Concrete pavement repair construction method based on convex structure

Abstract

The application discloses a concrete pavement repairing construction method based on a convex structure, sets a convex pit groove structure, effectively improves the interlayer contact state of the area except the joint of the new and old concrete panels, effectively improves the stress characteristics of the joint area of the new and old panels of the cement pavement under the coupling effect of heavy load and environment, effectively improves the load transmission capacity mechanism between the new and old panels of the cement pavement, eliminates the base water scouring effect caused by the pumping effect caused by the dynamic load at the joint position, sets a composite isolation layer, uses a double-layer geotextile to sandwich a waterproof film layer, effectively solves the defect of poor puncture resistance of the waterproof layer to gravel or sharp objects, guarantees the integrity of the geotextile under the pavement, and strengthens the stress transmission efficiency of the repaired panel and the adjacent old panel through the composite assembly of the dowel bar reinforcing rib, and improves the stress concentration state at the joint.

Description

Technical Field

[0001] This invention belongs to the field of maintenance and repair technology for damaged concrete pavement in highway engineering, and particularly relates to a construction method for repairing concrete pavement based on a convex structure. Background Technology

[0002] The current method for repairing concrete pavements mainly involves marking and cutting, chiseling away the damaged concrete, and then pouring repair concrete. This method does not address the contact between the concrete pavement and the subgrade in the repair area, nor does it treat the joints between the old and new concrete panels. This approach does not conform to the design theory of thin plates with small deflection on elastic half-space foundations for cement concrete pavements in my country. This theory assumes that the surface layer and the base layer have a vertically continuous and smooth contact, meaning that the contact surfaces of the panel and the base layer always match during deformation, the vertical displacements of the panel and the base layer are equal, and there is no frictional resistance on the contact surfaces of the panel and the base layer.

[0003] Currently, when repairing and paving concrete pavements, cement slurry seeps into the base layer through cracks, forming a weak transition layer between the base and the surface layer. This transition layer creates high friction between the base and the concrete surface. The bottom of the joint between the old and new concrete is a weak point, experiencing stress concentration under heavy traffic loads, warping stress from temperature or humidity gradients, or drying shrinkage stress. The bottom of the slab experiences tensile stress, leading to cracks. The moment the crack penetrates the slab's thickness, the tensile stress near the crack's ends is completely released, like a taut spring suddenly snapping. This generates a tremendous restoring force, causing the surface layer to shrink back. This sudden restoring force is enormous. Because the transition layer bonds the surface and base layers together, the base layer prevents this restoring movement, inevitably generating huge shear forces near the interface. These shear forces quickly create horizontal cracks at the interface between the surface and base layers, causing them to separate along the transition layer, resulting in a separation interface.

[0004] After the interlayer transition layer breaks down, the broken layer will expand unevenly, exacerbating uneven voids in the pavement and reducing its load-bearing capacity. Water will enter the interface between the surface layer and the base layer along the pavement joints or cracks. Under the impact of vehicle loads, the joints will experience a pumping effect, causing the broken layer to be eroded and voided. This will further deteriorate the contact between the surface layer and the base layer, accelerating the damage rate of the cement concrete pavement repair structure. Consequently, the service life of the cement concrete pavement repair structure will be shorter, and the repair effect will be poor.

[0005] To address the aforementioned technical issues, there is an urgent need to design a concrete pavement repair construction method based on a convex structure. Summary of the Invention

[0006] The purpose of this invention is to provide a concrete pavement repair construction method based on a convex structure to solve the problem that cement concrete pavement repair structures are prone to secondary damage.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A concrete pavement repair construction method based on a convex structure includes the following steps;

[0009] Step 1 involves cutting and breaking up the damaged cement concrete pavement, and excavating downwards along the damaged cement concrete pavement to the top of the roadbed to form a convex pit.

[0010] Step 2: Compact the convex groove and level the bottom of the convex groove with mortar; after leveling, embed a pressure box in the convex groove.

[0011] Step 3: Lay the composite isolation layer. The composite isolation layer is laid on top of the pre-embedded pressure box, and both sides of the composite isolation layer are tightly bonded to the roadbed at the edge of the convex pit.

[0012] Step 4: Drill holes in the cut surface of the cement concrete pavement and install a dowel bar reinforcing composite assembly in the drilled holes; the dowel bar reinforcing composite assembly is arranged above the composite isolation layer;

[0013] Step 5: Reserve a grouting pipe in the convex pit and connect the grouting pipe outlet to the elastic grouting bag; place the elastic grouting bag in the cavity of the convex pit and inflate the elastic grouting bag to fill the top area of ​​the roadbed.

