Portable semi-precast UHPC cover beam formwork mold

Abstract

The utility model relates to a portable semi-precast UHPC cover beam formwork mould, relates to bridge technical field, including mould shell, vibration support, hoist reinforcing bar, prestressed bellows, inner support, mould inner shell, mould shell material adopts steel form, adopts bolt connection between steel form, mould inner shell adopts the form of steel form plus elastic rubber form, uses steel form in curb plate, adopts elastic rubber form in bottom plate, adopts bolt connection between curb plate, adopts rivet plus bolt's mode connection between rubber bottom plate and steel form, the utility model can improve the current for semi-precast cover beam formwork mould in engineering application's insufficient, overcomes the problem that traditional mould needs special customization and is difficult to recycle, effectively solves cover beam formwork dismounting difficult, pouring difficult, demoulding difficult and other problems, lays solid foundation for the extensive application and popularization of semi-precast UHPC cover beam in solid engineering.

Description

Technical Field

[0001] This invention belongs to the field of bridge technology, and specifically relates to a convenient semi-prefabricated UHPC cap beam mold. Background Technology

[0002] Currently, there are three main structural forms for bridge cap beams in my country: integral cast-in-place cap beams, fully precast cap beams, and semi-precast cap beams.

[0003] The construction of monolithic cast-in-place cap beams requires a large labor force, has a long construction period, and significantly impacts existing traffic. Furthermore, their durability is insufficient, often requiring multiple repairs in a short period. Fully precast cap beams are very heavy, placing high demands on lifting and hoisting machinery, and the quality control at the joints of segmented precast cap beams is difficult. Research on semi-precast cap beams, especially ultra-high performance concrete (UHPC) shell-ordinary concrete (NC) semi-precast composite cap beams, is still in its nascent stage in China, with limited engineering applications. However, due to their exceptional engineering properties, they hold immense potential.

[0004] However, in the current small-scale engineering applications of UHPC-NC composite cap beams, it has been found that demolding is often difficult or even impossible during the fabrication of the UHPC shell. Custom-made models of various sizes are required, and they cannot be recycled. Furthermore, due to the poor fluidity of UHPC, problems such as voids, air bubbles, and even delamination often occur during casting.

[0005] Current research on the design of girder formwork is limited. Existing research primarily focuses on adjustable formwork, without addressing the difficulties encountered during actual demolding or the quality issues arising from voids and air bubbles during UHPC casting. Furthermore, the design is complex and operation cumbersome, with improvements only made to the formwork assembly process. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technologies. This invention provides a convenient semi-prefabricated UHPC cap beam mold.

[0007] A convenient semi-precast UHPC cap beam mold shell includes a mold shell, a vibration support, lifting steel bars, prestressed corrugated pipes, an inner support, and an inner mold shell. The mold shell consists of two long side steel templates, two short side steel templates, and a bottom steel template. The bottom steel template has two mold shell slots. The bottom steel template and the two short side steel templates have evenly spaced through holes for passing through the prestressed corrugated pipes.

[0008] The prestressed corrugated pipes are fixedly and intermittently installed on the inner side of the long side steel template and the outer side of the bottom steel template along a direction parallel to the long side steel template of the outer shell.

[0009] The inner shell of the mold is composed of two long side steel templates and an integrated rubber template for the short side and bottom of the inner shell. The outer walls of the two long side steel templates of the inner shell are provided with evenly spaced shear keyways, and lifting steel bars are fixedly installed between the two long side steel templates of the inner shell.

[0010] The inner support is in the form of a highly elastic rubber box, and its shape corresponds to the internal shape of the mold shell. Several inflation valves are provided on the upper surface of the inner support. It has a certain rigidity when filled with gas and can quickly lose rigidity when the gas is released.

[0011] The vibration support includes a vibration base, a rigid extension, and a rubber buffer layer. The vibration support is fixedly connected to the mold shell through a slot in the mold shell, and its diameter corresponds to the slot in the mold shell.

[0012] The lifting steel bars are embedded in the middle of both ends of the cap beam formwork during concrete pouring.

[0013] The two long side steel templates, two short side steel templates, and bottom steel template of the mold shell are connected to each other by bolts and waterproofed by sealing strips.

[0014] The spacing between the inwardly recessed shear keyways on the two long side steel templates of the inner shell of the mold is greater than 10cm, and the depth of the recess should be greater than half the spacing between the shear keyways.

[0015] The vibration support has an upper rubber buffer layer and a rigid extension bonded together by gluing and riveting, and a sealing strip is provided at the connection.

[0016] The inner shell of the mold is provided with an inward positioning ring at the vibration support, the size of which should be just enough to allow the vibration support to be nested on the inner shell of the mold.

[0017] The mold housing should rest on the rigid extension of the vibration support, and a rubber buffer layer should be provided between the rigid extension and the mold housing.

