A test device and method for detecting concrete strength by a combination of diameter and axial shear cleaving

Abstract

The application belongs to the technical field of concrete strength detection, and discloses a test device and method for detecting concrete strength by using a radial-axial shear splitting comprehensive method. The test device for detecting concrete strength by using the radial-axial shear splitting comprehensive method comprises a radial shear splitting assembly, an axial shear splitting assembly, a first mounting seat and a pressure sensor. The radial shear splitting assembly comprises a lower shear head and an upper shear head. The lower shear head can move along a vertical direction to approach the upper shear head to shear a core sample in a radial direction. A lower splitting rod and an upper splitting rod can be symmetrically abutted on the core sample about an axis of the core sample and split the core sample in an axial direction. The first mounting seat can drive the lower shear head and the lower abutting plate to move along the vertical direction. The pressure sensor is used to detect a shearing force when the radial shear splitting assembly shears the core sample and a splitting force when the axial shear splitting assembly splits the core sample. The test device for detecting concrete strength by using the radial-axial shear splitting comprehensive method can reduce the splitting difficulty of the core sample, simplify a detection process and steps, and improve the accuracy of core sample detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete strength detection, and particularly relates to a test device and method for detecting concrete strength by a radial-axial shear and split method. BACKGROUND

[0002] Concrete strength detection is an indispensable technical means in engineering quality control, and the concrete compressive strength is an important technical index in concrete structure and an important basis for design, construction, acceptance and use. At present, a press is usually used to axially split a concrete cylindrical core sample, the obtained sample needs to be cut and processed into a certain length, and then the sample is split on the press, and the axial splitting tensile strength or the compressive strength of the core sample is obtained by conversion through a regression curve formula.

[0003] The existing concrete compressive strength detection device, such as the device for detecting concrete tensile and compressive strength by an in-situ shear and split method provided in the invention patent with the application number CN 201510564665.X, directly detects the compressive strength of concrete by setting replaceable first and second clamping jaws to perform in-situ shear or split operation on the concrete core sample along the radial direction and measuring the actual pressure of the clamping jaw assembly through a calibration sensor. However, the device for detecting concrete tensile and compressive strength by the in-situ shear and split method has the following problems:

[0004] 1. The end surface of the core sample after being sheared by the shear head is an irregular section, which affects the splitting strength of the core sample, thereby causing the compressive strength detection result to be inaccurate.

[0005] 2. The biting teeth on the clamping jaw assembly are arranged along the circumference of the clamping jaw, which increases the difficulty of axial splitting and makes it difficult to split the core sample.

[0006] 3. The single method mainly detects the position affected by the coarse and fine aggregates, and the proportion of the coarse and fine aggregates accounts for more than 80% of the concrete. Due to the influence of the aggregate particle size, the detection data is discrete, and the detection precision is affected.

[0007] 4. When performing in-situ detection, the force moment of the lever principle needs to be provided with a driving force by a guide rod, but the angle between the guide rod and the moment arm is different, the force effect is also different, and the power function relationship between the in-situ shear and split tensile strength and the concrete compressive strength is presented, rather than a linear relationship, that is, the shear and split strength is not the actual shear and split strength of the concrete, and the actual shear and split strength is twice the method. SUMMARY

[0008] The present application aims to provide a test device and method for detecting concrete strength by a radial-axial shear and split method, which can simplify the detection process and steps and improve the accuracy of the detection result.

[0009] To achieve the above object, the present application adopts the following technical solutions:

[0010] The test device for detecting the strength of concrete by the radial-axial shear and split method comprises:

[0011] The radial shear and split assembly comprises a lower shear head and an upper shear head arranged on both sides of the core sample in the height direction, the shear surface of the upper shear head and the shear surface of the lower shear head are located on the same plane, and the lower shear head can move vertically towards the upper shear head to radially shear the core sample;

[0012] The axial shear and split assembly comprises a lower pressing plate and an upper pressing plate arranged on both sides of the core sample in the height direction, a lower split rod is arranged on the lower pressing plate in the axial direction of the core sample, an upper split rod is arranged on the upper pressing plate in the axial direction of the core sample, and the lower pressing plate can drive the lower split rod to move vertically towards the upper pressing plate, so that the lower split rod and the upper split rod can symmetrically abut on the core sample about the axis of the core sample and axially split the core sample;

[0013] The first mounting seat is arranged on the lower shear head and the lower pressing plate, the first mounting seat can drive the lower shear head and the lower pressing plate to move vertically, a first compression spring is arranged between the lower pressing plate and the first mounting seat, the lower pressing plate elastically abuts on the core sample under the elastic force of the first compression spring when the radial shear and split assembly shears the core sample, and the first compression spring is compressed to the limit state when the axial shear and split assembly splits the core sample, so that the lower pressing plate rigidly abuts on the core sample;

[0014] The pressure sensor is used to detect the shearing force when the radial shear and split assembly shears the core sample and the splitting force when the axial shear and split assembly splits the core sample.

