Push-out specimen and production and experimental method for shear capacity of post-bonded connection

Abstract

The application discloses a post-bonding connection mode anti-shear bearing capacity push-out test piece and a manufacturing and experimental method, and relates to the technical field of bridge engineering, comprising: two push-out test piece bodies, the push-out test piece body comprising a T-shaped steel beam, a first welding nail, a second welding nail, a third welding nail, a fourth welding nail, a shear groove, a prefabricated reinforced concrete slab, a top UHPC cast-in-place section and a bottom UHPC cast-in-place section, the shear groove is arranged on one side of the flange of the T-shaped steel beam away from the web, one side of the shear groove away from the T-shaped steel beam is in a concave-convex key tooth shape, the fourth welding nail is embedded and fixed in the shear groove, the prefabricated reinforced concrete slab is embedded and fixedly connected on one side of the concave-convex key tooth shape of the shear groove, the second welding nail is embedded and fixed in the prefabricated reinforced concrete slab through the shear groove, and the two push-out test piece bodies are detachably fixedly connected at the web of the T-shaped steel beam, so that the results of the push-out test are more in line with actual engineering conditions, and the accuracy of the experimental results is improved.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, and in particular to a method for producing and testing a test specimen for shear bearing capacity of a post-joint connection method. Background Technology

[0002] The push-out test is the primary experimental method for examining the shear performance of steel-concrete composite beam connectors. A standard push-out specimen for studded connectors consists of a short I-beam, studded connectors, and two concrete slabs. The two concrete slabs are connected on both sides of the I-beam by studs. An axial load is applied to the I-beam from top to bottom on a testing machine, causing slippage between the I-beam and the concrete, ultimately resulting in the studs shearing off. By measuring the relative slippage at the steel-concrete interface, the load-slip curve of the studded connector can be obtained through the push-out test, thus revealing its ultimate bearing capacity and shear stiffness, among other mechanical properties.

[0003] Existing standard test methods primarily target conventional connectors. However, post-joint connections used in actual field construction employ shear grooves with interlocking teeth on top of conventional welded stud connectors, resulting in a more complex load transfer path. The concrete interlocking teeth at the interface between the shear groove and the precast concrete slab are also crucial load-bearing components, affecting the shear resistance of multi-row, multi-column welded studs. Existing standard test methods cannot comprehensively describe the shear resistance performance of shear connectors with interlocking teeth in shear grooves. Therefore, a new test method for the shear bearing capacity of post-joint connections is urgently needed to ensure that the test results better reflect actual engineering conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a push-out specimen for shear bearing capacity of post-jointed connection method, as well as a method for its fabrication and testing, to solve the problems existing in the prior art, so that the push-out test results of shear bearing capacity of post-jointed connection method are more consistent with actual engineering conditions and improve the accuracy of the test results.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a push-out specimen for testing the shear bearing capacity of a combined connection method, comprising: two push-out specimen bodies, each body including a T-shaped steel beam, a first weld stud, a second weld stud, a third weld stud, a fourth weld stud, a shear groove, a precast reinforced concrete slab, a top UHPC cast-in-place section, and a bottom UHPC cast-in-place section. The first, second, third, and fourth weld studs are welded and fixed to the flange of the T-shaped steel beam on the side away from the web. The shear groove is located on the flange of the T-shaped steel beam on the side away from the web, and the side of the shear groove away from the T-shaped steel beam has a concave-convex key tooth shape. The fourth weld stud is embedded and fixed to the... The shear groove is described above. The precast reinforced concrete slab is fitted and fixedly connected to one side of the shear groove with a toothed shape. The second weld stud passes through the shear groove and is embedded and fixed to the precast reinforced concrete slab. The top UHPC cast-in-place section is set at the top of the shear groove and the precast reinforced concrete slab, and the first weld stud is embedded and fixed in the top UHPC cast-in-place section. The bottom UHPC cast-in-place section is set at the bottom of the shear groove and the precast reinforced concrete slab, and the third weld stud is embedded and fixed in the bottom UHPC cast-in-place section. The two ejected specimen bodies are detachably fixedly connected at the web of the T-shaped steel beam.

[0007] Preferably, it further includes a clamping device for applying lateral pressure toward the shear groove to the two precast reinforced concrete slabs.

