A curing device and method for cast-in-situ box girders

Abstract

The present invention provides a curing device for cast-in-situ box girders, comprising a geotextile, a pressing device for pressing the geotextile to fit the outer contour of the cast-in-situ box girder, and a spraying system for spraying and moisturizing the geotextile; the pressing device comprises a counterweight trolley capable of traveling along the beam wing plate, a support rod fixedly connected to the counterweight trolley and extending horizontally to the outer side of the wing plate, an adjustment mechanism mounted on the support rod, and a pressing rod corresponding to the outer contour of the cast-in-situ box girder; the pressing rod is connected to the adjustment mechanism, and the adjustment mechanism can be used to adjust the degree to which the pressing rod presses the geotextile to the outer contour of the cast-in-situ box girder. The curing device for cast-in-situ box girders provided by the present invention has a simple structure, is easy to install and disassemble, can travel on the cast-in-situ box girder, and can be cured synchronously with the construction progress of the cast-in-situ box girder, effectively solving the problem of insufficient curing of existing cast-in-situ box girders and greatly improving the curing quality of cast-in-situ box girders.

Description

Technical Field

[0001] The present invention belongs to the technical field of building construction, and in particular relates to a curing device and method for cast-in-situ box beams. Background Art

[0002] Cast-in-situ box girders are a very common structural form in current highway bridge design and construction, effectively increasing bridge loads and shortening construction cycles. However, due to the inherent characteristics of cast-in-situ box girders, stress analysis is complex and construction quality control is difficult. Furthermore, cast-in-situ box girders are very sensitive to changes in temperature and humidity during the hardening process. If curing is improper or untimely, the concrete surface loses moisture too quickly, and cracks easily form before the concrete is removed from the formwork, or even before final setting, affecting the durability and load-bearing capacity of the cast-in-situ box girder. Therefore, concrete curing is crucial to improving the quality of cast-in-situ box girders.

[0003] Currently, most cast-in-place bridge construction processes follow conventional methods, using manual watering to maintain the cast-in-place box girders. However, manual watering maintenance is significantly affected by human factors, and often results in problems such as untimely maintenance, insufficient maintenance time, and improper maintenance methods. Furthermore, since the edges of the cast-in-place box girders are exposed to the air, maintenance measures are generally not taken, resulting in frequent shrinkage cracks in the concrete. This is especially true for the variable-section continuous cast-in-place box girders of continuous rigid frame bridges, where only the top deck concrete of the cast-in-place box girders is often maintained. This results in shrinkage cracks in the webs and flanges of the beam body due to inadequate maintenance, affecting their durability. Summary of the Invention

[0004] The main purpose of the present invention is to provide a maintenance device that is easy to install and disassemble, can be walked on the cast-in-place box girder bridge deck, and can be adjusted according to the outer contours of both sides of the cast-in-place box girder to maintain the webs and wing plates on both sides of the cast-in-place box girder, so as to solve the problem of insufficient maintenance of existing cast-in-place box girders.

[0005] The present invention is achieved in that:

[0006] A curing device for cast-in-situ box girders, comprising a geotextile, a pressing device for pressing the geotextile to fit the outer contour of the cast-in-situ box girder, and a spraying system for spraying and moisturizing the geotextile; the pressing device comprises a counterweight trolley capable of traveling along the beam wing, a support rod fixedly connected to the counterweight trolley and extending horizontally to the outside of the wing, an adjustment mechanism mounted on the support rod, and a pressing rod corresponding to the outer contour of the cast-in-situ box girder; the pressing rod is connected to the adjustment mechanism, and the adjustment mechanism can be used to adjust the degree to which the pressing rod presses the geotextile to the outer contour of the cast-in-situ box girder.

[0007] Preferably, there are at least two counterweight trolleys on each side wing plate, and the two adjacent counterweight trolleys are connected by a cross bar.

[0008] Preferably, the geotextile is rectangular, and its horizontal length is the same as the length of the cross bar. The top edge of the geotextile is tied to the cross bar by a strap and hangs on the outside of the box beam. Its area can completely cover the outer contour of the single-sided box beam.

