A system and method for detecting the degree of crack repair of a cracked concrete test piece

Abstract

The application discloses a kind of detection system and method of the degree of crack repair of cracking concrete test piece crack, the detection system includes frame system, crack resistance to penetration ability test system, array type ultrasonic wave and resistivity test system, water collection and drainage system, electric control system, water collection and drainage system are installed in the bottom of frame system for supporting the test piece and collecting test piece effluent, electric control system is used to control crack resistance to penetration ability test system, array type ultrasonic wave and resistivity test system and monitor, process the data measured by test system.This application sets crack resistance to penetration ability test system, array type ultrasonic wave and resistivity test system, based on the water resistance of crack repair test piece, the ultrasonic wave propagation speed inside test piece, the resistivity size of test piece crack two sides, make multidimensional, all-around comprehensive evaluation to crack closure effect, simple operation, high integration, and improve the accuracy of repair test result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete repair detection, and particularly relates to a detection system and method for crack repair degree of cracked concrete test piece. BACKGROUND

[0002] Cracks are the most common disease of concrete, and the main form of damage to concrete material is also cracks of various types affecting the basic performance. However, cracks are inevitably generated in the service process of concrete due to drying shrinkage, temperature stress and external load. For some non-structural cracks, the method of post-repair can effectively restore the basic performance and prolong the service durability of the building structure. In recent years, the repair technology of concrete cracks has been highly concerned by many scholars and technical personnel in the field of civil engineering. At present, the repair of non-structural cracks in concrete mainly adopts artificial repair, and the effect of crack sealing is achieved by pouring or filling repair materials into the concrete cracks. Several commonly used grouting materials include epoxy resin grout, polyurethane grout and acrylic rubber, but the viscosity and curing degree of each material are different, and the repair effect of concrete cracks also has obvious differences. On the other hand, there are also self-repairing technologies for concrete cracks by using mineral expansion crystallization and microbial mineralization, which can complete the sealing of concrete cracks without manual repair operation.

[0003] For different service environments of concrete members, the most suitable crack repair method is selected, which can not only increase the service durability of the building, but also save costs. However, the evaluation method and test means of the repair effect of concrete cracks by different technologies and different repair materials are still immature, so it is difficult to select the appropriate crack repair method. At the same time, there are few integrated, high-precision and comprehensive test equipment for the repair degree of cracked concrete test pieces. In general, there is an urgent need for a test system and method that can accurately test the repair effect of cracked concrete cracks. SUMMARY

[0004] The present application provides a detection system and method for crack repair degree of cracked concrete test piece.

[0005] Technical scheme: In order to solve the above problems, the present application adopts a detection system for crack repair degree of cracked concrete test piece, which comprises a frame system, a crack impermeability test system, an array type ultrasonic wave and resistivity test system, a water collection and drainage system and an electric control system. The water collection and drainage system is installed at the bottom of the frame system for supporting the test piece and collecting water from the test piece. The electric control system is used to control the crack impermeability test system and the array type ultrasonic wave and resistivity test system, and monitor and process the data measured by the crack impermeability test system and the array type ultrasonic wave and resistivity test system.

[0006] The crack impermeability test system comprises a lifting device, a cylinder, the lifting device is installed on a frame system, the cylinder is detachably installed on the lifting device, a booster piston and a water level pressure test sensor are arranged inside the cylinder, the water pressure in the cylinder is regulated by adjusting the position of the booster piston; a water inlet is arranged on the upper part of the cylinder, a water outlet is arranged at the bottom of the cylinder, and the opening and closing of the water outlet are controlled by an electric control system.

[0007] The array type ultrasonic wave and resistivity test system comprises two test panels arranged in parallel, the test panels are movably installed on a frame system, ultrasonic wave test point probes and voltage emission probes are arranged on the opposite two surfaces of the test panels.

[0008] Further, the frame system comprises a support stand, a slot for installing the lifting device is arranged on the upper part of the support stand, and an opening for installing the array type ultrasonic wave and resistivity test system is arranged on the lower part of the support stand.