[0008] Preferably, the clamping device includes two transverse frames arranged parallel to each other vertically. Each transverse frame includes two I-beams, two fixing screws, and multiple nuts. The two ends of the I-beams are provided with screw pre-drilled holes. The two I-beams are respectively located on the side of the two precast reinforced concrete slabs away from the shear groove. The two ends of the fixing screws that extend through the screw pre-drilled holes on the same side of the two I-beams are threadedly connected to the nuts. Tightening the nuts ensures that the preload applied by the clamping device to the ejected specimen reaches the design value.

[0009] Preferably, it further includes multiple through-hole pressure sensors and multiple steel pads. The fixing screw passes through the through-hole pressure sensor and fixes it between the nut and the I-beam. A steel pad is provided between the through-hole pressure sensor and the I-beam, and a steel pad is provided between the fixing nut and the through-hole pressure sensor.

[0010] Preferably, the T-shaped steel beam is welded with seven rows and four columns of welding studs, wherein the height direction is a row, wherein the welding studs in the first row are the first welding studs, the welding studs in the fourth row are the second welding studs, the welding studs in the seventh row are the third welding studs, and the welding studs in the second, third, fifth and sixth rows are the fourth welding studs, and the first welding studs, second welding studs and third welding studs are longer than the fourth welding studs.

[0011] Preferably, it also includes two splicing steel plates and multiple bolts. The web of the T-shaped steel beam is provided with multiple first connecting holes, and the splicing steel plate is provided with multiple second connecting holes. The two splicing steel plates are disposed on both sides of the web of the two T-shaped steel beams after they are joined together and are fixed by multiple bolts. One bolt passes through the second connecting holes on the two splicing steel plates and the first connecting holes on the web of the T-shaped steel beam.

[0012] Preferably, the ejected specimen further includes multiple vertical displacement sensors, one end of each vertical displacement sensor being fixed to the T-shaped steel beam and the other end being fixed to the precast reinforced concrete slab.

[0013] The present invention also provides a method for fabricating a test specimen for shear bearing capacity of the combined connection method as described above, comprising the following steps:

[0014] S1: The T-shaped steel beam is manufactured in the factory, and multiple rows of weld studs are welded on the flange of the T-shaped steel beam;

[0015] S2: Fabricate the precast reinforced concrete slab and embed corresponding through holes at the positions corresponding to each of the second weld studs on the precast reinforced concrete slab;

[0016] S3: Fabricating shear grooves: The precast reinforced concrete slab is placed on the T-shaped steel beam, and the fourth welding stud is aligned with the position of each of the through holes. One of the through holes is selected as a grouting hole, and the remaining through holes are used as grout outlet holes. Grout is poured into the grouting hole until the grouting hole and each of the grout outlet holes are filled. Then the opening of each of the through holes is smoothed.

[0017] S4: Construct the top UHPC cast-in-place section and the bottom UHPC cast-in-place section: Cast UHPC on top of the precast reinforced concrete slab and the shear groove to form the top UHPC cast-in-place section, and cast UHPC at the bottom of the precast reinforced concrete slab and the shear groove to form the bottom UHPC cast-in-place section.

[0018] S5: Connect and fix the two ejected specimen bodies;

[0019] Preferably, after step S5, the method further includes a step...

[0020] S6: Install clamping devices on the outer sides of the two precast reinforced concrete slabs that have been connected, the clamping devices being used to apply lateral pressure toward the shear groove to the two precast reinforced concrete slabs.

[0021] The present invention also provides a test method for testing the shear bearing capacity of a combined connection method, comprising the following steps:

[0022] S1: Place the ejection specimen as described above into the bottom tray of the press, install a distribution beam on top of the two T-beams, the distribution beam is in full contact with the top of the T-beams, install a pressure sensor on the upper part of the distribution beam, and the output end of the press is in contact with the pressure sensor.

[0023] S2: The press continuously and steadily applies pressure to the ejected specimen from top to bottom until the ejected specimen is destroyed. During the test, the changes in the overall load-slip curve of the ejected specimen and the failure mode of the ejected specimen are observed.

[0024] The present invention achieves the following technical effects compared to the prior art:

[0025] This invention provides a push-out specimen for shear bearing capacity of a post-jointed connection method, as well as a method for its fabrication and testing. The push-out specimen of this invention includes a welded stud connector and a shear groove. The shear mechanical properties measured by the test method of this push-out specimen can more comprehensively reflect the characteristics of the welded stud connector and the shear groove in the post-jointed connection method, so that the results of the push-out test are consistent with the actual engineering situation.

