A prefabricated crash barrier and cast-in-place beam body joint UHPC segmented cooperative pouring method

Abstract

This invention discloses a method for segmented coordinated grouting of UHPC (Underfilled High-Pressure Polymer) at the junction of prefabricated crash barriers and cast-in-place beams, applicable to UHPC grouting construction at the junction of prefabricated crash barriers and cast-in-place beams. Based on the extension length, local cross-sectional changes, and internal connection structure of the grouting space at the junction, the grouting space is divided into multiple adjacent segmented grouting areas, and corresponding grouting holes and observation holes are set for each segment. UHPC grouting is performed according to a predetermined sequence. The grouting sequence and position of adjacent segments are adjusted based on the filling status reflected by the observation holes, so that adjacent segments form coordinated filling. When insufficient filling occurs in a local area, adjacent grouting holes are switched to change the UHPC entry position and supplementary grouting is performed until all segments form a continuous filling state. This invention can improve the continuity and overall compactness of the UHPC filling at the junction, and reduce local under-grouting and cavity defects.

Description

Technical Field

[0001] This invention relates to the field of prefabricated bridge construction and concrete connection technology, specifically to a method for segmented and coordinated grouting of UHPC at the junction of prefabricated crash barriers and cast-in-place beams. Background Technology

[0002] Precast crash barriers are characterized by factory production, high construction efficiency, and easy quality control, and are widely used in prefabricated bridges and rapid bridge construction. Precast crash barriers typically require reliable connection to cast-in-place beams to form a continuous bridge protection structure. Ultra-high performance concrete (UHPC), with its high strength, high toughness, and good durability, can fill the connection space between precast crash barriers and cast-in-place beams through grouting, and is therefore widely used for the connection construction of precast crash barriers at the joints with cast-in-place beams.

[0003] The existing UHPC (Ultra-High-Pressure Polymer) grouting construction at the junction of precast crash barriers and cast-in-place beams often involves setting up grouting ports, vents, or slurry outlets at the junction, and filling the junction by injecting UHPC into the interior through single points or a small number of grouting locations. Because the junction space between the precast crash barrier and the cast-in-place beam is typically long, has significant local cross-sectional changes, and contains numerous internal connecting steel bars and embedded parts, the flow of UHPC within the junction is easily affected by changes in spatial dimensions and internal structures, leading to uneven slurry flow paths. When using a single continuous grouting method, it is difficult to simultaneously monitor the filling status of the far and near areas, and some areas may experience reduced slurry flow velocity, stagnation, or even incomplete filling.

[0004] Currently, the assessment of UHPC filling status during construction relies primarily on the grouting personnel's observation of grout flow, grouting time, and construction experience. When the UHPC has not yet reached a localized area within the joint, it is often difficult for external personnel to directly determine the actual filling status of that area. Even if grout flow is observed through the grout outlet, it is difficult to accurately determine whether continuous and sufficient filling has been achieved at different locations within the joint. Especially when the joint is long or contains densely reinforced areas, a single grout flow pattern cannot reflect the actual filling status of the entire joint, easily leading to hidden defects such as localized under-grouting, cavities, and incomplete compaction.

[0005] Furthermore, existing grouting methods typically treat the joint as a single, continuously filled space, lacking independent control for different areas during the grouting process. When flow is obstructed in a certain area due to reinforcement or structural changes, continuing to pressurize or grout from the original grouting location does not effectively improve the filling status of the obstructed area and may cause local grout accumulation, pressure changes, or premature filling of other areas, thus increasing the difficulty of controlling the grouting process. For areas with localized under-grouting or insufficient filling, existing methods also lack supplementary grouting paths corresponding to specific defect locations. Usually, problems need to be identified and addressed manually after construction, which is detrimental to improving construction efficiency and connection quality.

