CN114383745A - Fixing method and device for internal thermocouple of steel-clad concrete composite member - Google Patents

Abstract

The invention relates to a method and a device for fixing a thermocouple inside a composite member of an outer steel plate and concrete. Measure the distance from the measuring point to the outer surface of the drilled steel plate and make a mark, arrange the thermocouples in an approximate circle and bind them with iron wires in the non-penetrating section; drill through circular holes in the above positions of the component steel plate, and weld the fixing bracket on the component ; First pour concrete to the lowest point of the round hole, extend the thermocouple from the round hole to the mark and fix it on the bracket, pour the concrete manually and make the concrete cover the thermocouple; finally pour the upper concrete and vibrate and compact. Using the method, the thermocouple inside the composite component can be accurately positioned and fixed, so that the internal concrete temperature field can be measured, and the damage to the component and the thermocouple is small, the method is simple, and the operation is easy.

Description

Fixing method and device for internal thermocouple of steel-clad concrete composite member

technical field

The invention relates to the technical field of building disaster prevention and mitigation, in particular to a method and a device for fixing a thermocouple inside a composite steel plate-concrete composite member.

Background technique

The outer steel plate concrete composite structure is a composite structure in which the outer steel plate and the inner filling concrete form a joint working system through connecting parts such as studs. The common vertical composite members in practical engineering include rectangular concrete columns with outer steel plates, concrete filled steel tubular columns, special-shaped columns with outer steel plates and concrete composite shear walls with outer steel plates. In terms of mechanical properties, this composite structure combines the good compressive properties of concrete and the superior tensile properties of steel plates. It has high bearing capacity, excellent seismic resistance and good impact resistance. It also has outstanding advantages in accelerating the construction progress and comprehensive economic benefits, and can achieve the goal of efficient, orderly, green and environmentally friendly construction. Therefore, the composite structure of steel plate and concrete has been widely used in high-rise and super high-rise buildings, bridges, nuclear power plants and other fields. Because the strength of steel and concrete under high temperature (after) fire is reduced to varying degrees, after a high temperature for a certain period of time, it may even lose its bearing capacity completely. Performance Research is key to ensuring its safe use. In the fire resistance experiment of steel plate concrete composite structure, the real-time measurement of the concrete temperature field inside the composite member is one of the very important test contents. In the experiment, a specific section of the composite component is usually selected and multiple thermocouples are installed along the thickness direction to measure the internal concrete temperature field (CN2020206260751).

At present, there is no unified method for burying and fixing thermocouples in the fire resistance test of the outer-clad steel-concrete composite structure, and there is no relevant normative regulation. In the research on the mechanical properties of the double-steel-steel-steel-concrete composite shear wall stud connector at room temperature and after fire, the test piece production part of the push-out test of the double-steel-steel-steel-concrete composite shear wall stud connector after fire is made of steel plates. Weld the thin steel bars between each other and fix the thermocouple to the additional steel bar, and pay attention to avoid the vibrating rod disturbing the position of the thermocouple during pouring. In addition to the above methods, the common fixing method is to directly place the thermocouple from the reserved circle after pouring concrete. hole insertion. However, the existing methods of fixing thermocouples have the following shortcomings: ① Too high welding temperature will damage the thermocouple itself, resulting in a decrease in measurement accuracy; ② During the construction process, the thermocouple is easily disturbed and shifted, and the position of the measuring point Accuracy cannot be guaranteed; ③The thermocouple is easily damaged by impact during the concrete pouring process.

SUMMARY OF THE INVENTION

In view of the deficiencies of the above experimental techniques, the purpose of the present invention is mainly to provide a fixing method and device for the thermocouple inside the outer-clad steel plate concrete composite member, aiming at reducing the disturbance of the thermocouple during the construction process, ensuring the accuracy of the temperature measuring point position; and avoiding construction Factors can damage the thermocouple, so as to better realize the real-time measurement of the concrete temperature field inside the outer steel plate-concrete composite structure.