[0026] Furthermore, by setting up a double-layer transverse frame to apply lateral pressure to the ejected specimen, the normal stress applied to the shear groove interface by the precast concrete bridge deck in the actual bridge was simulated. Increasing the normal stress at the concave-convex key interface can improve its shear bearing capacity and reduce the normal separation from the precast concrete interface, making the ejection test results closer to the shear bearing capacity in the actual structure. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A front view of the ejection specimen for the shear bearing capacity of the post-joint connection method provided by the present invention;

[0029] Figure 2 for Figure 1 The left view;

[0030] Figure 3 for Figure 1 Top view;

[0031] In the diagram: 1. T-shaped steel beam; 3. Shear groove; 4. Precast reinforced concrete slab; 5. Top UHPC cast-in-place section; 6. Bottom UHPC cast-in-place section; 7. I-beam; 8. Fixing bolt; 9. Nut; 10. Through-type pressure sensor; 11. Steel pad; 12. First welding stud; 13. Fourth welding stud; 14. Splicing steel plate; 15. Bolt; 16. Stiffening rib; 17. Second welding stud; 18. Third welding stud. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The purpose of this invention is to provide a push-out specimen for shear bearing capacity of post-joint connection method, as well as a method for its fabrication and testing, to solve the problems existing in the prior art, so that the results of the push-out test are more consistent with actual engineering conditions and improve the accuracy of the test results.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] This embodiment provides a test specimen for testing the shear bearing capacity of a combined connection method, such as... Figures 1-3As shown, the test specimen includes: two ejector bodies, each comprising a T-shaped steel beam 1, a first weld stud 12, a second weld stud 17, a third weld stud 18, a fourth weld stud 13, a shear groove 3, a precast reinforced concrete slab 4, a top UHPC cast-in-place section 5, and a bottom UHPC cast-in-place section 6. The first weld stud 12, second weld stud 17, third weld stud 18, and fourth weld stud 13 are welded and fixed to the flange of the T-shaped steel beam 1 on the side away from the web. The shear groove 3 on the side away from the T-shaped steel beam 1 has a serrated shape. The fourth weld stud 13 is embedded and fixed in the shear groove 3. The precast reinforced concrete slab 4 is fitted and fixed to the serrated side of the shear groove 3. The second weld stud 17 passes through the shear groove 3 and is embedded and fixed to the precast reinforced concrete slab 4. The top UHPC cast-in-place section 6... The casting section 5 is located at the top of the shear groove 3 and the precast reinforced concrete slab 4, and the first weld stud 12 is embedded and fixed in the top UHPC casting section 5. The bottom UHPC casting section 6 is located at the bottom of the shear groove 3 and the precast reinforced concrete slab 4, and the third weld stud 18 is embedded and fixed in the bottom UHPC casting section 6. The two ejection specimen bodies are detachably fixed and connected at the web of the T-shaped steel beam 1 to form a double-axis symmetrical structure. They are symmetrical about the plane where the web of the T-shaped steel beam is located and the contact position of the two webs is perpendicular to the plane of the web. The shear mechanical properties measured by the test method of this ejection specimen can more comprehensively reflect the characteristics of the weld stud connector and the shear groove 3 in the post-joint connection method, so that the results of the ejection test are consistent with the actual engineering situation.

[0037] In a preferred embodiment, the ejection specimen further includes a clamping device for applying lateral pressure to the two ejection specimen bodies to simulate the normal stress applied to the shear groove key interface by the self-weight of the precast concrete bridge deck in an actual structure. Increasing the normal stress at the shear groove key interface can improve its shear bearing capacity and reduce the normal separation from the precast steel-concrete slab interface, making the ejection test results closer to the shear bearing capacity in the actual structure.

[0038] In a preferred embodiment, the clamping device includes two transverse frames arranged parallel to each other vertically. Each transverse frame includes two I-beams 7, two fixing screws 8, and multiple nuts 9. The two ends of the I-beams 7 are provided with screw pre-drilled holes. The two ends of the fixing screws 8 that extend through the screw pre-drilled holes on the same side of the two I-beams 7 are threadedly connected to the nuts 9. Tightening each nut 9 makes the pre-tightening force applied by the clamping device to the ejected specimen reach the design value. By setting up a double-layer transverse frame to apply lateral pressure to the ejected specimen, the normal stress applied to the shear groove 3 interface by the precast concrete bridge deck in the actual bridge is simulated. Increasing the normal stress at the concave-convex keyway interface can improve its shear bearing capacity and reduce the normal separation from the precast concrete interface, making the ejection test results closer to the shear bearing capacity in the actual structure.

