3D printing concrete carbonization curing regulation and control device and method

Abstract

The invention discloses a 3D printing concrete carbonization curing regulation and control device and method.The device comprises a curing box, a 3D printing device, a carbonization curing device and a control system, and the 3D printing device is movably installed in the curing box; a humidity adjusting device for adjusting the humidity in the curing box and a temperature control device for adjusting the temperature in the curing box are arranged at the bottom of the curing box; the carbonization curing device comprises a gas cylinder used for containing CO2 and a spraying device, the spraying device is connected with the gas cylinder through a gas conveying pipe, the spraying device is fixedly connected with the 3D printing device, and during 3D printing, the spraying device moves along with the 3D printing device and sprays CO2 to concrete layers. According to the invention, CO2 is directly introduced into the interlayer of the concrete being printed through the carbonization curing device, the interlayer carbonization reaction is promoted, and the depth of the carbonization reaction is ensured, so that the strength and stability of each layer of printed concrete can be rapidly improved, and the performance and durability of the concrete are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building material maintenance, and in particular to a 3D printed concrete carbonization maintenance control device and method. Background Art

[0002] Architectural 3D printing technology has significant advantages in improving construction efficiency, reducing costs, promoting design innovation, improving quality and precision, and promoting green buildings and sustainable development. With the continuous development of technology and the expansion of its application scope, 3D printing is expected to become an important development trend in the construction industry in the future, providing strong support for the transformation and upgrading of the construction industry, the realization of environmental protection goals, and the resolution of labor problems. However, 3D printed concrete generally has interlayer weak areas during the printing process. The porosity in this area is high, there are a large number of interconnected pores, and the cementitious material is not fully hydrated. This leads to the deterioration of the mechanical properties and integrity of cement-based materials, seriously endangering the safety of the structure, significantly weakening its durability, and thus increasing the maintenance and use costs.

[0003] Carbonation curing of concrete is considered to be a curing method that reduces carbon footprint and effectively improves the mechanical properties and durability of concrete. Carbonation curing provides an innovative solution for improving the performance of 3D printed concrete. By effectively reducing the porosity of 3D printed concrete and improving mechanical properties and durability, carbonation curing can not only make up for the shortcomings of 3D printed concrete in terms of mechanical anisotropy and durability, but also achieve rapid curing and improve the construction efficiency of 3D printed concrete. While reducing the cost and time of traditional curing, it helps reduce carbon emissions and achieve carbon capture and storage. However, the existing 3D printed concrete has uneven carbonization reaction and insufficient reaction depth during the curing process, which leads to the problem that the improvement of concrete mechanical properties and durability is not significant. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings of uneven carbonization reaction and insufficient reaction depth in the curing process of the prior art, the present invention provides a 3D printed concrete carbonization curing control device and method.

[0005] Technical solution: To solve the above problems, the present invention adopts a 3D printing concrete carbonization curing and regulating device, including a curing box, a 3D printing device, a carbonization curing device and a control system. The 3D printing device is movably installed in the curing box, and a humidity regulating device for adjusting the humidity in the curing box and a temperature control device for adjusting the temperature in the curing box are provided at the bottom of the curing box; the carbonization curing device includes a gas cylinder for containing CO2 and a spray device, the spray device is connected to the gas cylinder through a gas pipe, and the spray device is fixedly connected to the 3D printing device. When 3D printing is performed, the spray device moves with the 3D printing device and sprays CO2 between concrete layers;

[0006] A temperature sensor and a humidity sensor are provided in the curing box, and a CO2 concentration detector is provided on the spray device; the control system is used to monitor the data of the temperature sensor, the humidity sensor and the CO2 concentration detector and control the humidity regulating device, the temperature control device and the spray device according to the data to adjust the humidity, temperature and CO2 concentration in the curing box.

[0007] Furthermore, the 3D printing device includes a printer hopper for containing and mixing concrete raw materials, and a printing nozzle installed at the bottom of the printer hopper. The printer hopper is provided with a material injection port, which is connected to a concrete pumping device through a pumping pipe. The concrete pumping device is used to provide concrete raw materials.

