Construction method for outdoor steam curing of PHC pipe pile

Abstract

The invention discloses a construction method for outdoor steam curing of a PHC tubular pile, which comprises the following steps: S1, dividing an outdoor steam curing area, hoisting the centrifuged PHC tubular pile together with a template to the outdoor steam curing area, stably placing the PHC tubular pile on a cushion ridge, and standing for 3 hours; s2, two phi 50mm steam branch pipes connected with a steam valve are connected into the pipe pile from the two ends of the PHC pipe pile; s3, the PHC pipe pile is covered with a layer of cotton quilt with the thickness of 5 cm, and then covered with a layer of heat preservation tarpaulin; s4, a steam valve is opened, a steam curing procedure is started, and steam is sprayed into the PHC pipe pile through a steam branch pipe; and S5, until steam curing is completed, the PHC pipe pile is hoisted to a demolding area for demolding. The PHC pipe pile steam curing area can be reduced, the PHC pipe pile steam curing work efficiency and steam curing effect are improved, and the purposes of reducing cost and improving efficiency are achieved.

Description

Technical Field

[0001] This invention relates to a construction method for outdoor steam curing of PHC pipe piles. Background Technology

[0002] The concrete mix design for PHC pipe piles requires either atmospheric pressure steam curing or high-pressure steam curing to improve early concrete strength, ensure timely demolding, and enhance production efficiency. During PHC pipe pile production, both steam and autoclaving processes require significant time and energy, and both atmospheric and high-pressure steam curing can negatively impact concrete performance. Steam curing increases internal porosity, reducing resistance to chloride ion penetration. Incorrect curing regimes can also negatively affect later compressive strength, and insufficient curing time can cause horizontal cracks on the surface of the steam-cured concrete. High-pressure steam curing requires 3-5 hours at a steam pressure of 0.95–1.0 MPa and a temperature of 170–180°C. Autoclaving affects concrete performance, especially since the temperature upon exiting the autoclave is very high. Without effective cooling, the temperature difference can cause cracks in the PHC pipe pile concrete, negatively impacting its durability. If steam curing or high-pressure steam curing is not used, the existing PHC pipe pile concrete preparation method cannot meet the production needs.

[0003] Therefore, in order to improve the steam curing efficiency of PHC pipe piles without increasing the steam curing tank, a construction method for outdoor steam curing of PHC pipe piles is provided. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides a construction method for outdoor steam curing of PHC pipe piles, which can reduce the steam curing area of ​​PHC pipe piles, improve the steam curing efficiency and effect, and achieve the goal of cost reduction and efficiency improvement.

[0005] The technical solution to achieve the above objectives is:

[0006] A construction method for outdoor steam curing of PHC pipe piles includes:

[0007] Step S1: Divide the outdoor steam curing area, hoist the centrifuged PHC pipe piles together with the template to the outdoor steam curing area, place them stably on the pads, and let them stand for 3 hours.

[0008] Step S2: Connect the two φ50mm steam branch pipes that are connected to the steam valve to the inside of the PHC pipe pile from both ends;

[0009] Step S3: Cover the PHC pipe pile with a 5cm thick cotton quilt, and then cover it with a layer of heat-insulating tarpaulin.

[0010] Step S4: Open the steam valve to start the steam curing process, and inject steam into the PHC pipe pile through the steam branch pipe.

[0011] Step S5: Once steam curing is complete, hoist the PHC pipe pile to the demolding area for demolding.

[0012] Preferably, in step S2, two steam branch pipes are respectively connected to the inside of the PHC pipe pile from both ends, each extending 6m inward. A jet hole is set every 2m on the steam branch pipe, and two temperature sensors are installed on the branch pipe to sense the temperature inside the pipe pile.

[0013] Preferably, in step S3, the thermal insulation tarpaulin is in contact with the ground on all four sides, with an overlap length of not less than 0.5m.

[0014] Preferably, in step S4, the temperature sensor is connected to an external digital display thermometer. The temperature sensor senses the temperature inside the pipe pile, and the digital display thermometer provides real-time feedback on the internal temperature value of the PHC pipe pile.

