Spontaneous heating curing system for concrete construction in winter and curing method thereof

Abstract

The invention belongs to the technical field of concrete construction curing, and particularly relates to a winter concrete construction spontaneous heating curing system and a curing method thereof.The winter concrete construction spontaneous heating curing system comprises a heating model formed by splicing heat conduction metal plates, the heating model is arranged above a to-be-cured concrete structure through a formwork, and the heating model comprises a top layer and a bottom layer; the middle layer is clamped between the top layer and the bottom layer, both the top layer and the bottom layer are filled with paraffin phase change materials, the middle layer comprises a formwork layer, a functional layer and a heat preservation layer which are sequentially arranged, the formwork layer is close to the concrete structure, and the functional layer is divided into a plurality of reaction intervals capable of being independently triggered through longitudinal battens. The double-heat-source collaborative heat supply system has the beneficial effects that the double-heat-source collaborative heat supply system is constructed by combining the repeated charging and heat release characteristics of the paraffin phase change material and the chemical heat release characteristics of the calcium oxide, and on-demand release and continuous supply of heat are achieved through sequential control.

Description

Technical Field

[0001] This invention relates to the field of concrete construction and curing technology, specifically to a self-heating curing system for winter concrete construction and its curing method. Background Technology

[0002] In cold regions, winter concrete construction and curing are crucial for ensuring project quality. If the curing temperature is insufficient in the low-temperature winter environment, the strength development of concrete will stagnate, and structural damage may even occur due to the freezing and swelling of internal moisture. According to the current standard JGJ / T104-2011, the surface temperature of concrete must be maintained above a specific value before it reaches its critical strength for freezing.

[0003] Currently, the most common method for concrete curing in cold regions during winter is to use external heat sources, such as erecting insulated sheds combined with coal-fired boilers, electric blankets, or hot air blowers. However, these traditional methods have many drawbacks: First, they rely on external energy supplies, resulting in high energy consumption and operating costs, and are limited by site energy conditions; second, external heating methods have high thermal inertia and lag in temperature control, leading to large fluctuations in curing temperature and affecting the development of concrete strength; third, they pose safety risks such as fire and electric shock, do not meet the environmental protection requirements of green construction, and result in high carbon emissions.

[0004] While some existing technologies have attempted to utilize phase change materials (PCMs) for heat storage during curing, the heat release power of a single PCM is limited and the heat release rate is slow, making it difficult to maintain the temperature required for concrete curing for extended periods under extremely cold conditions. Therefore, it is imperative to develop a winter concrete curing technology that requires no external energy source, provides continuous and stable heating, offers precise temperature control, and is environmentally friendly and safe. Summary of the Invention

[0005] The present invention addresses the problems mentioned above by designing a self-heating curing system and curing method for winter concrete construction, thereby overcoming the deficiencies of existing technologies.

[0006] To achieve the above objectives, this invention provides a self-heating curing system for winter concrete construction, comprising a heating model assembled from heat-conducting metal plates. The heating model is supported above the concrete structure to be cured by formwork. The heating model includes a top layer, a bottom layer, and an intermediate layer sandwiched between the top and bottom layers. Both the top and bottom layers are filled with paraffin phase change material. The intermediate layer includes a template layer, a functional layer, and an insulation layer arranged sequentially. The template layer is close to the concrete structure. The functional layer is divided into multiple independently triggerable reaction zones by longitudinal timber. Each reaction zone is filled with an equal mass of calcium oxide and equipped with a water supply device. The water supply device is also electrically connected to a control module, which is electrically connected to a temperature sensor for monitoring the surface temperature of the concrete structure. When the surface temperature of the concrete structure is lower than a set threshold, the control module controls the water supply device to sequentially supply water to the multiple reaction zones of the functional layer, thereby achieving a phased release of heat.

[0007] Furthermore, the template layer is an inner thermally conductive metal template, the insulation layer is an outer insulation board, the template layer separates the functional layer from the bottom layer, and the insulation layer separates the functional layer from the top layer.

[0008] Furthermore, the surface of the template layer is provided with pores.

[0009] Furthermore, the water supply device includes a water pipe and a water pump. The water pipe is configured to correspond to each reaction zone of the functional layer. One end of the water pipe is connected to the water pump, and the other end extends into each reaction zone. A pipe valve is provided in the middle of the water pipe. The control module is electrically connected to the water pump and the pipe valve respectively.