[0015] Preferably, two groups of the radial shear and split assembly are arranged in the axial direction of the core sample, and the axial shear and split assembly is arranged between the two groups of the radial shear and split assembly, and the distance between the two groups of the radial shear and split assembly is less than the length of the core sample.

[0016] Preferably, the test device for detecting the strength of concrete by the radial-axial shear and split method further comprises a jacking device, the jacking device is connected with the first mounting seat, and the jacking device can drive the first mounting seat to move vertically.

[0017] Preferably, the test device for detecting the strength of concrete by the radial-axial shear and split method further comprises a second mounting seat and an upper moving beam, the upper shear head and the upper pressing plate are arranged on the second mounting seat, the second mounting seat is rotationally arranged on the upper moving beam, and the rotation axis of the second mounting seat is perpendicular to the axial direction of the core sample.

[0018] Preferably, a vertical limiting slot is formed on the first mounting base, a guide protruding column is arranged on the second mounting base, the width of the vertical limiting slot is greater than the outer diameter of the guide protruding column, and the guide protruding column can move up and down in the vertical limiting slot.

[0019] Preferably, the axial shear wedge assembly further comprises an anti-rolling piece arranged on the lower pressing plate, and the anti-rolling piece abuts against the core sample.

[0020] Preferably, the anti-rolling piece comprises two positioning wing plates symmetrically arranged with respect to the lower shear wedge, the two positioning wing plates abut against the core sample from both sides, and the distance between the two positioning wing plates gradually increases in the vertical direction upwards.

[0021] Preferably, the anti-rolling piece further comprises a torsional spring, the positioning wing plates are rotationally arranged on the lower pressing plate, the torsional spring is arranged between the positioning wing plates and the lower pressing plate, and the positioning wing plates elastically abut against the core sample under the elastic force of the torsional spring.

[0022] Preferably, the test device for detecting the strength of concrete by the radial-axial shear wedge comprehensive method further comprises a vertical guide column, and the first mounting base is slidingly arranged on the vertical guide column.

[0023] The method for detecting the strength of concrete by the radial-axial shear wedge comprehensive method uses the test device for detecting the strength of concrete by the radial-axial shear wedge comprehensive method, and comprises the following steps:

[0024] S1, placing the core sample on the lower shear head, driving the lower shear head to move upwards in the vertical direction by the first mounting base, making the upper shear head and the lower shear head radially shear the core sample and recording the peak shear force;

[0025] S2, continuing to move the first mounting base upwards in the vertical direction until the first compression spring is compressed to the limit state, making the lower shear wedge and the upper shear wedge axially shear the core sample and recording the peak shear force;

[0026] S3, converting the peak shear force and the peak shear force into the compressive strength of the core sample.

[0027] The method has the following beneficial effects:

[0028] The test device for detecting the strength of concrete by the radial-axial shear and split comprehensive method comprises a first mounting seat, a lower shear head, an upper shear head, a lower pressing plate, an upper pressing plate, a radial shear and split assembly and an axial shear and split assembly.

[0029] The method for detecting the strength of concrete by the radial-axial shear and split comprehensive method comprises the following steps: first, the radial shear and split assembly is used to shear the core sample in the radial direction; second, the axial shear and split assembly is used to split the core sample in the axial direction; third, the peak shear force and the peak split force are obtained; and fourth, the compressive strength of the core sample is obtained by conversion. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural schematic view of the test device for detecting the strength of concrete by the radial-axial shear and split comprehensive method provided in the specific embodiment of the present application;

[0031] Figure 2 is an exploded view of the radial shear and split assembly and the axial shear and split assembly provided in the specific embodiment of the present application;

[0032] Figure 3 is a side view of the axial shear and split assembly provided in the specific embodiment of the present application.