[0039] In a preferred embodiment, a through-type pressure sensor 10 is provided at the portion between the nut 9 at one end of each fixing screw 8 and the I-beam 7. A steel pad 11 is provided at each end of the through-type pressure sensor 10. The reading on the through-type pressure sensor 10 can indicate the applied preload and can be clearly applied to the design value. The through-type pressure sensor 10 continuously collects data during the actual loading process.

[0040] In a preferred embodiment, the T-shaped steel beam 1 is welded with seven rows and four columns of weld studs, with each row representing a section along its height. The first row of weld studs consists of the first weld stud 12, the fourth row of weld studs consists of the second weld stud 17, the seventh row of weld studs consists of the third weld stud 18, and the second, third, fifth, and sixth rows of weld studs consist of the fourth weld stud 13. The first weld stud 12, second weld stud 17, and third weld stud 18 are longer than the fourth weld stud 13. The connectors (i.e., weld studs) connecting the concrete slab and the steel beam in the composite beam primarily bear the horizontal shear force between the steel beam and the concrete. The first weld stud 12, the second weld stud 17, the third weld stud 18, and the fourth weld stud 13 can all play the role of transmitting shear force, while the first weld stud 12, the second weld stud 17, and the third weld stud 18 play the main role of transmitting separation force. The shear force in the composite beam is greater than the separation force, so it is sufficient to arrange a large number of fourth weld studs 13 to resist shear and a small number of first weld studs 12, the second weld stud 17, and the third weld stud 18 to resist separation. In this way, the conflict between the position of the first weld stud 12 and the steel reinforcement in the concrete is reduced during construction.

[0041] In a preferred embodiment, the ejected specimen also includes two spliced ​​steel plates 14 and multiple bolts 15. The web of the T-shaped steel beam 1 is provided with multiple first connecting holes, and the spliced ​​steel plate 14 is provided with multiple second connecting holes. The two spliced ​​steel plates 14 are disposed on both sides of the web of the two T-shaped steel beams 1 after being joined together and are fixed by multiple bolts 15. One bolt 15 passes through the second connecting holes on the two spliced ​​steel plates 14 and the first connecting holes on the web of the T-shaped steel beam 1 respectively, resulting in a simple structure.

[0042] In a preferred embodiment, the ejected specimen also includes multiple vertical displacement sensors, one end of each vertical displacement sensor being fixed to the T-shaped steel beam 1 and the other end being fixed to the precast reinforced concrete slab 4. The deformation of the connector is indicated by testing the relative slippage between the two.

[0043] Example 2

[0044] This embodiment also provides a test method for testing the shear bearing capacity of the combined connection method after testing. The test method includes the following steps:

[0045] (1) Two T-shaped steel beams 1 and splicing steel plates 14 are fabricated in the factory, and welding studs are welded on the flanges of the T-shaped steel beams 1, which includes seven rows and four columns of welding studs. The welding studs in the first row are called the first welding studs 12, the welding studs in the fourth row are called the second welding studs 17, the welding studs in the seventh row are called the third welding studs 18, and the welding studs in the remaining rows are called the fourth welding studs 13 with smaller heights.

[0046] (2) Make the first template of the precast reinforced concrete slab 4, and tie and position the reinforcing bars in it. The template that contacts the shear groove 3 is composed of continuous concave and convex key teeth on the top and side surfaces. The concave and convex key teeth are in the shape of a quadrangular pyramid and are arranged sequentially along the height direction of the specimen. The thicker ones are called convex key teeth and the thinner ones are called concave key teeth. The shear groove 3 is composed of three convex key teeth and three concave key teeth arranged at intervals. Grouting holes and grout outlet holes are provided on the middle convex key teeth along the height direction of the specimen. Then, the precast concrete slab is poured. After the concrete has initially hardened, the slab is demolded.