The present invention is realized by at least one of the following technical solutions.

The fixing method of the inner thermocouple of the outer-clad steel plate concrete composite member includes the following steps:

According to the measurement position of the temperature field, determine the drilling position of the outer steel plate of the experimental component and drill the hole; according to the measurement needs, determine the measurement point position and quantity of the thermocouple along the thickness direction;

Arrange the thermocouples in order and bind them into a thermocouple bundle, measure the distance from the measuring point to the outer surface of the drilled steel plate on the thermocouple and mark the thermocouple;

Weld the fixing bracket on the outer surface of the experimental component to fix the thermocouple beam;

First, pour concrete into the interior of the experimental component and vibrate and compact it, and make the upper surface of the concrete flush with the lowest point of the drilled hole;

Extend the thermocouple beam from the drilled hole and stop at the mark. The part that does not extend into the thermocouple beam is welded to the fixed bracket. Glue is dripped at the drilling position to seal the gap between the thermocouples and the gap between the thermocouples and the steel plate. pore;

Concrete is then poured again so that the concrete completely covers the thermocouple beam;

Finally, concrete is poured from the upper part of the concrete and vibrated and compacted, and the internal concrete pouring of the composite component is completed. After the concrete curing is completed, the fixing bracket is cut off.

Preferably, the thermocouples of the thermocouple beams in each borehole are arranged by serial numbers, and the arrangement shape is approximately a circle.

Preferably, the drilled hole is a penetrating circular hole, and the diameter of the circular hole is determined according to the number and arrangement of thermocouples and should be 1-2 mm larger than the outer diameter of the thermocouple bundle.

Preferably, concrete is poured to the lowest point of the drill hole for the first time, and the thermocouple beam is extended from the drill hole to the mark, and the unprotruded part of the thermocouple beam is fixed on the horizontal steel plate by iron wires.

Preferably, glue is dripped at the positions of the circular holes to seal the gaps between the thermocouples and the pores between the thermocouples and the experimental components, and then concrete is poured manually so that the concrete completely covers the thermocouple bundles.

Preferably, the distance from the measuring point position to the surface of the drilled experimental component is measured and marked on the thermocouple in advance, the thermocouple is fastened with an iron wire in the non-penetrating section, and the thermocouple label and the corresponding thermocouple label are The distance from the measuring point to the inner surface of the drilled test member is recorded in the table.

Preferably, the mark on the thermocouple is flush with the outer surface of the drilled experimental component, and the number of iron wires bound and the distance between the iron wires are set in the non-protruding section of the thermocouple bundle according to the number of thermocouples in the thermocouple bundle.

The device for realizing the fixing method of the inner thermocouple of the outer-clad steel plate concrete composite member includes a thermocouple fixing bracket, and the fixing bracket includes a horizontal steel plate and a plurality of steel bar diagonal braces; the horizontal steel plate is installed on the experimental member through several steel bar diagonal braces On the surface, the experimental member includes an outer steel plate and an inner filled concrete, which together form a vertical composite member, and the vertical composite member simultaneously bears vertical loads and bending moments.

Preferably, the upper surface of the horizontal steel plate is tangent to the lowest point of the circular hole on the vertical composite member, one end is connected to the outer surface of the vertical composite member, and the other end is supported on a plurality of steel bar diagonal braces.

Preferably, both ends of the steel bar diagonal brace are respectively connected to the lower surface of the horizontal steel plate and the surface of the vertical composite member.

Compared with the prior art, the beneficial effects of the present invention are:

The method and the device for fixing the thermocouple inside the composite member of the outer-clad steel plate concrete according to the invention, and the additional fixing bracket can prevent the thermocouple from being disturbed in the construction process, and ensure the accurate positioning of the temperature measuring point; It is damaged due to impact in the middle of the hole; the size of the drill hole is small, the damage to the experimental component is small, and the position of the drill hole and the measuring point along the thickness direction is basically unlimited. The invention can improve the quality of the fire resistance test of the outer steel plate concrete composite member, the method is simple, the operation is easy, and it is worth popularizing.

