Pre-tensioning method tensioning pedestal and installation method

Abstract

The invention belongs to the field of building construction, and relates to a pre-tensioning method tensioning pedestal and a mounting method, which can enable the internal prestress of poured concrete to be uniformly distributed and improve the overall strength. According to the technical scheme, a cross beam, a bearing support and a plurality of prestressed tendon sets are included. And the two cross beams are arranged in parallel. And a bearing bracket is arranged between the two cross beams. And the plurality of prestressed tendon groups are fixed between the two cross beams. The prestressed tendon group comprises a prestressed tendon section, a length adjusting piece, a strain gauge sensor and a detection circuit. The multiple prestressed tendon sections are sequentially arranged in the direction of the center line of the prestressed tendon sections, and the head prestressed tendon section and the tail prestressed tendon section are fixedly connected with the two cross beams in a one-to-one correspondence mode. A length adjusting part is arranged between every two adjacent prestressed tendon sections, and the two ends of each length adjusting part are fixedly connected with the corresponding prestressed tendon sections in a one-to-one correspondence mode. A strain gauge sensor is fixed in the middle of the prestressed tendon section. The detection circuit is electrically connected with the strain gauge sensor, and the detection circuit obtains the current passing through the strain gauge sensor.

Description

Technical Field

[0001] The invention belongs to the field of building construction and relates to a pre-tensioning pedestal and an installation method. Background Art

[0002] The principle of the pre-tensioning pedestal is to tension the prestressed tendons and temporarily anchor them on the pedestal or steel form before pouring the concrete components. Then pour the concrete components, and when the concrete reaches a certain strength (usually not less than 75% of the standard value of concrete strength), relax the prestressed tendons to make them elastically shrink, and generate pre-compression stress on the concrete by virtue of the bonding force between the concrete and the prestressed tendons.

[0003] The pre-stressing pedestal can make the concrete prestressed to offset the tension; or the concrete can form a slight curve to increase the load capacity.

[0004] However, prestressed tendons are usually set as one steel bar, so that the deformation in the middle of the steel bar is larger and the deformation at both ends is smaller. Therefore, when the prestressed tendons are relaxed, the prestress strength received in the middle of the concrete is greater than the prestress strength at both ends, which makes the prestress inside the concrete unevenly distributed and even has a certain stress concentration. This increases the brittleness of the concrete to a certain extent, and there is a certain slippage between the concrete and the prestressed tendons. Summary of the invention

[0005] In order to overcome the defects in the above-mentioned related technologies, on the one hand, the present invention proposes a pre-tensioning pedestal, which can make the prestress inside the concrete after pouring uniform and improve the overall strength.

[0006] To achieve the above technical objectives, the present invention provides a pre-tensioning pedestal. The pre-tensioning pedestal comprises: a crossbeam, a load-bearing support, and a plurality of prestressed tendon groups. Two crossbeams are arranged in parallel. A load-bearing support is arranged between the two crossbeams. A plurality of prestressed tendon groups are fixed between the two crossbeams.

[0007] Each prestressed tendon group includes: a prestressed tendon segment, a length adjustment member, a strain gauge sensor and a detection circuit. The prestressed tendon segment is a straight steel bar, and multiple prestressed tendon segments are arranged in sequence along the center line direction, and the first and last prestressed tendon segments are fixedly connected to the two cross beams in a one-to-one correspondence. A length adjustment member is provided between two adjacent prestressed tendon segments, and the two ends of the length adjustment member are fixedly connected to the corresponding prestressed tendon segments in a one-to-one correspondence. A strain gauge sensor is fixed in the middle of the prestressed tendon segment. The detection circuit is electrically connected to the strain gauge sensor, and the detection circuit obtains the current passing through the strain gauge sensor.

[0008] Preferably, the length adjustment member comprises: a threaded rod, a collar and a nut. One end of the threaded rod is coaxially fixedly connected to a prestressed tendon segment. The collar comprises an annular member, which is movably sleeved on the threaded rod and is also fixedly connected to another prestressed tendon segment. The nut is arranged on the threaded rod between the collar and another prestressed tendon segment, and the outer diameter of the nut is greater than the inner diameter of the annular member of the collar.