[0033] In the drawings:

[0034] 1-radial shear and split assembly; 11-lower shear head; 12-upper shear head;

[0035] 2-axial shear wedge assembly; 21-lower pressing plate; 22-upper pressing plate; 23-lower wedge rod; 24-upper wedge rod; 25-positioning wing plate;

[0036] 3-first mounting seat; 31-first compression spring; 32-vertical limiting slot;

[0037] 4-jacking device;

[0038] 5-pressure sensor; 51-display;

[0039] 6-second mounting seat; 61-second compression spring; 62-guiding convex column;

[0040] 7-upper moving cross beam; 71-mounting frame;

[0041] 8-vertical guide column;

[0042] 9-core sample;

[0043] 10-fixing plate;

[0044] 101-lower moving cross beam;

[0045] 102-base. DETAILED DESCRIPTION

[0046] The present application will be further described below in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described herein are intended to be illustrative only and are not intended to limit the scope of the present application. In addition, it should be noted that, for the purpose of clarity, only those structures related to the present application are shown in the drawings and not all structures.

[0047] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0049] In the description of the present embodiment, the terms "upper", "lower", "right", "left", and the like orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in description and have no special meaning.

[0050] As shown in Figure 1 The present application provides a test device for detecting the strength of concrete by a radial-axial shear combined method, which comprises a radial shear assembly 1, an axial shear assembly 2, a first mounting seat 3, and a pressure sensor 5. The radial shear assembly 1 comprises a lower shear head 11 and an upper shear head 12 arranged on both sides of a core sample 9 in the height direction. The shear surface of the upper shear head 12 and the shear surface of the lower shear head 11 are located on the same plane. The lower shear head 11 can approach the upper shear head 12 in the vertical direction to radially shear the core sample 9. In the present embodiment, the core sample 9 is a cylindrical concrete specimen. The core sample 9 is horizontally placed between the upper shear head 12 and the lower shear head 11, and the upper shear head 12 and the lower shear head 11 are respectively placed on the upper and lower sides of the core sample 9. Since the shear surface of the upper shear head 12 and the shear surface of the lower shear head 11 are located on the same plane, when the lower shear head 11 approaches the upper shear head 12 in the vertical direction to shear the core sample 9, it can make the core sample 9 produce a neat shear surface, without affecting the splitting strength of the core sample 9, thereby ensuring the accuracy of the compression strength detection of the core sample 9. Specifically, the upper shear head 12 and the lower shear head 11 are both arc-shaped, which can better fit the core sample 9, thereby facilitating the shearing of the core sample 9.

[0051] As shown in Figure 2 and Figure 3As shown, the axial shear splitting assembly 2 comprises a lower pressing plate 21 and an upper pressing plate 22 arranged on both sides of the core sample 9 in the height direction, the lower pressing plate 21 is provided with a lower splitting rod 23 in the axial direction of the core sample 9, the upper pressing plate 22 is provided with an upper splitting rod 24 in the axial direction of the core sample 9, and the lower pressing plate 21 can drive the lower splitting rod 23 to approach the upper pressing plate 22 in the vertical direction, so that the lower splitting rod 23 and the upper splitting rod 24 can be symmetrically abutted on the core sample 9 about the axis of the core sample 9 and axially split the core sample 9; in this embodiment, since the lower pressing plate 21 is provided with the lower splitting rod 23 in the axial direction of the core sample 9 and the upper pressing plate 22 is provided with the symmetric upper splitting rod 24, when the lower pressing plate 21 drives the lower splitting rod 23 to approach the upper splitting rod 24 in the vertical direction to axially split the core sample 9, the lower splitting rod 23 and the upper splitting rod 24 can concentrate the splitting load on the side surface of the core sample 9, so that the core sample 9 is more easily split, the splitting difficulty of the core sample 9 is reduced, and the splitting force is conveniently collected; specifically, the diameters of the lower splitting rod 24 and the upper splitting rod 24 are much smaller than the diameter of the core sample 9, the lower pressing plate 21 is provided with a semicircular long groove in the axial direction of the core sample 9, the lower splitting rod 23 is embedded in the semicircular long groove, the upper part of the semicircular long groove, from which the lower splitting rod 23 protrudes, can abut against the core sample 9, and the upper splitting rod 24 is also arranged in the upper pressing plate 22 in the same way; when the lower splitting rod 23 and the upper splitting rod 24 are worn, the tester can take them out of the semicircular long groove and replace them.