[0009] Further, the lifting device comprises a lifting suspension plate, a lifting adjustment knob installed on the support stand, and pulleys installed on both ends of the lifting suspension plate, the lifting adjustment knob is connected with the pulleys through a steel strand, and the pulleys are controlled to slide up and down in the slot by rotating the lifting adjustment knob.

[0010] Further, a mounting hole matched with the cross section of the cylinder is formed in the middle of the lifting suspension plate, an internal thread is arranged in the mounting hole, an external thread is arranged on the outside of the cylinder, and the detachable installation of the cylinder is realized through thread cooperation.

[0011] Further, the array type ultrasonic wave and resistivity test system further comprises a sliding rod and a moving support member sleeved and installed on the sliding rod, round holes are formed on both sides of the test panel, the sliding rod is installed in the holes, and the sliding rod passes through the round holes on the test panel; the moving support member abuts against both sides of the test panel to support the test panel, and rollers are arranged on the inner side of the moving support member to drive the test panel to move along the sliding rod, and the rollers are controlled by an electric control system.

[0012] Further, the moving support member is made of rubber.

[0013] Further, the water collecting and draining system comprises a net-shaped test piece supporting box, a water carrying box and an asbestos net, the top of the net-shaped test piece supporting box is a hollow grid with an open side, the water carrying box is installed in the net-shaped test piece supporting box in a drawer type, and the asbestos net is laid on the top of the net-shaped test piece supporting box.

[0014] Further, four columns of 1x2 arranged ultrasonic wave test point probes and one column of 1x2 arranged voltage emission probes are arranged on the test panel, and the four columns of ultrasonic wave test point probes are arranged on both sides of the voltage emission probe in a group.

[0015] Further, the electric control system comprises transmission wires and an electric control screen, the transmission wires are used for the connection and data transmission of the crack impermeability test system, the arrayed ultrasonic and resistivity test system and the electric control system, and the electric control screen is used for controlling the test system and monitoring and processing data.

[0016] The application further provides a detection method of the detection system, comprising the following steps:

[0017] Step 1, placing the test piece on the water collecting and draining system and making the test piece located between two test panels;

[0018] Step 2, closing the water outlet and adding water into the cylinder, then installing the cylinder on the lifting device, and adjusting the lifting device to make the bottom of the cylinder abut against the upper end surface of the test piece;

[0019] Step 3, controlling the two test panels to move and abut against the two side surfaces of the test piece;

[0020] Step 4, setting the water pressure in the cylinder, the ultrasonic emission frequency and the potential difference of the two test panels through the electric control system;

[0021] Step 5, opening the open-close type water outlet to start the test, observing the changes of key index parameters on the electric control screen, the parameters including the water flow permeability coefficient, the ultrasonic velocity and the resistivity, and analyzing the crack repair effect of the test piece according to the parameters;

[0022] Step 6, closing the water outlet, adjusting the ultrasonic emission frequency and the potential difference of the two test panels to 0, controlling the test panels to move to the two sides, taking down the cylinder, and ending the test.

[0023] Advantages: compared with the prior art, the application has the following advantages: the crack impermeability test system and the arrayed ultrasonic and resistivity test system are arranged, the resistance of the repaired material to the applied water pressure is tested by water flow impact, the arrayed ultrasonic and resistivity are used to evaluate the deep and internal repair effect of the crack, the crack sealing effect is comprehensively evaluated in multiple dimensions and in all aspects based on the impermeability of the test piece after crack repair, the ultrasonic propagation speed in the test piece and the resistivity of the two sides of the crack of the test piece, the operation is simple, the integration degree is high, and the accuracy of the repair test result is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a whole structure schematic view of the crack repair degree detection system of the cracked concrete test piece.

[0025] Figure 2 It is a structure schematic view of the crack impermeability test system.

