Low-strength concrete core sample clamping device
Technical Field
The invention relates to a low-strength concrete core sample clamping device.
Background
The core drilling method is a semi-damage detection method which directly drills a core sample from a structure by using a special drilling machine and deduces the strength and durability of concrete according to the index of the core sample. Since the samples are directly from the concrete entity, the results can better reflect the actual concrete condition, and therefore, the method is often used as an arbitration detection method.
In actual testing work, how to take out a concrete core sample smoothly with small damage is an important step. In the prior art, a concrete core sample is taken out mainly by adopting the following method: and after the concrete core sample is broken, clamping the side surface of the top of the core sample by using a core sample clamp, and taking out the core sample. The method has the following defects: for low-strength concrete, such as plastic concrete, composite foundation and the like, the core sample clamp clamps the core sample due to low strength (generally lower than 8 MPa), and the core sample cannot be completely and effectively clamped due to the fact that the clamped core sample is small in length and uneven in stress, and the concrete core sample is broken in a prying mode at a weak stress position (the edge of the top surface of the concrete core sample), so that the core sample cannot be taken out.
In summary, the existing method has the defect that the low-strength concrete core sample cannot be completely and effectively clamped and taken out, so design innovation is needed.
Disclosure of Invention
The invention provides a low-strength concrete core sample clamping device with strong practicability and reasonable design and a method using the device.
The technical scheme adopted by the invention is as follows: a low-strength concrete core sample clamping device comprises a metal counterforce steel ring sleeved in an annular groove on the side surface of a concrete core sample in solid concrete; two wedge-shaped steel inserting pieces are symmetrically arranged between the metal counterforce steel ring and the side surface of the concrete core sample; a pressing steel plate, a counter-force device and a force application device are sequentially arranged on the wedge-shaped steel insertion piece; the counterforce device is erected and welded on the metal counterforce steel ring, and covers the concrete core sample, the wedge-shaped steel insert, the pressing steel plate and part of the force application device. The wedge-shaped steel insert is inserted between the metal counterforce steel ring and the side surface of the concrete core sample, and then the wedge-shaped steel insert is clamped and the concrete core sample is taken out by pressing the steel plate, the counterforce device and the force application device.
Furthermore, the annular groove is coaxial with the longitudinal axis of the concrete core sample, the bottom surface of the annular groove is coplanar with the bottom surface of the concrete core sample, and the top surface of the annular groove is coplanar with the top surface of the concrete core sample and the surface of the solid concrete.
Furthermore, the metal counterforce steel ring is in a hollow cylindrical shape, the top surface of the metal counterforce steel ring is in the same plane with the top surface of the concrete core sample, the diameter of the outer ring is slightly smaller than the outer diameter of the annular groove, the diameter of the inner ring is slightly larger than the diameter of the concrete core sample, the height of the inner ring is not smaller than 1/3 of the height of the concrete core sample, and 2 facing arc-shaped wedge-shaped grooves are symmetrically arranged on the; the height of the arc-shaped wedge-shaped groove is equal to the height of the metal reaction steel ring, the width of the arc-shaped wedge-shaped groove is 1/4-1/3 of the diameter of the concrete core sample, the thickness of the top surface groove is equal to the thickness of the metal reaction steel ring, and the thickness of the bottom surface groove is 0.
Furthermore, the wedge-shaped steel inserting piece is an arc-shaped wedge body, the top surface of the wedge-shaped steel inserting piece is in contact with the lower surface of the lower pressing steel plate, the lower portion of the wedge-shaped steel inserting piece can be extruded into the space between the arc-shaped wedge groove and the concrete core sample, the inner wall of the wedge-shaped steel inserting piece is attached to the outer wall of the concrete core sample, the outer wall of the wedge-shaped steel inserting piece is attached to the wall of the arc-shaped wedge groove, the width of the wedge-shaped steel inserting.
