A prestressed pretensioning device

Abstract

The present application relates to the field of construction, specifically to a prestressed pre-tensioning device, comprising two moving beams arranged in parallel at intervals, a force transmission mechanism and a jacking mechanism between the two moving beams; the force transmission mechanism is connected to the two ends of the opposite side of the two moving beams respectively, and the jacking mechanism is arranged between the two force transmission mechanisms on the same side of the two moving beams, and the jacking mechanism is abutted to the force transmission mechanism on both sides to provide horizontal thrust for tensioning the two moving beams. The present application has simple structure, does not need to set the fixed device for bearing the reaction force of the tension force, is convenient to install and disassemble, and can be completely reused.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of construction, in particular to a pre-tensioning device for precast members. BACKGROUND

[0002] With the improvement of living standards, the requirements for space and span of buildings are becoming higher and higher, and the application of prestressed technology is becoming more and more widespread. With the development of assembly technology, pre-tensioning prestress can be constructed parallel to the main foundation, without occupying the total construction period, and is applied more and more in large-span workshops. The existing pier-type tensioning platform needs to excavate a large amount of earthwork, and then construct a steel-concrete structure. The pier-type tensioning platform relies on its own weight to balance the external load and maintain its stability, so its size is large, and most of the foundation is deeply buried in the stratum. When the production site needs to be changed, the pier-type tensioning platform cannot be disassembled and reused, and the material recovery rate is low and the reuse rate is low.

[0003] For example, Chinese patent 202110396585.3 discloses an assembly type pre-tensioning method precast beam platform structure, which uses a reinforced concrete platform at both ends of the steel strand, and then uses a jack and a tensioning beam moving trolley to tension.

[0004] In order to improve the reuse of the pre-tensioning device, some improvements have been made to reduce the size of the pier-type tensioning platform. However, in order to facilitate force application, at least one fixed device serving as a force application foundation must be provided at one end of the precast member. The fixed device must be fixed to the ground, and it must meet the tensioning strength during tensioning. If necessary, anchoring must be performed on the fixed device to improve its strength.

[0005] For example, Chinese patent 202011112521.8 discloses a pre-tensioning method precast beam plate synchronous tensioning and releasing system. Although it does not need to excavate a large amount of earthwork, it must excavate the foundation and build three counterforce walls on the foundation, and then use a bogie to tension. The counterforce wall in the patent technology cannot be disassembled and reused as an important component.

[0006] In summary, the existing pre-tensioning device must use a fixed device at least at one end, so when the production site is changed, it cannot be completely disassembled and reused, and a new fixed device must be built. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a pre-tensioning device for prestressed concrete, which needs to be provided with a fixed device at both ends of the precast member, has a simple structure, is convenient to apply force, and can be completely disassembled and reused.

[0008] To solve the above technical problems, the technical scheme provided by the present application is a prestressed pre-tensioning device, which comprises two moving cross beams arranged in parallel at intervals, a force transmission mechanism and a jacking mechanism arranged between the two moving cross beams; the force transmission mechanism is connected to the two ends of the opposite sides of the two moving cross beams, respectively; the jacking mechanism is arranged between the two force transmission mechanisms on the same side of the two moving cross beams, and the jacking mechanism is abutted on the force transmission mechanism on both sides to provide horizontal thrust for tensioning the two moving cross beams.

[0009] Preferably, the jacking mechanism comprises at least one hydraulic jack arranged vertically, and a jacking block arranged above the hydraulic jack; the opposite sides of the jacking block are provided with the same inclined surface structure, and the inclined surface structure is abutted on the force transmission mechanism to provide horizontal thrust.

[0010] Preferably, the jacking mechanism further comprises a base and a mounting plate; a guide rod is arranged on the base, and the mounting plate is horizontally sleeved on the guide rod; and the jacking block is arranged on the mounting plate.

[0011] Preferably, a limiting block is arranged on the guide rod below the mounting plate to limit the lowest position of the mounting plate.

[0012] Preferably, a connecting rod is arranged on the upper end of the guide rod to enhance the stability thereof.

[0013] Preferably, the force transmission mechanism comprises a guide rail arranged in parallel with the strand bundle; a sliding block is arranged on the guide rail; and a push rod is arranged on the sliding block; one end of the push rod is connected to the moving cross beam, and the other end is abutted on the side surface of the jacking block.

[0014] Preferably, the end of the push rod is in surface contact or line contact with the inclined surface structure of the side surface of the jacking block.

[0015] Preferably, the longitudinal section of the guide rail is in inverted convex structure or I-shaped structure, and the sliding block is slidably arranged on the guide rail.

[0016] Preferably, the length of the push rod is adjustable.

