Bracket welding temperature control and construction method of concrete filled steel tubular column
By using temperature measurement and welding thermal simulation technology in the construction of the beef leg welding of the steel pipe concrete column, monitor and control the welding temperature in real time, solve the problem of too high temperature during welding, which causes the concrete strength to decrease or burst. Construction.
Patent Information
- Application Number
- CN202411708713.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-01-24
AI Technical Summary
When welding and repairing the steel pipe concrete columns, the heat transfer temperature is too high, resulting in a dangerous problem of the concrete strength drop or burst.
The temperature measurement pen and welded thermal simulation technology are adopted, and the temperature measurement holes are set up during the construction of beef leg welding to monitor the combined temperature of the steel pipe and the concrete surface in real time. The control temperature does not exceed 300 degrees Celsius to avoid the cracking of the concrete.
It effectively avoids the risk of strength reduction or bursting of concrete due to high temperatures, ensures the safety of the building, and achieves rapid repair and efficient construction.
Smart Images
Figure CN119347184A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of building structures, in particular to a corbel welding temperature control of a steel tube concrete column and a construction method thereof. Background Art
[0002] Due to its structural characteristics, the steel tube concrete column has the properties of both steel tube and concrete. The outside of the column is wrapped with steel tube material, and the inside of the column is filled with concrete material. The rigid restraint formed by the steel tube wall on the concrete inside the tube prevents brittle failure of the concrete inside the tube.
[0003] During on-site construction of steel tube concrete columns, maintenance operations such as cutting, carbon arc gouging and welding are involved. The strength of existing ordinary concrete will be significantly reduced at temperatures above 300 degrees Celsius, and it will burst at 400 degrees Celsius. Therefore, the repair temperature of the interface between the steel tube and concrete must be controlled at 300 degrees Celsius or below. The average temperature of the molten pool of low-alloy steel gas shielded welding is about 1700 degrees Celsius, and the heat-affected zone is generally above 700 degrees Celsius. However, the width of the heat-affected zone of gas shielded welding is about 2 to 3 mm, and the temperature gradient varies greatly. It can be seen that it is crucial to control the temperature of the interface between the steel tube and concrete during welding repair. Because there is concrete inside the steel tube concrete column, the temperature of the repaired corbel weld must be controlled to avoid concrete cracking. Temperature control becomes a key link, so a new technical solution is needed to solve it. Summary of the invention
[0004] In view of the deficiencies in the prior art, the present invention provides a welding temperature control and construction method for the corbel of a steel tube concrete column. With the help of a temperature measuring pen, the temperature has the advantages of high measurement accuracy and easy observation. The construction temperature of the steel tube concrete joint surface can be measured during welding. At the same time, welding thermal simulation is used to establish isotherms on the outer surface for easy observation at any time. The temperature is measured mainly by the inner wall temperature measuring line of the temperature measuring hole and supplemented by the outer color isotherm temperature measuring line, thereby combining temperature measurement with control. The problem of excessively high heat transfer temperature leading to a decrease in concrete strength or bursting when welding and repairing corbels and steel pipes of steel tube concrete columns is solved. This method has the advantages of not changing the concrete strength, rapid repair, and efficient construction.
[0005] To achieve the above object, the present invention provides the following technical solutions: a corbel welding temperature control and construction method of a steel tube concrete column, comprising: a concrete layer, a steel tube, and a corbel;
[0006] A concrete layer is provided inside the steel pipe, and a corbel is provided outside the steel pipe, wherein the corbel includes a box-type corbel and an H-type corbel, and a plurality of temperature measuring holes are provided on the periphery of the connection between the corbel and the steel pipe, wherein the temperature measuring holes are distributed near the connection between the corbel and the steel pipe, wherein the connection includes a weld, wherein the temperature measuring hole is 10-30 mm away from the weld, wherein the diameter of the temperature measuring hole is a circular hole of 10-30 mm, and the depth of the temperature measuring hole (5) exceeds the thickness of the steel pipe (2).
