CN-121994391-A - Unbonded effective prestress detection equipment and detection method

CN121994391ACN 121994391 ACN121994391 ACN 121994391ACN-121994391-A

Abstract

The invention provides unbonded effective prestress detection equipment and a unbonded effective prestress detection method, wherein a concrete member to be detected comprises a prestress anchor ring and an anchor backing plate which are adjacent, the detection equipment comprises a constraint anchor ring, a fastening clamping piece, a loading device and a sensing device, the constraint anchor ring is of an annular structure, the inner ring surface of the constraint anchor ring is of a cone shape which is contracted from a first end to a second end along the axial direction, the constraint anchor ring is sleeved on the circumferential side of the prestress anchor ring, the second end of the constraint anchor ring faces the anchor backing plate, the fastening clamping piece is at least partially arranged between the constraint anchor ring and the prestress anchor ring, the loading device is arranged between the constraint anchor ring and the anchor backing plate, one end of the loading device is abutted against the anchor backing plate, the other end of the loading device applies pressure to the constraint anchor ring, and the sensing device comprises a pressure sensing component, and the pressure sensing component detects the pressure of the loading device on the constraint anchor ring. The detection device of the invention can detect the effective prestress of the built unbonded prestressed concrete member.

Inventors

MAO SHIYANG
SUN BIN
DU YANCHENG
ZHAO BOHAO
YU XIANYUAN

Assignees

建研院检测中心有限公司

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (10)

1. An unbonded effective pre-stressing detection device, characterized in that the concrete member to be detected comprises an adjoining pre-stressing anchor ring and anchor pad, said detection device comprising: The inner ring surface of the constraint anchor ring is in a conical shape shrinking from the first end to the second end along the axial direction, the constraint anchor ring is sleeved on the circumferential side of the prestress anchor ring, and the second end of the constraint anchor ring faces the anchor backing plate; The fastening clamping piece is at least partially arranged between the constraint anchor ring and the prestress anchor ring; The loading device is arranged between the constraint anchor ring and the anchor backing plate, one end of the loading device is abutted against the anchor backing plate, and the other end of the loading device applies pressure to the constraint anchor ring; the sensing device comprises a pressure sensing assembly, and the pressure sensing assembly detects the pressure of the loading device on the constraint anchor ring.
2. The unbonded, effective prestressing force detection apparatus of claim 1, wherein the sensing means further includes a displacement sensing assembly that detects a loading displacement of the loading means.
3. The unbonded, effective prestressing force inspection apparatus of claim 2, further including a load cut-off device, the load cut-off device including: The first conducting piece is connected to the anchoring plate; A second conductive member connected to the pre-stressed anchor ring; The first conducting piece and the second conducting piece are connected into a loop of the relay induction element, and the relay induction element is in control connection with the loading device; If the first conducting piece is in contact conduction with the second conducting piece, the loading device continuously increases pressure to the constraint anchor ring; And if the first conducting piece and the second conducting piece are disconnected, the relay sensing element controls the loading device to stop increasing pressure.
4. A non-binding effective pre-stress detection apparatus according to claim 3, wherein the loading means comprises two or more numbers of lifting mechanisms arranged circumferentially of the constraint anchor ring, the lifting mechanisms comprising a fixed end and a lifting end movable relative to the fixed end, the fixed end being in abutment with the anchor pad, the lifting end being in abutment with the constraint anchor ring.
5. The unbonded, effective prestressing force inspection apparatus of claim 4, wherein the lifting mechanism is a fluid pressure driven jack, and the loading device further includes a pressure equalizing system in communication with each of the jacks to equalize the lifting pressure of each of the jacks.
6. The unbonded effective prestressing force detection apparatus of claim 4, wherein the loading device further includes leveling work pieces in one-to-one correspondence with the jacking mechanisms, one side of the leveling work pieces being a plane abutting against the constraint anchor ring; the other side of the leveling workpiece is a concave spherical surface, and the lifting end of the lifting mechanism is a convex spherical surface matched with the leveling workpiece, or The other side of the leveling workpiece is a convex spherical surface, and the lifting end of the lifting mechanism is a concave spherical surface matched with the leveling workpiece.
7. The unbonded, effective prestressing force inspection apparatus according to any of claims 1-6, characterized in that the sides of the fastening clips have a relief structure and/or The inner ring surface of the constraint anchor ring is provided with a concave-convex structure.
8. The unbonded active prestressing force detection apparatus of any of claims 1-6, wherein a magnetic member is disposed within the confinement anchor ring and the fastening clip is ferromagnetic.
9. A method for unbonded active prestressing, characterized in that a detection device according to any of claims 1-8 is used, said detection method comprising: S1, placing the loading device on the anchor backing plate, sleeving the constraint anchor ring on the circumference of the prestress anchor ring, and placing the fastening clamping piece between the constraint anchor ring and the prestress anchor ring; s2, driving the loading device to enable the loading device to apply incremental pressure to the constraint anchor ring; s3, continuously acquiring a pressure value of the pressure sensing component; And S4, determining a pressure value at the moment that the prestress anchor ring is separated from the anchor backing plate, wherein the pressure value is an effective prestress value.
10. The unbonded effective prestressing force detection method of claim 9, wherein the sensing device further includes a displacement sensing assembly that detects a loading displacement of the loading device; step S3 also comprises the steps of continuously obtaining the displacement value of the displacement sensor; the step S4 includes: S41, recording a pressure-displacement curve in real time; s42, calculating the slope value of the curve, and comparing the slope value of each section of the curve to obtain a section with the slope value reduced for the first time, wherein the pressure value of the lowest point of the section is the effective stress value.