Description of drawings

Fig. 1 is the schematic diagram of the fixing device of the inner thermocouple of the outer steel plate concrete composite member;

Figure 2 is a schematic diagram of a fixed bracket;

Fig. 3a is a schematic diagram of thermocouple arrangement and thermocouple beam in Example 1;

Figure 3b is a schematic diagram of thermocouple marking;

Figure 4 is a schematic diagram of the thermocouple fixing device and the concrete pouring sequence;

5 is a schematic diagram of the arrangement of thermocouples in Example 2;

6 is a schematic diagram of the arrangement of thermocouples in Example 3;

Figure 7 is a schematic diagram of a thermocouple;

Among them, 1-thermocouple bundle, 2-binding iron wire, 3-through round hole, 4-horizontal steel plate for fixing bracket, 5-diagonal bracing for fixing bracket, 6-cladding steel plate, 7-first pouring concrete, 8-th 2nd hand poured concrete, 9 - 3rd poured concrete.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific examples, wherein the indicative positional relationships such as the terms “upper”, “lower”, “left” and “right” appearing in the description are only based on the positional relationship shown in the accompanying drawings, and the purpose is to facilitate the The present invention is described and simplified, rather than implying that the device must have a specific orientation configuration and operation, so the description of the positional relationship should not be construed as a limitation of the present invention; in addition, the general techniques and descriptions used in the present invention should be considered to be related to the present invention. The understanding of those skilled in the same technical field has the same meaning.

This specification may use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," which may all refer to the same in accordance with the present disclosure or one or more of different embodiments.

As shown in Figures 1 and 2, the fixing device of the thermocouple inside the outer steel plate concrete composite member includes a thermocouple fixing bracket, and the fixing bracket includes a horizontal steel plate 4 and a number of steel bar diagonal braces 5; the horizontal steel plate 4 passes through a number of steel bars. The diagonal brace 5 is installed on the surface of the experimental member, and the experimental member includes an outer steel plate and an inner filled concrete, which together form a vertical composite member, and the vertical composite member bears vertical load and bending moment at the same time.

The cross section of the vertical assembly member is circular, rectangular, T-shaped, L-shaped, I-shaped or cross-shaped.

A circular hole 3 is drilled at the predetermined drilling position of the outer steel plate of the experimental component, the upper surface of the horizontal steel plate 4 is tangent to the lowest point of the circular hole 3, and one end of the horizontal steel plate 4 is welded to the outer surface of the composite component, and the other end It is supported on two reinforced diagonal braces 5, and the two ends of the reinforced diagonal braces 5 are respectively welded to the lower surface of the horizontal steel plate 4 and the outer surface of the vertical composite member.

The invention also provides a method for fixing the internal thermocouple of the outer steel plate concrete composite member, comprising the following steps:

1) Determine the drilling position of the composite component (experimental component) outsourcing steel plate according to the measurement position of the temperature field and drill the hole, and determine the position and number of thermocouple measuring points along the thickness direction according to the measurement needs;

2) Arrange the thermocouples in a certain order and bind them with iron wire 2 to form a thermocouple bundle. Measure the distance from the corresponding measuring point to the outer surface of the steel plate on the thermocouple and make a mark. Then align the marks of all the thermocouples, starting from the left To the right, arrange from top to bottom to make it a thermocouple bundle with a shape close to a circle; the size of the drill hole should be determined according to the number and arrangement of thermocouples, and its diameter is slightly larger than the outer diameter of the thermocouple bundle by 1-2mm ;

3) Weld the fixing bracket on the surface of the steel plate;

