermined injection volume for the corresponding area and UHPC slurry continuously appears in the venting observation hole, the corresponding area is determined to have reached a normal filling state. When the actual injection volume is significantly lower than the predetermined injection volume or the venting observation hole does not show continuous slurry discharge, the corresponding area is determined to have insufficient filling or abnormal venting.

[0020] In a preferred embodiment of the present invention, the predetermined injection volume is determined based on the volume of the connecting cavity of the corresponding injection area, the actual construction state of the UHPC grout, and the construction loss, and the relationship between the actual injection volume and the predetermined injection volume is used as the basis for dynamic adjustment of the injection state.

[0021] In a preferred embodiment of the present invention, when a certain grouting area is underfilled, the spatial location corresponding to the abnormal area and the adjacent grouting holes are first determined. By closing the grouting path of the already filled area and opening the grouting hole connected to the abnormal area, the UHPC grout enters the connecting cavity from the new grouting position, thereby reducing the grout accumulation caused by the continued grouting of the already filled area and improving the filling efficiency of the abnormal area.

[0022] In a preferred embodiment of the present invention, when an abnormal venting state occurs in a certain grouting area, the state of the venting observation hole corresponding to that area is adjusted first, and the grouting speed of the corresponding grouting area is reduced so that the air inside the connecting cavity has sufficient time to be vented; after the venting state is restored, UHPC grouting continues to reduce the risk of local cavities formed due to air retention.

[0023] In a preferred embodiment of the present invention, when a local stagnation occurs in a certain injection area, the opening and closing sequence of the injection holes is adjusted according to the positional relationship between the stagnation area and the adjacent injection holes. By changing the position and flow direction of the UHPC slurry entering the connecting cavity, the slurry bypasses the local obstruction area and enters the insufficiently filled area.

[0024] In a preferred embodiment of the present invention, the flow performance of the UHPC slurry is checked before injection, and the initial injection speed is determined according to the flow state of the slurry. When the flow state of the slurry changes significantly during the injection process and affects the filling of the connecting cavity, the injection speed and the switching time of the injection hole are adjusted so that the injection process is adapted to the actual flow state of the UHPC slurry.

[0025] In a preferred embodiment of the present invention, the adaptive irrigation process is carried out in a cyclical manner of "irrigation - status judgment - parameter adjustment - continued irrigation - abnormal supplementary irrigation - re-judgment", so that the actual irrigation status of each irrigation area participates in the subsequent irrigation decision, rather than completing all irrigation areas in a fixed irrigation sequence.

[0026] In a preferred embodiment of the present invention, the compaction state after the injection is completed is determined by a comprehensive assessment of the correspondence between the actual injection volume and the predetermined injection volume, the final slurry discharge state of each venting observation hole, and the verification results after the injection of abnormal areas. When any injection area fails to reach the predetermined filling state, the final sealing of the hole is not performed, but the injection path of the area is re-determined and injection is carried out.

[0027] In a preferred embodiment of the present invention, the interface between the precast component and the cast-in-place structure is cleaned and treated before UHPC injection to remove debris and loose material that affects UHPC filling from the connection cavity, and the state of the interface is controlled according to the construction conditions to ensure that the UHPC grout can form a continuous bond with the precast component and the cast-in-place structure.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] By organizing the grouting process in zones and grades, the controllability of the grouting path is improved. This invention divides the grouting areas and establishes grouting levels according to the spatial morphology, internal structure, and elevation relationship of the connecting cavity, so that the UHPC grout is filled area by area and level by level according to the predetermined path, avoiding the incomplete filling of local areas caused by using a single grouting point or a fixed sequence;

[0030] This invention achieves adaptive adjustment of the grouting process by dynamically identifying the grouting status. It correlates the actual grouting volume, grouting duration, grout flow state, and grout discharge status from the venting observation hole, and dynamically adjusts the opening and closing sequence of the grouting holes, the grouting speed, and the grouting path according to the actual filling status of different areas, so that the grouting plan can be adjusted according to changes in the actual site conditions.

[0031] It can perform targeted replenishment in abnormal areas. When there is insufficient filling, abnormal air release, or local stagnation, the present invention does not require repeated filling of the entire connecting cavity. Instead, it selects the corresponding filling hole according to the location of the abnormal area for targeted replenishment, and determines the replenishment effect by observing and verifying again, thereby reducing the waste of UHPC materials and improving construction efficiency.