[0014] Step 6: Install a prefabricated panel above the elastic grouting bag, and perform preliminary grouting into the elastic grouting bag through the reserved grouting pipe according to the feedback of the pre-embedded pressure box;

[0015] Step 7: After the initial grouting material has hardened, observe the pressure feedback from the pre-embedded pressure box. If the feedback pressure drops and remains stable without change, then grout the elastic grouting bag again.

[0016] In step one, the excavation depth is greater than the thickness of the precast panel, but less than the thickness of the precast panel plus 5cm.

[0017] The convex pothole includes a section for breaking up the damaged concrete pavement, a section for chiseling off the top of the roadbed, and an extension cavity. The extension cavity is formed by the section for chiseling off the top of the roadbed extending to both sides of the non-damaged concrete pavement. Both extension cavities are perpendicular to the direction of travel. The extension length of the extension cavity is greater than 0.5m and less than 1m.

[0018] The pressure boxes are respectively arranged at the center of the bottom surface of the roadbed top chisel section, the center of the bottom surface of the extension cavity, the edge corner of the roadbed top chisel section, and the edge corner of the extension cavity near the roadbed top chisel section.

[0019] In step three, the composite isolation layer consists of a lower geotextile layer, a waterproof film layer, and an upper geotextile layer from bottom to top; the lower geotextile layer is laid on the bottom surface of the convex pit after leveling.

[0020] In step four, the force transmission rod and reinforcing rib composite assembly includes a force transmission rod and a reinforcing rib; the force transmission rod has a U-shaped structure; one end of the force transmission rod is inserted into the drill hole in the cut surface of the cement concrete pavement, and the other end of the force transmission rod extends into the extension cavity and is in close contact with the top surface of the upper geotextile layer;

[0021] Several force transmission rods are horizontally arranged, and their installation direction is consistent with the driving direction; the force transmission rods are connected to each other by the reinforcing ribs.

[0022] In step five, the grout outlet of the grouting pipe faces into the extension cavity; the elastic grouting bag has two grouting ports and an air inlet, and the grouting ports are connected to the grouting pipe; air is injected into the air inlet of the elastic grouting bag until the elastic grouting bag fills the gap of the extension cavity.

[0023] The outer surface of the elastic grouting bag is provided with a mesh-like channel, and the mesh-like channel has evenly distributed holes. The elastic grouting bag is also provided with a grouting port that communicates with the mesh-like channel. The grouting port that communicates with the mesh-like channel is used to inject grouting material into the mesh-like channel and release it through the evenly distributed holes, so as to fill the gap between the elastic grouting bag and the base layer.

[0024] In step six, the initial grouting involves injecting grout into the elastic grouting bag. One grouting port is opened while the other remains closed. Pressurized grouting is performed through the open port, with the grouting pressure exceeding the measured pressure of the pre-embedded pressure box in the extension cavity by no more than 10%. Once the grouting is nearly complete, the grouting pressure is maintained. The pressure is then observed by the pressure box in the extension cavity area. If the measured pressure remains stable without significant change, the pressure is maintained for another 2 minutes before closing the grouting port valve to prevent pressure drop.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects: (1) By setting a convex pothole repair structure, in addition to effectively improving the interlayer contact state in areas other than the joint between the new and old concrete panels, under the action of heavy load and environmental coupling, it effectively improves the stress characteristics of the joint area between the new and old cement pavement panels. The load transfer mechanism between the new and old cement pavement panels is effectively improved. Compared with conventional concrete pavement pothole repair, by extending the laying length of the composite isolation layer, when the concentrated load of the vehicle is applied to the joint, the new and old panels work together, and the reinforcing ribs at the bottom of the panel and the composite isolation layer can effectively disperse the stress, reduce the bending tensile stress at the bottom of the panel, and effectively improve the stress concentration phenomenon.

[0026] (2) By setting up a composite isolation layer and using a double-layer geotextile sandwiched with a waterproof membrane layer, the defect of poor resistance to puncture by gravel or sharp objects in the waterproof layer can be effectively solved, ensuring the integrity of the geomembrane below the road surface. At the same time, when cracks occur in the surface layer or at the joints, the waterproof membrane layer in the composite isolation layer can prevent water from flowing into the base layer, thereby preventing pumping and mud pumping of the pavement slab under traffic loads, thus preventing misalignment and detachment of the slab at the joints, and extending the service life of the cement concrete pavement repair structure.