[0008] Furthermore, the concrete pumping device is located outside the curing box, and a feeding hole for the pumping pipe to pass through is opened on the curing box.

[0009] Furthermore, the gas cylinder is provided with a pressure reducing valve, a first pressure gauge and a second pressure gauge, the first pressure gauge is used to monitor the internal pressure of the gas cylinder, and the second pressure gauge is used to monitor the gas outlet pressure of the gas cylinder.

[0010] Furthermore, the gas cylinder is located outside the maintenance box, and the maintenance box is provided with an opening for the gas pipe to pass through. The gas pipe is provided with a gas pressure reducing valve and a normal pressure CO2 input end, and the normal pressure CO2 input end is located inside the maintenance box.

[0011] Furthermore, the spray device is provided with a flow controller for adjusting the spray concentration, and the CO2 concentration detector includes a CO2 concentration detection head and a digital concentration meter.

[0012] Furthermore, the control system includes an intelligent control device and a computer, the computer is used to input preset humidity, temperature and CO2 concentration values ​​and display sensor monitoring data, and the intelligent control device is used to control the humidity regulating device, temperature control device and spray device according to the monitoring data and preset humidity, temperature and CO2 concentration values.

[0013] Furthermore, a slide rail is provided in the maintenance box, a mobile bracket is fixed on the slide rail, and the 3D printing device is fixedly installed on the mobile bracket.

[0014] The present invention also provides a method for using the 3D printing concrete carbonization curing and regulating device, comprising the following steps:

[0015] Step 1: Input the humidity preset value, temperature preset value, first stage CO2 concentration preset value, and second stage CO2 concentration preset value into the control system;

[0016] Step 2: Turn on the 3D printing device to perform 3D printing of concrete, and at the same time turn on the carbonization curing device, so that the spray device moves with the 3D printing device and sprays CO2 between the concrete layers;

[0017] Step 3: The control system receives data from the temperature sensor, humidity sensor, and CO2 concentration detector and controls the humidity adjustment device, temperature control device, and spray device according to the data, so that the humidity, temperature, and CO2 concentration in the curing box are maintained at the preset humidity value, the preset temperature value, and the preset CO2 concentration value of the first stage until the 3D printing is completed, and the spray device is turned off;

[0018] Step 4: Keep the humidity and temperature in the curing box at the preset humidity and temperature values, and let the printed concrete stand for T1;

[0019] Step 5, open the spray device again to spray CO2, so that the humidity, temperature and CO2 concentration in the curing box are maintained at the preset humidity value, temperature preset value and second-stage CO2 concentration preset value. After maintaining for time T2, close the spray device and take out the concrete specimen.

[0020] Furthermore, the humidity preset value is 25±3°C, the temperature preset value is 65±5%, the CO2 concentration preset value in the first stage is 50±10%, the CO2 concentration preset value in the second stage is 20±3%, T1 is 8h, and T2 is 16h.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) CO2 is directly introduced into the interlayer of concrete being printed through the carbonization curing device, which promotes the interlayer carbonization reaction and ensures the depth of the carbonization reaction, so that each layer of printed concrete can quickly improve its strength and stability, thereby improving the performance and durability of the concrete; and (2) the CO2 concentration and environmental conditions are adjusted in real time in combination with an intelligent control system to ensure the efficiency and uniformity of the carbonization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the carbonization curing and regulating device of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the spray device of the present invention. DETAILED DESCRIPTION

[0024] like Figure 1 and Figure 2As shown, a 3D printed concrete carbonization curing and regulating device in this embodiment includes a curing box 1, a 3D printing device, a carbonization curing device and a control system. A humidity regulating device 11 for adjusting the humidity in the curing box 1 and a temperature control device 12 for adjusting the temperature in the curing box 1 are provided at the bottom of the curing box 1. The humidity regulating device 11 includes a water tank and a humidifier and a dehumidifier connected to the water tank. When the humidity of the curing box 1 needs to be increased, the humidifier is turned on for humidification, and when the humidity needs to be reduced, the dehumidifier is turned on for dehumidification. The temperature control device 12 is an electric heater or an infrared heating device. A circulating fan 183 is also provided in the curing box 1 to circulate and circulate the gas in the box.