[0026] Figure 3 It is an arrayed ultrasonic and resistivity test system

[0027] Figure 4 This is a schematic diagram of the test panel structure of the present invention;

[0028] Figure 5 This is a schematic diagram of the water collection and drainage system of the present invention;

[0029] Figure 6 This is a schematic diagram of the test status of the test system of the present invention. Detailed Implementation

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment of a cracked concrete specimen crack repair degree detection system includes a frame system, a crack impermeability testing system, an array-type ultrasonic and resistivity testing system, a water collection and drainage system, and an electrical control system. The frame system includes support frames 1 located on both sides. The upper part of the support frame 1 is provided with a slot 11 for installing a lifting device, and the lower part of the support frame 1 is provided with an opening 12 for installing the array-type ultrasonic and resistivity testing system.

[0032] The crack impermeability testing system includes a lifting device and a cylinder 2. Inside the cylinder 2 is a pressure booster piston 22 and a water level and pressure sensor 23. The water pressure inside the cylinder is regulated by adjusting the position of the pressure booster piston 22, and the water level and pressure sensor 23 monitors the water pressure and level inside the cylinder. A water inlet 28 is located at the top of the cylinder 2, and a water outlet 21 is located at the bottom of the cylinder 2. The opening and closing of the water outlet 21 is controlled by an electronic control system. The lifting device includes a lifting suspension plate 25, a lifting adjustment knob 26 mounted on a support frame 1, and pulleys 27 mounted at both ends of the lifting suspension plate 25. The lifting adjustment knob 26 and the pulleys 27 are connected by a steel strand 29. Rotating the lifting adjustment knob 26 controls the pulleys 27 to slide up and down within the slot 11. The lifting suspension plate 25 has a mounting hole in the middle that matches the cross-section of the cylinder 2. The mounting hole has an internal thread 24, and the outer side of the cylinder 2 has an external thread, allowing for the detachable installation of the cylinder 2 through threaded engagement. The crack permeability testing system utilizes Darcy's law (water flow permeability coefficient = water mass (m³)). 3 / s)×Specimen height (m) / Specimen cross-sectional area (m²) 2 The permeability coefficient (flow velocity) of the crack is calculated in real time using the head difference (m) and the result is displayed on the electronic control screen.

[0033] The array ultrasonic and resistivity testing system comprises two testing panels 3 arranged in parallel, a slide rod 33, and a moving support 34 sleeved and mounted on the slide rod 33. The testing panels 3 are provided with circular holes on both sides, the slide rod 33 is mounted in the holes 12 at both ends, and the slide rod 33 penetrates through the circular holes on the testing panels 3. The moving support 34 abuts against both sides of the testing panels 3 to support the testing panels 3. The moving support 34 is made of rubber material to increase the friction between the moving support 34 and the testing panels 3 and improve the stability during support. The inside of the moving support 34 is provided with rollers to drive the testing panels 3 to move along the slide rod 33. The rollers are controlled by an electric control system. The ultrasonic point probes 31 and the voltage emission probes 32 are arranged on the opposite two sides of the testing panels 3 to test the ultrasonic propagation speed inside the test piece and the resistivity of the test piece. Four columns of 1x2 arranged ultrasonic point probes 31 and one column of 1x2 arranged voltage emission probes 32 are arranged on each testing panel 3. The four columns of ultrasonic point probes 31 are arranged in two groups on both sides of the voltage emission probes 32. The ultrasonic point probes 31 are used to realize the emission and reception of ultrasonic signals, and the precise test of the crack repair condition inside the test piece is realized through the multi-point and array arrangement. The voltage emission probes 32 are used to form a potential difference on both sides of the concrete test piece 6 to test the resistivity of different parts of the test piece. During testing, the positions of test pieces of different sizes are different, but it is necessary to ensure that they are in close connection with the ultrasonic point probes (at least one pair of left and right panels) and the voltage emission probes (at least one of left and right panels).