Description

Unbonded effective prestress detection equipment and detection method Technical Field The invention belongs to the field of buildings, and particularly relates to unbonded effective prestress detection equipment and a detection method. Background The concrete pre-stressing technique is an engineering technique for counteracting or reducing the tensile stress generated in the using stage by pre-stressing the concrete structure before bearing the load, thereby improving the crack resistance, rigidity and durability of the structure. The prestress technology stretches high-strength steel bars (or steel strands) in a concrete member, the retraction force of the steel bars is utilized to enable the concrete to be subjected to prestress, and when the structure is subjected to external load, part or all of tensile stress can be counteracted by the prestress, so that the occurrence of cracks is delayed, and even the cracks are avoided. The unbonded prestress technology is a special process of prestressed concrete structure, and its core is that the surface of prestressed rib is coated with special-purpose anti-corrosion lubricating material and covered with jacket, so that it is not bonded with surrounding concrete, and can be freely slid relative to concrete in the stage of tensioning and using. The unbonded prestress technology is widely applied to modern prestress retarding soil structures due to the advantages of convenience in construction, clear stress, replaceability and the like. However, the effective prestressing of unbonded prestressing steel bars (or bundles, strands, etc.) is a key parameter that directly affects the safety of the structure. In the service process of the structure, the effective prestress can be gradually attenuated due to the factors of shrinkage creep of concrete, relaxation of reinforcing steel bars, slippage and corrosion of anchors, and the like, so that the structure can be cracked, deformed and even damaged. The existing unbonded effective prestress detection method mainly converts effective prestress in an embedded sensor mode or by testing vibration frequency indirectly, cannot detect an established structure or a structure without the embedded sensor, is easy to be subjected to electromagnetic interference, has poor long-term use stability and is high in cost. Disclosure of Invention The invention aims to provide an unbonded effective prestress detection device and a detection method, and aims to detect unbonded effective prestress of a concrete member, in particular to detect unbonded effective prestress of a concrete member with built and unburied sensors. In the aspect 1, the detection apparatus includes: The inner ring surface of the constraint anchor ring is in a conical shape shrinking from the first end to the second end along the axial direction, the constraint anchor ring is sleeved on the circumferential side of the prestress anchor ring, and the second end of the constraint anchor ring faces the anchor backing plate; The fastening clamping piece is at least partially arranged between the constraint anchor ring and the prestress anchor ring; The loading device is arranged between the constraint anchor ring and the anchor backing plate, one end of the loading device is abutted against the anchor backing plate, and the other end of the loading device applies pressure to the constraint anchor ring; the sensing device comprises a pressure sensing assembly, and the pressure sensing assembly detects the pressure of the loading device on the constraint anchor ring. In the aspect 2 based on the aspect 1, the sensing device further includes a displacement sensing assembly that detects a loading displacement of the loading device. In the aspect 3 based on the aspect 2, the detecting apparatus further includes a load cut-off device including: The first conducting piece is connected to the anchoring plate; A second conductive member connected to the pre-stressed anchor ring; The first conducting piece and the second conducting piece are connected into a loop of the relay induction element, and the relay induction element is in control connection with the loading device; If the first conducting piece is in contact conduction with the second conducting piece, the loading device continuously increases pressure to the constraint anchor ring; And if the first conducting piece and the second conducting piece are disconnected, the relay sensing element controls the loading device to stop increasing pressure. In the scheme 4 based on the scheme 3, the loading device comprises two or more lifting mechanisms, the two or more lifting mechanisms are arranged along the circumferential direction of the constraint anchor ring, the lifting mechanisms comprise a fixed end and a lifting end moving relative to the fixed end, the fixed end is abutted to the anchor pad, and the lifting end is abutted to the constraint anchor ring. In the 5 th aspect based on the 4 th aspect, the lifting mechanism i