[0010] Furthermore, the number of reaction zones is 12, and the 12 reaction zones are evenly divided into three groups. The control module triggers one group of reaction zones each day to carry out the hydration exothermic reaction.

[0011] Preferably, the mass ratio of calcium oxide to water is 2:1.

[0012] Preferably, the set threshold is 5°C.

[0013] This invention also includes a curing method for a self-heating curing system for concrete construction in winter, comprising the following steps: Step 1: Template splicing. The bottom layer, template layer, functional layer, insulation layer and top layer of the heating model are spliced ​​and fixed on the concrete structure with the help of formwork. Step 2: Arrange water pipes and temperature control sensors. The water pipes are arranged in an alternating pattern with the frame beams, and the built-in temperature control sensors are used to monitor the surface temperature of the concrete structure in real time. Step 3: The temperature sensor is electrically connected to the input terminal of the control module, and the water supply device is electrically connected to the output terminal of the control module. When the temperature sensor detects that the temperature is below 5°C, it outputs a signal to the control module, and the control module controls the water supply device to supply water to the reaction zone, triggering the exothermic hydration of calcium oxide. Step 4: After the concrete has reached the required strength, remove the heated mold, take out the built-in paraffin phase change material, heat and dry it for reuse.

[0014] Furthermore, in step three, the control module adds an appropriate amount of water to one of the three reaction zones each day according to the timing control logic, ensuring that the heat released by calcium oxide sustains the heating model for 3 days until the concrete reaches the required strength.

[0015] In summary, the present invention has the following advantages and beneficial technical effects: 1. This invention fully utilizes the exothermic chemical reaction of calcium oxide and water and the physical phase change of paraffin phase change materials to provide energy, constructing a dual-heat-source synergistic heating system. Through time-series control, it achieves on-demand release and continuous supply of heat, eliminating the need for external energy sources. This enables the self-supply, continuous stability, and precise control of concrete winter curing temperature, thereby ensuring construction quality.

[0016] 2. The present invention has good temperature controllability. Through the partitioning design of the reaction zone where calcium oxide is located, the timing control trigger, and the optimization of the ratio of calcium oxide to water, combined with the real-time monitoring of the temperature control sensor and the automatic control of pipeline valves and water pumps, it can achieve precise control of the heating process and temperature curve, and avoid excessive temperature fluctuations from affecting the quality of concrete.

[0017] 3. This invention utilizes the excess water design and the heat absorption properties of paraffin phase change materials to effectively suppress the risk of excessively high temperatures that may result from the calcium oxide reaction. The entire system is flameless and requires no electricity, thus fundamentally eliminating safety hazards such as fire and electric shock.

[0018] 4. This invention is cost-effective. The materials used, such as calcium oxide and paraffin, are low-cost. The device can be designed for modular installation, making it easy to assemble and disassemble. The paraffin phase change material can be reused after heating and drying, and the long-term cost is far lower than that of traditional heating methods. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the heating template in this invention; Figure 2 This is a schematic diagram of the structure of the intermediate layer in this invention; Figure 3This is a schematic diagram of the arrangement of the reaction zone in this invention; Figure 4 This is a schematic diagram of the temperature change during the paraffin phase transition process of this invention.

[0020] The reference numerals in the attached figures are: 1. Heating model; 11. Top layer; 12. Middle layer; 121. Template layer; 122. Functional layer; 123. Insulation layer; 13. Bottom layer; 14. Longitudinal timber; 2. Water pipes; 3. Reaction zone group one; 4. Reaction zone group two; 5. Reaction zone group three. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout; the described embodiments are some embodiments of this invention, but not all embodiments; the embodiments and directional terms described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting this invention; all other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings: The following is in conjunction with the appendix Figures 1-4 The present invention will be further described in detail below: Example 1 like Figures 1-3As shown, this embodiment discloses a self-heating curing system for winter concrete construction, including a rectangular heating model 1 made of aluminum plates. The heating model 1 is supported above the concrete structure to be cured by formwork. The heating model 1 includes a top layer 11, a bottom layer 13, and an intermediate layer 12 sandwiched between the top layer 11 and the bottom layer 13. The top layer 11 and the bottom layer 13 are both filled with paraffin phase change material for slow-release heat storage and release. The intermediate layer 12 includes a template layer 121, a functional layer 122, and an insulation layer 123 arranged sequentially. The template layer 121 is close to the concrete structure, and the functional layer 122 is divided into sections by longitudinal timber 14. Multiple independently triggerable reaction zones are provided. Each reaction zone is filled with an equal mass of calcium oxide and equipped with a water supply device to quantitatively supply water to the reaction zone to trigger the exothermic hydration reaction of calcium oxide. The thickness of the top layer 11 is 3 cm, the thickness of the bottom layer 13 is 1 cm, and the thickness of the middle layer 12 is 2 cm. The water supply device is also electrically connected to a control module, which is electrically connected to a temperature control sensor for monitoring the surface temperature of the concrete structure. When the surface temperature of the concrete structure is lower than a set threshold, the control module controls the water supply device to sequentially supply water to the multiple reaction zones of the functional layer 122 to achieve the phased release of heat.