[0034] The water collecting and draining system comprises a mesh test piece supporting box 41, a water carrying box 42, and an asbestos mesh 43. The mesh test piece supporting box 41 is hollow and open on the side with a hollow grid-shaped top. The water carrying box 42 is installed in the mesh test piece supporting box 41 in a drawer type. The asbestos mesh 43 is laid on the top of the mesh test piece supporting box 41. The asbestos mesh 43 has good water flow permeation effect and insulation. The water flowing through the cracks quickly permeates through the mesh test piece supporting box 41 and flows into the inner water carrying box 42 to realize the collection and carrying of the water flow.

[0035] The electric control system comprises transmission wires 51 and an electric control screen 52. The transmission wires 51 are used for the connection and data transmission of the crack impermeability testing system, the array ultrasonic and resistivity testing system, and the electric control system. The electric control screen 52 is used to control the booster piston 22, the water outlet 21, the rollers, the ultrasonic point probes 31, and the voltage emission probes 32 to adjust the water pressure in the crack impermeability testing system, the ultrasonic emission frequency in the array ultrasonic and resistivity testing system, and the potential difference between the two panels 3. The electric control screen 52 is also used to display the permeation coefficient of the water flow through the cracks, the ultrasonic propagation speed on both sides of the cracks, and the resistivity of the test piece in real time. When setting the position of the booster piston, the ultrasonic emission frequency, and the potential difference between the two panels, it is necessary to observe whether the data displayed on the electric control screen is stable. If it is not stable, the parameters or the position of the test piece need to be adjusted again.

[0036] Example Two

[0037] The present embodiment provides a detection method for a detection system for detecting the crack repair degree of the above-mentioned cracked concrete test piece, comprising the following steps:

[0038] Step 1, place the test piece for repairing cracks by filling epoxy resin on the mesh test piece support box 41, the test piece has a 1mm wide through crack before crack repair, and the test piece has a size of 100mm x 100mm x 400mm, so that the test piece is located between the two test panels 3, and the side of the test piece with a size of 100mm x 400mm faces the panels.

[0039] Step 2, close the water outlet 21 and add water to the cylinder 2 to 1 / 3 of the volume of the cylinder, after adding water, install the cylinder 2 on the lifting device, adjust the lifting device so that the bottom of the cylinder 2 abuts and tightly contacts the upper end surface of the test piece.

[0040] Step 3, control the two test panels 3 to move and abut the test piece on both sides, so that the ultrasonic wave measurement point probe 31 and the voltage emission probe 32 tightly contact the side of the test piece.

[0041] Step 4, adjust the water pressure in the cylinder 2 to 1MPa, the ultrasonic wave emission frequency to 2MHz, and the potential difference of the two panels to 500V through the electric control screen 52.

[0042] Step 5, open the open-close type water outlet 21 to start the test, and observe that the water flow permeability coefficient on the electric control screen is stable at 3.1 x 10 -4 m / s, the ultrasonic wave speed is maintained at about 1.9km / s, and the resistivity fluctuates in a very small range of about 300Ω·cm, indicating that the crack is filled with epoxy resin, the crack has a strong resistance to water flow, and basically no leakage occurs. Compared with the concrete with a through crack (ultrasonic wave speed less than 0.2km / s), the ultrasonic wave speed is significantly improved, indicating that the deep crack is also effectively filled; the resistivity is greatly improved compared with the resistivity of the uncracked concrete (about 100Ω·cm), which is due to the fact that the epoxy resin is a good insulating material, which also proves that the compatibility of the epoxy resin with the concrete matrix is not strong, and there is a difference in material properties. Overall, the crack repair effect is significant.

[0043] Step 6, close the water outlet 21, adjust the ultrasonic wave emission frequency and the potential difference of the two test panels 3 to 0, control the test panels 3 to move to both sides, take out the water carrying box, find that there is basically no permeable water flow, rotate and disassemble the threads to remove the cylinder, pour out the excess water source, and clean the mesh test piece support box, and end the test.