[0017] The prestressed pre-tensioning device of the present application converts the vertical force of the jacking mechanism upward into horizontal thrust, avoids the arrangement of fixed devices such as counterforce wall and fixed wall at one end of the strand, has simple structure, is convenient to install and disassemble, and can be completely disassembled for reuse. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a side view structural schematic diagram of the present application.

[0019] Figure 2It is a top view structural schematic diagram of the present application, in which only the jacking block and the push rod are embodied, and other components of the jacking mechanism and the force transmission mechanism are not embodied.

[0020] Figure 3 It is a jacking mechanism structural schematic diagram.

[0021] Figure 4 It is a guide rail inverted convex structure and a slider structure schematic diagram.

[0022] Figure 5 It is a guide rail I-shaped structure and a slider structure schematic diagram. DETAILED DESCRIPTION

[0023] For the above technical solution, a preferred embodiment is described in detail in combination with the drawings.

[0024] Referring to Figure 1 The prestressed pretensioning device of the present application comprises a steel strand fixing device, a jacking mechanism, and a force transmission mechanism.

[0025] The steel strand fixing device comprises a movable cross beam 11 at both ends, and the two ends of the steel strand bundle A pass through the movable cross beam 11 and are anchored on the movable cross beam 11 by an anchor (not shown). The bottom of the movable cross beam 11 is in sliding contact with the operation platform for prefabrication, so that it can displace relative to the operation platform. To reduce friction, a metal plate with a smooth surface for reducing friction can be arranged on the operation platform where the movable cross beam is located.

[0026] A jacking mechanism is arranged at the length center position on each side of the steel strand bundle A, and a force transmission mechanism is arranged on each side of each jacking mechanism. One end of the transmission mechanism is connected with one end of the movable cross beam, and under the drive of the jacking mechanism, the upward jacking force is converted into horizontal thrust of the force transmission mechanism, and the movable cross beam is pushed outward to realize the tensioning of the steel strand bundle A. The specific structure of the jacking mechanism and the force transmission mechanism is as follows:

[0027] The jacking mechanism is arranged in the accommodating limiting groove at the length center position on both sides of the prefabrication platform.

[0028] The jacking mechanism comprises a base 21, a guide rod 22, a mounting plate 23, a jacking block 24, and a jack 25. The base 21 is horizontally arranged at the bottom of the accommodating limiting groove, and the guide rod 22 is arranged on the base 21. The guide rod 22 is vertically arranged in four guide rods 22, the top ends of the guide rods 22 are connected by a connecting rod to strengthen the stability of the guide rod 22, and the bottom of the guide rod 22 is fixed on the base 21 by a fixing screw.

[0029] A mounting plate 23 is sleeved on the guide rod 22, and the mounting plate 23 is horizontally arranged. A limiting block (not shown) is arranged on the guide rod 22 below the mounting plate 23, and is used for limiting the lowest position of the mounting plate 23. A jacking block 24 is arranged above the mounting plate 23, and the jacking block 24 is fixedly mounted on the mounting plate through fixing bolts. The jacking block 24 is a slope structure which is the same in structure relative to the two side surfaces of the moving beam 11. A jack 25 is arranged between the base 21 and the mounting plate 23. The jack 25 is an automatically controlled hydraulic jack, and one or more jacks can be arranged in one jacking mechanism according to the jacking force required.

[0030] The force transmission mechanism 30 comprises a guide rail 31, a sliding block 32 and a push rod 33. The guide rail 31 is arranged on one side of the strand bundle and is parallel to the strand bundle A. The guide rail 31 is fixed on the foundation through bolts. The longitudinal section of the guide rail 31 is in an inverted convex structure. The sliding block 32 is arranged on the guide rail 31, and the inverted convex structure of the guide rail 31 limits the upward displacement of the sliding block 32. The guide rail 31 can also be an I-beam structure, and the sliding block is slidably arranged in the groove at the two ends of the I-beam, and the I-beam limits the upward displacement of the sliding block. The push rod 33 is fixedly connected to the sliding block 32 through fastening bolts. One end of the push rod 33 is connected to the moving beam 11 on the outer side of the strand bundle A through fixing bolts, and the other end of the push rod 33 abuts against the side slope structure of the jacking block 24 of the jacking mechanism 20. The end 331 of the push rod 33 is in surface contact or line contact with the side surface of the jacking block 24. The surface contact means that the end of the push rod is also a slope structure, and the line contact means that the end surface of the push rod in contact with the side surface of the jacking block is a line structure.

[0031] During tensioning, one push rod 33 abuts against each side surface of the jacking block 24, and then the strand bundle A is fixed on the moving beam 11 through an anchor. After the strand bundle A is fixed, the two jacks 25 located on the two sides of the strand bundle are controlled to synchronously drive the jacking block 24 to displace upward, and under the extrusion of the slope structures on the two side surfaces of the jacking block 24, the push rod 33 is subjected to an outward thrust and slides along the guide rail 31 to the outer side of the two ends of the prefabricated part, thereby realizing tensioning of the strand bundle. Since the jacking block 24 is subjected to the same reverse force of the push rod relative to the two side surfaces, under the reverse force of the push rod 33, the jacking block 24 can remain stable without an additional limiting structure for limiting left-right displacement or preventing tilting caused by uneven force.