[0032] Improve the overall compactness and filling uniformity of the UHPC in the connection cavity. Through staged grouting from low to high position, air venting observation, and re-grouting of abnormal areas, the UHPC grout can continuously fill the internal space of the connection cavity and expel trapped air, reducing the risk of incomplete grouting, under-grouting, and the formation of local cavities;

[0033] This invention reduces the reliance on personnel experience during the construction process. It establishes a continuous construction process for dividing the connection cavity, grouting sequence, status judgment, parameter adjustment, and re-grouting verification, transforming UHPC grouting from solely relying on the experience of construction personnel to dynamically adjusting based on the actual grouting status. This facilitates the formation of standardized and repeatable construction methods.

[0034] This invention is applicable to precast-cast-in-place joints with different spatial forms. By adjusting the grouting zone division method, grouting grade, grouting hole position, and supplementary grouting path for abnormal areas, this invention can adapt to UHPC connection cavities of different lengths, heights, spatial shapes, and internal structures, and has good engineering applicability and promotional value. Attached Figure Description

[0035] Figure 1 Schematic diagram of UHPC zoning and grouting hole layout at the precast-cast-in-place joint;

[0036] Figure 2 Schematic diagram of the UHPC zonal and graded grouting sequence for the precast-cast-in-place joint;

[0037] Figure 3 UHPC infusion status identification and adaptive adjustment flowchart;

[0038] Figure 4 Schematic diagram of directional grouting in abnormal areas of UHPC at the precast-cast-in-place joint;

[0039] Figure 5 Schematic diagram of UHPC zoned and graded adaptive grouting closed-loop control for precast-cast-in-place joint. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the following embodiments are used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the technical concept of the present invention, those skilled in the art can make adaptive adjustments to the number of grouting areas, the arrangement of grouting holes and venting observation holes, the grouting grade, and the grouting sequence based on the actual dimensions of the joint between the precast component and the cast-in-place structure, the spatial shape of the connection cavity, the internal structure, and the construction conditions; all of these adjustments fall within the scope of the technical concept of the present invention.

[0041] Example

[0042] This embodiment uses the UHPC connection between a precast crash barrier and a cast-in-place bridge beam as the construction object to illustrate the UHPC zoned and graded adaptive grouting method for the precast-cast-in-place joint of the present invention. The precast crash barrier is arranged longitudinally along the bridge beam, and its bottom forms a UHPC connection cavity with the cast-in-place bridge beam. The connection cavity contains embedded reinforcing bars to connect the precast crash barrier to the cast-in-place bridge beam. Because the connection cavity has a certain length and contains embedded reinforcing bars, the UHPC grout is prone to changes in flow path, local stagnation, and air accumulation during its flow within the connection cavity. Therefore, the zoned and graded adaptive grouting method described in this invention is used for construction.

[0043] like Figure 1 As shown, before construction, the UHPC connection cavity formed between the precast crash barrier and the cast-in-place bridge beam is first inspected. Based on the length, height, width, cross-sectional changes, spatial elevation difference, and the arrangement of the internal embedded steel bars, the connection cavity is divided into grouting zones. In this embodiment, the connection cavity is divided longitudinally into grouting zone I, grouting zone II, and grouting zone III. Grouting zone I is located at a relatively low position, grouting zone II is located in the middle position, and grouting zone III is located at a relatively high position. The three grouting zones maintain a spatial relationship that allows for continuous diffusion of the UHPC grout.

[0044] Each injection zone is provided with a corresponding injection hole, and an exhaust observation hole is provided at the top, high point, or location prone to air accumulation in each injection zone. The injection holes are used to input UHPC slurry into the connection cavity, and the exhaust observation holes are used to expel air from the connection cavity and to observe the flow and discharge status of the UHPC slurry within the corresponding zone. In this embodiment, injection zone I is provided with injection hole P1 and exhaust observation hole O1, injection zone II is provided with injection hole P2 and exhaust observation hole O2, and injection zone III is provided with injection hole P3 and exhaust observation hole O3. The specific number of injection holes and exhaust observation holes can be adjusted according to the actual length and spatial shape of the connection cavity.