[0025] The 3D printing device includes a printer hopper 21 for containing and mixing concrete raw materials, a printing nozzle 23 installed at the bottom of the printer hopper 21, and a material injection port 22 is provided on the printer hopper 21. The material injection port 22 is connected to the concrete pumping device 17 through a pumping pipe 171. The concrete pumping device 17 is used to provide concrete raw materials. The concrete pumping device 17 is located outside the curing box 1. The curing box 1 is provided with a feeding hole 15 for the pumping pipe 171 to pass through. A slide rail 13 is provided in the curing box 1, and a mobile bracket 2 is fixed on the slide rail 13. The 3D printing device is fixedly installed on the mobile bracket 2. The 3D printing device slides on the slide rail 13 following the mobile bracket 2 to perform 3D printing.

[0026] The carbonization curing device includes a gas cylinder 16 for containing CO2 and a spray device 3. A gas delivery port 31 is provided on the upper part of the spray device 3, and the gas delivery port 31 is connected to the gas cylinder 16 through a gas delivery pipe 162. The gas cylinder 16 is located outside the curing box 1, and an opening is provided on the curing box 1 for the gas delivery pipe 162 to pass through. The gas cylinder 16 is provided with a pressure reducing valve 161, a first pressure gauge 163 and a second pressure gauge 164. The first pressure gauge 163 is used to monitor the internal pressure of the gas cylinder, and the second pressure gauge is used to monitor the gas outlet pressure of the gas cylinder. The gas cylinder 16 in this embodiment is a high-pressure gas cylinder, the gas delivery pipe section located outside the curing box 1 is a high-pressure gas delivery pipe, and the gas delivery pipe section located inside the curing box 1 is a normal-pressure gas delivery pipe. A gas pressure reducing valve 14 is provided between the two sections of the gas pipeline, and the high-pressure CO2 gas inputted from the gas cylinder 162 is reduced to normal-pressure CO2 gas through the gas pressure reducing valve 14. A normal-pressure CO2 input terminal 141 is provided on the normal-pressure gas pipeline. A part of the CO2 gas in the gas pipeline is discharged into the curing box through the normal-pressure CO2 input terminal 141, and a part of the CO2 gas is sprayed onto the concrete layer being printed through the spray device 3. A flow controller 32 for adjusting the spray concentration is provided in the spray device 3. The spray device 3 is fixedly connected to the 3D printing device. When 3D printing is performed, the spray device 3 moves with the 3D printing device and sprays CO2 onto the concrete layers.

[0027] In order to accurately monitor the temperature, humidity and CO2 concentration inside the curing box 1, a temperature sensor 181 and a humidity sensor 182 are provided in the curing box 1. A CO2 concentration detector 33 is provided on the side wall of the spray device 3 near the carbon dioxide spray range 34. The CO2 concentration detector 33 includes a CO2 concentration detection head 332 and a digital display concentration meter 331. The control system includes an intelligent control device 18 and a computer 19. The computer 19 is used to input preset humidity, temperature and CO2 concentration values ​​and display sensor monitoring data. The intelligent control device 18 is used to control the humidity adjustment device 11, the temperature control device 12 and the spray device 3 according to the monitoring data and the preset humidity, temperature and CO2 concentration values.

[0028] The present invention also provides a method for using the above-mentioned 3D printed concrete carbonization curing and regulating device, wherein the concrete ratio is 950 kg of silicate cement, 50 kg of sulphoaluminate cement, 1000 kg of quartz sand, 400 kg of water, 2.2 kg of polycarboxylate water reducer, and 4.9 kg of hydroxypropylmethyl cellulose ether, and specifically comprises the following steps:

[0029] Step 1: Input the humidity preset value, temperature preset value, first stage CO2 concentration preset value, and second stage CO2 concentration preset value into the computer 19. To ensure a better carbonization curing effect, the humidity preset value is set to 25±3°C, the temperature preset value is set to 65±5%, the first stage CO2 concentration preset value is set to 50±10%, and the second stage CO2 concentration preset value is set to 20±3%.