[0032] The jacking mechanism of the pre-tensioning method device has the same horizontal pushing force on the two push rods on both sides of the jacking block, and the jacking block bears the same reverse force while providing the horizontal pushing force. After the concrete of the prefabricated part reaches a certain strength, the jacks 25 are controlled to gradually displace downward, the pushing force is reduced, and the jacking block 24 displaces downward along with the jacks under the action of the reverse force of the push rods 33 on both sides of the jacking block and the gravity of the jacking block. With the displacement of the moving beam 11 toward the jacking block 24, the steel strand bundle A in tension between the moving beam 11 and the prefabricated part also gradually becomes loose until the jacking block 24 returns to the initial position, the steel strand bundle A tensioned by the moving beam 11 is completely released from the tensioned state and is completely in the relaxed state, and then the steel strand bundle is disconnected, which can avoid the rebound of the steel strand bundle on the prefabricated part and the impact force caused by directly disconnecting the steel strand bundle after the concrete reaches a certain strength, improve the safety of operation, and improve the quality of the prefabricated part.

[0033] The pre-tensioning method device of the application can realize the tensioning of the steel strand bundle by converting the vertical upward force of the jacking mechanism into horizontal pushing force, does not need any fixed device such as counterforce wall or fixed wall bearing the reverse force of the moving beam, has simple structure, is convenient to install and disassemble, and can be completely reused.

[0034] The pre-tensioning method device of the application can be applied to the pre-tensioning method manufacturing of prefabricated parts of various sizes. Only the length of the push rod needs to be adjusted, and whether to increase the counterweight block and the size of the counterweight block is determined according to the size of the pushing force. When the prefabricated part is relatively short and the tensioning force is small, the guide rail and the sliding block can also not be used, and only the moving beam, the push rod and the jacking mechanism can be used to realize the tensioning.

[0035] In order to make the pre-tensioning method device of the application have wider application range and be convenient to adjust the length of the push rod, the push rod can be provided as a length-adjustable push rod. The length-adjustable push rod can be sleeved at one end of two push rods, and then a plurality of fixing holes are arranged at intervals on the sleeved end. After the length of the push rod is adjusted, the push rod can be fixed and connected by fastening bolts penetrating through the overlapped sleeved part.

[0036] In order to improve the stability of jacking and reduce the jacking friction, the end surface area of the push rod abutting against the side surface of the jacking block is relatively small, such as line contact or small surface contact between the push rod and the side surface of the jacking block.

[0037] In order to improve the rigidity and strength of the pre-tensioning method device, the moving beam, the guide rail, the sliding block, the push rod, the jacking block, the mounting plate, the base and the guide rod can all be made of steel.

Claims

1. A prestressed pretensioning device, characterized in that, It includes two parallel moving beams, a force transmission mechanism and a lifting mechanism located between the two moving beams; a force transmission mechanism is connected to both ends of the opposite side of the two moving beams, and a lifting mechanism is provided between the two force transmission mechanisms located on the same side of the two moving beams. The lifting mechanism abuts against the force transmission mechanism on both sides to provide it with a horizontal thrust to tension the two moving beams. The lifting mechanism includes at least one vertically arranged hydraulic jack and a lifting block located on the hydraulic jack. The two opposite sides of the lifting block have the same inclined structure, and the inclined structure abuts against the force transmission mechanism to provide it with horizontal thrust. The force transmission mechanism includes a guide rail arranged parallel to the steel strand bundle, a slider on the guide rail, a push rod on the slider, one end of the push rod being connected to the moving crossbeam, and the other end abutting against the side of the lifting block. The longitudinal section of the guide rail is an inverted convex structure or an I-shaped structure, and the slider is slidably mounted on the guide rail; The length of the push rod is adjustable.

2. The prestressed pretensioning device according to claim 1, characterized in that, The lifting mechanism also includes a base and a mounting plate. A guide rod is provided on the base, the mounting plate is horizontally sleeved on the guide rod, and the lifting block is provided on the mounting plate.

3. The prestressed pretensioning device according to claim 2, characterized in that, A limiting block is provided on the guide rod below the mounting plate to limit the lowest position of the mounting plate.

4. The prestressed pretensioning device according to claim 2, characterized in that, A connecting rod is provided at the upper end of the guide rod to enhance its stability.

5. The prestressed pretensioning device according to claim 1, characterized in that, The end of the push rod is in surface or line contact with the inclined surface structure on the side of the lifting block.

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