[0007] The steps of the welding seam construction temperature control construction method are as follows:
[0008] Step 1, using welding thermal simulation technology to determine the welding line energy and the back temperature and front temperature of the heat affected zone of the welded steel pipe and their relationship, setting the temperature measuring hole, during the construction process of the bracket weld, including carbon arc gouging and welding processes, the temperature of the steel pipe will rise sharply during this process, which will indirectly cause the temperature of the concrete layer to rise, and the interface temperature must be controlled not to exceed 300 degrees Celsius;
[0009] Step 2, the temperature at the weld during the welding process is the highest, a temperature measuring hole is set in the heat affected zone at a distance of 10-30mm from the edge of the weld groove, and a temperature monitoring color line is set at the temperature measuring hole, and the temperature of the interface between the steel pipe and the concrete caused by the bracket welding is converted to no more than 200 degrees Celsius at the temperature measuring hole, and the outer and inner layers of the steel pipe of the temperature measuring hole are drawn with a temperature measuring pen with a temperature of 200 degrees Celsius;
[0010] Step 3. When the monitored temperature at the temperature measuring hole exceeds 200 degrees Celsius during construction, stop construction immediately and use a fan or air compressor to cool the weld, the temperature measuring hole and the heat affected zone. If the weld is not suitable for air cooling, use natural cooling. When the temperature drops to the normal temperature on site, continue the carbon arc gouging and welding construction steps. When measuring temperature, the temperature measuring color line on the inner wall of the temperature measuring hole is used as the main measure, and the outer color isothermal temperature measuring line is used as the auxiliary measure, which realizes the combination of temperature measurement and control. Welding at this temperature can effectively prevent the concrete from being damaged.
[0011] Furthermore, during the welding process, small line energy welding and intermittent welding are required. If the temperature exceeds the limit, the welding must be stopped and cooled before welding again, so as to combine temperature measurement and control.
[0012] Furthermore, the depth of the temperature measuring hole exceeds the thickness of the steel pipe, and at least the concrete layer can be seen in the temperature measuring hole.
[0013] Further, the concrete layer at the temperature measuring hole is provided with a color line representing temperature control;
[0014] Furthermore, the color line can also be used on the inner wall of the temperature measuring hole. When the temperature reaches or exceeds 200 degrees Celsius, the color line will automatically disappear.
[0015] Compared with the prior art, the technical solution of this application has the following beneficial effects:
[0016] 1. The repair temperature of the contact surface between the back of the steel tube and the concrete must be controlled for the corbel weld of the steel tube concrete column. The strength of ordinary concrete will be significantly reduced at a high temperature above 300 degrees Celsius, and it will burst at 400 degrees Celsius. Its heat-resistant temperature must be controlled below 300 degrees Celsius. Therefore, the repair temperature of the interface between the steel tube and concrete must be controlled at 300 degrees Celsius or below. This solution can ensure that during the construction of the corbel weld, the surface temperature of the concrete at the construction site is controlled below 300 degrees Celsius, which will not cause the concrete strength to decrease and ensure the safety of the building;
[0017] 2. This temperature measurement method is simple and easy to operate. Multiple temperature measuring holes are set on the heat affected zone at the connection between the corbel and the steel pipe. The distance between the temperature measuring hole and the weld at the connection is maintained at 10-30mm. The distance is set according to the ambient temperature and the thickness of the steel pipe. In order to accurately measure and ensure the temperature of the back concrete at the steel pipe weld, the line energy and the back temperature and front temperature of the heat affected zone of the welded steel pipe are determined in advance based on the welding thermal simulation technology. Considering the large temperature gradient in the heat affected zone, a gentle area must be selected and combined with convenient measurement, the temperature measurement conversion point is determined by welding thermal simulation to achieve mutual verification of internal and external temperatures: the inner wall of the temperature measuring hole and the outer layer temperature of the steel pipe are 200 degrees Celsius, and the equivalent conversion of the back concrete at the steel pipe weld is 300 degrees Celsius as the benchmark, that is, when the temperature of the temperature measuring hole is 200 degrees Celsius, the back concrete at the steel pipe weld is 300 degrees Celsius. Therefore, when the temperature of the temperature measuring hole is 200 degrees Celsius, the construction must be stopped immediately and cooled, which can well control the construction temperature and ensure safety.