[0052] As Figure 1 and Figure 2As shown, the lower shearing head 11 and the lower pressing plate 21 are arranged on the first mounting seat 3, and the first mounting seat 3 can drive the lower shearing head 11 and the lower pressing plate 21 to move vertically; a first compression spring 31 is arranged between the lower pressing plate 21 and the first mounting seat 3, and the lower pressing plate 21 elastically presses on the core sample 9 under the elastic force of the first compression spring 31 when the radial shearing assembly 1 shears the core sample 9; when the axial shearing assembly 2 splits the core sample 9, the first compression spring 31 is compressed to the limit state, and the lower pressing plate 21 rigidly presses on the core sample 9; the pressure sensor 5 is used to detect the shearing force when the radial shearing assembly 1 shears the core sample 9 and the splitting force when the axial shearing assembly 2 splits the core sample 9. In this embodiment, since the lower shearing head 11 and the lower pressing plate 21 are arranged on the first mounting seat 3, the first mounting seat 3 can simultaneously drive the lower shearing head 11 and the lower pressing plate 21 to ascend vertically to detect the core sample 9, thereby simplifying the structure; since the first compression spring 31 is arranged between the lower pressing plate 21 and the first mounting seat 3, the lower pressing plate 21 can elastically press on the core sample 9 when the radial shearing assembly 1 shears the core sample 9, thereby avoiding affecting the shearing of the core sample 9; meanwhile, since the lower pressing plate 21 can always press on the upper core sample 9, the stability of the position of the core sample 9 in the shearing process is ensured; when the axial shearing assembly 2 splits the core sample 9, the lower pressing plate 21 can rigidly press on the core sample 9, and cooperates with the upper pressing plate 22 to complete the normal splitting of the core sample 9, thereby realizing the detection process of shearing the same core sample 9 in the radial direction first and then in the axial direction, simplifying the detection process and operation steps; since the test device for detecting the strength of concrete by the radial and axial shearing and splitting comprehensive method comprises the pressure sensor 5, the monitoring personnel can accurately obtain the shearing force and the splitting force in the detection process. Specifically, the lower pressing plate 21, the lower shearing head 11 and the first mounting seat 3 are all made of steel, the lower pressing plate 21 and the lower shearing head 11 are fixed on the first mounting seat 3 by bolts, the head of the bolt connecting the lower pressing plate 21 and the first mounting seat 3 does not press on the lower pressing plate 21, that is, the lower pressing plate 21 has a certain space for movement in the vertical direction, the first compression spring 31 is arranged between the lower pressing plate 21 and the first mounting seat 3, the first compression spring 31 is sleeved on the bolt, and the two ends of the first compression spring 31 abut against the lower pressing plate 21 and the first mounting seat 3, so that the lower pressing plate 21 can elastically displace under the pressure in the vertical downward direction; the pressure sensor 5 is specifically a spoke type pressure sensor, the spoke type pressure sensor has a short cylindrical appearance, adopts a spoke type elastic body structure, is a force sensor made by using a shearing type stress principle, has good natural linearity, has strong anti-unbalanced load capacity, high precision, low height and convenient and stable installation, and is widely applied in the field of detection of the strength of concrete. In addition, the pressure sensor 5 is externally connected with a display 51, can display the detected force value and automatically record the value, and is convenient for the detection personnel to record data.The test device for detecting the strength of concrete by the radial and axial shear and split method detects the core sample 9 with a length less than 100 mm, and has small damage to the overall structure. Different specifications of the radial shear assembly 1 and the axial shear assembly 2 can meet the radial and axial shear operation of the core sample with a diameter of 38 mm to 55 mm. One operation can collect two parameters, i.e., the shear force of the radial shear along the core sample 9 and the shear force of the axial split along the core sample 9. The radial shear strength represented by coarse and fine aggregates and the axial tensile strength represented by cementitious materials can be detected simultaneously.

[0053] Further, as shown in Figure 1 and Figure 2 , the radial shear assembly 1 is provided with two groups in the axial direction of the core sample 9, and the axial shear assembly 2 is arranged between the two groups of radial shear assemblies 1. The distance between the two groups of radial shear assemblies 1 is less than the length of the core sample 9. Specifically, the core sample 9 is horizontally placed on the radial shear assembly 1, and the length of the core sample 9 is greater than the distance between the two groups of radial shear assemblies 1, so that the two ends of the core sample 9 are exposed outside the radial shear assembly 1, thereby facilitating the shearing of the radial shear assembly 1. The two groups of radial shear assemblies 1 improve the stability during shearing, and compared with single shearing, the two shearing can improve the accuracy of the detection result and reduce the instability of the single shearing value. In addition, when the core sample 9 is sheared, the two ends sheared off naturally fall off, and the remaining part of the core sample 9 is on the axial shear assembly 2 between the two groups of radial shear assemblies 1, which facilitates the split operation, simplifies the detection process, and improves the detection efficiency.