[0006] Therefore, considering the long UHPC grouting space, complex internal structure, difficulty in directly judging the filling status, and the tendency for insufficient filling in some areas at the junction of precast crash barriers and cast-in-place beams, it is necessary to propose a UHPC grouting method that can organize grouting in segments based on the characteristics of the junction space, observe the filling status in different zones, and coordinate the grouting process of adjacent zones according to the actual filling conditions of different zones. This would improve the filling continuity and overall compactness of UHPC in the junction and reduce the probability of grouting defects such as local under-grouting and cavities. Summary of the Invention

[0007] The purpose of this invention is to provide a method for segmented and coordinated grouting of UHPC at the junction of prefabricated crash barriers and cast-in-place beams. This method involves dividing the grouting space at the junction between the prefabricated crash barriers and cast-in-place beams into segments, setting corresponding grouting holes and observation holes in each segment, and organizing UHPC grouting in a forward-to-backward order. The grouting sequence and position of adjacent segments are adjusted based on the actual filling status reflected by the observation holes. When insufficient filling occurs in a local area, the UHPC entry position is changed through adjacent grouting holes to implement supplementary grouting, thus forming continuous and coordinated filling between adjacent segments. This solves the problems of uneven filling in near and far areas, local flow obstruction, difficulty in judging the filling status, and difficulty in timely handling of under-grouting areas in the existing overall grouting process for the junction, improving the continuity and overall compactness of the UHPC filling at the junction.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for segmented collaborative grouting of UHPC at the junction of prefabricated crash barriers and cast-in-place beams, characterized in that it includes:

[0009] The steps for segmenting the joint grouting space are as follows: A joint grouting space is formed between the prefabricated guardrail and the cast-in-place beam. Based on the longitudinal extension length of the joint grouting space, local cross-sectional changes, and the arrangement of connecting steel bars and embedded components, the joint grouting space is divided into multiple sequentially adjacent segmented grouting areas. The adjacent segmented grouting areas are kept connected to allow the flow of UHPC, so that each segmented grouting area together covers the entire joint grouting space.

[0010] Steps for setting up injection holes and observation holes: For each segmented injection area, injection holes and observation holes connected to the corresponding area are set up respectively, so that each segmented injection area forms a corresponding UHPC input position and filling status observation position. The injection hole is used to input UHPC into the corresponding segmented injection area, and the observation hole is used to observe the flow, rise and filling status of UHPC in the corresponding segmented injection area.

[0011] Segmented Injection Procedure: UHPC is injected sequentially from the distal end to the proximal end of the joint. First, UHPC is introduced through the injection hole corresponding to the distal segmented injection area, allowing the UHPC to diffuse from the low position to the high position within the corresponding segmented injection area. The rising and filling status of the UHPC is observed through the corresponding observation hole. When the current segmented injection area reaches the predetermined filling state, injection is then carried out into the next adjacent segmented injection area, allowing the UHPC to advance segment by segment towards the proximal end of the joint.

[0012] Adjacent segment collaborative filling steps: During the sequential advancement of adjacent segment grouting areas, based on the UHPC filling status reflected by the observation holes of the current segment and the adjacent grouting segments, the adjacent segments are alternately grouted or supplemented with grouting, so that the grouting segments and subsequent segments form continuous UHPC filling, and the filling status of adjacent segments are gradually connected.

[0013] Filling status adjustment steps: When the observation hole corresponding to any segmented grouting area does not show continuous UHPC slurry, the UHPC rising status is abnormal, or the predetermined filling status is not reached during the predetermined grouting process, the segment is identified as an insufficient filling area. Based on the filling status of the insufficient filling area and the adjacent segmented grouting areas, the adjacent grouting hole is selected for supplementary grouting, so that UHPC enters the joint grouting space from an entry position different from the original grouting position and diffuses into the insufficient filling area, thereby changing the original flow path and promoting the filling of the area.

[0014] Overall filling confirmation steps: After completing the initial filling and necessary supplementary filling of each segmented grouting area, the observation holes corresponding to each segmented grouting area are checked for the final verification. When each observation hole shows continuous UHPC slurry and a continuous filling state is formed between adjacent segmented grouting areas, UHPC grouting is stopped, the grouting holes and observation holes are sealed, and the joint UHPC is cured as a whole.