4) pour the concrete 7 at the bottom of the circular hole for the first time and vibrate and compact it, and make the upper surface of the concrete 7 flush with the lowest point of the circular hole; extend the thermocouple beam from the circular hole and stop at the mark, the thermocouple beam The non-protruding part is welded to the steel plate of the fixed bracket through its binding iron wire; drip 502 glue at the drilling position to seal the gap between the thermocouples and the pores between the thermocouple and the steel plate;

5) Continue to artificially pour concrete 8 and vibrate and compact it, pay attention to avoid the position of the thermocouple beam during vibrating, and make the concrete completely cover the thermocouple beam;

6) Finally, the remaining upper concrete 9 is poured and vibrated and compacted to complete the pouring of the concrete inside the experimental member. After the concrete curing is completed, the fixed bracket is carefully cut off to avoid damage to the outer steel plate of the experimental member.

As shown in Figure 3a and Figure 3b, determine the position and number of thermocouple measuring points along the thickness direction of the vertical composite member, and record the thermocouple number and the distance from the position of the thermocouple measurement point to the outer surface of the composite member in the table (such as Table 1), measure the distance from the corresponding measuring point position to the outer surface of the composite component on the thermocouple and make a mark, then align the marks of all thermocouples, from left to right, from top to bottom, so that It becomes a thermocouple bundle with a shape close to a circle; the diameter of the circular hole 3 should be slightly larger than the outer diameter of the thermocouple bundle 1 by 1-2mm; in the non-protruding section of the thermocouple bundle, use the iron wire 2 to fasten it at a certain distance.

Table 1 Thermocouple Recording Table

As shown in Figure 4, the experimental operation sequence is: pour concrete 7 below the circular hole 3 for the first time, and vibrate and compact so that the upper surface of the concrete is flush with the lowest point of the circular hole 3; then the bound thermocouple bundle 1 is inserted into the The circular hole 3 ends at the mark, and the non-protruding section of the thermocouple bundle 1 is welded to the fixing bracket through the iron wire 2, and the 502 glue is dripped at the position of the drill hole 3 to seal the gap between the thermocouples and the thermocouple. The hole between the hole and the round hole; then manually pour concrete 8 so that the concrete completely covers the thermocouple bundle 1; pour the upper concrete 9 for the third time and vibrate and compact it; after the concrete curing is completed, the fixing bracket is carefully cut off, and care should be taken when cutting it. damage to experimental components. It should be pointed out that the purpose of manually pouring concrete 8 is to prevent the thermocouple from being damaged by the impact of the concrete mixture during the construction process, and attention should be paid to avoid the position of the thermocouple beam when vibrating; The number of binding iron wires can be increased according to the actual situation. Measure the internal concrete temperature field of the steel-clad concrete composite member; label the thermocouples according to the distance from the measuring point of the thermocouple to the outer surface of the drilled steel plate.

As shown in Figure 7, the temperature measured by the thermocouple in the experiment is the concrete temperature between the inner surface of the drilled steel plate and the inner surface of the other side of the steel plate. Thermocouple is a commonly used temperature measuring element in temperature measuring instruments. It directly measures the temperature, converts the temperature signal into a thermoelectromotive force signal, and converts it into the temperature of the measured medium through an electrical instrument. Thermocouples are usually composed of main parts such as hot electrode probes, insulating sleeve protection tubes and junction boxes, and are usually used in conjunction with display instruments, recording instruments and electronic regulators. The thermocouple used in the present invention is shown in FIG. 7 , and its probe part is inserted into the combined structure through the circular hole 3 to measure the temperature inside the concrete. Due to the small diameter of the thermocouple probe, the diameter of the drill hole required to bind the thermocouple is small, the damage to the experimental component is small, and it does not require much operating space, so the drilling position and measuring points along the thickness direction are required. The location is basically unlimited.

