Electric heating maintenance equipment for concrete pouring in winter

Abstract

The utility model discloses electric heating maintenance equipment for concrete pouring in winter, which comprises a fixed base, a supporting mechanism mounted at the top end of the fixed base, an insulating plate mounted at the top end of the supporting mechanism, a transformer fixedly mounted at the top of the insulating plate, and a fixing piece arranged on one side of the fixed base. According to the electric heating maintenance equipment for concrete pouring in winter, the resistance wire with the insulating rubber skin is laid in a concrete structure, and after the resistance wire is powered on, two electrodes of the resistance wire form a conductive loop through unsolidified concrete, so that the resistance wire is fixed to the bottom end of the fixing part, and the resistance wire is fixed to the bottom end of the fixing part. At the moment, the secondary current of the transformer is large, the wire is heated and releases heat energy, the heat can be transmitted to concrete in a loss mode, and due to the fact that the heating resistance wire is embedded in the concrete, the generated heat can be completely transmitted to a concrete member. Therefore, it is guaranteed that the concrete is cured under the positive temperature condition.

Description

Technical Field

[0001] The utility model relates to the technical field of winter concrete pouring, in particular to electric heating and curing equipment for winter concrete pouring. Background Art

[0002] In engineering construction, concrete pouring and curing in winter is more difficult, and the quality and strength of concrete are difficult to guarantee. After the construction practice of many projects in cold areas, a set of relatively mature technologies for pouring and curing concrete under negative temperature conditions has been formed - electric heating curing technology, which effectively solves the construction problem of concrete structures under negative temperature conditions in severe cold and high-altitude areas. There are currently three main electric heating curing methods in use or research, namely electrode heating method, resistance wire heating method and coil induction heating method. Resistance wire heating method has become the preferred option due to its low technical requirements, simple construction, safety and low loss.

[0003] Concrete pouring and curing in winter is more difficult, and the quality and strength of concrete are difficult to guarantee. In winter, many engineering projects in high-altitude cold areas such as the north basically stop concrete construction due to economic and technical factors, affecting the progress of the entire project. It is particularly important to carry out concrete operations in a negative temperature environment and ensure its construction quality. The ambient temperature for traditional concrete pouring generally needs to be maintained above +5°C. The use of electric heating curing technology effectively solves the problem of construction and curing of concrete structures in severe cold and high-altitude cold areas under negative temperature conditions.

[0004] However, traditional maintenance equipment has the following disadvantages:

[0005] During the curing process of concrete using traditional curing equipment, if the concrete is exposed to a negative temperature environment before final setting, the hydration of the cement is hindered, and the free water begins to freeze, increasing its volume, causing the concrete to crack and seriously affecting its quality. After the initial freezing of the concrete, if it is then cured at normal temperature, its strength can still increase, but the porosity of the concrete increases irreversibly due to the volume expansion, and the strength cannot be restored to normal levels. Utility Model Content

[0006] The purpose of the utility model is to provide an electric heating curing device for pouring concrete in winter, so as to solve the problem proposed in the above-mentioned background art that during the curing process of concrete with traditional curing equipment, if the concrete is exposed to a negative temperature environment before final setting, the hydration of cement is hindered, and the free water begins to freeze and increase in volume, causing the concrete to crack and seriously affect the quality of the concrete; after the concrete is initially frozen and then cured at normal temperature, its strength can still increase, but the porosity of the concrete increases and is irreversible due to the volume expansion, and the strength cannot be restored to a normal level.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an electric heating and curing equipment for pouring concrete in winter, comprising a fixed base, a supporting mechanism installed on the top of the fixed base, an insulating plate installed on the top of the supporting mechanism, a transformer fixedly installed on the top of the insulating plate, a fixing piece provided on one side of the fixed base, a connecting wire fixedly connected to the bottom end of the fixing piece, a plurality of binding pieces fixedly installed on the surface of the fixing piece, a plurality of heating resistance wires connected to the fixing piece through the binding pieces, a plurality of temperature sensors fixedly installed on the middle part of the fixing piece, a main cable fixedly connected to one side of the transformer, and one end of the main cable connected to the side opposite to the fixing piece.

[0008] Preferably, a power switch is fixedly mounted on the surface of the transformer, and a user presses the power switch to control whether the transformer is started.

[0009] The top end face of said sliding arm is fixedly provided with a toothed connecting strip which is cooperatively connected with said toothed connecting gear.