[0054] Further, as shown in Figure 1 , the test device for detecting the strength of concrete by the radial and axial shear and split method further comprises a jacking device 4, and the jacking device 4 is connected with the first mounting seat 3. The jacking device 4 can drive the first mounting seat 3 to move vertically. Specifically, the jacking device 4 can be a jack or an air cylinder, as long as it can apply an upward force, which is not limited here.

[0055] Further, as shown in Figure 1 and Figure 2As shown, the test device for detecting the strength of concrete by the radial-axial shear combined method further comprises a second mounting seat 6 and an upper movement beam 7, the upper shear head 12 and the upper pressing plate 22 are arranged on the second mounting seat 6, the second mounting seat 6 is rotationally arranged on the upper movement beam 7, and the rotation axis of the second mounting seat 6 is perpendicular to the axial direction of the core sample 9. Specifically, the upper movement beam 7 is provided with a mounting bracket 71, the mounting bracket 71 is fixed on the bottom of the upper movement beam 7 by bolts, the two sides of the mounting bracket 71 are provided with lugs, through holes are formed in the lugs, and the second mounting seat 6 is arranged on the lugs of the mounting bracket 71 through a pin shaft, wherein the pin shaft is arranged perpendicular to the axial direction of the core sample 9, so that the second mounting seat 6 can rotate around the pin shaft, thereby adjusting the shear angle according to the appearance of the core sample 9 during shearing of the core sample 9, and the two radial shear assembly groups 1 can fully contact with the core sample 9, avoiding that the two radial shear assembly groups 1 cannot simultaneously shear the core sample 9 due to irregular shape of the core sample 9. In addition, the same as the first mounting seat 3, the second mounting seat 6 and the upper pressing plate 22 are provided with a second compression spring 61, the second compression spring 61 cooperates with the first compression spring 31 to elastically press the upper pressing plate 22 and the lower pressing plate 21 on the core sample 9, further improving the stability of the core sample 9 during the detection process.

[0056] Specifically, as shown in Figure 1 and Figure 2 , the first mounting seat 3 is provided with a vertical limiting groove 32, the second mounting seat 6 is provided with a guide protruding column 62, the width of the vertical limiting groove 32 is greater than the outer diameter of the guide protruding column 62, and the guide protruding column 62 can move up and down in the vertical limiting groove 32. In this embodiment, the two sides of the first mounting seat 3 are provided with vertical limiting grooves 32, and the two sides of the second mounting seat 6 are provided with guide protruding columns 62. When the jacking device 4 drives the first mounting seat 3 to move upward and close to the second mounting seat 6, the guide protruding column 62 can move in the vertical limiting groove 32. Due to the guide protruding column 62 and the vertical limiting groove 32, the horizontal displacement of the second mounting seat 6 is limited, so the angle of the second mounting seat 6 rotating around the pin shaft on the mounting bracket 71 is also limited, thereby ensuring that the second mounting seat 6 rotates and adjusts within a certain angle, avoiding that the second mounting seat 6 is damaged due to too large rotation angle, and the upper shear head 12 and the upper pressing plate 22 are damaged.

[0057] Further, as shown in Figure 2 , the axial shear assembly group 2 further comprises an anti-rolling piece arranged on the lower pressing plate 21, and the anti-rolling piece abuts against the core sample 9. In this embodiment, the anti-rolling piece abuts against the core sample 9, can limit the core sample 9, and prevent the core sample 9 from rolling or even falling out of the test device for detecting the strength of concrete by the radial-axial shear combined method during the upward movement of the jacking device 4 driving the first mounting seat 3.