Example 1

The vertical composite member used in this embodiment has a rectangular cross-section, and the drilling position and drilling of the outer steel plate of the experimental member are determined according to the measurement position of the temperature field, and the position and number of thermocouple measuring points along the thickness direction are determined according to the measurement needs;

Arrange and bind the thermocouples into a thermocouple beam. The cross-section of the thermocouple beam is shown in Figure 3a. Measure the distance from the measuring point to the outer surface of the drilled steel plate on the thermocouple and mark it;

Weld the fixed bracket on the outer surface of the experimental component;

First pour the concrete under the borehole and vibrate and compact it, and make the upper surface of the concrete flush with the lowest point of the borehole;

Extend the thermocouple beam from the drilled hole and stop at the mark. The part that does not extend into the thermocouple beam is welded to the fixed bracket. Glue is dripped at the drilling position to seal the gap between the thermocouples and the gap between the thermocouples and the steel plate. porosity; concrete was subsequently poured manually so that the concrete completely covered the thermocouple beam;

Finally, the upper concrete is poured and vibrated and compacted, and the internal concrete pouring of the composite component is completed. After the concrete curing is completed, the fixed bracket is cut off.

Example 2

The cross section of the vertical composite member used in this embodiment is circular, and the position and number of holes for drilling the outer steel plate of the experimental member are determined according to the measurement position of the temperature field, and the position and number of thermocouple measuring points along the thickness direction are determined according to the measurement needs;

Arrange and bind the thermocouples into a thermocouple beam. The cross-section of the thermocouple beam is shown in Figure 5. Mark the position of the outer surface of the experimental component corresponding to the drill hole on the thermocouple beam;

Weld the fixed bracket on the outer surface of the experimental component;

First pour the concrete under the borehole and vibrate and compact it, and make the upper surface of the concrete flush with the lowest point of the borehole;

Extend the thermocouple beam from the drilled hole and stop at the mark. The part that does not extend into the thermocouple beam is welded to the fixed bracket. Glue is dripped at the drilling position to seal the gap between the thermocouples and the gap between the thermocouples and the steel plate. Pores; 10cm thick concrete was subsequently poured manually so that the concrete completely covered the thermocouple beam;

Finally, the upper concrete is poured and vibrated and compacted, and the internal concrete pouring of the composite component is completed. After the concrete curing is completed, the fixed bracket is cut off.

Example 3

The cross section of the vertical composite member used in this embodiment is an I-shaped, and the drilling position and drilling of the outer steel plate of the experimental member are determined according to the measurement position of the temperature field, and the position and number of thermocouple measuring points along the thickness direction are determined according to the measurement needs;

Arrange and bind the thermocouples into a thermocouple beam. The cross-section of the thermocouple beam is shown in Figure 6. Measure the distance from the measuring point to the outer surface of the drilled steel plate on the thermocouple and mark it;

Weld the fixed bracket on the outer surface of the experimental component;

First pour the concrete under the borehole and vibrate and compact it, and make the upper surface of the concrete flush with the lowest point of the borehole;

Extend the thermocouple beam from the drilled hole and stop at the mark. The part that does not extend into the thermocouple beam is welded to the fixed bracket. Glue is dripped at the drilling position to seal the gap between the thermocouples and the gap between the thermocouples and the steel plate. porosity; concrete was subsequently poured manually so that the concrete completely covered the thermocouple beam;

Finally, the upper concrete is poured and vibrated and compacted, and the internal concrete pouring of the composite component is completed. After the concrete curing is completed, the fixed bracket is cut off.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent substitutions are made without departing from the spirit and scope of the technical solution, and they should all be included in the scope of the claims of the present invention.