[0018] 3. The temperature measuring hole is a round hole with a diameter of 10-30mm, which does not affect the rigidity of the steel pipe and is convenient for temperature observation. A 200-degree Celsius temperature color line is drawn on the inner wall of the hole and the outer layer of the steel pipe, or a temperature gun or temperature sensor is used to monitor the temperature. It is easy to operate, efficient and practical. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the structure of the present invention;
[0020] Figure 2 It is a schematic diagram of the temperature measuring hole structure of the present invention.
[0021] In the figure: 1. Concrete layer; 2. Steel pipe; 3. Box-type corbel; 4. H-type corbel; 5. Temperature measuring hole. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] See also Figure 1-2 In this embodiment, a temperature control method for the construction of a steel tube concrete column corbel weld includes a concrete layer 1, a steel tube 2, and a corbel.
[0024] A concrete layer 1 is provided inside the steel pipe 2, and a corbel is provided outside the steel pipe 2, and the corbel includes a box-type corbel 3 and an H-type corbel 4. A plurality of temperature measuring holes 5 are provided on the periphery of the connection between the corbel and the steel pipe 2, and the temperature measuring holes 5 are distributed near the connection between the corbel and the steel pipe 2. The connection includes a weld, and the temperature measuring hole 5 is 10-30 mm away from the weld. The temperature measuring hole 5 is a circular hole with a diameter of 10-30 mm, and the depth of the temperature measuring hole 5 exceeds the thickness of the steel pipe 2.
[0025] The steps of the welding seam construction temperature control method are as follows:
[0026] Step 1, using welding thermal simulation technology to determine the welding line energy and the back temperature and front temperature of the heat-affected zone of the welded steel pipe 2 and their relationship, setting the temperature measuring hole 5, during the construction process of the bracket weld, including carbon arc gouging and welding processes, the temperature of the steel pipe 2 will rise sharply during this process, which will indirectly cause the temperature of the concrete layer 1 to rise, and the interface temperature must be controlled not to exceed 300 degrees Celsius;
[0027] Step 2, the temperature at the weld during the welding process is the highest, a temperature measuring hole 5 is set in the heat affected zone at a distance of 10-30mm from the edge of the weld groove, and a temperature color line is drawn on the outer layer of the steel pipe 2 and the inner wall of the hole at the temperature measuring hole 5 with a temperature measuring pen with a temperature of 200 degrees Celsius, and the temperature of the interface between the steel pipe and the concrete caused by the bracket welding is converted to no more than 200 degrees Celsius at the temperature measuring hole;
[0028] Step 3: When the monitored temperature at the temperature measuring hole 5 exceeds 200 degrees Celsius during construction, stop construction immediately and use a fan or air compressor to cool the weld, the temperature measuring hole 5 and the heat affected zone. If the weld is not suitable for air cooling, use natural cooling. Wait until the temperature drops to the normal temperature on site before continuing the carbon arc gouging and welding construction steps.
[0029] In this scheme, the temperature of the concrete on the back of the weld of the steel pipe 2 is obtained by measuring the internal temperature of the temperature measuring hole 5 and the temperature of the steel pipe 2 outside the temperature measuring hole 5, which can effectively monitor the temperature of the concrete layer 1 and has the characteristics of simple operation, high efficiency and practicality.
[0030] In this embodiment, when welding the connection, the welding current does not exceed 300 amps, the welding voltage is about 30 volts, the flat welding speed is about 350 mm / minute, and the vertical welding speed is about 70 mm / minute (remove:, this can ensure that the temperature during welding does not affect the strength of the concrete).