[0015] In a preferred embodiment of the present invention, the segmented grouting area is divided sequentially along the longitudinal extension direction of the joint between the prefabricated crash barrier and the cast-in-place beam. Each segmented grouting area has a corresponding grouting range and observation range. The number and division position of the segmented grouting areas are determined according to the joint length, local cross-sectional changes and internal connection structure, so that multiple segmented grouting areas together cover the entire joint grouting space.

[0016] In a preferred embodiment of the present invention, the division of the segmented grouting areas avoids dense areas of connecting steel bars and embedded components, and is determined in conjunction with the main flow direction of UHPC in the joint grouting space, so that each segmented grouting area has a relatively clear filling range, while maintaining the continuous flow of UHPC between adjacent segmented grouting areas.

[0017] In a preferred embodiment of the present invention, each of the segmented injection areas is provided with at least one injection hole and at least one observation hole. The injection hole is located at a low position in the corresponding segmented injection area or at a position that facilitates the entry of UHPC, and the observation hole is located at a high position in the corresponding segmented injection area or at a position that can reflect the filling status of the area, so that UHPC diffuses into the corresponding area after entering through the injection hole, and the rising and discharge status of UHPC can be observed through the observation hole.

[0018] In a preferred embodiment of the present invention, each of the injection holes and observation holes is connected to the corresponding segmented injection area. The injection holes and observation holes are positioned to avoid connecting steel bars and embedded components, so that the UHPC entry direction of the injection hole matches the main filling direction of the corresponding segmented injection area, and the observation hole can reflect the actual filling state of the corresponding segmented injection area.

[0019] In a preferred embodiment of the present invention, the UHPC is injected in segments from the distal end to the proximal end of the joint. When the observation hole corresponding to the distal segment injection area shows that the UHPC has reached the predetermined filling state, UHPC is then injected into the injection hole corresponding to the adjacent segment injection area, so that the injection process gradually advances to the proximal end of the joint, thereby reducing the adverse effects of premature filling of the proximal segment on the filling of the distal segment.

[0020] In a preferred embodiment of the present invention, the adjacent segmented injection areas are filled in a coordinated manner using an alternating injection method. When the first segmented injection area reaches a first predetermined filling state, injection is performed into the adjacent second segmented injection area. When the second segmented injection area reaches a second predetermined filling state, injection is performed back into the first segmented injection area for supplementary injection based on the filling state of the observation holes corresponding to the first and second segmented injection areas, and then the injection is advanced into the subsequent segmented injection areas, so that the UHPC filling states between adjacent segmented injection areas are gradually connected.

[0021] In a preferred embodiment of the present invention, when the observation hole corresponding to any segmented injection area does not show continuous UHPC slurry during the injection process, the UHPC rising state is significantly different from that of the adjacent segment, or the predetermined filling state is not reached during the predetermined injection process, the input of UHPC from the injection hole corresponding to that segment is suspended, and an injection hole adjacent to the insufficiently filled area is selected for supplementary injection, so that UHPC diffuses from an entry position different from the original injection position to the insufficiently filled area.

[0022] In a preferred embodiment of the present invention, when supplementing the filling of the insufficient area through adjacent injection holes, the observation holes corresponding to the insufficient area and the observation holes corresponding to the adjacent segmented injection areas are observed simultaneously. When the observation holes of the insufficient area show continuous UHPC slurry again, and the UHPC filling state between adjacent observation holes forms a continuous connection, the supplementing of the insufficient area is stopped, and the subsequent segmented injection is resumed.

[0023] In a preferred embodiment of the present invention, after the initial filling of each segmented injection area is completed, the UHPC liquid level, slurry continuity and discharge status of the observation holes corresponding to adjacent segmented injection areas are checked. When there is a difference in the filling status reflected by adjacent observation holes, the injection hole corresponding to the segmented injection area with weaker filling status or the injection hole adjacent to the segment is selected for directional supplementary injection until adjacent observation holes all show a continuous UHPC slurry status.