[0044] Example Three

[0045] The embodiment provides a detection method of the detection system for the crack repair degree of the above-mentioned cracked concrete test piece, and the method comprises the following steps:

[0046] Step 1, place the test piece with cracks repaired by the microbial self-repairing method on the mesh test piece supporting box 41, the test piece has a 1mm-wide through crack before crack repair, the test piece has a size of 100mm*100mm*400mm, the test piece is located between the two test panels 3, and the side of the test piece with a size of 100mm*400mm faces the panels.

[0047] Step 2, close the water outlet 21, and add water to the cylinder 2 until the water reaches 2 / 3 of the volume of the cylinder, then install the cylinder 2 on the lifting device after the water is added, and adjust the lifting device so that the bottom of the cylinder 2 abuts against and tightly contacts the upper end surface of the test piece.

[0048] Step 3, control the two test panels 3 to move and abut against the two side surfaces of the test piece, so that the ultrasonic wave measuring point probe 31 and the voltage emission probe 32 tightly contact the side surfaces of the test piece.

[0049] Step 4, adjust the water pressure in the cylinder 2 to 0.5MPa, the ultrasonic wave emission frequency to 1MHz, and the potential difference of the two side panels to 500V through the electric control screen 52.

[0050] Step 5, open the open-close type water outlet 21 to start the test, and it is observed that the water flow permeability coefficient on the electric control screen is stabilized at 8.2*10 -4 m / s, the ultrasonic wave speed is maintained at about 1.7km / s, and the resistivity fluctuates in a very small range of about 90Ω*cm, which indicates that the cracks are filled by the microbial mineralization, the resistance of the cracks to water flow is obviously improved, and basically no leakage occurs. Compared with the concrete with through cracks (the ultrasonic wave speed is less than 0.2km / s), the ultrasonic wave speed is obviously improved, which indicates that the deep cracks are also effectively filled; the resistivity is slightly lower than that of the uncracked concrete (about 100Ω*cm), which is because the microbial mineralization material mainly comprises calcium carbonate, which proves that the compatibility of the mineralization product and the concrete matrix is good, and the material properties are not much different. Overall, the cracks are effectively filled, and the leakage is obviously improved.

[0051] Step 6, close the water outlet 21, adjust the ultrasonic wave emission frequency and the potential difference of the two test panels 3 to 0, control the test panels 3 to move to the two sides, take out the water carrying box, find that there is basically no permeable water flow in the water carrying box, rotate and disassemble the threads to take down the cylinder, pour out the excess water in the cylinder, clean the mesh test piece supporting box, and end the test.

[0052] The application sets the crack impermeability test system, the array type ultrasonic wave and the resistivity test system, tests the resistance of the water flow impact test repair material to the applied water pressure, evaluates the deep layer and internal repair effect of the crack by the array type ultrasonic wave and the resistivity, makes the multi-dimensional and all-around comprehensive evaluation on the crack sealing effect based on the impermeability of the test piece after the crack repair, the ultrasonic wave propagation speed in the test piece and the resistivity of the two sides of the test piece crack, is simple to operate, has high integration, and improves the accuracy of the repair test result.

Claims

1. A system for detecting the degree of crack repair in cracked concrete specimens, characterized in that, It includes a frame system, a crack impermeability testing system, an array-type ultrasonic and resistivity testing system, a water collection and drainage system, and an electrical control system. The water collection and drainage system is installed at the bottom of the frame system to support the test specimen and collect the water discharged from the specimen. The electrical control system is used to control the crack impermeability testing system and the array-type ultrasonic and resistivity testing system and to monitor and process the data measured by the crack impermeability testing system and the array-type ultrasonic and resistivity testing system. The crack impermeability testing system includes a lifting device and a cylinder (2). The lifting device is installed on the frame system, and the cylinder (2) is detachably installed on the lifting device. The cylinder (2) is equipped with a booster piston (22) and a water level pressure test sensor (23) inside. The water pressure inside the cylinder is regulated by adjusting the position of the booster piston (22). The upper part of the cylinder (2) is equipped with a water inlet (28), and the bottom of the cylinder (2) is equipped with a water outlet (21). The opening and closing of the water outlet (21) is controlled by an electronic control system. The array-type ultrasonic and resistivity testing system includes two parallel test panels (3), which are movably mounted on the frame system. Ultrasonic measuring probes (31) and voltage emission probes (32) are provided on the two opposite sides of the test panels (3).