Furthermore, the pressing steel plate is a rectangular body, the length of the pressing steel plate is greater than the distance between the outer side and the outer side of the top surface of the wedge-shaped steel inserting piece, the width of the pressing steel plate is equal to the width of the wedge-shaped steel inserting piece, and the thickness of the pressing steel plate is not less than 10 mm.
Furthermore, the reaction device is a concave main body and comprises a metal reaction beam and two pairs of metal reaction support legs symmetrically arranged at two ends of the metal reaction beam; the metal counterforce cross beam is a rectangular plate, is perpendicular to the pressing steel plate and is parallel to the top surface of the concrete core sample, the thickness of the metal counterforce cross beam is not less than 20mm, the width of the metal counterforce cross beam is 1/4-1/3 of the diameter of the concrete core sample, the length of the metal counterforce cross beam is greater than the outer diameter of the annular groove, a through force application screw hole is drilled in the centers of the top surface and the bottom surface, and the bottom surfaces at two ends of the metal; the metal reaction stabilizer blade is the crooked cuboid, and bottom surface and metal reaction steel ring top surface welded connection, the distance equals metal reaction crossbeam width between two parallel rectangles, and two parallel curved surfaces are the same curved surface with metal reaction steel ring outer wall, inner wall respectively.
Furthermore, the force application device is a hexagon flat-bottomed bolt and can be screwed into a force application screw hole from the top surface of the metal reaction cross beam to tightly push the upper surface of the pressing steel plate.
The invention has the beneficial effects that: (1) during detection, the wedge-shaped steel inserting pieces are inserted into the arc-shaped wedge-shaped grooves, and then the steel plates, the counter-force devices and the force application devices are pressed downwards, so that the wedge-shaped steel inserting pieces are clamped and a concrete core sample is taken out, and the concrete core sample is high in practicability and reasonable in design; (2) instruments and equipment and spare parts used by the clamping device are purchased, processed, assembled and carried conveniently, so that the popularization value is greatly improved; (3) the clamping device has the advantages of large clamping core sample length and area, uniform stress and no problem that the concrete core sample cannot be completely and effectively clamped and taken out due to prying and cracking at the weak stress position (the edge of the top surface of the concrete core sample).
Drawings
Fig. 1 is a schematic front view of the present invention in use.
FIG. 2 is a schematic cross-sectional view of the invention using A-A.
Fig. 3 is a schematic cross-sectional view of the present invention using B-B.
Figure 4 is a schematic cross-sectional view of the invention using C-C.
Figure 5 is a schematic cross-sectional view of the invention using D-D.
FIG. 6 is a schematic cross-sectional view of the invention using E-E.
FIG. 7 is a schematic cross-sectional view of the present invention using F-F.
FIG. 8 is a schematic cross-sectional view of the invention using G-G.
Fig. 9 is a schematic top view of the structure of the present invention.
FIG. 10 is a schematic cross-sectional view of structure H-H of the present invention.
FIG. 11 is a schematic cross-sectional view of structure I-I of the present invention.
Detailed Description
The present invention is further illustrated by the following examples, which are not intended to limit the invention to these embodiments. It will be appreciated by those skilled in the art that the present invention encompasses all alternatives, modifications and equivalents as may be included within the scope of the claims.
Referring to fig. 1-11, a low strength concrete core sample gripping device includes a metal reaction steel ring 11 sleeved in an annular groove 9 in the side of a concrete core sample 10 in solid concrete 7; two wedge-shaped steel inserting pieces 6 are symmetrically arranged between the metal counterforce steel ring 11 and the side surface of the concrete core sample 10; the wedge-shaped steel inserting piece 6 is sequentially provided with a lower pressing steel plate 5, a counter-force device 12 and a force application device 1; the reaction device 12 is erected and welded on the metal reaction steel ring 11 and covers the concrete core sample 10, the wedge-shaped steel insert 6, the pressing steel plate 5 and part of the force application device 1. The wedge-shaped steel insert 6 is inserted between the metal reaction steel ring 11 and the side surface of the concrete core sample 10, and then the steel plate 5, the reaction device 12 and the force application device 1 are pressed downwards, so that the wedge-shaped steel insert 6 is clamped and the concrete core sample 10 is taken out.