[0009] Preferably, the strain gauge sensor comprises a resistance strain gauge.

[0010] Preferably, the detection circuit includes a current detection circuit, and the current detection circuit includes: a battery, a detection resistor, an ammeter and a safety resistor. The positive electrode of the battery is electrically connected to one end of the detection resistor, and the other end of the detection resistor is a first test end. One end of the ammeter is a second test end. One end of the safety resistor is electrically connected to the other end of the ammeter, and the other end of the safety resistor is electrically connected to the negative electrode of the battery.

[0011] On the other hand, a method for installing a pre-tensioning pedestal is applicable to the above-mentioned pre-tensioning pedestal.

[0012] The installation method of the pre-tensioning pedestal comprises: establishing two beams and a load-bearing support on a base. Multiple through holes are arranged on each beam, and a prestressed tendon segment is movably arranged in each through hole, and an anti-slip block is welded on the prestressed tendon segment outside the two beams, and the diameter of the anti-slip block is greater than the inner diameter of the through hole. The prestressed tendon segments on the two beams, and multiple prestressed tendon segments are arranged in sequence between the two prestressed tendon segments on the same center line. A length adjustment member is arranged between two adjacent prestressed tendon segments, one end of the threaded rod of the length adjustment member is welded to one prestressed tendon segment, and the collar of the length adjustment member is welded to another prestressed tendon segment. A strain gauge sensor is fixed in the middle of each prestressed tendon segment. The nut of the length adjustment member is screwed to make the tension of the multiple prestressed tendon segments on the same center line meet the engineering requirements. The strain gauge sensors on the multiple prestressed tendon segments on the same center line are detected in sequence by using a detection circuit, and while ensuring that the tension of the prestressed tendon segment meets the engineering requirements, each current value passing through the strain gauge sensor fluctuates within the first range.

[0013] Preferably, the difference between the maximum value and the minimum value of the first range is less than 1 / 10 of the average value of multiple current values ​​of the same prestressed tendon group.

[0014] Preferably, the installation method of the pre-tensioning pedestal further comprises: removing the strain gauge sensor, pouring concrete between the crossbeam and the load-bearing support to wrap the prestressed tendon group, and removing the anti-detachment block after the concrete solidifies.

[0015] The beneficial effects of the present invention are: The present invention adopts a length adjustment piece and a strain gauge sensor, which can make the deformation of each prestressed tendon segment basically the same under the premise of ensuring that the prestressed tendon segment is subjected to the minimum tension in accordance with engineering requirements, and ensure that after the prestressed tendon segment is loosened, the rebound amounts of multiple prestressed tendon segments inside the concrete are basically the same, thereby ensuring that the prestress inside the concrete is evenly distributed and the structural strength is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural diagram of the present invention; Figure 2 It is a structural diagram of the length adjusting member of the present invention.

[0018] In the figure: 1, cross beam; 2, load-bearing support; 3, prestressed tendon group; 31, prestressed tendon segment; 32, length adjustment piece; 33, strain gauge sensor; 34, detection circuit; 321, threaded rod; 322, collar; 323, nut. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0022] like Figure 1 and Figure 2 As shown, some embodiments of the present invention provide a pre-tensioning pedestal. The pre-tensioning pedestal comprises: a cross beam 1, a load-bearing support 2, and a plurality of prestressed tendon groups 3. Two cross beams 1 are arranged in parallel. A load-bearing support 2 is arranged between the two cross beams 1. A plurality of prestressed tendon groups 3 are fixed between the two cross beams 1.

[0023] Each prestressed tendon group 3 includes: a prestressed tendon segment 31, a length adjustment member 32, a strain gauge sensor 33 and a detection circuit 34. The prestressed tendon segment 31 is a straight steel bar, and multiple prestressed tendon segments 31 are arranged in sequence along the center line direction, and the first and last prestressed tendon segments 31 are fixedly connected to the two cross beams 1 in a one-to-one correspondence. A length adjustment member 32 is provided between two adjacent prestressed tendon segments 31, and the two ends of the length adjustment member 32 are fixedly connected to the corresponding prestressed tendon segments 31 in a one-to-one correspondence. A strain gauge sensor 33 is fixed in the middle of the prestressed tendon segment 31. The detection circuit 34 is electrically connected to the strain gauge sensor 33, and the detection circuit 34 obtains the current passing through the strain gauge sensor 33.