[0045] After completing the partitioning and hole layout of the connection cavity, prepare the interior of the connection cavity for construction. Remove debris, loose particles, and other residues that may affect the flow and bonding of the UHPC grout from the connection cavity. Clean any accumulated water inside the connection cavity and check that the embedded reinforcing bars and other connection structures are in their intended positions. At the same time, check that the grouting holes and venting observation holes are unobstructed to ensure that the UHPC grout can smoothly enter the connection cavity and that air inside the connection cavity can be promptly expelled during the grouting process.

[0046] like Figure 2 As shown, after the connection cavity is divided into zones, the grouting level is determined based on the spatial elevation of each grouting zone, its adjacency relationship, the distance from the grouting hole, and the degree of influence of the internal structure on the grout flow. In this embodiment, grouting zone I is designated as a Level I grouting zone, grouting zone II as a Level II grouting zone, and grouting zone III as a Level III grouting zone, and grouting is performed in order from low to high level.

[0047] Specifically, first, the injection hole P1 corresponding to injection area I is opened, allowing UHPC slurry to enter the lower region of the connecting cavity. Simultaneously, the injection holes corresponding to injection areas II and III are kept closed, and the corresponding venting observation holes are kept unobstructed. During continuous input, the UHPC slurry diffuses along the internal space of the connecting cavity towards injection area I and its adjacent areas, gradually filling the region.

[0048] Once grouting zone I reaches the predetermined filling state, grouting proceeds to stage II. Grouting hole P2 corresponding to grouting zone II is opened, allowing the UHPC grout to continue diffusing towards the mid-level region. After grouting zone II reaches the predetermined filling state, grouting hole P3 corresponding to grouting zone III is opened, allowing the UHPC grout to continue diffusing towards the higher-level region. After completing stage III grouting, the overall connection cavity is checked for compaction.

[0049] The aforementioned tiered injection sequence is not based solely on a fixed injection time as the basis for switching between different injection levels. Instead, it is based on the actual filling status of the current injection area as a crucial factor in the switching process. If the current area has not yet reached the predetermined filling status, it will not directly proceed to the next injection level. Instead, it will enter the injection status identification process, and the identification results will determine whether the current injection process needs to be adjusted.

[0050] like Figure 3As shown, during the grouting process in each grouting area, the grouting status of the current area is dynamically collected. The collected data includes the actual grouting volume, grouting duration, UHPC slurry flow status, and slurry discharge status from the venting observation hole. Specifically, the actual grouting volume reflects the amount of UHPC slurry entering the current area; the grouting duration helps determine whether the slurry filling process is normal; the slurry flow status determines whether there is flow obstruction within the connecting cavity; and the slurry discharge status from the venting observation hole determines whether the slurry has reached the corresponding area and formed continuous filling.

[0051] Based on the above grouting status information, a comprehensive judgment is made on the current grouting area. When the actual grouting volume continues to increase, the UHPC grout flows continuously, no obvious abnormalities occur during the grouting process, and UHPC grout continuously appears in the corresponding venting observation hole, the current grouting area is determined to be in a normal filling state, and the next grouting area is then entered.

[0052] When the actual injection volume increases abnormally, the expected slurry discharge does not appear at the venting observation hole, or the slurry flow slows down significantly, the next injection area is not directly entered. Instead, it is determined that the current area may have insufficient filling, abnormal venting, or local stagnation, and the location and type of abnormal area are further determined.

[0053] When insufficient filling is identified, the area of ​​inadequate filling is determined based on changes in the actual injection volume and the slurry discharge status from the venting observation hole. When abnormal venting is identified, the location of potential air accumulation is determined based on the slurry discharge status from the venting observation hole. When local stagnation is identified, the location of potential flow obstruction is determined based on changes in the slurry flow state and the injection duration. After identifying the abnormal areas, the adaptive adjustment process begins.

[0054] During the adaptive adjustment process, the opening and closing sequence of the injection holes, the injection path, and the injection parameters are adjusted according to the spatial relationship between the abnormal area and each injection hole. For areas that have been normally filled, the injection path corresponding to them is stopped from continuing to input UHPC slurry to prevent slurry from continuously entering areas that have already been filled. For areas with abnormalities, the injection holes connected to these areas are identified and the corresponding injection holes are opened, allowing UHPC slurry to enter the connecting cavity from a position closer to the abnormal area, thereby changing the original injection path.