[0010] Preferably, two second active umbrella-shaped bevel gears are fixedly installed on the surface of the direction shaft, and the outer sides of the two second active umbrella-shaped bevel gears are respectively meshed with the outer sides of the two second driven umbrella-shaped bevel gears. A handle is fixedly installed on one end of the direction shaft, and spring shock absorbers are fixedly installed on the top ends of the two lifting blocks. The top ends of the two spring shock absorbers are respectively fixedly connected to the bottom ends of the two support frames. When the user turns the handle, the handle drives the direction shaft to rotate, and the direction shaft drives the second active umbrella-shaped bevel gear to rotate. The second active umbrella-shaped bevel gear contacts the second driven umbrella-shaped bevel gear, and the second driven umbrella-shaped bevel gear drives the screw to rotate.

[0011] Compared with the prior art, the beneficial effect of the present invention is as follows: when the resistance wire with an insulating rubber sheath is laid in a concrete structure, after the resistance wire is connected to the power supply, the two electrodes of the resistance wire form a conductive circuit by the unsolidified concrete. At this time, the secondary current of the transformer is very large, causing the wire to heat up and release heat energy, and the heat will be transferred to the concrete in the form of dissipation. Since the heating resistance wire is buried inside the concrete, the heat generated by it will be fully transferred to the concrete component; thereby ensuring that the concrete is cured under positive temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a side view of the utility model;

[0013] Figure 2 It is a cross-sectional view of the support mechanism of the utility model;

[0014] Figure 3 This is a connection diagram of the fixed base and the support mechanism of the utility model;

[0015] Figure 4 This is a connection diagram of the fixing part and the binding part of the utility model.

[0016] In the figure: 1. Fixed base; 2. Support mechanism; 201. Steering shaft; 202. Second active umbrella-shaped bevel gear; 203. Second driven umbrella-shaped bevel gear; 204. Screw; 205. Lifting column; 206. Support frame; 207. Spring shock absorber; 208. Support casing; 209. Lifting slot; 210. Lifting block; 211. Handle; 3. Insulating plate; 4. Transformer; 5. Power switch; 6. Main cable; 7. Connecting wire; 8. Fixing piece; 9. Binding piece; 10. Heating resistor wire; 11. Temperature sensor. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0018] See also Figure 1-4 The utility model provides an electric heating and curing equipment for pouring concrete in winter, including a fixed base 1, a supporting mechanism 2 is installed on the top of the fixed base 1, an insulating plate 3 is installed on the top of the supporting mechanism 2, a transformer 4 is fixedly installed on the top of the insulating plate 3, a fixing part 8 is provided on one side of the fixed base 1, the bottom end of the fixing part 8 is fixedly connected to a connecting wire 7, a plurality of binding parts 9 are fixedly installed on the surface of the fixing part 8, the fixing part 8 is connected to a plurality of heating resistance wires 10 through the binding parts 9, a plurality of temperature sensors 11 are fixedly installed on the middle part of the fixing part 8, a main cable 6 is fixedly connected to one side of the transformer 4, and one end of the main cable 6 is connected to the side opposite to the fixing part 8.

[0019] A power switch 5 is fixedly mounted on the surface of the transformer 4 , and a user presses the power switch 5 to control whether the transformer 4 is started.

[0020] The support mechanism 2 includes a direction shaft 201 and two lifting columns 205. The top of the direction shaft 201 is provided with two second driven umbrella-shaped bevel gears 203. The middle parts of the two second driven umbrella-shaped bevel gears 203 are fixedly installed with screws 204. The outer sides of the two screws 204 are provided with support casings 208. The tops of the two support casings 208 are slidably connected with support frames 206. The tops of the two support frames 206 are respectively fixedly connected to the two sides of the bottom end of the insulating plate 3. The bottom ends of the two sides of the inner wall of the two support casings 208 are provided with lifting grooves 209. The insides of the four lifting grooves 209 are slidably connected with lifting blocks 210. Every two lifting blocks 210 are respectively opposite to each other. The two lifting columns 205 are respectively fixedly connected to the two sides of the two lifting columns 205, and the bottom ends of the two lifting columns 205 are respectively threadedly connected to the top ends of the two screws 204. The bottom ends of the two support casings 208 are fixedly connected to the fixed base 1. One end of the direction shaft 201 is rotatably connected to the fixed base 1. The threads on the surface of the screw 204 match the threads on the inner walls of the lifting columns 205. The lifting columns 205 slide relative to the lifting slots 209 through the lifting blocks 210. The lifting blocks 210 squeeze the spring shock absorbers 207 from the bottom. The spring shock absorbers 207 push the support frame 206 in the opposite direction. The support frame 206 pushes the insulating plate 3 from the bottom to adjust the use height of the transformer 4.