[0015] Preferably, in step S4, the steam curing process is as follows: heat up to 78°C, maintain the temperature for 8-10 hours, and then cool down for 2-3 hours.

[0016] Preferably, in step S4, the steam curing process specifically includes:

[0017] Open the steam valve to its maximum opening and introduce steam into the PHC pipe pile through the steam branch pipe to gradually increase the temperature. When the digital thermometer shows that the internal temperature of the PHC pipe pile reaches 78°C, reduce the opening of the steam valve and maintain a constant temperature for 8-10 hours. Finally, close the steam valve and gradually decrease the temperature for 2-3 hours.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention reduces the need for a steam curing tank, avoids affecting the steam curing efficiency of PHC pipe piles due to insufficient area of ​​the steam curing tank, and reduces the cost of constructing a steam curing tank; it can achieve the purpose of steam curing a single PHC pipe pile, and compared with the process of steam curing multiple piles together in a steam curing tank, it reduces the settling time and improves the steam curing efficiency; the steam pipe of the present invention extends directly into the interior of the PHC pipe pile, which significantly helps the strength growth of the pipe pile concrete and improves the steam curing effect; the use of cotton quilts and thermal insulation cloth to wrap and cover the PHC pipe pile reduces the space that the steam needs to fill, reduces the steam consumption during the heating and constant temperature periods, and saves steam consumption. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0020] Figure 1This is a flowchart of a construction method for outdoor steam curing of PHC pipe piles according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, a construction method for outdoor steam curing of PHC pipe piles includes:

[0023] Step S1: Divide the outdoor steam curing area, hoist the centrifuged PHC pipe piles along with the template to the outdoor steam curing area, place them stably on the pads, and let them stand for 3 hours.

[0024] In this embodiment, before hoisting, ensure all equipment involved in the hoisting is in good condition, including cranes and slings; check the slings for sturdiness and ensure there are no damaged items; calculate the hoisting point positions based on the length of the pipe pile; for pipe piles exceeding 20 meters, a 4-point hoisting method is typically used. Specific hoisting point positions can be calculated using formulas and measured and marked on the corresponding piles with a steel ruler; use a crane to hoist the centrifuged PHC pipe piles along with the formwork to the outdoor steam curing area; during hoisting, ensure the pipe piles are stable to avoid collisions and damage.

[0025] In this embodiment, the pipe piles are placed in a flat and firm location in the outdoor steam curing area; ensure that there is enough space in the outdoor steam curing area and that the ground is flat to avoid the pipe piles tilting or rolling during placement.

[0026] Pads should be placed at the placement location, and the pads should be evenly distributed and kept on the same plane; the position of the pads should correspond to the position of the lifting point to ensure the stability of the pipe pile placement;

[0027] Place the pipe piles along with the template on the support ribs to ensure that the pipe piles are placed stably. When placing the pipe piles, place wooden wedges on both sides of the pipe piles to prevent them from rolling. For pipe piles with anti-corrosion coatings, lay rubber sheets on the support wood to protect the coating.

[0028] Step S2: Connect the two φ50mm steam branch pipes that are connected to the steam valve to the inside of the PHC pipe pile from both ends.

[0029] In this embodiment, two steam branch pipes are connected to the inside of the PHC pipe pile from both ends, each extending 6m inward. A jet nozzle is installed on the steam branch pipe every 2m, and two temperature sensors are installed on the branch pipe to sense the temperature inside the pipe pile. The steam pipe extends directly into the inside of the PHC pipe pile, which significantly helps the strength growth of the pipe pile concrete and improves the steam curing effect.

[0030] Step S3: Cover the PHC pipe pile with a 5cm thick cotton quilt, and then cover it with a layer of thermal insulation tarpaulin. Wrapping the PHC pipe pile with cotton quilt and thermal insulation tarpaulin reduces the space required for steam filling, reduces steam consumption during the heating and constant temperature periods, and saves steam consumption.

[0031] In this embodiment, the thermal insulation tarpaulin is in contact with the ground on all four sides, with an overlap length of not less than 0.5m.