[0055] like Figure 4 As shown, when it is determined that there is insufficient filling in the grouting area II, the grouting path corresponding to the already filled grouting area I is first closed to prevent UHPC slurry from continuing to be input into the completed area; then the replenishment hole P2 connected to the abnormal grouting area II is opened to allow the UHPC slurry to directly enter the abnormal area II, and the UHPC slurry is diffused to the insufficiently filled position by adjusting the grouting path.

[0056] During targeted replenishment in abnormal areas, the venting observation hole (O2) corresponding to the abnormal area should be kept unobstructed. The slurry discharge status of O2 is observed to determine whether the UHPC slurry has reached the abnormal position. When O2 changes from a state of no slurry or intermittent slurry discharge to a state of continuous slurry discharge, the abnormal area is rechecked in conjunction with the actual injection volume during the replenishment process. If the actual injection volume matches the predetermined injection volume for that area and slurry continues to discharge from the venting observation hole, the abnormal area is determined to have reached the predetermined filling state.

[0057] If slow slurry flow, abnormal increase in actual injection volume, or discontinuous slurry discharge from the venting observation hole still occur during the replenishment process in abnormal areas, the injection status identification should be repeated, and the opening and closing sequence of the injection holes or the injection path should be further adjusted. Through the cyclical approach of "abnormal identification - path adjustment - directional replenishment - status verification", the UHPC slurry is gradually introduced into the insufficiently filled areas.

[0058] Once the abnormal area reaches the predetermined filling state, the refilling of the abnormal area is completed, and subsequent staged irrigation resumes. For example, if an abnormality is found in irrigation area II during stage II irrigation and refilling is completed, then irrigation hole P3 is opened according to the actual state of irrigation area III to enter stage III irrigation, instead of directly entering the next stage area before the abnormal area has been refilled.

[0059] In case of abnormal venting, during the adaptive adjustment process, priority is given to keeping the corresponding venting observation hole unobstructed, and the injection speed is adjusted appropriately according to the actual slurry flow state to allow sufficient time for air to escape from the connecting cavity. Once the venting observation hole resumes continuous slurry flow, the filling of the current area continues. In case of localized stagnation, the opening and closing sequence of the injection holes is adjusted according to the positional relationship between the abnormal area and adjacent injection holes, causing the UHPC slurry to change its original flow direction and enter the stagnation area.

[0060] In this embodiment, the UHPC grout undergoes a flow performance test before formal grouting. Grouting can only proceed after the prepared UHPC grout meets the construction requirements, and the initial grouting speed is determined based on the actual flow state of the grout on site. During grouting, when the grout flow state changes significantly, the grouting speed and grouting hole switching status are adjusted according to the actual filling state of the current area to adapt the grouting process to the actual flow conditions inside the connecting cavity.

[0061] In this embodiment, the predetermined injection volume for each injection area is determined based on the spatial volume of the corresponding connecting cavity and is corrected for reasonable losses during actual construction. After the actual injection volume reaches the predetermined injection volume, the injection volume is not used alone as the basis for determining the compaction state. Instead, a comprehensive judgment is made by combining the slurry discharge state from the venting observation hole, the slurry flow state, and the injection duration, thereby reducing the possibility of misjudgment caused by slurry loss, local stagnation, or air accumulation.

[0062] like Figure 5 As shown, this invention forms a complete zoned and graded adaptive grouting closed loop through the above steps. The specific process is as follows: First, the cavity is divided into zones according to its spatial morphology. Then, the grouting level is determined according to the spatial elevation and interrelationship of each zone, and grading grouting is carried out in order from low to high level. During each grouting stage, the actual grouting volume, grouting duration, slurry flow state, and slurry discharge state from the venting observation hole are collected, and the grouting state is identified. When a zone is in a normal filling state, the next grouting zone is entered. When a zone is abnormal, adaptive adjustment is performed, and directional replenishment is carried out in the abnormal zone. After replenishment is completed, the grouting state is identified again. After all zones are grouted, the overall compaction state is checked.

[0063] During the overall compaction verification process, a comprehensive assessment is made of the actual injection volume of each injection zone, the final slurry discharge status of the venting observation holes, and any abnormalities that occur during the injection process. When all zones reach the predetermined filling state and the corresponding venting observation holes reflect continuous filling, the connecting cavity is deemed to have met the compaction requirements. If any injection zone still has insufficient actual injection volume, abnormal slurry discharge from the venting observation holes, or other filling abnormalities, the abnormal zone is re-identified, and adaptive adjustment and directional replenishment are performed until the compaction requirements are met.