[0024] In a preferred embodiment of the present invention, after the coordinated filling of all segmented injection areas is completed, the observation holes corresponding to each segmented injection area are checked one by one. When each observation hole shows continuous UHPC slurry and a continuous filling body is formed between adjacent segmented injection areas, the UHPC injection is stopped, and each injection hole and observation hole is sealed in a predetermined order. The joint UHPC is cured as a whole, so that the UHPC in each segmented injection area is solidified to form a continuous joint connector.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention divides the overall grouting space into multiple adjacent segmented grouting areas based on the length, local cross-sectional changes, and internal connection structure of the grouting space at the junction of the prefabricated crash barrier and the cast-in-place beam. This transforms the UHPC grouting at long-distance junctions from overall control to segmented organizational control, which is beneficial for implementing grouting in different areas.

[0027] This invention sets up corresponding injection holes and observation holes in each segmented injection area, so that the UHPC input position corresponds to the filling status observation position. This allows for observation of the flow, rise, and filling of UHPC in different segments, improving the ability to judge the internal filling status during the injection process.

[0028] This invention employs a segmented filling method from far to near, and implements alternating or supplementary filling based on the filling status feedback from the observation holes of adjacent segments, so as to form a continuous and coordinated filling process between adjacent segments, avoiding the difference in filling status between far and near areas caused by using only a single filling path.

[0029] This invention addresses areas where filling is obstructed or insufficient. By switching the adjacent injection holes to change the entry position of UHPC, UHPC can be re-diffused into the insufficiently filled area from different locations. Combined with observation holes, the results of supplementary filling are verified, thus forming a targeted method for handling abnormal areas.

[0030] After completing the grouting of each segment, this invention performs a final check on the filling status of each observation hole and adjacent segments to confirm that each area has formed continuous UHPC filling before sealing and curing the holes. This can reduce the risk of grouting defects such as local under-grouting, discontinuous filling, and internal voids.

[0031] This invention is mainly achieved through spatial segmentation of the joint, reasonable arrangement of grouting holes and observation holes, and adjustment of grouting sequence and position. It does not require changing the basic connection structure between the prefabricated crash barrier and the cast-in-place beam. The construction method has good compatibility with the existing UHPC on-site grouting process and is easy to implement in actual bridge engineering. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure and segmented grouting areas of the joint between the prefabricated crash barrier and the cast-in-place beam of the present invention.

[0033] Figure 2 This is a schematic diagram showing the arrangement of the injection holes and observation holes at the joint of the present invention.

[0034] Figure 3 This is a schematic diagram of the segmented injection and co-filling process of UHPC according to the present invention.

[0035] Figure 4 This is a schematic diagram illustrating abnormal filling states and injection path adjustments during the segmented injection process of the present invention.

[0036] Figure 5 This is a schematic diagram of the final continuous filling state of the UHPC joint of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings. It should be noted that the following embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention.

[0038] like Figure 1 As shown, this embodiment provides a segmented collaborative grouting method for the UHPC (Ultra-High-Pressure Polymer) joint between a prefabricated crash barrier and a cast-in-place beam, applicable to the UHPC connection construction at the joint between the prefabricated crash barrier and the cast-in-place beam. The prefabricated crash barrier is installed along the longitudinal extension direction of the cast-in-place beam, forming a grouting space between the prefabricated crash barrier and the cast-in-place beam for UHPC grouting. This grouting space has a certain longitudinal extension length and contains connecting reinforcing bars and other embedded components, resulting in differences in the grouting space and UHPC flow conditions at different locations.

[0039] Before UHPC grouting, this embodiment divides the grouting space of the joint into four segments based on the longitudinal extension length, local cross-sectional changes, and the arrangement of connecting steel bars and embedded components. These segments are designated as a first grouting area, a second grouting area, a third grouting area, and a fourth grouting area. Each grouting area is arranged adjacent to the other along the longitudinal direction of the joint and together covers the entire grouting space.

[0040] The boundaries of the segmented grouting zones are used to determine the main filling range corresponding to different grouting stages. No solid baffles are installed to completely block the flow of UHPC, and adjacent segmented grouting zones maintain a continuous flow of UHPC. Therefore, during construction, each segmented grouting zone can be observed for its grouting and filling status separately, while also enabling continuous flow and coordinated filling of UHPC between adjacent zones.