[0022] like Figure 2 As shown, template layer 121 is an inner heat-conducting metal template, and insulation layer 123 is an outer insulation board. Template layer 121 separates functional layer 122 from bottom layer 13, and insulation layer 123 separates functional layer 122 from top layer 11. The surface of template layer 121 has pores to ensure water vapor circulation during the curing process. The water supply device includes a water pipe 2 and a water pump. The water pipe 2 is correspondingly set for each reaction zone of functional layer 122. One end of the water pipe 2 is connected to the water pump, and the other end extends into each reaction zone. A pipe valve is installed in the middle of the water pipe 2. The control module is electrically connected to the water pump and the pipe valve to adjust the water flow rate in the water pipe 2 and control the amount of water added to each reaction zone.

[0023] like Figure 3 As shown, there are 12 reaction intervals, which are evenly divided into three groups: reaction interval group 1 (3), reaction interval group 2 (4), and reaction interval group 3 (5). Each group corresponds to a triggering sequence. The control module triggers one group of reaction intervals daily to carry out the hydration exothermic reaction.

[0024] Calculations show that 20g of calcium oxide contains 0.357mol of substance, and 10g of water contains 0.555mol of substance. During the reaction, calcium oxide reacts completely and releases a large amount of heat, causing a rapid rise in temperature. The excess water acts as a buffer, absorbing some of the heat or evaporating, effectively limiting the temperature peak and preventing damage to the concrete structure from excessively high temperatures. Therefore, in this embodiment, the mass ratio of calcium oxide to water is 2:1, ensuring complete reaction of the calcium oxide and an excess of water to limit the temperature peak.

[0025] 246 g of liquid paraffin was weighed and placed in an insulated container. Several temperature probes were placed at the bottom and top of the container, on the surface of the liquid paraffin, and on the outside of the container to monitor the temperature change of the paraffin from a room-temperature liquid state to a low-temperature solid state. Figure 4 The magnified view in the upper right corner shows that when the temperature drops to near During this period, the temperature change becomes relatively gradual, indicating that paraffin is undergoing a phase transition from liquid to solid. During this phase transition, paraffin releases heat, but the temperature change is relatively slow. Only after the phase transition is essentially complete does the temperature continue to decrease over time, further illustrating that temperature is a key factor affecting the phase transition of paraffin. When the temperature falls below the phase transition temperature, paraffin gradually transforms from a liquid to a solid state. Therefore, in this embodiment, a threshold of 5°C is set. When the temperature sensor detects that the surface temperature of the concrete structure is below 5°C, the control module activates the water supply device.

[0026] Example 2 The present invention provides a curing method for a self-heating curing system for winter concrete construction: Step 1: Template splicing. The bottom layer 13, template layer 121, functional layer 122, insulation layer 123 and top layer 11 of the heating model 1 are spliced ​​and fixed on the concrete structure with the help of formwork.

[0027] Step 2: Arrange water pipe 2 and temperature control sensor. To ensure the strength of the template, water pipe 2 is arranged in an alternating manner with the frame beams, and a built-in temperature control sensor is installed to monitor the surface temperature of the concrete structure in real time.