[0032] Step S4: Open the steam valve to start the steam curing process, and inject steam into the PHC pipe pile through the steam branch pipe.

[0033] In this embodiment, the temperature sensor is connected to an external digital thermometer. The temperature sensor senses the temperature inside the pipe pile, and the digital thermometer provides real-time feedback on the internal temperature value of the PHC pipe pile.

[0034] In this embodiment, the steam curing process is as follows: heat up to 78°C, maintain the temperature for 8-10 hours, and then cool down for 2-3 hours.

[0035] In this embodiment, the steam curing process is as follows:

[0036] Open the steam valve to its maximum opening and introduce steam into the PHC pipe pile through the steam branch pipe to gradually increase the temperature. When the digital thermometer shows that the internal temperature of the PHC pipe pile reaches 78°C, reduce the opening of the steam valve and maintain a constant temperature for 8-10 hours. Finally, close the steam valve and gradually decrease the temperature for 2-3 hours.

[0037] Step S5: Once steam curing is complete, hoist the PHC pipe pile to the demolding area for demolding.

[0038] In this embodiment, the pipe pile needs to be thermally cured before demolding; this process helps the concrete to harden initially and reduces damage during demolding; the specific time and temperature of the thermal curing need to be adjusted according to the actual situation.

[0039] After steam curing, the pipe piles are hoisted from the autoclave to the demolding area. In the demolding area, special equipment is used to remove the mold from the pipe piles. Care should be taken to protect the surface of the pipe piles during demolding to avoid damage.

[0040] After demolding, the pipe piles are lifted to the storage area using a crane or special equipment. When storing, attention should be paid to the placement of the pipe piles to avoid stacking them too high and causing damage. At the same time, the storage area should be kept dry and ventilated to prevent the pipe piles from getting damp or deformed.

[0041] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for outdoor steam curing of PHC pipe piles, characterized in that, include: Step S1: Divide the outdoor steam curing area, hoist the centrifuged PHC pipe piles together with the template to the outdoor steam curing area, place them stably on the pads, and let them stand for 3 hours. Step S2: Connect the two φ50mm steam branch pipes that are connected to the steam valve to the inside of the PHC pipe pile from both ends; Step S3: Cover the PHC pipe pile with a 5cm thick cotton quilt, and then cover it with a layer of heat-insulating tarpaulin. Step S4: Open the steam valve to start the steam curing process, and inject steam into the PHC pipe pile through the steam branch pipe. Step S5: Once steam curing is complete, hoist the PHC pipe pile to the demolding area for demolding.

2. The construction method for outdoor steam curing of PHC pipe piles according to claim 1, characterized in that, In step S2, two steam branch pipes are connected to the inside of the PHC pipe pile from both ends, each extending 6m. A jet hole is set every 2m on the steam branch pipe, and two temperature sensors are installed on the branch pipe to sense the temperature inside the pipe pile.

3. The construction method for outdoor steam curing of PHC pipe piles according to claim 1, characterized in that, In step S3, the thermal insulation tarpaulin is in contact with the ground on all four sides, with an overlap length of not less than 0.5m.

4. The construction method for outdoor steam curing of PHC pipe piles according to claim 1, characterized in that, In step S4, the temperature sensor is connected to an external digital thermometer. The temperature sensor senses the temperature inside the pipe pile, and the digital thermometer provides real-time feedback on the internal temperature value of the PHC pipe pile.

5. The construction method for outdoor steam curing of PHC pipe piles according to claim 1, characterized in that, In step S4, the steam curing process is as follows: heat up to 78°C, maintain the temperature for 8-10 hours, and then cool down for 2-3 hours.

6. The construction method for outdoor steam curing of PHC pipe piles according to claim 5, characterized in that, In step S4, the steam curing process is specifically as follows: Open the steam valve to its maximum opening and introduce steam into the PHC pipe pile through the steam branch pipe to gradually increase the temperature. When the digital thermometer shows that the internal temperature of the PHC pipe pile reaches 78°C, reduce the opening of the steam valve and maintain a constant temperature for 8-10 hours. Finally, close the steam valve and gradually decrease the temperature for 2-3 hours.

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