[0009] Preferably, the adjustment mechanism includes a first adjusting rod and a second adjusting rod whose working length can be freely adjusted, one end of the first adjusting rod is vertically mounted on the support rod, and the other end is rotatably connected to the clamping rod below through a rotating pair, one end of the second adjusting rod is vertically mounted on the support rod, and the other end is movably connected to the clamping rod below; the first adjusting rod and the second adjusting rod are separated by a certain distance, and the clamping rod can be rotated around the rotating pair by adjusting the length of the second adjusting rod, thereby realizing the contact and separation of the clamping rod and the outer contour of the cast-in-place box girder.

[0010] Preferably, the first adjusting rod includes a fixing screw, the upper portion of which is detachably fixedly connected to the support rod via a fixing nut, and the lower end of which is rotatably connected to the clamping rod via a bolt.

[0011] Preferably, the second adjustment rod includes a pull rod, the top of the pull rod is connected to the support rod through an adjusting screw, the upper and lower heights of the pull rod can be adjusted through the adjusting screw, and a hook is provided at the bottom of the pull rod, and the clamping rod is placed on the hook.

[0012] Preferably, the spraying system includes at least one spray pipe, several atomizing nozzles installed on the spray pipe at a certain interval and aimed at the geotextile, a water tank for storing curing water and a water pump. The spray pipe is connected to the water outlet of the water pump through a water hose. The water pump can pump the curing water in the water tank into the spray pipe at a certain pressure and evenly spray it onto the geotextile through the atomizing nozzle.

[0013] Preferably, the spray pipe is a hard PVC water pipe, and the spray pipe is detachably fixed to the cross bar through a clamp.

[0014] Preferably, the spraying system also includes a timer for timing control of the opening and closing of the water pump, thereby realizing regular spraying maintenance of the cast-in-place box girder.

[0015] A curing method for cast-in-situ box beams, comprising the following steps:

[0016] Step 1: Hoist the counterweight trolley to the top surface of the cast-in-place box girder flange and assemble the curing device;

[0017] Step 2: Then, the pressing rod is moved close to the outer contour of the cast-in-situ box beam through the adjustment mechanism to ensure that the geotextile is in close contact with the outer surface of the cast-in-situ box beam;

[0018] Step 3: Then turn on the spray system to spray and maintain the cast-in-place box girder;

[0019] Step 4: After completing the maintenance task of the segment, the clamping rod is moved away from the outer contour of the cast-in-place box girder through the adjustment mechanism, and then the counterweight trolley is pushed to the next segment for maintenance.

[0020] The beneficial effects of the present invention are:

[0021] The curing device for cast-in-situ box girders provided by the present invention has a simple structure and is easy to install and disassemble. It can be walked on the cast-in-situ box girders and can be cured synchronously with the construction progress of the cast-in-situ box girders. It effectively solves the problem of insufficient curing of the webs and wing plates of the existing cast-in-situ box girders, especially the variable-section continuous cast-in-situ box girders of continuous rigid frame bridges, and greatly improves the curing quality of the cast-in-situ box girders. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a working state of a curing device for a cast-in-situ box girder provided by an embodiment of the present invention when used in pairs and a schematic cross-sectional diagram of a cast-in-situ box girder;

[0023] Figure 2 A structural perspective diagram of a curing device for cast-in-situ box girders provided in an embodiment of the present invention;

[0024] Figure 3 A schematic structural diagram of a counterweight trolley in a curing device for cast-in-situ box girders provided in an embodiment of the present invention;

[0025] Figure 4 A schematic structural diagram of a compression plate in a curing device for cast-in-situ box girders provided in an embodiment of the present invention;

[0026] Figure 5 A schematic structural diagram of a first adjusting rod in a curing device for a cast-in-situ box girder provided in an embodiment of the present invention;

[0027] Figure 6 A schematic structural diagram of a second adjusting rod in a curing device for a cast-in-situ box girder provided in an embodiment of the present invention;

[0028] Figure 7 A schematic diagram of the installation method of geotextile and sprinkler system in a curing device for cast-in-situ box girders provided in an embodiment of the present invention.