[0024] The length adjustment member 32 comprises: a threaded rod 321, a collar 322 and a nut 323. One end of the threaded rod 321 is coaxially fixedly connected to a prestressed tendon segment 31. The collar 322 comprises an annular member, which is movably sleeved on the threaded rod 321 and is also fixedly connected to another prestressed tendon segment 31. The nut 323 is arranged on the threaded rod 321 between the collar 322 and another prestressed tendon segment 31, and the outer diameter of the nut 323 is greater than the inner diameter of the annular member of the collar 322.

[0025] The ring 322 also includes a fixing rod, the center line of which is colinear with the center line of the annular member. The fixing rod is fixedly connected to the annular member through two connecting rods, and the nut 323 is arranged between the two connecting rods. Sufficient clearance is provided between the nut 323 and the connecting rod to facilitate the screwing of the nut 323.

[0026] The fixing rod is welded to another prestressed tendon segment 31 .

[0027] The strain gauge sensor 33 includes a resistance strain gauge.

[0028] The detection circuit 34 includes a current detection circuit 34, and the current detection circuit 34 includes: a battery, a detection resistor, an ammeter and a safety resistor. The positive electrode of the battery is electrically connected to one end of the detection resistor, and the other end of the detection resistor is a first test end. One end of the ammeter is a second test end. One end of the safety resistor is electrically connected to the other end of the ammeter, and the other end of the safety resistor is electrically connected to the negative electrode of the battery.

[0029] Generally, two to three prestressed tendon segments 31 can be arranged between two cross beams 1, and further including the prestressed tendon segments 31 arranged on the cross beams 1, that is, one prestressed tendon group 3 includes four or five prestressed tendon segments 31. Accordingly, the number of length adjusting members 32 is three or four.

[0030] The strain gauge sensor 33 can be attached to the middle of the prestressed tendon segment 31. It is understandable that there are certain errors in on-site construction, but the strain gauge sensor 33 should be attached to the middle position of the prestressed tendon segment 31 as much as possible to reduce the error.

[0031] Each prestressed tendon segment 31 is attached with a strain gauge sensor 33 on site, and the current passing through the strain gauge sensor 33 is detected after the prestressed tendon group 3 is straightened to ensure that the deformation of the prestressed tendon segments 31 of the same prestressed tendon group 3 is the same. Of course, the deformation of other prestressed tendon segments 31 of the same prestressing pedestal should be kept basically consistent to ensure uniform prestress of the entire prestressing pedestal.

[0032] On the other hand, a method for installing a pre-tensioning pedestal is applicable to the above-mentioned pre-tensioning pedestal.

[0033] The installation method of the pre-tensioning pedestal comprises: S1. Build two beams and load-bearing supports on the base.

[0034] S2. A plurality of through holes are arranged on each cross beam, and a prestressed tendon segment is movably arranged in each through hole. Anti-slipping blocks are welded on the prestressed tendon segments on the outer sides of the two cross beams, and the diameter of the anti-slipping blocks is larger than the inner diameter of the through holes.

[0035] S3. Prestressed tendon segments on two cross beams, and multiple prestressed tendon segments are arranged in sequence from head to tail between two prestressed tendon segments with a common center line.

[0036] S4. A length adjusting member is arranged between two adjacent prestressed tendon segments, one end of the threaded rod of the length adjusting member is welded to one prestressed tendon segment, and the sleeve ring of the length adjusting member is welded to the other prestressed tendon segment.

[0037] S5. Fix the strain gauge sensor in the middle of each prestressed tendon segment. Tighten the nut of the length adjustment piece to make the tension of multiple prestressed tendon segments with the same center line meet the engineering requirements.

[0038] S6. Use a detection circuit to detect the strain gauge sensors on multiple prestressed tendon segments on the same center line in sequence, and while ensuring that the tension of the prestressed tendon segment meets the engineering requirements, each current value passing through the strain gauge sensor fluctuates within a first range. The difference between the maximum value and the minimum value of the first range is less than 1 / 10 of the average value of multiple current values ​​of the same prestressed tendon group.