[0047] (3) Affix sealing rubber strips to both sides of the flange of T-beam 1 to prevent grout leakage when pouring shear groove. Apply lubricating oil to the side of the flange of T-beam 1 near shear groove 3 to weaken the bond between the concrete interface of T-beam 1 and shear groove 3. Then, place the precast reinforced concrete slab 4 on T-beam 1. Make sure to align the second welding stud 17 with the grouting hole and the grout outlet hole respectively. Use the second template to close the opening between the precast reinforced concrete slab 4 and T-beam 1. When grouting, pour the grout with good fluidity into the grouting hole. Use a vibrator to fully vibrate the grouting hole and the grout outlet hole. After the grouting hole and the grout outlet hole are filled, manually smooth the hole opening.

[0048] (4) After the grout has hardened, remove the outer second formwork, tie the reinforcing bars of the top and bottom cast-in-place sections respectively, and use UHPC to cast the cast-in-place sections; after the UHPC material has hardened, remove the third formwork to form the top UHPC cast-in-place section 5 and the bottom UHPC cast-in-place section 6, and ensure that the specimens are cured under suitable conditions for at least 28 days until the loading test.

[0049] (5) Before the loading test, the two ejection test specimens are assembled with splicing steel plates 14 and bolts 15. A double-layer transverse frame is used to apply lateral pressure to the ejection test specimens. The pressure is calculated from the normal stress applied to the shear groove key interface by the self-weight of the precast concrete bridge deck in the actual structure. Each layer of transverse frame consists of two I-beams 7. Screw holes are opened on the upper and lower flanges of the beams, and vertical stiffening ribs 16 are set at the mid-span, side support and on both sides of the reserved holes. When the lateral pressure is applied, the I-beams 7 on both sides of the bottom frame are first supported on the ground with the bracket, and then the two fixing screws 8 on the left and right are tightened at the same time until the pre-tightening force reaches the design value. The upper frame is assembled in the same way. The tension of the fixing screw 8 is read by the through-type pressure sensor 10 set at one end of it. A steel pad 11 is set at both ends of the sensor. The through-type pressure sensor continuously collects data during the actual loading process.

[0050] (6) The specimen is a double-axis symmetrical structure. A vertical displacement sensor is arranged at the front, back, left and right symmetrical positions at the height corresponding to the second weld stud 17 in the middle, in order to test the relative slip between the precast reinforced concrete slab 4 and the T-shaped steel beam 1.

[0051] (7) Before the ejected specimen is installed on the press, a layer of fine sand is laid in the bottom tray to ensure that both sides of the ejected specimen are evenly pressurized. After the ejected specimen is installed on the press, a distribution beam and a pressure sensor are set on the top surface of the T-shaped steel beam 1 to make the force transmission from the press to the upper edge of the T-shaped steel beam 1 of the ejected specimen more uniform. The ejected specimen is continuously and stably pressurized from top to bottom until the ejected specimen fails. During the test, the changes in the overall load-slip curve of the ejected specimen and the failure mode of the ejected specimen are observed.

[0052] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A test specimen for testing the shear bearing capacity of a combined connection method, characterized in that: include: Two ejection specimen bodies are provided, each comprising a T-shaped steel beam, a first weld stud, a second weld stud, a third weld stud, a fourth weld stud, a shear groove, a precast reinforced concrete slab, a top UHPC cast-in-place section, and a bottom UHPC cast-in-place section. The first, second, third, and fourth weld studs are welded and fixed to the flange of the T-shaped steel beam on the side away from the web. The shear groove is located on the flange of the T-shaped steel beam on the side away from the web, and the side of the shear groove away from the T-shaped steel beam has a serrated shape. The fourth weld stud is embedded and fixed in the shear groove. The precast reinforced concrete slab... The first weld stud is embedded and fixedly connected to one side of the shear groove with a concave-convex key tooth shape. The second weld stud passes through the shear groove and is embedded and fixed to the precast reinforced concrete slab. The top UHPC cast-in-place section is set at the top of the shear groove and the precast reinforced concrete slab, and the first weld stud is embedded and fixed in the top UHPC cast-in-place section. The bottom UHPC cast-in-place section is set at the bottom of the shear groove and the precast reinforced concrete slab, and the third weld stud is embedded and fixed in the bottom UHPC cast-in-place section. The two ejected specimen bodies are detachably fixedly connected at the web of the T-shaped steel beam.

2. The tested specimen for shear bearing capacity using the combined connection method according to claim 1, characterized in that: It also includes a clamping device for applying lateral pressure toward the shear groove to the two precast reinforced concrete slabs.