[0029] In the figure: 1- cast-in-place box girder, 101- wing plate, 102- web plate, 2- geotextile, 201- binding strap, 3- counterweight trolley, 301- vertical pole, 302- bottom plate, 303 roller, 304- counterweight block, 4- support rod, 401- mounting hole, 402- blind hole, 5- cross bar, 501- slot, 6- fixing screw, 601- fixing nut, 602- channel steel, 603- bolt, 7- pull rod, 701 connecting plate, 702- adjusting screw, 703- adjusting nut, 704- hook, 8 clamping rod, 9- spray pipe, 901- clamp, 10- atomizing nozzle, 11- water hose. DETAILED DESCRIPTION

[0030] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0031] Since curing the top surface concrete of a cast-in-place box girder 1 is common knowledge in the art and relatively simple, curing can be completed by simply laying the geotextile 2 flat on the top surface of the cast-in-place box girder 1 and then spraying it regularly to maintain moisture. Therefore, the curing device provided in this embodiment is primarily used to cure the webs 102 and flanges 101 on both sides of the cast-in-place box girder 1.

[0032] like Figure 1 As shown, in this embodiment, there are two groups of curing devices with the same structure, which are symmetrically arranged on the left and right sides of the cast-in-situ box beam 1 to simultaneously maintain the outer contours of both sides of the cast-in-situ box beam 1. Figure 2 As shown, taking one set of curing devices as an example, its structure includes: geotextile 2, a pressing device for pressing the geotextile 2 onto the outer contour of the cast-in-situ box beam 1, and a spraying system for spraying and moisturizing the geotextile 2. Specifically:

[0033] like Figures 1 to 3 As shown, the clamping device includes a counterweight trolley 3, a support rod 4, a crossbar 5, an adjustment mechanism, and a clamping rod 8. There are at least two counterweight trolleys 3 on the top surface of the cast-in-place box girder 1 on each side. Each counterweight trolley 3 includes a vertical rod 301, a bottom plate 302, rollers 303, and a counterweight block 304. The vertical rod 301 is welded to the bottom plate 302, and four rollers 303 are installed at the four corners of the bottom of the bottom plate 302. This allows the counterweight trolley 3 to travel on the top surface of the wing plate 101, thereby curing the cast-in-place box girder 1 section by section. The counterweight blocks 304 are placed on the bottom plate 302 to give the counterweight trolley 3 a certain mass, thereby ensuring the stability of the clamping device set on the outside of the cast-in-place box girder 1.

[0034] like Figure 2 and Figure 3As shown, the support rods 4 are square steel tubes of a certain length, and the number is the same as the number of the counterweight trolleys 3. One side of each support rod 4 is horizontally welded to the vertical rod 301 of the counterweight trolley 3, and the other side is exposed outside the flange 101 of the cast-in-situ box girder 1. In addition, the support rods 4 exposed outside the flange 101 of the cast-in-situ box girder 1 are vertically opened with a mounting hole 401 and a blind hole 402. The mounting hole 401 and the blind hole 402 are separated by a certain distance to facilitate the installation of the subsequent adjustment device. Figure 7 As shown, the crossbar 5 is a square aluminum tube with a slot 501 at each end, the same width as the support bar 4. The crossbar 5 is snapped onto the two support bars 4 of the front and rear counterweight trolleys 3 via the slots 501, enabling two adjacent counterweight trolleys 3 on a single wing plate 101 to move forward synchronously. The length of the crossbar 5 is the length of the cast-in-situ box girder 1 that can be cured in one go by the curing device provided by the present invention. Therefore, by rationally selecting a longer crossbar 5 and increasing the number of counterweight trolleys 3, the curing efficiency of the cast-in-situ box girder 1 can be further improved to a certain extent. The geotextile 2 has a certain moisture retention property and can improve the moisturizing effect of spray curing. The geotextile 2 is rectangular, and its horizontal length is the same as the length of the crossbar 5. The top edge of the geotextile 2 is tied to the crossbar 5 by a strap 201 so that it can move with the counterweight trolley 3. The geotextile 2 is suspended on the outside of the cast-in-place box girder 1, and its area is larger than the single-side area of the box girder to be cured in this section, so as to ensure that the outer contour of the single-side box girder can be completely covered. Figure 4 As shown, the number of the clamping rods 8 is the same as the number of the counterweight trolleys 3. Each clamping rod 8 is made of two sections of rectangular steel pipes welded according to the outer contour shape of the wing plate 101 and the web 102 of the cast-in-place box girder 1. It is installed under the support rod 4 through an adjustment mechanism and is connected to the side of the geotextile 2 to press the geotextile 2 to fit the outer contour of the cast-in-place box girder 1.