[0021] Two second active umbrella-shaped bevel gears 202 are fixedly installed on the surface of the direction shaft 201. The outer sides of the two second active umbrella-shaped bevel gears 202 are respectively meshed with the outer sides of the two second driven umbrella-shaped bevel gears 203. A handle 211 is fixedly installed at one end of the direction shaft 201. Spring shock absorbers 207 are fixedly installed on the tops of the two lifting blocks 210. The tops of the two spring shock absorbers 207 are respectively fixedly connected to the bottom ends of the two support frames 206. The user rotates the handle 211, and the handle 211 drives the direction shaft 201 to rotate. The direction shaft 201 drives the second active umbrella-shaped bevel gears 202 to rotate. The second active umbrella-shaped bevel gears 202 contact the second driven umbrella-shaped bevel gears 203, and the second driven umbrella-shaped bevel gears 203 drive the screw 204 to rotate.

[0022] Example 1: When using the embodiment of the present application: determine the scope of pouring concrete and the type of components according to the actual construction conditions on site; calculate the concrete volume, the concrete area where the heating resistor wire needs to be arranged, the area that needs to be insulated, and determine the electric heating parameters and power; prepare the main equipment: step-down transformer, main cable 6, connecting wire 7, heating resistor wire 10, other auxiliary equipment and facilities, and tools; taking a certain construction project as an example, the equipment system commonly used in the local market is used as the basis for calculation, the transformer 4 is selected to be 100KVA, the maximum current is 500A, the step-down output voltage is divided into five levels of 55V, 65V, 75V, 85V, and 95V, and the heating resistor wire adopts an iron core insulated resistance wire with a diameter of 1.2mm and a resistivity of 0.1 5 (Ω.m), rated current 8A. Data varies by brand and manufacturer, so actual installation requires careful reading of the instructions or on-site measurement. Connecting conductor 7 uses 4mm² copper-core single-strand cable, and the main power supply cable 6 uses 35mm² copper-core single-strand cable. The formula for calculating resistance wire length is: L = U / IR, where I is the rated current of the wire; L is the wire length; U is the operating voltage, which is 55V; and R is the resistivity of the wire. The above calculation shows that when the operating voltage is 55V, the maximum length of a single resistance wire is 45m. However, for electrical safety, the heating wire length should be limited to 40m. Calculate how many single 40m resistance wires can be connected to each transformer 4: N = 500A / 8A = 62.5. In fact, during the construction process, environmental factors have a greater impact. In order to ensure the safety and effectiveness of the entire heating system, the maximum number of heating wires connected to a single transformer 4 is ≤50. The fixing part 8 is a steel cage, and the binding part 9 is a special rubber binding belt. The rubber sheath of the resistance wire cannot be damaged during binding or other operations, otherwise the short-circuit resistor may be burned out, affecting the heating effect and ultimately affecting the curing quality of the concrete. If the external insulating rubber skin is damaged, the entire heating wire needs to be replaced. The damaged part cannot be repaired by wrapping it with insulating tape. The depth of the heating wire buried in the concrete is about 5 to 10 cm. In concrete components with steel bars, we choose to arrange the resistance wire on the outside of the steel grid. The thickness of the steel protective layer is the buried depth of the resistance wire. The spacing between the heating wires is 100 to 400 mm, which needs to be based on The heating wires must be completely buried in the concrete and must not come into contact with the formwork. Before installing the resistor wires, remove any debris, snow, or ice from the formwork and rebar. Avoid pulling the wires during installation. Protective materials such as rubber pads must be installed at corners with sharp edges to prevent damage to the insulation and breakage of the wires. The heating resistor wire 10 must not be directly connected to the main cable 6 to form an electrical circuit and must not be exposed to air. Uneven heat dissipation can easily cause the insulation to burn out, leading to grounding failures and short circuits. Therefore, a wire with a cross-sectional area 2 to 3 times that of the heating resistor wire 10 must be used to lead the heating resistor wire 10 from the concrete component. A 4mm diameter wire is commonly used. 2 Single-core copper cable; use electrical tape to insulate the connection, and 35mm 2 The main cable 6 is connected to the transformer 4 and arranged around the components that need to be heated. All cables must be overhead with an overhead height of ≥800mm. The overhead lines must be parallel and straight and cannot cross to avoid possible connection errors during the connection of the wires. It is also convenient for quick inspection and repair in case of failure. 2 Connect the connecting wire 7 to the main cable 6, and use electrical tape to insulate the joint. The temperature sensor 11 installation specification requires: For concrete floors, concrete floors and other plate structures, the temperature sensor 11 should be installed every 50m. 2Set up a temperature measuring point; set up a temperature measuring point for every 3m3 of foundation concrete, and the temperature measuring points are evenly spaced; set up a temperature measuring point every 6m for components such as beams and strip foundations; the temperature sensor 11 is inserted into the concrete ≥10cm; in actual construction, an infrared temperature measuring gun is often used to conduct real-time and all-round monitoring of the outer surface temperature of the concrete component, and the transformer 4 is arranged in a flat and solid site within 25m of the building component. If necessary, precast concrete panels can be laid in advance; the transformer 4 cannot be in direct contact with the ground and needs to be insulated from the earth. Therefore, a rubber insulating pad is required before arranging the transformer 4. A hard enclosure with a height of ≥1.5m is set up in the layout site of the transformer 4, and the distance between the enclosure railing and the transformer is ≥2m. No debris can be piled up in the site, and flammable and explosive materials are strictly prohibited. Two 5L carbon dioxide fire extinguishers are configured, and safety warning signs are hung. All power switches 5 on the transformer 4 are turned off, the transformer 4 is connected to the external power supply, and the transformer 4 switch is turned on as required to perform a no-load test on the transformer 4.