Claims (10)

1. the fixing method of the inner thermocouple of the outer-clad steel plate concrete composite member, is characterized in that, comprises the following steps: According to the measurement position of the temperature field, determine the drilling position of the outer steel plate of the experimental component and drill the hole; according to the measurement needs, determine the measurement point position and quantity of the thermocouple along the thickness direction; Arrange the thermocouples in order and bind them into a thermocouple bundle, measure the distance from the measuring point to the outer surface of the drilled steel plate on the thermocouple and mark the thermocouple; Weld the fixing bracket on the outer surface of the experimental component to fix the thermocouple beam; First, pour concrete (7) into the interior of the experimental member and vibrate and compact, and make the upper surface of the concrete flush with the lowest point of the drilled hole; Extend the thermocouple beam from the drilled hole and stop at the mark. The part that does not extend into the thermocouple beam is welded to the fixed bracket. Glue is dripped at the drilling position to seal the gap between the thermocouples and the gap between the thermocouples and the steel plate. pore; Concrete (8) is then poured again so that the concrete (8) completely covers the thermocouple beam; Finally, the concrete (9) is poured from the upper part of the concrete (8) and the vibration is compacted to complete the internal concrete pouring of the composite member, and the fixing bracket is cut off after the concrete curing is completed. 2 . The method for fixing the internal thermocouples of the outer-clad steel plate concrete composite member according to claim 1 , wherein the thermocouples of the thermocouple bundles in each borehole are arranged by serial numbers, and the arrangement shape is approximately circular. 3 . 3. The fixing method of the inner thermocouple of the outer-clad steel plate-concrete composite member according to claim 1, characterized in that: the drilled hole is a circular hole that runs through, and the diameter of the circular hole is determined according to the number of thermocouples and the arrangement and should be larger than the thermoelectric The outer diameter of the even beam is 1-2mm larger. 4. the fixing method of the inner thermocouple of the outer-clad steel plate concrete composite member according to claim 1, is characterized in that: pouring concrete for the first time to the lowest point of the borehole, the thermocouple beam is extended from the borehole and ends at the mark , the unprotruded part of the thermocouple beam is fixed on the horizontal steel plate (4) by iron wires. 5. the fixing method of the inner thermocouple of the outer-clad steel plate-concrete composite member according to claim 1, is characterized in that: the gap between the thermocouple and the thermocouple and the experimental member is blocked by drip irrigation glue at the circular hole position, The concrete was then poured by hand to completely cover the thermocouple beam. 6. The fixing method of the inner thermocouple of the outer-clad steel plate-concrete composite member according to claim 1, is characterized in that: measure the distance from the measuring point position to the surface of the experimental member of the drill hole on the thermocouple in advance and make a mark. Tie the thermocouple with iron wire in the protruding section, and record the thermocouple number and the distance from the measuring point corresponding to the thermocouple number to the inner surface of the drilled experimental member in the table. 7. The fixing method of the inner thermocouple of the outer-clad steel plate concrete composite member according to any one of claims 1 to 6, it is characterized in that: the mark on the thermocouple is flush with the outer surface of the experimental member of the drilled hole, according to the thermocouple beam The number of thermocouples in the non-protruding section of the thermocouple bundle sets the number of tying iron wires and the spacing distance between the iron wires. 8. the device that realizes the fixing method of the inner thermocouple of the outer-clad steel plate concrete composite member according to claim 1, it is characterized in that, comprises thermocouple fixing bracket, and described fixing bracket comprises horizontal steel plate (4) and some steel bar diagonal braces (5) ); The horizontal steel plate (4) is installed on the surface of the experimental member by some steel reinforced diagonal braces (5), and the experimental member includes the outer steel plate and the concrete filled inside, which together form a vertical composite member, and the vertical composite member is simultaneously Withstand vertical loads and bending moments. 9. The device for the fixing method of the inner thermocouple of the outer-clad steel plate-concrete composite member according to claim 8, characterized in that: the upper surface of the horizontal steel plate (4) and the circular hole (3) on the vertical composite member The lowest point is tangent, one end is connected to the outer surface of the vertical composite member, and the other end is supported on a plurality of steel bar diagonal braces (5). 10. The device of the fixing method of the inner thermocouple of the outer-clad steel plate-concrete composite member according to claim 8, characterized in that: the two ends of the steel bar diagonal brace (5) are respectively connected to the lower surface and the vertical surface of the horizontal steel plate (4). towards the composite surface.

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