[0041] The number of segments is determined based on the length, cross-sectional dimensions, and internal connection structure of the joint between the precast crash barrier and the cast-in-place beam in a specific project, and is not limited to the four segmented grouting areas in this embodiment. When the joint length is long or there are many local cross-sectional changes, the number of segments can be increased; when the joint length is short and the internal structure is simple, the number of segments can be appropriately reduced.

[0042] After completing the segmented grouting area division, the grouting space at the joints is cleaned to remove debris that may affect the flow and filling of the UHPC. The connecting reinforcing bars, embedded components, and the condition of the joint space are checked to confirm that the grouting path is basically connected. The corresponding grouting holes and observation holes are determined according to the location of each segmented grouting area and numbered according to the segmentation sequence.

[0043] like Figure 2 As shown, in this embodiment, a first injection hole, a second injection hole, a third injection hole, and a fourth injection hole are respectively provided in the first segmented injection region, the second segmented injection region, the third segmented injection region, and the fourth segmented injection region. Simultaneously, a first observation hole, a second observation hole, a third observation hole, and a fourth observation hole are also provided. Each injection hole is connected to the corresponding segmented injection region for inputting UHPC into the corresponding region; each observation hole is connected to the corresponding segmented injection region for observing the flow, rise, and filling status of UHPC within the corresponding region.

[0044] In this embodiment, each injection hole is located at a low position in the corresponding segmented injection area or at a position that facilitates the entry of UHPC, and each observation hole is located at a high position in the corresponding segmented injection area or at a position that can reflect the main filling state of the area, so that after UHPC enters the joint injection space through the injection hole, it can diffuse to the corresponding segmented injection area, and the observation hole can be used to determine whether UHPC has reached the corresponding observation position.

[0045] The specific locations of the injection holes and observation holes are determined based on the actual dimensions of the joint and the arrangement of internal connecting steel bars and embedded components. While meeting the requirements for injection and observation, the injection holes and observation holes should avoid connecting steel bars and embedded components to prevent direct obstruction of UHPC entry and observation by the internal structure. Simultaneously, each hole location should maintain connectivity with its corresponding injection segment, ensuring that each segment has a relatively clear UHPC input location and filling status observation location.

[0046] After completing the setting of the injection holes and observation holes, UHPC injection is carried out. Before injection, UHPC is prepared according to design requirements, and the mixing state and injection conditions of UHPC are checked to confirm that UHPC has the flow properties to meet the filling requirements of the joint. During the injection process, a continuous and stable feeding state is maintained to avoid significant changes in the flow state of UHPC inside the joint due to irrelevant interruptions.

[0047] like Figure 3 As shown, this embodiment employs segmented grouting from the distal end to the proximal end of the joint. First, UHPC is introduced into the first segmented grouting area through the first grouting hole. After entering the first segmented grouting area, the UHPC diffuses outwards and gradually fills the higher positions. Simultaneously, the rising and discharge status of the UHPC are observed through the first observation hole.

[0048] When the first observation port indicates that the UHPC has reached the predetermined filling state, the continuous input from the first injection port is stopped or paused, and the process switches to the second segmented injection area. UHPC is then input into the second segmented injection area through the second injection port. During the filling process, the UHPC in the second segmented area diffuses to the surrounding area and forms a continuous connection with the UHPC in the first segmented area through the connecting space adjacent to the first segmented area.

[0049] Once the second observation port shows that the UHPC has reached the predetermined filling state, the first segmented injection area is checked based on the actual filling state reflected by the first and second observation ports. If the filling state shown by the first observation port is still lower than the predetermined state, the injection is returned to the first injection port for supplementary injection to further fill the first segmented injection area; if both the first and second observation ports show a continuous UHPC state, the injection continues to the third segmented injection area.

[0050] The third and fourth grouting zones were grouted according to the same basic principles. By advancing segment by segment, UHPC gradually diffused from the distal end of the junction to the proximal end, avoiding premature full filling in the proximal region and thus preventing the continued flow of UHPC in the distal region.