3. The ejected specimen with tested shear bearing capacity using the combined connection method according to claim 2, characterized in that: The clamping device includes two transverse frames arranged parallel to each other vertically. Each transverse frame includes two I-beams, two fixing screws, and multiple nuts. The two ends of the I-beams are provided with screw pre-drilled holes. The two I-beams are respectively located on the side of the two precast reinforced concrete slabs away from the shear groove. The two ends of the fixing screws that extend through the screw pre-drilled holes on the same side of the two I-beams are threadedly connected to the nuts. Tightening the nuts makes the preload applied by the clamping device to the ejected specimen reach the design value.

4. The ejected specimen with tested shear bearing capacity using the combined connection method according to claim 3, characterized in that: It also includes multiple through-hole pressure sensors and multiple steel pads. The fixing screw passes through the through-hole pressure sensor and fixes it between the nut and the I-beam. A steel pad is provided between the through-hole pressure sensor and the I-beam, and a steel pad is provided between the nut and the through-hole pressure sensor.

5. The ejected specimen with tested shear bearing capacity using the combined connection method according to claim 1, characterized in that: The T-shaped steel beam is welded with seven rows and four columns of welding studs, with the height direction being a row. The welding studs in the first row are the first welding studs, the welding studs in the fourth row are the second welding studs, the welding studs in the seventh row are the third welding studs, and the welding studs in the second, third, fifth, and sixth rows are the fourth welding studs. The first, second, and third welding studs are longer than the fourth welding stud.

6. The ejected specimen with tested shear bearing capacity using the combined connection method according to claim 1, characterized in that: It also includes two splicing steel plates and multiple bolts. The web of the T-shaped steel beam is provided with multiple first connecting holes, and the splicing steel plate is provided with multiple second connecting holes. The two splicing steel plates are set on both sides of the web of the two T-shaped steel beams after they are joined together and are fixed by multiple bolts. One bolt passes through the second connecting holes on the two splicing steel plates and the first connecting holes on the web of the T-shaped steel beam.

7. The ejected specimen with tested shear bearing capacity using the combined connection method according to claim 1, characterized in that: The ejected specimen also includes multiple vertical displacement sensors, one end of each vertical displacement sensor is fixed to the T-shaped steel beam, and the other end is fixed to the precast reinforced concrete slab.

8. A method for fabricating a test specimen for assessing the shear bearing capacity of a combined connection method as described in any one of claims 1 to 7, characterized in that: Includes the following steps: S1: The T-shaped steel beam is manufactured in the factory, and multiple rows of weld studs are welded on the flange of the T-shaped steel beam; S2: Fabricate the precast reinforced concrete slab and embed corresponding through holes at the positions corresponding to each of the second weld studs on the precast reinforced concrete slab; S3: Fabricating shear grooves: The precast reinforced concrete slab is placed on the T-shaped steel beam, the fourth welding stud is aligned with the position of each through hole, one of the through holes is selected as a grouting hole, and the remaining through holes are used as grout outlet holes. Grout is poured into the grouting hole until the grouting hole and each of the grout outlet holes are filled, and then the opening of each of the through holes is smoothed. S4: Construct the top UHPC cast-in-place section and the bottom UHPC cast-in-place section: Cast UHPC on top of the precast reinforced concrete slab and the shear groove to form the top UHPC cast-in-place section, and cast UHPC at the bottom of the precast reinforced concrete slab and the shear groove to form the bottom UHPC cast-in-place section; S5: Connect and fix the two ejected specimen bodies together.

9. The method for preparing a test specimen for testing the shear bearing capacity of the combined connection method according to claim 8, characterized in that: The step S5 is followed by another step. S6: Install clamping devices on the outside of the two already connected ejection specimens, the clamping devices being used to apply lateral pressure toward the shear groove to the two precast reinforced concrete slabs.

10. A test method for testing the shear bearing capacity of a combined connection method, characterized in that: Includes the following steps: S1: Place the ejection specimen as described in any one of claims 1 to 7 into the bottom tray of the press, install a distribution beam on the top of the two T-shaped steel beams, the distribution beam is in full contact with the top of the T-shaped steel beams, install a pressure sensor on the upper part of the distribution beam, and the output end of the press is in contact with the pressure sensor; S2: The press continuously and steadily applies pressure to the ejected specimen from top to bottom until the ejected specimen is destroyed. During the test, the changes in the overall load-slip curve of the ejected specimen and the failure mode of the ejected specimen are observed.

Images