[0030] Step 2: Turn on the 3D printing device to perform 3D printing of concrete, and at the same time turn on the carbonization curing device, so that the spray device 3 moves with the 3D printing device and sprays CO2 between the concrete layers.

[0031] Step 3, the control system receives data from the temperature sensor 181, the humidity sensor 182, and the CO2 concentration detector 33 and controls the humidity adjustment device 11, the temperature control device 12 and the spray device 3 according to the data, so that the humidity, temperature and CO2 concentration in the curing box 1 are maintained at the preset humidity value, the preset temperature value and the first-stage CO2 concentration preset value until the 3D printing is completed and the spray device 3 is turned off.

[0032] Step 4: Keep the humidity and temperature in the curing box 1 at the preset humidity and temperature values, and let the printed concrete stand for 8 hours;

[0033] Step 5, open the spray device 3 again to spray CO2, so that the humidity, temperature and CO2 concentration in the curing box 1 are maintained at the preset humidity value, temperature preset value and second-stage CO2 concentration preset value. After maintaining for 16 hours, close the spray device 3 and take out the concrete specimen.

[0034] The concrete specimens were subsequently subjected to standard curing until the corresponding test age was reached. After testing, the concrete prepared in this embodiment had a cubic compressive strength of 41.2MPa after 28 days of pouring, a 3D printed specimen had an interlayer splitting compressive strength of 3.75MPa after 28 days, and a specimen without carbonization curing had an interlayer splitting compressive strength of 3.13MPa after 28 days. In comparison, the interlayer splitting compressive strength of this embodiment increased by 19.8%. The mercury injection test of the 3D printed samples 28 days before and after carbonization showed that the total porosity before and after carbonization was 11.57% and 9.34%, respectively, a decrease of 19.27%. It can be seen that the compressive strength of concrete after carbonization curing is significantly improved compared with traditional curing methods. According to experimental data, the interlayer splitting strength 28 days after carbonization curing is about 20% higher than that of traditional curing, and the porosity is effectively reduced. This improvement helps to improve the compactness of concrete, thereby enhancing its mechanical properties and durability. In addition, this carbonization curing significantly enhances the carbonization efficiency.

[0035] In summary, the present invention directly introduces CO2 into the interlayer of concrete being printed through the carbonization curing device, promotes the interlayer carbonization reaction, ensures the depth of the carbonization reaction, enables each layer of printed concrete to quickly improve its strength and stability, and improves the performance and durability of the concrete. In addition, the CO2 concentration and environmental conditions are adjusted in real time in combination with an intelligent control system to ensure the efficiency and uniformity of the carbonization process.

Claims

1. A 3D printed concrete carbonization curing and control device, characterized in that: The invention comprises a curing box (1), a 3D printing device, a carbonization curing device and a control system. The 3D printing device is movably installed in the curing box (1). The bottom of the curing box (1) is provided with a humidity regulating device (11) for adjusting the humidity in the curing box (1) and a temperature control device (12) for adjusting the temperature in the curing box (1). The carbonization curing device comprises a gas cylinder (16) for containing CO2 and a spray device (3). The spray device (3) is connected to the gas cylinder (16) via a gas pipe (162). The spray device (3) is fixedly connected to the 3D printing device. When 3D printing is performed, the spray device (3) moves with the 3D printing device and sprays CO2 between concrete layers. A temperature sensor (181) and a humidity sensor (182) are provided in the curing box (1), and a CO2 concentration detector (33) is provided on the spray device (3); the control system is used to monitor data from the temperature sensor (181), the humidity sensor (182), and the CO2 concentration detector (33), and to control the humidity adjustment device (11), the temperature control device (12), and the spray device (3) according to the data to adjust the humidity, temperature, and CO2 concentration in the curing box (1).