[0051] In this embodiment, segmented filling does not treat each segment completely independently. Instead, it involves coordinated adjustments based on the filling status reflected in adjacent observation wells, while maintaining the flowability of UHPC between adjacent segments. For example... Figure 3 As shown, after the first segment completes its initial filling and enters the second segment for grouting, it can return to the first segment for supplementary grouting based on the filling status of the second segment, so that the UHPC between the first and second segments can be further connected; then it can proceed to the third segment, and supplement the second segment based on the filling status of the third and second segments, thus forming a collaborative filling process in which adjacent segments advance step by step and supplement each other.

[0052] In the above process, the observation holes are used not only to determine whether the UHPC has reached the corresponding position, but also to compare the filling status of adjacent segments. When UHPC slurry can be continuously observed in adjacent observation holes, and the filling status between adjacent areas can be connected, it can be considered that continuous filling has been formed between adjacent segments; when there is a significant difference in the filling status reflected by adjacent observation holes, the area with weaker filling status will be further grouted.

[0053] like Figure 4As shown, when a certain segment of the grouting area experiences abnormally slow UHPC rise during the grouting process, no continuous UHPC slurry is observed in the observation hole, or the predetermined filling state is not reached during the predetermined grouting process, that segment is identified as an underfilled area. In this case, instead of simply relying on the original grouting hole to continuously input UHPC, supplementary grouting is carried out by selecting a grouting hole adjacent to the underfilled area, based on the filling status of adjacent segments.

[0054] For example, during the second-stage grouting process, if continuous UHPC slurry does not form in the second observation hole, while the first and third stages have already achieved good filling, grouting of the second grouting hole can be paused. Supplementary grouting can then be performed using the first or third grouting hole adjacent to the second stage. This allows UHPC to enter the joint grouting space from a direction different from the original grouting location and diffuse into the insufficiently filled areas of the second stage. By changing the UHPC entry location, the original flow path is adjusted, promoting the re-formation of effective flow and filling in the locally obstructed areas.

[0055] When supplementing grouting using adjacent grouting holes, continue to observe the observation holes corresponding to the insufficiently filled areas and the observation holes corresponding to adjacent segments. When continuous UHPC slurry reappears in the observation holes of the insufficiently filled areas, and the UHPC filling status reflected by adjacent observation holes forms a continuous connection, stop supplementing grouting for the insufficiently filled areas and resume subsequent segment grouting.

[0056] If, after one round of supplementary grouting, the observation hole corresponding to the insufficiently filled area still does not reach the predetermined filling state, then a suitable adjacent grouting hole will be selected for supplementary grouting again based on the actual situation of the adjacent area. During the supplementary grouting process, the actual filling state reflected by the observation hole will be used as the basis for continuing or stopping grouting, avoiding indiscriminate continuous grouting.

[0057] For two adjacent segmented filling regions, this embodiment can also employ an alternating filling method for coordinated filling. Specifically, after the first segment reaches a first predetermined filling state, the filling process transitions to the second segment; after the second segment reaches a second predetermined filling state, the filling process returns to the first segment based on the states of the first and second observation holes, and then continues to the third segment. Through this alternating method, the UHPC filling states of adjacent segments gradually become consistent, and continuous filling is achieved between adjacent regions.

[0058] After completing the initial filling and necessary supplementary filling of all segmented grouting areas, a final check was performed on each segmented grouting area. First, the UHPC status of the first, second, third, and fourth observation holes was observed to confirm that continuous UHPC slurry could be observed in each observation hole. Then, the filling status between adjacent observation holes was compared to confirm that there was no obvious interruption in filling between adjacent segmented grouting areas.

[0059] like Figure 5 As shown, once each segment of the grouting area reaches the predetermined filling state, and a continuous UHPC filling body is formed between the first, second, third, and fourth segments, the UHPC grouting is stopped. Subsequently, each grouting hole and observation hole is sealed to ensure a complete connection between the grouting hole / observation hole and the joint UHPC, and the joint UHPC is cured according to construction requirements.