[0064] After confirming that the overall grouting is completed, stop the input of UHPC grout, seal the grouting holes and venting observation holes, and carry out subsequent curing in accordance with the UHPC construction requirements to ensure that the UHPC connection parts achieve stable strength development and overall connection performance.

[0065] It should be noted that this embodiment uses three grouting zones as an example for illustration, but the present invention does not limit the specific number of grouting zones. For precast-cast-in-place joints with a long length, multiple grouting zones can be divided according to the length of the connecting cavity and its internal structure; for connecting cavities with small spatial elevation differences and relatively simple internal structures, the number of grouting zones can also be appropriately reduced. The grouting level can be determined based on the actual spatial elevation, the grout flow path, and the influence of the embedded structure on the flow, and is not limited to Level I, Level II, and Level III.

[0066] Similarly, this invention does not limit the specific number and fixed position of the injection holes and venting observation holes. Their specific arrangement should be determined according to the space size of the connecting cavity, the connection form between the precast components and the cast-in-place structure, and the internal embedded structure. As long as it can achieve the regional input of UHPC grout, the venting of air inside the connecting cavity, and the observation of the injection status, the construction requirements of this invention can be met.

[0067] The key to this invention lies in dividing the UHPC (Ultra-High-Pressure Polymer) grouting process at the precast-cast-in-place junction into multiple interconnected regions and grouting levels, and using the actual grouting state as the basis for subsequent construction adjustments, so that the grouting sequence no longer completely depends on a pre-set fixed process. When insufficient filling, abnormal venting, or local stagnation occurs, the abnormal areas are directionally replenished by adjusting the opening and closing sequence of the grouting holes and the grouting path. After replenishment, the state is re-identified and compaction is verified, thereby forming a grouting process that can be dynamically adjusted according to the actual construction state.

[0068] Through the above-described embodiments, the present invention can realize the zonal organization, graded grouting, state identification, adaptive adjustment, abnormal replenishment grouting, and compaction verification of the precast-cast-in-place UHPC joint, reduce the ineffective accumulation of UHPC grout in the completed area, improve the filling uniformity and compactness of different areas in the complex connection cavity, and reduce the risk of under-grouting, leakage, poor air venting, and local cavity formation, thereby improving the construction quality and connection reliability of the precast-cast-in-place joint.

Claims

1. A zoned and graded adaptive grouting method for precast-cast-in-place UHPC joints, characterized in that, Includes the following steps: S1. Based on the spatial dimensions, cavity height, internal structure, and arrangement of embedded connectors of the UHPC connection cavity formed between the precast components and the cast-in-place structure, the UHPC connection cavity is divided into multiple grouting areas, and corresponding grouting holes and venting observation holes are set in each grouting area. S2. Determine the grouting level based on the spatial location, elevation, and connectivity of each grouting area, establish a graded grouting sequence from low to high, from far to near, or from downstream to upstream, and determine the initial opening and closing status and corresponding grouting parameters of each grouting hole. S3. Inject UHPC grout into each injection area in sequence according to the determined injection level, and obtain the actual injection volume, injection duration, grout flow state and grout discharge status of each injection stage in real time; S4. Compare the actual filling status of each filling area with the preset filling status to identify normal filling, insufficient filling, poor air venting or local stagnation, and adjust the opening and closing sequence of subsequent filling holes, filling speed and filling duration according to the identification results. S5. For grouting areas that are determined to be insufficiently filled, poorly vented, or locally stagnant, adjust the grouting path and implement supplementary grouting to allow the UHPC grout to continue to spread to the unfilled areas, and verify the supplementary grouting status through adjacent grouting holes or venting observation holes; S6. After completing the graded grouting of each grouting area and the supplementary grouting of abnormal areas, a comprehensive judgment is made on the grouting volume, slurry discharge status and filling status of each area. After the dense grouting requirements are met, grouting is stopped and the holes are sealed and cured.

2. The precast-cast-in-place UHPC zoned and graded adaptive grouting method according to claim 1, characterized in that... The grouting area is divided into multiple interconnected areas according to the length direction, height direction or internal structure of the UHPC connecting cavity. The corresponding grouting hole and exhaust observation hole are determined according to the spatial position of each grouting area, the cavity height and the flow obstruction position formed by the pre-embedded connector, so that each grouting area has an independent grouting path and a slurry flow path connected to the adjacent area.