2. The detection system as described in claim 1, characterized in that, The frame system includes a support frame (1), the upper part of which is provided with a slot (11) for installing a lifting device, and the lower part of which is provided with an opening (12) for installing an array-type ultrasonic and resistivity testing system.

3. The detection system as described in claim 2, characterized in that, The lifting device includes a lifting suspension plate (25), a lifting adjustment knob (26) installed on the support frame (1), and pulleys (27) installed at both ends of the lifting suspension plate (25). The lifting adjustment knob (26) and the pulleys (27) are connected by steel strands (29). The pulleys (27) can be controlled to slide up and down in the slot (11) by rotating the lifting adjustment knob (26).

4. The detection system as described in claim 3, characterized in that, The lifting suspension plate (25) has an installation hole in the middle that matches the cross-section of the cylinder (2). The installation hole is provided with an internal thread (24), and the cylinder (2) is provided with an external thread on the outside. The cylinder (2) can be detachably installed through the threaded engagement.

5. The detection system as described in claim 2, characterized in that, The array-type ultrasonic and resistivity testing system also includes a slide bar (33) and a movable support (34) sleeved and installed on the slide bar (33). The test panel (3) has round holes on both sides. The two ends of the slide bar (33) are installed in the openings (12) and the slide bar (33) passes through the round holes on the test panel (3). The movable support (34) abuts against both sides of the test panel (3) to support the test panel (3). The movable support (34) has rollers on its inner side to drive the test panel (3) to move along the slide bar (33). The rollers are controlled by an electronic control system.

6. The detection system as described in claim 5, characterized in that, The movable support (34) is made of rubber.

7. The detection system as described in claim 1, characterized in that, The water collection and drainage system includes a mesh specimen support box (41), a water-carrying box (42), and an asbestos mesh (43). The top of the mesh specimen support box (41) is a hollow mesh, the inside is hollow and the sides are open. The water-carrying box (42) is installed in the mesh specimen support box (41) in a drawer-like manner. The asbestos mesh (43) is laid on the top of the mesh specimen support box (41).

8. The detection system as described in claim 1, characterized in that, The test panel (3) is provided with four columns of 1×2 ultrasonic measuring point probes (31) and one column of 1×2 voltage emission probes (32). The four columns of ultrasonic measuring point probes (31) are arranged in pairs on both sides of the voltage emission probes (32).

9. The detection system as described in claim 1, characterized in that, The electrical control system includes a transmission line (51) and an electrical control screen (52). The transmission line (51) is used for connecting and transmitting data between the crack impermeability testing system, the array ultrasonic and resistivity testing system and the electrical control system. The electrical control screen (52) is used for controlling the testing system and monitoring and processing data.

10. A detection method for the detection system according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Place the specimen (6) on the water collection and drainage system and position the specimen (6) between the two test panels (3); Step 2: Close the outlet (21) and add water into the cylinder (2). After adding water, install the cylinder (2) on the lifting device and adjust the lifting device so that the bottom of the cylinder (2) is in contact with the upper surface of the specimen (6). Step 3: Control the two test panels (3) to move and make them contact the two sides of the specimen (6); Step 4: Set the internal water pressure, ultrasonic emission frequency, and potential difference between the two side panels of the cylinder (2) through the electronic control system; Step 5: Open the openable water outlet (21) to start the test and observe the changes in key indicator parameters on the electronic control screen. The parameters include water flow permeability coefficient, ultrasonic velocity, and resistivity. Analyze the crack repair effect of the specimen based on the parameters. Step 6: Close the outlet (21), adjust the ultrasonic emission frequency and potential difference of the two test panels (3) to 0, control the test panels (3) to move to both sides, remove the cylinder (2), and end the test.

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