[0060] In this embodiment, the final state of the observation hole can serve as one of the bases for determining whether the corresponding segmented grouting area has been filled. When the UHPC slurry can be continuously observed through the observation hole, and the filling states of adjacent observation holes can be connected, it can be confirmed that the corresponding segment and its adjacent areas have formed continuous filling. By checking each segment one by one, it is possible to avoid judging the completion of the entire joint grouting based solely on the slurry discharge at a single location.

[0061] This invention establishes a UHPC grouting method through the aforementioned construction process, characterized by "segmented organization, corresponding borehole positions, segmented advancement, status observation, adjacent coordination, anomaly adjustment, and overall verification." Compared to methods that treat the entire joint as a single space for continuous grouting, this embodiment can organize grouting for different longitudinal regions of the joint separately, and monitor the actual filling status of each segment through corresponding observation holes. When a segment is underfilled, adjacent grouting holes can be used to change the UHPC entry position for supplementary filling, making the grouting process highly targeted.

[0062] In this embodiment, the specific length, number of segments, number of injection holes, and number of observation holes for each segmented injection area can be adjusted according to the actual length, cross-sectional dimensions, arrangement of connecting reinforcing bars, and position of embedded components at the junction of the precast crash barrier and the cast-in-place beam. The segments maintain a flowable connection to the UHPC, without requiring a physical partition structure. The specific positions of the injection holes and observation holes can also be adjusted according to actual construction conditions, as long as they allow for UHPC input and filling status observation for the corresponding segments.

[0063] Furthermore, the "predetermined filling state" in this embodiment can be determined according to specific engineering construction requirements. The determination is mainly based on whether the UHPC slurry continuously reaches the predetermined observation position as reflected by the observation hole, whether the slurry forms a continuous discharge state, and whether adjacent segment observation states form a continuous connection. For joints with different cross-sectional dimensions and different connection structures, the corresponding observation positions and filling judgment requirements can be determined according to the actual situation.

[0064] Using the above method, the UHPC grouting process at the junction of the precast crash barrier and the cast-in-place beam is transformed from a single grouting path into a segmented collaborative grouting process with a clear regional correspondence. While ensuring that adjacent areas can be continuously filled, it provides corresponding supplementary grouting paths for areas with insufficient filling, thereby improving the filling continuity and overall compactness of UHPC in the grouting space of the junction.

Claims

1. A method for segmented and coordinated grouting of UHPC at the junction of precast crash barriers and cast-in-place beams, characterized in that, Includes the following steps: S1. A grouting space is formed between the precast crash barrier and the cast-in-place beam. Based on the longitudinal extension length, local cross-sectional changes, and the arrangement of connecting steel bars and embedded components of the grouting space, the grouting space is divided into multiple sequentially adjacent segmented grouting areas, ensuring that UHPC flows smoothly between adjacent segmented grouting areas. S2. For each segmented grouting area, a grouting hole and an observation hole are respectively provided, connected to the corresponding area. The grouting hole is used to input UHPC into the corresponding segmented grouting area, and the observation hole is used to observe the flow, rise, and filling status of UHPC within the corresponding segmented grouting area. S3. UHPC is grouted sequentially from far to near. When the observation hole of the current segmented grouting area shows that UHPC has reached the predetermined filling state, the grouting of the next adjacent segment begins. The area is grouted, and based on the filling status reflected by the observation holes of the current segment and adjacent grouted segments, the adjacent segments are alternately grouted or supplemented with grouted to form continuous filling between adjacent segments; S4, when the observation hole of any segment grouted area does not show continuous UHPC slurry, abnormal UHPC rise, or has not reached the predetermined filling state, based on the filling status of the segment grouted area and the adjacent segment grouted areas, the UHPC is switched to the adjacent grouted hole to input UHPC, so that the UHPC changes its entry position and diffuses into the insufficiently filled segment grouted area to complete the supplementary filling of the obstructed area; S5, the observation holes of each segment grouted area are finally checked. When all observation holes show continuous UHPC slurry and a continuous filling state is formed between adjacent segment grouted areas, grouted is stopped and the grouted holes and observation holes are sealed, and the joint UHPC is cured.

2. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, The segmented grouting areas are sequentially divided along the longitudinal extension direction of the joint between the precast crash barrier and the cast-in-place beam. Each segmented grouting area has a corresponding grouting range and observation range. The division position of the segmented grouting areas is determined according to the joint length, local cross-sectional changes and internal connection structure, so that multiple segmented grouting areas together cover the entire joint grouting space.

3. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, Each of the segmented injection areas is provided with at least one injection hole and at least one observation hole. The injection hole is located at the lower position of the corresponding segmented injection area or at a position that facilitates the entry of UHPC. The observation hole is located at the higher position of the corresponding segmented injection area or at a position that can reflect the filling status of the area. This allows UHPC to diffuse towards the higher position of the corresponding segmented injection area after entering through the injection hole, and the rising and discharge status of UHPC can be observed through the observation hole.

4. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 3, characterized in that, Each of the aforementioned injection holes and observation holes is connected to the corresponding segmented injection area, and the positions of the injection holes and observation holes avoid the connecting steel bars and embedded components, so that the UHPC entry direction of the injection hole matches the main filling direction of the corresponding segmented injection area, and the observation hole can reflect the actual filling state of the corresponding segmented injection area.

5. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, The UHPC injection is carried out from the distal end of the joint to the proximal end. When the observation hole of the distal segment injection area shows that the UHPC has reached the predetermined filling state, the injection hole corresponding to the adjacent segment injection area is opened for injection, so that the UHPC is advanced towards the proximal end of the joint segment by segment, thereby reducing the impact of the premature filling of the proximal segment on the filling of the distal segment.

6. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, The adjacent segmented injection areas are filled in a coordinated manner using an alternating injection method. When the first segmented injection area reaches the first predetermined filling state, injection is carried out into the adjacent second segmented injection area. When the second segmented injection area reaches the second predetermined filling state, injection is carried out back into the first segmented injection area for supplementary injection based on the filling state of the observation holes corresponding to the first and second segmented injection areas. Then, injection is carried out into the subsequent segmented injection areas, so that the UHPC filling state of the adjacent segmented injection areas is gradually connected.

7. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, If, during the grouting process, no continuous UHPC slurry is observed in the observation hole of any segmented grouting area, the UHPC rising state differs significantly from that of adjacent segments, or the predetermined filling state is not reached during the predetermined grouting process, the segmented grouting area is identified as an underfilled area. Continued UHPC input from the corresponding grouting hole of that segment is suspended, and a grouting hole adjacent to the underfilled area is selected for supplementary grouting, allowing UHPC to diffuse from an entry position different from the original grouting position into the underfilled area.

8. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 7, characterized in that, When supplementing the insufficiently filled area through adjacent injection holes, observe the observation holes corresponding to the insufficiently filled area and the observation holes corresponding to the adjacent segmented injection areas. When the observation holes of the insufficiently filled area show continuous UHPC slurry again and the UHPC filling state between adjacent observation holes forms a continuous connection, stop the supplementary injection for the insufficiently filled area and resume subsequent segmented injection.

9. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, After the initial filling of each segmented grouting area is completed, the UHPC liquid level, slurry continuity and slurry discharge status of the observation holes corresponding to adjacent segmented grouting areas are checked. When there are differences in the filling status reflected by adjacent observation holes, the grouting hole corresponding to the segmented grouting area with weaker filling status or the grouting hole adjacent to that segment is selected for directional supplementary grouting until adjacent observation holes show a continuous UHPC slurry status.

10. The UHPC segmented co-grouting method for the junction of prefabricated crash barriers and cast-in-place beams according to claim 1, characterized in that, After completing the coordinated filling of all segmented grouting areas, the observation holes corresponding to each segmented grouting area are checked one by one. Once it is confirmed that each observation hole shows continuous UHPC slurry and that a continuous filling body is formed between adjacent segmented grouting areas, the UHPC grouting is stopped, and each grouting hole and observation hole is sealed in a predetermined order. The joint UHPC is then cured as a whole, so that the UHPC in each segmented grouting area solidifies to form a continuous joint connector.

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