[0058] Specifically, as shown in Figure 3As shown, the anti-rolling piece includes two positioning wing plates 25 symmetrically arranged relative to the lower splitting rod 23, the two positioning wing plates 25 abut against the core sample 9 from both sides, and the distance between the two positioning wing plates 25 gradually increases vertically upward. In this embodiment, the two positioning wing plates 25 are arranged in a V shape on the lower pressing plate 21, and the lower splitting rod 23 is located on the center line of the connecting line of the lowermost ends of the two positioning wing plates 25, so that the positioning wing plates 25 can always make the core sample 9 abut against the lower splitting rod 23; the upper pressing plate 22 is also provided with two positioning wing plates 25 which are the same as those of the lower pressing plate 21, and the two positioning wing plates 25 on the upper pressing plate 22 gradually decrease vertically upward, forming an inverted V-shaped structure; the two groups of positioning wing plates 25 ensure that the lower splitting rod 23 and the upper splitting rod 24 can symmetrically abut against the core sample 9 about the axis of the core sample 9 and axially split the core sample 9, so as to accurately split the core sample 9.

[0059] Specifically, the anti-rolling piece further includes a torsion spring, the positioning wing plate 25 is rotationally arranged on the lower pressing plate 21, and the torsion spring is arranged between the positioning wing plate 25 and the lower pressing plate 21, and the positioning wing plate 25 elastically abuts against the core sample 9 under the elastic force of the torsion spring. In this embodiment, the positioning wing plate 25 can rotate on the lower pressing plate 21, so that the angle between the two positioning wing plates 25 changes, thereby being able to adapt to core samples 9 of different diameters; and the torsion spring is arranged between the positioning wing plate 25 and the lower pressing plate 21, so that the positioning wing plate 25 can always abut against the core sample 9 under the elastic force of the torsion spring, thereby ensuring the stability of the core sample 9 during detection.

[0060] Further, as shown in the drawings, Figure 1 The test device for detecting the strength of concrete by the radial-axial shear splitting combined method further includes vertical guide columns 8, and the first mounting seat 3 is slidingly arranged on the vertical guide columns 8. Specifically, there are two vertical guide columns 8, and the two ends of the first mounting seat 3 are respectively sleeved on the two vertical guide columns 8, so as to stably slide up and down along the vertical guide columns 8, and the second mounting seat 6 is arranged on the vertical guide column 8 above the first mounting seat 3, so that the radial shear splitting assembly 1 can smoothly complete the shearing of the core sample 9 when the first mounting seat 3 rises along the vertical guide column 8, and the axial shear splitting assembly 2 can smoothly complete the splitting of the core sample 9, thereby ensuring the stability and accuracy of the moving direction of the first mounting seat 3 during the rising process.

[0061] Further, as shown in the drawings, Figure 1As shown, the test device for detecting the strength of concrete by the radial-axial shear-splitting comprehensive method further comprises a fixed plate 10 fixedly installed at the top of the vertical guide column 8, a lower moving cross beam 101 slidingly arranged on the vertical guide column 8, and a base 102, the jacking device 4 is fixed on the base 102, the bottom end of the vertical guide column 8 is also fixed on the base 102, the first mounting seat 3 is bolted on the lower moving cross beam 101, the lower moving cross beam 101 can drive the first mounting seat 3 to move up and down along the vertical guide column 8, the pressure sensor 5 is arranged on the fixed plate 10 above the upper moving cross beam 7, the upper moving cross beam 7 can move up and down along the vertical guide column 8 by a certain distance and cannot move downward with the lower moving cross beam 101 to the bottom of the vertical guide column 8, thereby facilitating the detection personnel to place the core sample 9; the upper moving cross beam 7 can be pressed upward on the pressure sensor 5; after the detection starts, the jacking device 4 drives the lower moving cross beam 101 to drive the first mounting seat 3 to move upward, when the core sample 9 on the first mounting seat 3 contacts the upper shear head 12 and the upper pressing plate 22, the second mounting seat 6 drives the upper moving cross beam 7 to move upward and press on the pressure sensor 5 under the action of the thrust, since the pressure sensor 5 is installed on the fixed plate 10, the shear force and the splitting force are all transmitted to the pressure sensor 5 and collected by it.

[0062] Further, two protective plates are installed on the upper moving cross beam 7, the two protective plates respectively extend downward from both sides of the upper moving cross beam 7 to the height position of the first mounting seat 3 during the shear operation (for the convenience of showing the internal structure, the protective plates are not drawn in the figure), the core sample 9 is shielded by the protective plates, the protective plates can block the debris falling out during the shear and splitting process, thereby improving the safety of the test device for detecting the strength of concrete by the radial-axial shear-splitting comprehensive method.