[0027] (3) A composite isolation layer is set between the surface layer and the base layer to improve the interlayer contact state between the surface layer and the semi-rigid (or rigid) base layer. The surface layer and the base layer are in vertical continuous smooth contact. When the concrete panel bears the load, its most prominent feature is good integrity. The overall force distributes the external load evenly to the base layer. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart of the overall process.

[0030] Figure 2 This is a schematic diagram of the overall structure in cross-section;

[0031] Figure 3 Schematic diagram of the installation layout of the pre-embedded pressure box;

[0032] Figure 4 This is a schematic diagram of an elastic grouting bag structure. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] A concrete pavement repair construction method based on a convex structure includes the following steps;

[0036] Step 1 involves cutting and breaking up the damaged cement concrete pavement, and excavating downwards along the damaged cement concrete pavement to the top of the roadbed to form a convex pit.

[0037] Step 2: Compact the convex groove and level the bottom of the convex groove with mortar; after leveling, embed a pressure box in the convex groove.

[0038] Step 3: Lay the composite isolation layer. The composite isolation layer is laid on top of the pre-embedded pressure box, and both sides of the composite isolation layer are tightly bonded to the roadbed at the edge of the convex pit.

[0039] Step 4: Drill holes in the cut surface of the cement concrete pavement and install a dowel bar reinforcing composite assembly in the drilled holes; the dowel bar reinforcing composite assembly is arranged above the composite isolation layer;

[0040] Step 5: Reserve a grouting pipe in the convex pit and connect the grouting pipe outlet to the elastic grouting bag; place the elastic grouting bag in the cavity of the convex pit and inflate the elastic grouting bag to fill the top area of ​​the roadbed.

[0041] Step 6: Install a prefabricated panel above the elastic grouting bag, and perform preliminary grouting into the elastic grouting bag through the reserved grouting pipe according to the feedback of the pre-embedded pressure box;

[0042] Step 7: After the initial grouting material has hardened, observe the pressure feedback from the pre-embedded pressure box. If the feedback pressure drops and remains stable without change, then grout the elastic grouting bag again.

[0043] In one embodiment of the present invention, after the top surface of the base layer is partially removed in step two, a rough surface appears. Mortar is used to level the rough top surface of the base layer and form a leveling layer.

[0044] In step one, the excavation depth is greater than the thickness of the precast panel, but less than the thickness of the precast panel plus 5cm.

[0045] The convex pothole includes a section for breaking up the damaged concrete pavement, a section for chiseling off the top of the roadbed, and an extension cavity. The extension cavity is formed by the section for chiseling off the top of the roadbed extending to both sides of the non-damaged concrete pavement. Both extension cavities are perpendicular to the direction of travel. The extension length of the extension cavity is greater than 0.5m and less than 1m.

[0046] In one embodiment of the present invention, the extension cavity extends into the cutting surface of the damaged cement concrete pavement, and the actual length of the extension cavity is determined based on the extension length of the stress-induced cracks generated during the cutting process on the undamaged concrete pavement.

[0047] The pressure boxes are respectively arranged at the center of the bottom surface of the roadbed top chisel section, the center of the bottom surface of the extension cavity, the edge corner of the roadbed top chisel section, and the edge corner of the extension cavity near the roadbed top chisel section.

[0048] In step three, the composite isolation layer consists of a lower geotextile layer, a waterproof film layer, and an upper geotextile layer from bottom to top; the lower geotextile layer is laid on the bottom surface of the convex pit after leveling.

[0049] In one embodiment of the present invention, the composite isolation layer uses a double-layer geotextile sandwiched with a waterproof membrane layer, which effectively solves the defect of poor resistance to puncture by gravel or sharp objects in the waterproof layer, ensuring the integrity of the geomembrane below the road surface. Simultaneously, when cracks occur in the surface layer or at joints, the waterproof membrane layer in the composite isolation layer can prevent water from flowing into the base layer, thereby preventing pumping and mud pumping phenomena on the road slab under traffic loads, thus preventing misalignment and detachment at joints and extending the service life of the cement concrete pavement repair structure.

[0050] In step four, the force transmission rod and reinforcing rib composite assembly includes a force transmission rod and a reinforcing rib; the force transmission rod has a U-shaped structure; one end of the force transmission rod is inserted into the drill hole in the cut surface of the cement concrete pavement, and the other end of the force transmission rod extends into the extension cavity and is in close contact with the top surface of the upper geotextile layer;

[0051] Several force transmission rods are horizontally arranged, and their installation direction is consistent with the driving direction; the force transmission rods are connected to each other by the reinforcing ribs.