[0031] In this embodiment, the distance between the temperature measuring hole 5 and the weld is preferably 20 mm, and the diameter of the temperature measuring hole 5 is preferably a round hole of 20 mm, which can accurately detect the surface temperature of the concrete.
[0032] In this embodiment, the depth of the temperature measuring hole 5 exceeds the thickness of the steel pipe 2, and at least the concrete layer 1 can be seen. The temperature monitoring device can also draw two temperature color lines on the outer and inner layers of the steel pipe 2 at the temperature measuring hole 5 with a marker with a temperature of 200 degrees Celsius. When the temperature reaches or exceeds 200 degrees Celsius, the temperature color line will automatically disappear. This solution can accurately observe temperature changes and ensure the safety of the concrete layer.
[0033] The working principle of the above embodiment is:
[0034] Firstly, during the construction process of the connection between the corbel 4 and the steel pipe 2, including cutting, carbon arc gouging and welding processes, the temperature of the steel pipe 2 will rise sharply, which will indirectly cause the temperature of the concrete layer 1 to rise, requiring temperature control.
[0035] Secondly, the temperature at the weld is the highest during the welding process, and a temperature measuring hole 5 is set 10-30 mm away from the edge of the weld groove. A temperature monitoring device is set at the temperature measuring hole 5, and the temperature is set to 200 degrees Celsius, preferably 20 mm away from the edge of the weld groove.
[0036] Finally, when the monitored temperature exceeds 200 degrees Celsius during construction, construction is stopped immediately, and fans or air compressors are used to cool the welds and the 5 temperature measuring holes and the surrounding areas. For welds that are not suitable for air cooling, natural cooling is adopted. When the temperature drops to the normal temperature on site, the cutting, carbon arc gouging and welding construction steps are continued. During the welding process, small line energy welding and intermittent welding are required. If the temperature exceeds the limit, it is necessary to stop and wait for air to dry before welding again. Temperature measurement and control are combined to achieve the purpose of welding without damaging the concrete.
[0037] The specific implementation of this plan also includes the following:
[0038] 1. Use welding thermal simulation technology to determine the line energy and the back and front temperatures of the heat-affected zone of the welded steel pipe 2. Considering the large temperature gradient in the heat-affected zone, a gentle area must be selected and combined with convenient measurement. The temperature measurement conversion point is determined by welding thermal simulation to achieve mutual verification of the internal and external temperatures, that is, the back temperature of 300 degrees Celsius (equivalent conversion of 200 degrees Celsius for convenient measurement position) is used as the benchmark, and the front and back welding convenient measurement position equivalent to 200 degrees Celsius is used as a reference. The temperature measurement point must be converted to a position that is convenient for operation and the internal and external temperatures are consistent. In actual control, the inner wall of the temperature measuring hole 5 is given priority.
[0039] 2. The external positive temperature measuring point (usually the temperature measuring hole 5) is drawn with a temperature measuring pen with a colored temperature line, which has the characteristic that the line disappears after exceeding the set temperature; the equivalent temperature field area determined by welding thermal simulation is used on the back of the weld to form a temperature measuring hole 5 by drilling a vent hole, and the temperature color mark is also made on the inner wall of the hole with the crayon core of the temperature measuring pen.
[0040] 3. During the carbon arc gouging or welding process, observe the temperature lines of the welding heat affected zone on the inner and outer walls of the temperature measuring hole 5 respectively. If one of the temperature lines disappears, stop the carbon arc gouging or welding immediately, and then use the air compressor to force air cooling. It must be cooled before welding, that is, until the weld is not hot to the touch of the hand, to avoid continuous welding temperature exceeding the standard, which will cause concrete cracks inside the steel pipe, a fatal problem that cannot be repaired.