[0063] The embodiment also provides a method for detecting the strength of concrete by the radial-axial shear-splitting comprehensive method, using the test device for detecting the strength of concrete by the radial-axial shear-splitting comprehensive method, comprising the following steps:

[0064] S1, place the core sample 9 on the lower shear head 11, drive the lower shear head 11 to move upward along the vertical direction by the first mounting seat 3, make the upper shear head 12 and the lower shear head 11 radially shear the core sample 9 and record the peak shear force; specifically, the detection personnel horizontally places the core sample 9 on the lower shear head 11, and starts the jacking device 4 to drive the first mounting seat 3 to move upward along the vertical guide column 8; when the core sample 9 contacts the upper shear head 12, the jacking device 4 continues to drive the first mounting seat 3 to rise, the upper pressing plate 22 and the lower pressing plate 21 are elastically pressed on the core sample 9 under the elastic force of the second compression spring 61 and the first compression spring 31 respectively; the radial shear-splitting assembly 1 shears the core sample 9 until the both ends of the core sample 9 are sheared off; in this process, the pressure sensor 5 continuously monitors the shear force and records the peak shear force.

[0065] S2, continue to move the first mounting seat 3 vertically upward until the first compression spring 31 is compressed to the limit state, and then the lower splitting rod 23 and the upper splitting rod 24 axially split the core sample 9 and record the peak splitting force; specifically, the jacking device 4 is continuously turned on, and when the core sample 9 is sheared, the upper pressing plate 22 and the lower pressing plate 21 continuously bear pressure, and the second compression spring 61 and the first compression spring 31 are continuously compressed until they are compressed to the limit state; at this time, the lower splitting rod 23 and the upper splitting rod 24 are in rigid contact with the core sample 9 and exert a splitting force until the core sample 9 is split; in this process, the pressure sensor 5 continuously monitors the shearing force and records the peak splitting force.

[0066] S3, convert the peak shearing force and the peak splitting force into the compressive strength of the core sample 9; specifically, the detection personnel record the peak shearing force through the pressure sensor 5 and can calculate the radial shearing strength f rs as follows:

[0067]

[0068] In the formula:

[0069] f rs radial shearing strength, MPa;

[0070] F RS peak shearing force, N;

[0071] A RS radial shearing area, m 2 .

[0072] Then the detection personnel record the peak splitting force through the pressure sensor 5 and take the following mathematical model as the basis for fitting the curve:

[0073]

[0074] In the formula:

[0075] f as axial splitting strength, MPa;

[0076] F AS peak splitting force, N;

[0077] A AS radial splitting area, m 2 .

[0078] The radial shearing strength f rs and the axial splitting strength f as are obtained, and the detection personnel can obtain the compressive strength of the core sample 9 through a linear equation as follows:

[0079]

[0080] In the formula:

[0081] Concrete compressive strength, MPa

[0082] α, β - curve constant term.

[0083] By putting the detected peak shear force F RS and peak splitting force F AS into the above formula, the compressive strength of the core sample 9 can be obtained. Compared with the method of calculating the compressive strength of concrete only by using the axial splitting strength, the detection result is more accurate.

[0084] In another embodiment, after obtaining the radial shear strength f rs and the axial splitting strength f as , the detection personnel can also perform algebraic sum on the radial shear strength f rs and the axial splitting strength f as , and use the algebraic sum as the independent variable to convert the compressive strength of concrete, as shown in the following formula:

[0085]

[0086] In another embodiment, after obtaining the radial shear strength f rs and the axial splitting strength f as , the detection personnel can also respectively substitute the radial shear strength f rs and the axial splitting strength f as into a binary linear equation or a binary power function equation, and each participate in strength conversion, and each represent different weight proportions to affect the conversion strength, as shown in the following formula:

[0087]

[0088]

[0089] In the formula:

[0090] γ - curve constant term.