The annular groove 9 is coaxial with the longitudinal axis of the concrete core sample 10, the bottom surface of the annular groove is the same plane as the bottom surface of the concrete core sample 10, and the top surface of the annular groove is the same plane as the top surface of the concrete core sample 10 and the surface of the solid concrete 7; the diameter of the concrete core sample 10 is 120mm, the height is 150mm, and the outer diameter of the annular groove is 128 mm.
In the embodiment, the metal reaction steel ring 11 is hollow and cylindrical, the top surface of the metal reaction steel ring is coplanar with the top surface of the concrete core sample 10, the diameter of an outer ring is 127.5mm, the diameter of an inner ring is 120.5mm, the height of the inner ring is 70mm, and 2 facing arc-shaped wedge-shaped grooves 8 are symmetrically arranged on the ring wall; the height of the arc wedge-shaped groove 8 is 70mm, the width of the arc wedge-shaped groove is 35mm, the thickness of the top surface groove is 3.5mm, and the thickness of the bottom surface groove is 0.
In this embodiment, the wedge-shaped steel insert 6 is an arc-shaped wedge, the top surface of which is in contact with the lower surface of the lower pressing steel plate 5, the lower portion of which can be extruded between the arc-shaped wedge groove 8 and the concrete core sample 10, the inner wall of which is attached to the outer wall of the concrete core sample 10, and the outer wall of which is attached to the wall of the arc-shaped wedge groove 8, wherein the width of the wedge-shaped steel insert is 32mm, and the.
The lower pressing steel plate 5 in the embodiment is a rectangular body, and has the length of 150mm, the width of 32mm and the thickness of 12 mm.
The reaction device 12 of the present embodiment is a concave main body, and includes a metal reaction beam 3, and two pairs of metal reaction legs 4 symmetrically disposed at two ends of the metal reaction beam 3; the metal reaction cross beam 3 is a rectangular plate, is vertical to the lower pressing steel plate 5 and is parallel to the top surface of the concrete core sample 10, the thickness is 22mm, the width is 32mm, the length is 150mm, the center of the top surface and the center of the bottom surface are drilled with a force application screw hole 2 with the through specification M20, and the bottom surfaces at two ends are vertically welded and connected with the top surfaces of the metal reaction support legs 4; the metal reaction supporting legs 4 are bent rectangular bodies, the bottom surfaces of the metal reaction supporting legs are connected with the top surface of the metal reaction steel ring 11 in a welding mode, the distance between the two parallel rectangles is 32mm, and the two parallel curved surfaces are respectively identical to the outer wall and the inner wall of the metal reaction steel ring 11.
The force application device 1 of the present embodiment is a hexagon head flat-bottomed bolt of specification M20, and can be screwed into the force application screw hole 2 from the top surface of the metal reaction beam 3 to be pressed against the upper surface of the lower pressing steel plate 5.
The application process of the embodiment is as follows: (1) after the concrete core sample 10 is broken, a metal counterforce steel ring 11 is placed in the annular groove 9 to cover the concrete core sample 10, meanwhile, the counterforce device 12 covers the concrete core sample 10, and the bottom surface of the metal counterforce steel ring 11 is 80mm away from the top surface of the concrete core sample 10; (2) inserting the wedge-shaped steel insertion piece 6 into the arc-shaped wedge-shaped groove 8, and placing the pressing steel plate 5 on the top surface of the wedge-shaped steel insertion piece 6; (3) screwing a hexagon head flat-bottom bolt with the specification of M20 into the force application screw hole 2 from the top surface of the metal reaction cross beam 3 until the upper surface of the lower pressing steel plate 5 is tightly pressed; (4) the hexagonal head flat-bottom bolt is uniformly rotated by a wrench, and the wedge-shaped steel insert 6 is extruded downwards by pressing the steel plate 5 downwards, so that the concrete core sample 10 is firmly clamped and taken out.