3. The UHPC zoned and graded adaptive grouting method for precast-cast-in-place joints according to claim 1, characterized in that... The graded injection sequence is determined based on the elevation difference, injection distance, and cavity connectivity of each injection area. The lower area is injected first, and after the lower area reaches the preset filling state, the injection holes of the adjacent higher areas are opened step by step, so that the UHPC slurry forms a continuous upward filling path in the connecting cavity and reduces the formation of closed cavities.

4. The method for adaptive grouting of precast-cast-in-place UHPC joints according to claim 1, characterized in that... The determination of the grouting status is based on a comprehensive assessment of the actual grouting volume, grouting duration, and slurry discharge status from the venting observation hole. When the actual grouting volume reaches the predetermined grouting volume for the corresponding grouting area and UHPC slurry continuously appears in the venting observation hole, the corresponding area is determined to have reached the filling status. When there is a deviation between the actual grouting volume and the predetermined grouting volume, or when slurry does not continuously discharge from the venting observation hole, the corresponding area is determined to have insufficient filling or abnormal venting.

5. The UHPC zoned and graded adaptive grouting method for precast-cast-in-place joints according to claim 1, characterized in that... The injection parameters include injection speed, continuous injection time, injection hole opening and closing status, and injection hole switching sequence. When the slurry flow slows down, the injection volume increases abnormally, the slurry discharge from the exhaust observation hole is discontinuous, or the local area is not filled enough during the injection process, the injection hole opening and closing status and injection hole switching sequence are adjusted according to the location of the abnormal area, so that the UHPC slurry changes its original flow path and enters the corresponding abnormal area.

6. The precast-cast-in-place UHPC zoned and graded adaptive grouting method according to claim 1, characterized in that... When the grouting area is determined to be insufficiently filled, the location of the grouting hole is determined according to the location of the insufficiently filled area. Directional grouting is carried out by closing the grouting hole corresponding to the completed grouting area and opening the grouting hole connected to the insufficiently filled area. During the grouting process, the slurry entry status is monitored through the adjacent venting observation hole or grouting hole. After the grouting is completed, the grouting status of the area is re-determined.

7. The UHPC zoned and graded adaptive grouting method for precast-cast-in-place joints according to claim 1, characterized in that... The injection holes are set with multiple injection positions along the height direction of the UHPC connection cavity. The exhaust observation hole is set at the upper part of the corresponding injection area or at a position where gas is likely to accumulate. UHPC slurry is introduced into the connection cavity through the low injection hole, and air in the connection cavity is discharged through the high exhaust observation hole, so that the UHPC slurry gradually rises along the inside of the connection cavity and continuously fills the adjacent area.

8. The UHPC zoned and graded adaptive grouting method for precast-cast-in-place joints according to claim 1, characterized in that... Before injection, the flow properties of the UHPC grout are tested, and the injection window and initial injection speed are determined based on the test results. During the injection process, if the flow state of the grout changes and the corresponding area is not filled within the preset injection time, the opening and closing sequence of the injection holes is adjusted or the injection speed is reduced or increased to adapt to the influence of the change in the flow properties of the UHPC grout on the filling process of the connecting cavity.

9. The UHPC zoned and graded adaptive grouting method for precast-cast-in-place joints according to claim 1, characterized in that... Before UHPC grouting, the interface between the precast components and the cast-in-place structure is treated, and debris and water in the connection cavity are removed to ensure that the UHPC grouting area is in an interface state that meets the construction requirements. During the grouting process, the grouting path is adjusted according to the spatial obstruction relationship formed by the precast components, cast-in-place structure and embedded connectors to reduce the risk of local stagnation, bypass flow and discontinuous filling of UHPC grout in the connection cavity.

10. The method for adaptive grouting of precast-cast-in-place UHPC joints according to claim 1, characterized in that... After the UHPC connection cavity is filled, a filling quality record is established based on the actual filling volume of each filling area, the slurry discharge status of the vent observation hole, the number of times of replenishment and the final filling status. Areas with filling abnormalities are marked as verification areas. Verification areas are checked or replenished again until each filling area reaches the predetermined dense filling state before sealing and curing.

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