[0052] In one embodiment of the present invention, the force transmission rods arranged at the edge of the extension cavity have a relatively high density.

[0053] Furthermore, the dowel bars are connected into a whole by reinforcing ribs, which are respectively set at the ends of the dowel bars located in the roadbed, the two U-shaped connection nodes, and other areas that need to be reinforced.

[0054] In step five, the grout outlet of the grouting pipe faces into the extension cavity; the elastic grouting bag has two grouting ports and an air inlet, and the grouting ports are connected to the grouting pipe; air is injected into the air inlet of the elastic grouting bag until the elastic grouting bag fills the gap of the extension cavity.

[0055] The outer surface of the elastic grouting bag is provided with a mesh-like channel, and the mesh-like channel has evenly distributed holes. The elastic grouting bag is also provided with a grouting port that communicates with the mesh-like channel. The grouting port that communicates with the mesh-like channel is used to inject grouting material into the mesh-like channel and release it through the evenly distributed holes, so as to fill the gap between the elastic grouting bag and the base layer.

[0056] In step six, the initial grouting involves injecting grout into the elastic grouting bag. One grouting port is opened while the other remains closed. Pressurized grouting is performed through the open port, with the grouting pressure exceeding the measured pressure of the pre-embedded pressure box in the extension cavity by no more than 10%. Once the grouting is nearly complete, the grouting pressure is maintained. The pressure is then observed by the pressure box in the extension cavity area. If the measured pressure remains stable without significant change, the pressure is maintained for another 2 minutes before closing the grouting port valve to prevent pressure drop.

[0057] In one embodiment of the present invention, in step five, the extension cavity area is leveled and the surface of the joint is cleaned of scum and other impurities to keep it clean and tidy. Before pouring concrete, the elastic grouting bag is pre-inflated through the air inlet of the elastic grouting bag. There are two elastic grouting inlets. One grouting inlet valve is closed and the other grouting inlet is inflated until it supports the extension cavity area. Then the connection valve is closed.

[0058] After inflation, pour concrete and wait for the concrete to harden before grouting into the elastic grouting bag. When grouting into the elastic grouting bag, there are two grouting ports. One port is connected to the grouting pipe, and the other port is opened first. After the grout enters from the grouting pipe and fills the grouting bag, it flows out from the other grouting pipe. Then, close the port from which the grout flows out and hold the pressure for 2 minutes.

[0059] Furthermore, in step six, based on the repair material mix ratio and the original concrete pavement slab's length, width, and thickness, precast slabs of the same size and mix ratio are poured in an open area. These precast slabs are used to determine the grouting pressure; only one slab needs to be prepared. The precast slab, hardened to the corresponding strength grade, is hoisted to the repair area. After leveling, the pressure from the pressure cells embedded in the top surface of the roadbed and at the corners is collected. After pressure collection, the precast slab is removed. This step only needs to be performed once, and the obtained grouting pressure can be used in subsequent sections and at different station numbers. The precast pressure cells in the repair area do not need to be re-installed.

[0060] Furthermore, during the pressure collection process, the dowel bars are not installed, otherwise the precast panels cannot be placed; after the pressure collection is completed and the panels are lifted out, the dowel bars are then installed, and construction proceeds according to the normal procedures.

[0061] Pour repair material within the remaining construction area. The repair material is a micro-expansion, high-crack-resistant cement-based rapid repair material. After the repair material hardens, perform preliminary grouting in the extension cavity area based on the measured pressure of the pressure boxes in the central and corner areas. Preliminary grouting involves injecting grout into the elastic grouting bag. Open one of the two grouting ports with all interface valves closed, while keeping the other closed. Apply pressure grouting by opening grouting port 1. The grouting pressure should be greater than the measured pressure of the pre-embedded pressure box in the repair area, but not exceeding 10%. When grouting is nearly complete, maintain the grouting pressure. Observe the pressure measured by the pressure box in the extension cavity area. If the measured pressure is stable and shows no significant change, continue to maintain the pressure for 2 minutes, then close the grouting port valve to prevent pressure drop.

[0062] More specifically, after grouting is completed inside the elastic grouting bag, and after the material inside the elastic grouting bag solidifies, grouting is carried out through a mesh pipeline. The grouting principle is the same as that for grouting inside the elastic grouting bag. A mesh pipeline is provided on the outer surface of the elastic grouting bag. The grouting port connected to the mesh pipeline is used to inject the grouting material into the mesh pipeline and release it through the evenly distributed pipe holes, so as to fill the gap between the elastic grouting bag and the base layer.