[0091] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manner of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present application. Here, it is not necessary and impossible to enumerate all the implementation manners. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A test apparatus for detecting concrete strength using a combined radial and axial shear-splitting method, characterized in that, include: The radial shearing assembly (1) includes a lower shear head (11) and an upper shear head (12) disposed on both sides of the core sample (9) along the height direction. The shearing surface of the upper shear head (12) and the shearing surface of the lower shear head (11) are located on the same plane. The lower shear head (11) can radially shear the core sample (9) by approaching the upper shear head (12) vertically. The axial shearing assembly (2) includes a lower pressure plate (21) and an upper pressure plate (22) disposed on both sides of the core sample (9) along the height direction. A lower splitting rod (23) is disposed on the lower pressure plate (21) along the axial direction of the core sample (9), and an upper splitting rod (24) is disposed on the upper pressure plate (22) along the axial direction of the core sample (9). The lower pressure plate (21) can drive the lower splitting rod (23) to move vertically closer to the upper pressure plate (22), so that the lower splitting rod (23) and the upper splitting rod (24) can symmetrically abut against the core sample (9) about the axis of the core sample (9) and axially split the core sample (9). The first mounting base (3) is provided with the lower shear head (11) and the lower pressure plate (21) both mounted on the first mounting base (3). The first mounting base (3) can drive the lower shear head (11) and the lower pressure plate (21) to move vertically. A first compression spring (31) is provided between the lower pressure plate (21) and the first mounting base (3). When the radial shearing assembly (1) shears the core sample (9), the lower pressure plate (21) elastically presses against the core sample (9) under the elastic force of the first compression spring (31). When the axial shearing assembly (2) splits the core sample (9), the first compression spring (31) is compressed to the limit state, and the lower pressure plate (21) rigidly presses against the core sample (9). A pressure sensor (5) is used to detect the shearing force when the radial shearing assembly (1) shears the core sample (9) and the splitting force when the axial shearing assembly (2) splits the core sample (9).

2. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 1, characterized in that, Two sets of radial shearing components (1) are arranged along the axial direction of the core sample (9), and two sets of axial shearing components (2) are arranged between the two sets of radial shearing components (1). The distance between the two sets of radial shearing components (1) is less than the length of the core sample (9).

3. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 1, characterized in that, The test device for testing concrete strength using the combined radial and axial shear splitting method also includes a lifting device (4), which is connected to the first mounting base (3). The lifting device (4) can drive the first mounting base (3) to move vertically.

4. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 1, characterized in that, The test device for testing concrete strength by the combined radial and axial shear splitting method also includes a second mounting base (6) and an upper moving crossbeam (7). The upper shear head (12) and the upper pressure plate (22) are both mounted on the second mounting base (6). The second mounting base (6) is rotatably mounted on the upper moving crossbeam (7). The rotation axis of the second mounting base (6) is perpendicular to the axial direction of the core sample (9).

5. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 4, characterized in that, The first mounting base (3) has a vertical limiting groove (32), and the second mounting base (6) has a guide protrusion (62). The width of the vertical limiting groove (32) is greater than the outer diameter of the guide protrusion (62), and the guide protrusion (62) can move up and down in the vertical limiting groove (32).

6. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 1, characterized in that, The axial shearing assembly (2) also includes an anti-roll member disposed on the lower pressure plate (21), the anti-roll member abutting against the core sample (9).

7. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 6, characterized in that, The anti-roll member includes two positioning wing plates (25) symmetrically arranged about the lower splitting rod (23). The two positioning wing plates (25) abut against the core sample (9) from both sides, and the distance between the two positioning wing plates (25) gradually increases vertically upward.

8. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to claim 7, characterized in that, The anti-roll component also includes a torsion spring. The positioning wing plate (25) is rotatably mounted on the lower pressure plate (21). The torsion spring is located between the positioning wing plate (25) and the lower pressure plate (21). The positioning wing plate (25) elastically presses against the core sample (9) under the elastic force of the torsion spring.

9. The test apparatus for testing concrete strength using the combined radial and axial shear-splitting method according to any one of claims 1-8, characterized in that, The test device for detecting concrete strength by the radial and axial shear splitting combined method also includes a vertical guide column (8), and the first mounting base (3) is slidably disposed on the vertical guide column (8).

10. A method for testing concrete strength using a combined radial and axial shear splitting method, characterized in that, The test apparatus for testing concrete strength using the radial and axial shear-splitting combined method as described in any one of claims 1-9 includes the following steps: S1. Place the core sample (9) on the lower shear head (11), and drive the lower shear head (11) to move vertically upward through the first mounting base (3), so that the upper shear head (12) and the lower shear head (11) radially shear the core sample (9) and record the peak shear force; S2. Continue to move the first mounting base (3) vertically upward until the first compression spring (31) is compressed to its limit. Then, make the lower splitting rod (23) and the upper splitting rod (24) axially split the core sample (9) and record the peak splitting force. S3. Convert the peak shear force and the peak splitting force into the compressive strength of the core sample (9).

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