[0018] The prestressed corrugated pipe material is high-density polyethylene (HDPE).

[0019] The depth of the lifting steel bars shall not be less than 20cm, the exposed height shall not be less than 15cm, the length of the anchorage section shall not be less than 5 times the diameter of the steel bars, and the thickness of the protective layer shall not be less than 5 times the diameter of the steel bars.

[0020] The working process and working principle of this invention:

[0021] A convenient method for assembling a semi-prefabricated UHPC cap beam mold shell is as follows:

[0022] Step 1: Place the mold shell slots of the bottom steel template through the vibration support onto the rigid extension, and fix the vibration base to the ground to prevent the vibration support from tipping over during vibration. Then, use bolts to connect the long side steel template and the short side steel template of the outer shell to the bottom steel template of the outer shell in sequence. After that, install the prestressed corrugated pipe, and finally brush the inside of the mold shell with release agent and perform appropriate waterproofing and leak-proofing treatment.

[0023] Step 2: Insert the inner shell positioning ring at the bottom of the integrated rubber template for the short side and bottom of the inner shell onto the vibration support. Then, connect the steel template for the long side of the inner shell to the integrated rubber template for the short side and bottom of the inner shell using rivets and bolts. Weld the lifting steel bars to the steel template for the long side of the inner shell. Finally, brush the release agent on the outside of the inner shell and focus on brushing the release agent inside the shear keyway.

[0024] Step 3: Insert the deflated inner support into the inner shell of the mold, and complete the assembly after checking that the inflation valve is in the correct position.

[0025] A convenient method for fabricating a semi-prefabricated UHPC cap beam mold is as follows:

[0026] Step 1: First, open the inflation valve to inflate the internal support until the short side and bottom of the inner shell of the mold have sufficient rigidity. At this time, the casting space between the inner shell and the outer shell of the mold is stable and not easily deformed.

[0027] Step 2: Turn on the vibration motor of the vibratory support, and then slowly and continuously pour the well mixed UHPC high-performance concrete into the pouring space between the inner shell and the outer shell of the mold. When the UHPC liquid level is level with the top surface of the inner shell and the outer shell of the mold, stop pouring. When the bubbles no longer emerge, turn off the vibration motor and embed the lifting steel bars into the four corners of the UHPC cap beam mold.

[0028] Step 3: After steam curing for 3 days or conventional film covering for heat preservation and moisture retention for 7 to 15 days, the mold can be removed. During removal, first open the inflation valve to release air from the internal supports until the integrated rubber template on the short side and bottom of the inner shell loses sufficient rigidity. At this point, use lifting equipment and lifting steel bars to easily lift the inner shell and internal supports out. Then, remove the bolts from the long and short side steel templates of the outer shell. After a trial lift of the lifting steel bars to confirm that the lifting conditions are met, the semi-precast UHPC cap beam mold shell can be lifted out.

[0029] Step 4: After the curing of the semi-precast UHPC cap beam formwork is completed, prestress can be applied to it. The prestress is applied by post-tensioning through the reserved prestressed corrugated pipe. After the prestress is applied, the semi-precast UHPC cap beam formwork is completed, and the subsequent molds can be quickly assembled and put into use.

[0030] The completed semi-precast UHPC cap beam formwork is hoisted and transported to the construction site. Hoisting equipment is used to embed the semi-precast UHPC cap beam formwork into the pre-reserved steel reinforcement columns of the pier. Ordinary concrete is then poured into the formwork. After curing, the fabrication and construction of the semi-precast UHPC formwork-NC cap beam are completed.

[0031] The beneficial effects of this invention are:

[0032] Compared with existing technologies, this invention can improve the shortcomings of current semi-prefabricated cap beam mold shells in engineering applications, overcome the problem that traditional customized molds cannot be reused multiple times, and effectively solve problems such as difficulty in disassembling and assembling cap beam mold shells, difficulty in casting, and difficulty in demolding. Attached Figure Description

[0033] Figure 1 This is an overall schematic diagram of an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of the mold shell structure according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the inner shell structure of the mold according to an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the vibration support structure according to an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram of the internal support structure according to an embodiment of the present invention.

[0038] Figure 6 This is a schematic diagram of the lifting steel bar structure according to an embodiment of the present invention.

[0039] Figure 7 This is a schematic diagram of the mold shell and vibration support fitting together according to an embodiment of the present invention.

[0040] Figure 8 This is a schematic diagram of the mold inner shell and vibration support fitting together according to an embodiment of the present invention. Detailed Implementation

[0041] Please see Figures 1 to 8 The image shown is an embodiment of the present invention.

[0042] A convenient semi-precast UHPC cap beam mold shell includes a mold shell 1, a vibration support 2, lifting steel bars 3, prestressed corrugated pipes 4, an inner support 5, and a mold inner shell 6.