2. The 3D printing concrete carbonization curing and control device according to claim 1, characterized in that: The 3D printing device comprises a printer hopper (21) for containing and mixing concrete raw materials, and a printing nozzle (23) installed at the bottom of the printer hopper (21). The printer hopper (21) is provided with a material injection port (22), and the material injection port (22) is connected to a concrete pumping device (17) through a pumping pipe (171). The concrete pumping device (17) is used to provide concrete raw materials.

3. The 3D printing concrete carbonization curing and control device according to claim 2, characterized in that: The concrete pumping device (17) is located outside the curing box (1), and a material delivery hole (15) for a pumping pipe (171) to pass through is provided on the curing box (1).

4. The 3D printing concrete carbonization curing and control device according to claim 1, characterized in that: The gas cylinder (16) is provided with a pressure reducing valve (161), a first pressure gauge (163) and a second pressure gauge (164); the first pressure gauge (163) is used to monitor the internal pressure of the gas cylinder, and the second pressure gauge is used to monitor the gas outlet pressure of the gas cylinder.

5. The 3D printing concrete carbonization curing and regulating device according to claim 1, characterized in that: The gas cylinder (16) is located outside the curing box (1). The curing box (1) is provided with an opening for a gas delivery pipe (162) to pass through. The gas delivery pipe (162) is provided with a gas pressure reducing valve (14) and a normal-pressure CO2 input end (141). The normal-pressure CO2 input end (141) is located inside the curing box (1).

6. The 3D printing concrete carbonization curing and regulating device according to claim 1, characterized in that: The spray device (3) is provided with a flow controller (32) for adjusting the spray concentration, and the CO2 concentration detector (33) comprises a CO2 concentration detection head (332) and a digital concentration meter (331).

7. The 3D printing concrete carbonization curing and regulating device according to claim 1, characterized in that: The control system comprises an intelligent control device (18) and a computer (19), wherein the computer (19) is used to input preset humidity, temperature and CO2 concentration values ​​and display sensor monitoring data, and the intelligent control device (18) is used to control the humidity adjustment device (11), the temperature control device (12) and the spray device (3) according to the monitoring data and the preset humidity, temperature and CO2 concentration values.

8. The 3D printing concrete carbonization curing and regulating device according to claim 1, characterized in that: A slide rail (13) is provided in the maintenance box (1), a mobile bracket (2) is fixed on the slide rail (13), and the 3D printing device is fixedly mounted on the mobile bracket (2).

9. A method for using the 3D printing concrete carbonization curing and regulating device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Input the humidity preset value, temperature preset value, first stage CO2 concentration preset value, and second stage CO2 concentration preset value into the control system; Step 2, start the 3D printing device to perform 3D printing of concrete, and at the same time start the carbonization curing device, so that the spray device (3) moves with the 3D printing device and sprays CO2 between the concrete layers; Step 3, the control system receives data from the temperature sensor (181), the humidity sensor (182), and the CO2 concentration detector (33), and controls the humidity adjustment device (11), the temperature control device (12), and the spray device (3) according to the data, so that the humidity, temperature, and CO2 concentration in the curing box (1) are maintained at a preset humidity value, a preset temperature value, and a preset first-stage CO2 concentration value until 3D printing is completed, and the spray device (3) is turned off; Step 4, maintaining the humidity and temperature in the curing box (1) at the preset humidity and temperature values, and leaving the printed concrete to stand for a period of time T1; Step 5, open the spray device (3) again to spray CO2, so that the humidity, temperature and CO2 concentration in the curing box (1) are maintained at the preset humidity value, the preset temperature value and the second stage CO2 concentration preset value. After maintaining for time T2, close the spray device (3) and take out the concrete specimen.

10. The method of use according to claim 9, characterized in that: The humidity preset value is 25±3℃, the temperature preset value is 65±5%, the CO2 concentration preset value in the first stage is 50±10%, the CO2 concentration preset value in the second stage is 20±3%, T1 is 8h, and T2 is 16h.

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