[0035] like Figure 2 As shown, the adjustment mechanism is used to adjust the tightness of the geotextile 2 pressed against the outer contour of the cast-in-place box girder 1 by the compression rod 8, and includes a first adjustment rod and a second adjustment rod whose working length can be freely adjusted. One end of the first adjustment rod is vertically mounted on the support rod 4, and the other end is rotatably connected to the compression rod 8 below through a rotating pair. One end of the second adjustment rod is vertically mounted on the support rod 4, and the other end is movably connected to the compression rod 8 below. The first adjustment rod and the second adjustment rod are separated by a certain distance, and the compression rod 8 can be rotated around the rotating pair by adjusting the length of the second adjustment rod, thereby realizing the contact and separation of the compression rod 8 with the outer contour of the cast-in-place box girder 1. Specifically, as Figure 5 and Figure 6As shown, in this embodiment, the first adjusting rod is a fixed screw 6, and the upper part of the fixed screw 6 is vertically installed in the mounting hole 401 of the support rod 4 through a fixing nut 601. The working length of the first adjusting rod can be adjusted by screwing the fixing nut 601; a channel steel 602 is welded to the lower end of the fixed screw 6, and through holes are opened on the two side plates of the channel steel 602. Correspondingly, a bolt hole is also provided at the upper end of the clamping rod 8, and the channel steel 602 is rotatably connected to the upper end of the clamping rod 8 by a bolt 603, so that the clamping rod 8 can rotate with the bolt 603 as the fulcrum. The second adjustment rod comprises a tie rod 7 and an adjustment screw 702. The top of the tie rod 7 is integrally provided with a horizontally protruding connecting plate 701. The connecting plate 701 has a through hole and an adjustment nut 703 coaxially welded and fixed to the through hole. The adjustment screw 702 is threadedly connected to the adjustment nut 703 and passes through the adjustment nut 703 to press against the blind hole 402 of the support rod 4. A hook 704 is welded to the bottom end of the tie rod 7, and the clamping rod 8 is snapped onto the hook 704. By turning the adjustment screw 702, the height of the tie rod 7 can be adjusted, thereby adjusting the distance between the clamping rod 8 and the outer contour of the cast-in-place box girder 1, thereby achieving contact and separation between the geotextile 2 and the outer contour of the cast-in-place box girder 1.

[0036] like Figure 7 As shown, the spray system includes a spray pipe 9, an atomizing nozzle 10, a water hose 11, a water pump, and a water tank. The water tank and water pump are installed on the ground. At least one spray pipe 9 is a rigid PVC water pipe. The spray pipe 9 is removably secured to the middle of the crossbar 5 via a clamp 901 and connected to the water outlet of the water pump via a water hose 11. Several atomizing nozzles 10 are installed on the spray pipe 9 at regular intervals and aimed at the geotextile 2. The water pump pumps curing water from the water tank at a constant pressure into the spray pipe 9, where it is evenly sprayed onto the geotextile 2 through the atomizing nozzles 10. Furthermore, as a preferred embodiment, the spray system also includes a timer for timing the on / off control of the water pump, thereby enabling scheduled spray curing of the cast-in-place box girder 1 and saving manpower. Of course, the left and right curing devices can also share a single water tank and water pump to save costs.

[0037] The present invention also provides a maintenance method based on the above maintenance device, which specifically includes the following steps:

[0038] Step 1: First assemble the counterweight trolley 3, then hoist it to the top surface of the wing plate 101 of the cast-in-place box girder 1, connect the two adjacent counterweight trolleys 3 in front and behind through the crossbar 5, then fix one side of the geotextile 2 to the crossbar 5 through the strap 201, and then install the spray pipe 9 in the spray system to the crossbar 5, so that the atomizing nozzle 10 on the spray pipe 9 can be aimed at the geotextile 2, and finally install the pressing plate under the support rod 4 of the counterweight trolley 3 through the adjustment mechanism;

[0039] Step 2: Then tighten the adjusting screw 702 to make the pressing rod 8 and the outer contour of the cast-in-situ box beam 1 close to each other, so that the geotextile 2 is close to the surface of the cast-in-situ box beam 1;

[0040] Step 3: Then turn on the spray system and spray the outer contour of the cast-in-place box girder 1 for maintenance at regular intervals;

[0041] Step 4: After completing the maintenance task of the segment, loosen the adjusting screw 702 to move the clamping rod 8 away from the outer contour of the cast-in-place box beam 1, and then push the counterweight trolley 3 to the next segment for maintenance.