[0043] The mold shell 1 is composed of two long side steel templates 11, two short side steel templates 12 and a bottom steel template 13; the bottom steel template 13 has two mold shell slots 14; the bottom steel template 13 and the two short side steel templates 12 have evenly spaced through holes for passing through the prestressed corrugated pipe 4.

[0044] The prestressed corrugated pipes 4 are fixedly and intermittently installed on the inner side of the long side steel template 11 and the outer side of the bottom steel template 13 of the outer shell along a direction parallel to the long side steel template 11 of the outer shell.

[0045] The inner shell 6 of the mold is composed of two inner shell long side steel templates 61 and an inner shell short side and bottom integrated rubber template 62. The outer side walls of the two inner shell long side steel templates 61 are provided with evenly spaced shear keyways 63, and lifting steel bars 3 are fixedly installed between the two inner shell long side steel templates 61.

[0046] The inner support 5 is in the form of a high-elasticity rubber box, and its shape corresponds to the internal shape of the inner shell 6 of the mold. Several inflation valves 51 are provided on the upper surface of the inner support 5. When it is filled with gas, it has a certain rigidity, and when the gas is released, it can quickly lose its rigidity.

[0047] The vibration support 2 includes a vibration base 21, a rigid extension 22, and a rubber buffer layer 23. The vibration support 2 is fixedly connected to the mold housing 1 through the mold housing slot 14.

[0048] Its diameter corresponds to the groove 14 of the mold shell.

[0049] The two long side steel templates 11, the two short side steel templates 12, and the bottom steel template 13 of the mold shell 1 are connected to each other by bolts and waterproofed by sealing strips.

[0050] The spacing between the inwardly recessed shear keyways 63 on the two long side steel templates 61 of the inner shell 6 of the mold is greater than 10cm, and the depth of the recess should be greater than half the spacing of the shear keyways 63.

[0051] The upper rubber buffer layer 23 of the vibration support 2 is bonded and riveted to the rigid extension 22, and a sealing strip is provided at the connection.

[0052] The inner shell 6 of the mold is provided with an inward positioning ring 65 at the vibration support 2. The size of the ring should be just enough to allow the vibration support 2 to be nested on the inner shell 6 of the mold.

[0053] The mold housing 1 should rest on the rigid extension 22 of the vibration support 2, and a rubber buffer layer should be provided between the rigid extension 22 and the mold housing 1.

[0054] The prestressed corrugated pipe 4 is made of high-density polyethylene (HDPE).

[0055] The lifting steel bar 3 is embedded in the middle of both ends of the cover beam formwork during concrete pouring.

[0056] The buried depth of the lifting steel bar 3 shall not be less than 20cm, the exposed height shall not be less than 15cm, the anchorage length shall not be less than 5 times the diameter of the steel bar, and the protective layer thickness shall not be less than 5 times the diameter of the steel bar.

[0057] In this embodiment, a convenient method for assembling a semi-prefabricated UHPC cap beam mold shell is as follows:

[0058] Step 1: Pass the mold outer shell slot 14 of the bottom steel template 13 through the vibration support 2 and place it on the rigid extension 22. Fix the vibration base 21 to the ground to prevent the vibration support 2 from tipping over during vibration. Then, use bolts to connect the long side steel template 11 and the short side steel template 12 of the outer shell to the bottom steel template 13 of the outer shell in sequence. After that, install the prestressed corrugated pipe 4. Finally, brush the mold release agent inside the mold outer shell 1 and perform appropriate waterproofing and leak-proofing treatment.

[0059] Step 2: Insert the inner shell positioning ring 65 at the bottom of the integrated rubber template 62 on the short side and bottom of the inner shell onto the vibration support 2. Then, connect the steel template 61 on the long side of the inner shell to the integrated rubber template 62 on the short side and bottom of the inner shell using rivets and bolts. Weld the lifting steel bar 3 to the steel template 61 on the long side of the inner shell. Finally, brush the release agent on the outside of the inner shell 6 and brush the release agent in particular inside the shear keyway 63.

[0060] Step 3: Place the deflated inner support 5 into the inner shell 6 of the mold, and complete the assembly after checking that the position of the inflation valve 51 is correct.

[0061] In this embodiment, a convenient method for manufacturing a semi-prefabricated UHPC cap beam mold is as follows:

[0062] Step 1: First, open the inflation valve 51 to inflate the inner support 5 until the short side and bottom surface of the inner shell 6 of the mold inner shell have sufficient rigidity. At this time, the casting space between the inner shell 1 and the outer shell 6 of the mold is stable and not easily deformed.