[0041] 4. The welding line energy shall be carried out according to the upper limit of the line energy determined by the heat simulation technology. The thickness of each layer during carbon arc gouging or welding shall be below 5mm. The temperature between passes shall be strictly controlled. Before each pass, the weld shall be touched and not hot before starting the next operation. Otherwise, the next weld shall be welded the next day, and so on.
[0042] 5. Measure and record the temperature before and after carbon arc gouging or welding for reference. Welding can only be carried out after the inspector has checked and approved it each time. Equipped with inspection tools such as flashlight, temperature measuring pen, ruler, temperature measuring gun, etc.; the temperature measuring pen is the main one and the temperature measuring gun is the auxiliary one. Take photos after welding for reference and records, which must include the above two temperature lines.
[0043] This technical solution can also be applied to the repair of welds on corbels of steel tube concrete columns in high-rise and multi-story buildings and stadiums, and can also be used for temperature control of weld crack repair on steel box girders of highway and railway bridges.
[0044] Specific application examples include:
[0045] 1. The steel pipe and the bracket are made of Q355B, with a thickness of 30mm and a steel pipe diameter of Ф1400 x thickness of 50mm. According to the welding thermal simulation technology, the temperature measuring points of 200 degrees Celsius inside and outside the welding are determined (the repair temperature of the interface between the equivalent steel pipe and concrete is controlled at 300 degrees and below). Before each welding, use a 200-degree Celsius temperature measuring pen to draw the outer temperature line on the steel pipe 20mm away from the weld or the edge of the triangle plate groove; then, along the length direction of the weld and 20mm away from the edge of the weld groove, drill a hole with a diameter of Ф20mm every 300mm (welding temperature measurement and ventilation), and the inner wall of the hole near the weld is also painted with a temperature color line. The two temperature lines inside and outside can verify each other to monitor the temperature. Once one temperature line disappears, stop welding immediately;
[0046] 2. Each time before welding, the pipe should be cooled to room temperature before welding, that is, it should be cooled before welding to avoid cracking of concrete inside the steel pipe. For vertical welding of H-type bracket, the 200-degree Celsius temperature pen line 50-100mm below the welding pool must be observed, and the temperature line inside the air vent must be observed at the same time. Welding must be stopped if any temperature line disappears; flat welding of box-type bracket also needs to be staggered, and the two temperature lines inside and outside should be observed. The processing principle is the same as above;
[0047] 3. H-type brackets are repaired by cleaning the roots according to the thickness of the plate. When vertically welding, drill 20mm diameter air holes at 350mm and 650mm positions of one meter of the bracket height to observe the internal conditions of the concrete, and use a 200-degree Celsius temperature measuring pen to make color marks. Stop welding immediately if the temperature color line is not visible; take a photo of the first mark for reference before the second welding, and redraw the temperature line after cleaning, and so on;
[0048] 4. According to the design, the thickness of the box beam reinforcement triangle plate is 20 and 30 mm respectively, the single groove is 35 degrees (negative tolerance control), 6 gaps are left, and a 4mm steel pad is added;
[0049] 5. For triangle plate with thickness of 20 (30) mm, flat welding is carried out in 5 (8) layers according to equal thickness. The thickness of each weld seam shall not exceed 5 mm. The interval between each layer is generally five hours (from the end of the first welding to the beginning of the second welding). The weld seam must be cooled to room temperature before welding. That is, after inspection and confirmation, it can be welded after it has cooled down. Otherwise, the second weld seam shall be welded the next day.
[0050] 6. Welding specification: flat welding position, welding current not exceeding 300A, welding voltage about 30V, welding speed: about 350mm / min for flat welding, about 70mm / min for vertical welding, using flux-cored wire SH.Y71T-1 (Φ1.2mm);
[0051] The temperature must be measured and recorded before and after welding. Welding can only be carried out after each welding is confirmed. The inspector must follow and record the temperature for reference. The inspection tools such as flashlight, temperature measuring pen, ruler, temperature measuring gun, etc. are equipped. The temperature measuring pen is the main one, and the temperature measuring gun is the auxiliary one. The record sheet must be signed and approved by the welder and the inspector for reference. The process must be explained, and the welder must write or orally state the welding essentials, and print a copy for each person.