[0028] Step 3: The temperature sensor is electrically connected to the input terminal of the control module, and the water pump, pipeline valve and control module output terminal are electrically connected. When the temperature sensor detects that the temperature is below 5℃, it outputs a signal to the control module, and the control module controls the water supply device to supply water to the reaction zone, triggering the exothermic hydration of calcium oxide. According to the timing control logic, the control module adds an appropriate amount of water to one of the three reaction zones every day to ensure that the heat released by calcium oxide sustains the heating model 1 for 3 days until the concrete reaches the required strength. In the early stage of concrete pouring, the paraffin phase change material in the top layer 11 and the bottom layer 13 stores heat and keeps the temperature warm. When the temperature is lost in the later stage, an appropriate amount of water is added to the reaction zone through the water pipe 2. Calcium oxide reacts with water to release heat, which is used to provide heat in conjunction with the paraffin phase change material. The pores on the surface of the template layer 121 ensure the flow of water vapor and achieve the curing effect.

[0029] Step 4: After the concrete has reached the required strength, remove the heated model 1, take out the built-in paraffin phase change material, heat and dry it for reuse.

[0030] 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 foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-heating curing system for concrete construction in winter, characterized in that: The heating model includes a heating model made of thermally conductive metal plates, which is supported on the concrete structure to be cured by a formwork. The heating model includes a top layer, a bottom layer, and an intermediate layer sandwiched between the top layer and the bottom layer. The top and bottom layers are filled with paraffin phase change material. The middle layer includes a template layer, a functional layer and an insulation layer arranged in sequence. The template layer is close to the concrete structure. The functional layer is divided into multiple independently triggerable reaction zones by longitudinal timber. Each reaction zone is filled with an equal mass of calcium oxide and equipped with a water supply device. The water supply device is also electrically connected to a control module, which is electrically connected to a temperature control sensor for monitoring the surface temperature of the concrete structure. When the surface temperature of the concrete structure is lower than a set threshold, the control module controls the water supply device to supply water to multiple reaction zones of the functional layer in sequence, thereby realizing the phased release of heat.

2. The self-heating curing system for winter concrete construction according to claim 1, characterized in that: The template layer is an inner thermally conductive metal template, the insulation layer is an outer insulation board, the template layer separates the functional layer from the bottom layer, and the insulation layer separates the functional layer from the top layer.

3. The self-heating curing system for winter concrete construction according to claim 1, characterized in that: The surface of the template layer is provided with air holes.

4. The self-heating curing system for winter concrete construction according to claim 1, characterized in that: The water supply device includes a water pipe and a water pump. The water pipe is set in accordance with each reaction zone of the functional layer. One end of the water pipe is connected to the water pump, and the other end extends into each reaction zone. A pipe valve is set in the middle of the water pipe. The control module is electrically connected to the water pump and the pipe valve respectively.

5. The self-heating curing system for winter concrete construction according to claim 4, characterized in that: The number of reaction zones is 12, and the 12 reaction zones are evenly divided into three groups. The control module triggers one group of reaction zones to carry out the hydration exothermic reaction every day.

6. A self-heating curing system for winter concrete construction according to claim 5, characterized in that: The mass ratio of calcium oxide to water is 2:

1.

7. A self-heating curing system for winter concrete construction according to claim 6, characterized in that: The set threshold is 5°C.

8. A curing method for a self-heating curing system for concrete construction in winter, characterized in that: The curing method of the self-heating curing system for winter concrete construction as described in claim 7 includes the following steps: Step 1: Template splicing. The bottom layer, template layer, functional layer, insulation layer and top layer of the heating model are spliced ​​and fixed on the concrete structure with the help of formwork. Step 2: Arrange water pipes and temperature control sensors. The water pipes are arranged in an alternating pattern with the frame beams, and the built-in temperature control sensors are used to monitor the surface temperature of the concrete structure in real time. Step 3: The temperature sensor is electrically connected to the input terminal of the control module, and the water supply device is electrically connected to the output terminal of the control module. When the temperature sensor detects that the temperature is below 5°C, it outputs a signal to the control module, and the control module controls the water supply device to supply water to the reaction zone, triggering the exothermic hydration of calcium oxide. Step 4: After the concrete has reached the required strength, remove the heated mold, take out the built-in paraffin phase change material, heat and dry it for reuse.

9. A curing method for a self-heating curing system for winter concrete construction according to claim 8, characterized in that: In step three, the control module adds an appropriate amount of water to one of the three reaction zones each day according to the timing control logic, ensuring that the heat released by calcium oxide sustains the heating model for 3 days until the concrete reaches the required strength.

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