[0063] Step 2: Turn on the vibration motor of the vibration support 2, and then slowly and continuously inject the well mixed UHPC high-performance concrete into the pouring space between the inner shell 1 and the outer shell 6 of the mold. When the UHPC liquid level is level with the top surface of the inner shell 1 and the outer shell 6 of the mold, stop pouring. When the bubbles no longer emerge, turn off the vibration motor and embed the lifting steel bar 3 into the four corners of the UHPC cap beam mold.

[0064] Step 3: After steam curing for 3 days or conventional film covering for heat preservation and moisture retention for 7 to 15 days, the mold can be removed. During removal, first open the inflation valve 51 to release air from the inner support 5 until the integrated rubber template 62 on the short side and bottom of the inner shell loses sufficient rigidity. At this point, using lifting equipment and the lifting steel bars 3, the inner shell 6 and inner support 5 can be easily lifted out. Then, remove the bolts from the long side steel template 11 and short side steel template 12 of the outer shell. After a trial lift of the lifting steel bars 3 to confirm that the lifting conditions are met, the semi-precast UHPC cap beam mold shell can be lifted out.

[0065] Step 4: After the curing of the semi-precast UHPC cap beam mold is completed, prestress can be applied to it. The prestress is applied by post-tensioning through the pre-reserved prestressed corrugated pipe 4. After the prestress is applied, the semi-precast UHPC cap beam mold is completed, and the subsequent molds can be quickly assembled and put into use.

[0066] The completed semi-precast UHPC cap beam formwork is hoisted and transported to the construction site. Hoisting equipment is used to embed the semi-precast UHPC cap beam formwork into the pre-reserved steel reinforcement columns of the pier. Ordinary concrete is then poured into the formwork. After curing, the fabrication and construction of the semi-precast UHPC formwork-NC cap beam are completed.

Claims

1. A convenient semi-precast UHPC cap beam mold shell, comprising a mold shell (1), a vibration support (2), lifting steel bars (3), prestressed corrugated pipes (4), an inner support (5), and a mold inner shell (6), characterized in that: The mold shell (1) consists of two long side steel templates (11), two short side steel templates (12), and a bottom steel template (13); the bottom steel template (13) has two mold shell slots (14); the bottom steel template (13) and the two short side steel templates (12) have evenly spaced through holes for passing through prestressed corrugated pipes (4). The prestressed corrugated pipe (4) is fixedly and intermittently installed on the inner side of the long side steel template (11) and the outer side of the bottom steel template (13) of the outer shell along a direction parallel to the long side steel template (11) of the outer shell. The inner shell (6) of the mold consists of two inner shell long side steel templates (61) and an inner shell short side and bottom integrated rubber template (62). The outer walls of the two inner shell long side steel templates (61) are provided with evenly spaced shear keyways (63), and a lifting frame (64) is fixedly installed between the two inner shell long side steel templates (61). The inner support (5) is in the form of a high-elasticity rubber box, and its shape corresponds to the internal shape of the inner shell (6) of the mold. Several air valves (51) are provided on the upper surface of the inner support (5). When it is filled with gas, it has a certain rigidity, and when it is released from the gas, it can quickly lose its rigidity. The vibration support (2) includes a vibration base (21), a rigid extension (22), and a rubber buffer layer (23). The vibration support (2) is fixedly connected to the mold shell (1) through the mold shell slot (14). Its diameter corresponds to the size of the slot (14) in the mold shell; The lifting steel bars (3) are embedded in the middle of both ends of the cover beam formwork during concrete pouring.

2. The convenient semi-prefabricated UHPC cap beam mold according to claim 1, characterized in that: The two long side steel templates (11), two short side steel templates (12), and bottom steel template (13) of the mold shell (1) are connected to each other by bolts and waterproofed by sealing strips.

3. The convenient semi-prefabricated UHPC cap beam mold according to claim 1, characterized in that: The spacing of the shear keyways (63) recessed inward on the two inner shell long side steel templates (61) of the inner shell (6) of the mold is greater than 10cm, and the recess depth should be greater than half the spacing of the shear keyways (63).

4. The convenient semi-prefabricated UHPC cap beam mold according to claim 1, characterized in that: The vibration support (2) has an upper rubber buffer layer (23) and a rigid extension (22) bonded together with adhesive and riveted, and a sealing strip is provided at the connection.

5. A convenient semi-prefabricated UHPC cap beam mold according to claim 1, characterized in that: The inner shell (6) of the mold has an inward positioning ring (65) at the vibration support (2), the size of which should be just enough to allow the vibration support (2) to be nested on the inner shell (6).

6. The convenient semi-prefabricated UHPC cap beam mold according to claim 1, characterized in that: The mold shell (1) should rest on the rigid extension (22) of the vibration support (2), and a rubber buffer layer should be provided between the rigid extension (22) and the mold shell (1).

7. A convenient semi-prefabricated UHPC cap beam mold according to claim 1, characterized in that: The prestressed corrugated pipe (4) is made of high-density polyethylene (HDPE).

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