[0052] It should be noted that, in this article, terms such as "inside" and "outside" positions are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.
[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A corbel welding temperature control and construction method for a steel tube concrete column, comprising: Concrete layer (1), steel pipe (2), corbel; A concrete layer (1) is provided inside the steel pipe (2), and a corbel is provided outside the steel pipe (2), wherein the corbel comprises a box-type corbel (3) and an H-type corbel (4), and a plurality of temperature measuring holes (5) are provided on the periphery of the connection between the corbel and the steel pipe (2), wherein the temperature measuring holes (5) are distributed near the connection between the corbel and the steel pipe (2), wherein the connection includes a weld, and the temperature measuring hole (5) is 10-30 mm away from the weld, and the temperature measuring hole (5) is a circular hole with a diameter of 10-30 mm, and the depth of the temperature measuring hole (5) exceeds the thickness of the steel pipe (2). The steps of the welding seam construction temperature control and the construction method are as follows: Step 1, using welding thermal simulation technology to determine the welding line energy and the back temperature and front temperature of the heat-affected zone of the welded steel pipe (2) and their relationship, setting a temperature measuring hole (5), during the construction process of the bracket weld, including carbon arc gouging and welding processes, during which the temperature of the steel pipe (2) will rise sharply, which will indirectly cause the temperature of the concrete layer (1) to rise, and the interface temperature must be controlled not to exceed 300 degrees Celsius; Step 2, the temperature at the weld during the welding process is the highest, a temperature measuring hole (5) is set in the heat-affected zone at a distance of 10-30 mm from the edge of the weld groove, and a temperature monitoring color line is set at the temperature measuring hole (5), and the temperature of the interface between the steel pipe and the concrete caused by the bracket welding is converted to not more than 200 degrees Celsius at the temperature measuring hole, and the outer layer and the inner layer of the steel pipe 2 at the temperature measuring hole 5 are marked with a temperature measuring pen with a temperature of 200 degrees Celsius; Step 3, when the monitored temperature at the temperature measuring hole (5) exceeds 200 degrees Celsius during construction, stop construction immediately, and use a fan or air compressor to blow air to cool the weld, the temperature measuring hole (5) and the heat affected zone. If air cooling is not suitable for the weld, use natural cooling. When the temperature drops to the normal temperature on site, continue the carbon arc gouging and welding construction steps. When measuring temperature, the temperature measuring color line on the inner wall of the temperature measuring hole is used as the main method, and the outer wall color isothermal temperature measuring line is used as the auxiliary method, so as to realize the combination of temperature measurement and control. At this temperature, welding can effectively prevent the concrete from being damaged.
2. The temperature control and construction method of the corbel welding of a steel tube concrete column according to claim 1, characterized in that: During the welding process, small line energy welding and intermittent welding are required. If the temperature exceeds the limit, it is necessary to stop and wait for air to cool before welding again, so as to combine temperature measurement and control.
3. The temperature control of the corbel welding of a steel tube concrete column and the construction method thereof according to claim 1 are characterized in that: The depth of the temperature measuring hole (5) exceeds the thickness of the steel pipe (2), and at least the concrete layer (1) can be seen through the temperature measuring hole (5).
4. A corbel welding temperature control and construction method for a steel tube concrete column according to any one of claims 1 to 4, characterized in that: The concrete layer (1) at the temperature measuring hole (5) is provided with a color line representing temperature control.
5. The temperature control of corbel welding of a steel tube concrete column and the construction method thereof according to claim 5 are characterized in that: The color line can also be used on the inner wall of the temperature measuring hole (5). When the temperature reaches or exceeds 200 degrees Celsius, the color line will automatically disappear.