[0042] The above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be encompassed by the scope of the claims of the present invention.

Claims

1. A curing device for cast-in-situ box beams, characterized by: It includes a geotextile, a pressing device for pressing the geotextile to fit the outer contour of the cast-in-situ box beam, and a spraying system for spraying and moisturizing the geotextile; The pressing device includes a counterweight trolley capable of traveling along the beam flange, a support rod fixedly connected to the counterweight trolley and extending horizontally to the outside of the flange, an adjustment mechanism mounted on the support rod, and a pressing rod corresponding to the outer contour of the cast-in-situ box beam; the pressing rod is connected to the adjustment mechanism, and the adjustment mechanism can be used to adjust the degree to which the pressing rod presses the geotextile onto the outer contour of the cast-in-situ box beam; The adjustment mechanism includes a first adjustment rod and a second adjustment rod with freely adjustable working lengths, one end of the first adjustment rod being vertically mounted on the support rod, and the other end being rotatably connected to a clamping rod below via a revolving pair; one end of the second adjustment rod being vertically mounted on the support rod, and the other end being movably connected to the clamping rod below; the first adjustment rod and the second adjustment rod being spaced apart by a certain distance, and the clamping rod being rotated about the revolving pair by adjusting the length of the second adjustment rod, thereby achieving contact and separation between the clamping rod and the outer contour of the cast-in-place box girder; There are at least two counterweight trolleys on each side wing plate, and the two adjacent counterweight trolleys are connected by a cross bar; The geotextile is rectangular, and its horizontal length is the same as the length of the cross bar. The top edge of the geotextile is tied to the cross bar by a strap and hangs on the outside of the box beam. The area of the geotextile can completely cover the outer contour of the single-sided box beam.

2. A curing device for cast-in-situ box beams according to claim 1, characterized in that: The first adjusting rod includes a fixing screw rod, the upper portion of which is detachably fixedly connected to the support rod via a fixing nut, and the lower end of which is rotatably connected to the pressing rod via a bolt.

3. A curing device for cast-in-situ box beams according to claim 2, characterized in that: The second adjusting rod includes a pull rod, the top of the pull rod is connected to the support rod through an adjusting screw, the upper and lower heights of the pull rod can be adjusted through the adjusting screw, and a hook is provided at the bottom of the pull rod, and the clamping rod is placed on the hook.

4. A curing device for cast-in-situ box beams according to claim 3, characterized in that: The spraying system includes at least one spray pipe, several atomizing nozzles installed on the spray pipe at a certain interval and aimed at the geotextile, a water tank for storing maintenance water and a water pump. The spray pipe is connected to the water outlet of the water pump through a water hose. The water pump can pump the maintenance water in the water tank into the spray pipe at a certain pressure and evenly spray it onto the geotextile through the atomizing nozzle.

5. A curing device for cast-in-situ box beams according to claim 4, characterized in that: The spray pipe is a hard PVC water pipe, and the spray pipe is detachably fixed to the cross bar through a clamp.

6. A curing device for cast-in-situ box beams according to claim 5, characterized in that: The spraying system also includes a timer for timing control of the opening and closing of the water pump, thereby achieving regular spraying maintenance of the cast-in-place box girder.

7. A curing method for a cast-in-situ box girder curing device according to claim 6, characterized in that: The following steps are involved: Step 1: Hoist the counterweight trolley to the top surface of the cast-in-place box girder flange and assemble the curing device; Step 2: Then, the pressing rod is moved close to the outer contour of the cast-in-situ box beam through the adjustment mechanism to ensure that the geotextile is in close contact with the outer surface of the cast-in-situ box beam; Step 3: Then turn on the spray system to spray and maintain the cast-in-place box girder; Step 4: After completing the maintenance task of the segment, the clamping rod is moved away from the outer contour of the cast-in-place box girder through the adjustment mechanism, and then the counterweight trolley is pushed to the next segment for maintenance.

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