[0063] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0064] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for repairing concrete pavements based on a convex structure, characterized in that, Includes the following steps; Step 1 involves cutting and breaking up the damaged cement concrete pavement, and excavating downwards along the damaged cement concrete pavement to the top of the roadbed to form a convex pit. The convex pit includes the broken-up concrete pavement, the excavated portion at the top of the roadbed, and an extension cavity. The extension cavity is formed by the excavated portion at the top of the roadbed extending to both sides of the non-broken damaged concrete pavement. Both extension cavities are perpendicular to the direction of traffic. The excavation depth is greater than the thickness of the precast panel and less than the thickness of the precast panel + 5cm. Step 2: Compact the convex groove and level the bottom of the convex groove with mortar; after leveling, embed a pressure box in the convex groove. Step 3: Lay the composite isolation layer. The composite isolation layer is laid on top of the pre-embedded pressure box, and both sides of the composite isolation layer are tightly bonded to the roadbed at the edge of the convex pit. Step 4: Drill holes in the cut surface of the cement concrete pavement and install a dowel bar reinforcing composite assembly in the drilled holes; the dowel bar reinforcing composite assembly is arranged above the composite isolation layer; Step 5: A grouting pipe is pre-installed in the convex pit, with the grout outlet of the grouting pipe facing into the extended cavity; an elastic grouting bag is placed in the cavity of the convex pit, the elastic grouting bag has two grouting ports and an air inlet, one of the grouting ports is connected to the grouting pipe; the elastic grouting bag is inflated through the air inlet to fill the top area of ​​the roadbed in the cavity; Step 6: Install a prefabricated panel above the elastic grouting bag, and perform preliminary grouting into the elastic grouting bag through the reserved grouting pipe according to the pre-embedded pressure feedback from the pre-embedded pressure box. This replaces the gas inside the elastic grouting bag and allows the gas to be discharged through the other grouting port. The preliminary grouting involves injecting grout into the elastic grouting bag by opening one grouting port and keeping the other grouting port closed. Pressurized grouting is performed through the open grouting port, and the grouting pressure is greater than the measured pressure of the pre-embedded pressure box of the extension cavity, but not exceeding 10%. When the grouting is almost complete, maintain the grouting pressure and observe the pressure measured by the pre-embedded pressure box of the extension cavity. If the measured pressure is stable and does not change significantly, continue to hold the pressure for 2 minutes, and then close the grouting port valve to prevent the pressure from dropping. Step 7: After the initial grouting material has hardened, observe the pressure feedback from the pre-embedded pressure box. If the feedback pressure drops or remains stable without change, then grout the elastic grouting bag again.

2. The concrete pavement repair construction method based on a convex structure according to claim 1, characterized in that: The extension cavity has an extension length greater than 0.5m and less than 1m.

3. The concrete pavement repair construction method based on a convex structure according to claim 2, characterized in that: The pre-embedded pressure boxes are respectively arranged at the center of the bottom surface of the top chisel section of the roadbed, the center of the bottom surface of the extension cavity, the edge corner of the top chisel section of the roadbed, and the edge corner of the extension cavity near the top chisel section of the roadbed.

4. The concrete pavement repair construction method based on a convex structure according to claim 1, characterized in that: In step three, the composite isolation layer consists of a lower geotextile layer, a waterproof film layer, and an upper geotextile layer from bottom to top; the lower geotextile layer is laid on the bottom surface of the convex pit after leveling.

5. The concrete pavement repair construction method based on a convex structure according to claim 4, characterized in that: In step four, the force transmission rod and reinforcing rib composite assembly includes a force transmission rod and a reinforcing rib; the force transmission rod has a U-shaped structure; one end of the force transmission rod is inserted into the drill hole in the cut surface of the cement concrete pavement, and the other end of the force transmission rod extends into the extension cavity and is in close contact with the top surface of the upper geotextile layer; Several force transmission rods are horizontally arranged, and their installation direction is consistent with the driving direction; the force transmission rods are connected to each other by the reinforcing ribs.

6. The concrete pavement repair construction method based on a convex structure according to claim 1, characterized in that: The outer surface of the elastic grouting bag is provided with a mesh-like channel, and the mesh-like channel has evenly distributed holes. The elastic grouting bag is also provided with a grouting port that communicates with the mesh-like channel. The grouting port that communicates with the mesh-like channel is used to inject grouting material into the mesh-like channel and release it through the evenly distributed holes, so as to fill the gap between the elastic grouting bag and the base layer.

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