[0039] In some embodiments, after step S6, the method for installing the pre-tensioning pedestal further includes step S7: S7. Remove the strain gauge sensor and pour concrete between the beam and the load-bearing support to wrap the prestressed tendon group. After the concrete solidifies, remove the anti-dropout block.

[0040] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0041] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A pre-tensioning pedestal, characterized in that: include: Crossbeams, two crossbeams are arranged in parallel; A load-bearing support is provided between the two beams; A plurality of prestressed tendon groups, wherein the plurality of prestressed tendon groups are fixed between two beams; Each prestressing tendon group includes: Prestressed tendon segments, wherein the prestressed tendon segments are straight steel bars, and a plurality of the prestressed tendon segments are arranged in sequence along the center line direction, and the first and last prestressed tendon segments are fixedly connected to the two cross beams in a one-to-one correspondence; A length adjusting member, wherein a length adjusting member is provided between two adjacent prestressed tendon segments, and both ends of the length adjusting member are fixedly connected to the corresponding prestressed tendon segments in a one-to-one correspondence; A strain gauge sensor is fixed to the middle of the prestressed tendon segment; A detection circuit is electrically connected to the strain gauge sensor, and the detection circuit obtains the current passing through the strain gauge sensor.

2. The pre-tensioning pedestal according to claim 1, characterized in that: The length adjusting member comprises: A threaded rod, one end of which is coaxially fixedly connected to a prestressed tendon segment; A collar, the collar comprising an annular member, the collar being movably sleeved on the threaded rod, and the collar being fixedly connected to another prestressed tendon segment; A nut is arranged on the threaded rod between the collar and another prestressed tendon segment, and the outer diameter of the nut is greater than the inner diameter of the annular member of the collar.

3. The pre-tensioning pedestal according to claim 2, characterized in that: The strain gauge sensor includes a resistance strain gauge.

4. The pre-tensioning pedestal according to claim 3, characterized in that: The detection circuit includes a current detection circuit, and the current detection circuit includes: Battery; A detection resistor, wherein the positive electrode of the battery is electrically connected to one end of the detection resistor, and the other end of the detection resistor is a first test end; an ammeter, one end of which is a second test end, A safety resistor, one end of which is electrically connected to the other end of the ammeter, and the other end of which is electrically connected to the negative electrode of the battery.

5. A method for installing a pre-tensioning pedestal, applicable to the pre-tensioning pedestal according to any one of claims 1 to 4, characterized in that: The installation method of the pre-tensioning pedestal comprises: Build two beams and load-bearing supports on the abutment; A plurality of through holes are arranged on each cross beam, a prestressed tendon segment is movably arranged in each through hole, and an anti-slip block is welded on the prestressed tendon segments on the outer sides of the two cross beams, and the diameter of the anti-slip block is larger than the inner diameter of the through hole; Prestressed tendon segments on two cross beams, and multiple prestressed tendon segments are arranged in sequence between the two prestressed tendon segments with a common center line; A length adjusting piece is arranged between two adjacent prestressed tendon segments, one end of the threaded rod of the length adjusting piece is welded to one prestressed tendon segment, and the sleeve ring of the length adjusting piece is welded to the other prestressed tendon segment; A strain gauge sensor is fixed in the middle of each prestressed tendon segment; Tighten the nut of the length adjustment piece to make the tension of multiple prestressed tendon segments with the same center line meet the engineering requirements; The detection circuit is used to detect the strain gauge sensors on multiple prestressed tendon segments on the same center line in sequence, and while ensuring that the tension of the prestressed tendon segment meets the engineering requirements, each current value passing through the strain gauge sensor fluctuates within a first range.

6. The method for installing a pre-tensioning pedestal according to claim 5, characterized in that: The difference between the maximum value and the minimum value of the first range is less than 1 / 10 of the average value of multiple current values ​​of the same prestressed tendon group.

7. The method for installing a pre-tensioning pedestal according to claim 5 or 6, characterized in that: The installation method of the pre-tensioning pedestal also includes: removing the strain gauge sensor, pouring concrete between the crossbeam and the load-bearing support to wrap the prestressed tendon group, and removing the anti-dropping block after the concrete solidifies.

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