[0023] Implementation 2: When the embodiment of the present application is in use: the difference from Example 1 is that the fixing member 8 is a skeleton rib, and the binding member 9 is provided with insulating rubber skin.

[0024] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electric heating curing device for winter concrete pouring, comprising a fixed base (1), characterized in that: A support mechanism (2) is installed at the top of the fixed base (1), an insulating plate (3) is installed at the top of the supporting mechanism (2), a transformer (4) is fixedly installed on the top of the insulating plate (3), a fixing member (8) is provided on one side of the fixed base (1), a connecting wire (7) is fixedly connected to the bottom end of the fixing member (8), a plurality of binding members (9) are fixedly installed on the surface of the fixing member (8), the fixing member (8) is connected to a plurality of heating resistor wires (10) through the binding members (9), a plurality of temperature sensors (11) are fixedly installed in the middle of the fixing member (8), a main cable (6) is fixedly connected to one side of the transformer (4), and one end of the main cable (6) is connected to the side directly opposite to the fixing member (8).

2. The electric heating curing equipment for winter concrete pouring according to claim 1, characterized in that: A power switch (5) is fixedly mounted on the surface of the transformer (4).

3. The electric heating curing equipment for winter concrete pouring according to claim 1, characterized in that: The support mechanism (2) comprises a direction shaft (201) and two lifting columns (205), the top of the direction shaft (201) is provided with two second driven umbrella-shaped bevel gears (203), the middle parts of the two second driven umbrella-shaped bevel gears (203) are fixedly mounted with screws (204), the outer sides of the two screws (204) are provided with support housings (208), the tops of the two support housings (208) are slidably connected with support frames (206), the tops of the two support frames (206) are respectively fixedly connected to the two sides of the bottom end of the insulating plate (3), the bottom ends of the two sides of the inner walls of the two support housings (208) are provided with lifting grooves (209), the interiors of the four lifting grooves (209) are slidably connected with lifting blocks (210), and every two of them facing the lifting blocks (210) are respectively fixedly connected to the two sides of the two lifting columns (205), and the bottom ends of the two lifting columns (205) are respectively threadedly connected to the tops of the two screws (204).

4. The electric heating curing equipment for winter concrete pouring according to claim 3, characterized in that: The bottom ends of the two supporting housings (208) are fixedly connected to the fixed base (1), and one end of the direction shaft (201) is rotatably connected to the fixed base (1).

5. The electric heating curing equipment for winter concrete pouring according to claim 3, characterized in that: Two second active umbrella-shaped bevel gears (202) are fixedly mounted on the surface of the direction shaft (201), and the outer sides of the two second active umbrella-shaped bevel gears (202) are respectively meshed and connected with the outer sides of the two second driven umbrella-shaped bevel gears (203). A handle (211) is fixedly mounted on one end of the direction shaft (201), and spring shock absorbers (207) are fixedly mounted on the top ends of the two lifting blocks (210), and the top ends of the two spring shock absorbers (207) are respectively fixedly connected to the bottom ends of the two support frames (206).

Images