A method for reserving construction holes or grooves through a thermoplastic mold

Abstract

This invention provides a method for pre-reserving construction holes or pits using a thermoplastic mold, comprising the following steps: S1: preparing a thermoplastic mold; S2: placing the thermoplastic mold at the reserved position in the building structure to be constructed; S3: after fixing the thermoplastic mold, pouring concrete; S4: after the concrete has solidified, softening the thermoplastic mold by heating; S5: removing and recycling the softened thermoplastic material for subsequent reuse. The thermoplastic mold used in this invention is simple to operate and easy to dismantle, effectively improving the quality of pre-reserved construction holes or pits without affecting the quality of the cast-in-place concrete surface; furthermore, it can be recycled and reshaped for reuse, offering both economic and environmental advantages.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and specifically to a method for pre-reserving construction holes or pits using thermoplastic molds. Background Technology

[0002] Currently, in civil engineering construction processes such as wall construction, concrete construction, and waterproofing structure construction, the methods for reserving construction holes or pits typically involve using wooden molds, steel molds, or combinations thereof. Wooden molds have drawbacks such as large production volumes and significant waste of timber resources; debris left behind during construction is also difficult to clean, leading to poor fit between the insert and the hole surface. Steel molds, on the other hand, suffer from numerous and poorly sealed joints, resulting in poor appearance quality after concrete molding. Furthermore, these traditional molds must be removed before the concrete has fully set, making timing difficult to control. During concrete pouring, the molds must be frequently shaken to reduce the adhesion between the mold and the concrete for easier removal. This not only severely damages the quality of the molds and the reserved construction holes or pits, but the trampling of the unset concrete surface by demolition personnel also significantly affects the quality of the concrete surface.

[0003] The investigation revealed that the success rate of removing molds with pre-reserved construction holes or pits using traditional methods is only 8.33%, with 70.4% leaving residue after removal, 17.6% of the foundation holes being damaged, and 88% of the molds being damaged after demolding. Clearly, a solution for economically and efficiently reserving construction holes or pits urgently needs to be found. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method for pre-reserving construction holes or pits using thermoplastic molds. The thermoplastic molds used in this invention are simple to operate, easy to dismantle, effectively improve the quality of pre-reserved construction holes or pits, and do not affect the quality of cast-in-place concrete surfaces in civil engineering; they are also recyclable and remodelable for reuse, offering both economic and environmental advantages.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] A method for pre-reserving construction holes or grooves using a thermoplastic mold, characterized by comprising the following steps:

[0007] S1: Prepare the thermoplastic mold;

[0008] S2: Place the thermoplastic mold in the reserved position in the building structure to be constructed;

[0009] S3: After fixing the thermoplastic mold, pour the concrete;

[0010] S4: After the concrete has hardened, the thermoplastic mold is softened by heat.

[0011] S5: Remove and recycle the softened thermoplastic material for future reuse.

[0012] Furthermore, the material of the thermoplastic mold is thermoplastic plastic with a softening temperature range of 80℃-300℃.

[0013] Furthermore: the thermoplastic mold is a rigid molding material, which can be integrally molded or assembled from multiple parts. The thermoplastic mold can be prefabricated in the factory or made on-site.

[0014] Furthermore: In step S4, after the concrete has fully set, the thermoplastic mold is softened by a PTC heater through contact or non-contact heating at a constant temperature. The heating temperature is controlled to be higher than the softening point of the thermoplastic material but not exceeding the melting point of the thermoplastic material. The thermoplastic mold can be softened by heating in sections or as a whole.

[0015] Furthermore: In step S5, after the thermoplastic mold is softened by heat, it can be dismantled by cutting along the seam, cutting in sections, or cutting in layers, and the dismantled thermoplastic material can be retrieved for recycling.

[0016] Further: The method for retrieving and recycling dismantled thermoplastic materials is to transfer the dismantled thermoplastic materials to the hopper of the injection molding machine for recycling, or to transfer them to a gas or liquid below the softening point temperature to cool and solidify until a hard outer shell appears, and then store them temporarily in a storage device. When recycling is required, the thermoplastic material with a hard outer shell is placed in the hopper of the injection molding machine.

[0017] Furthermore, the recycling method involves using a heater to raise the temperature inside the barrel of the injection molding machine to a level higher than the melting point of the thermoplastic material but not exceeding its decomposition temperature. Once the thermoplastic material is in a fluid state, it is extruded into a shaping mold via a screw, cooled, and shaped into the thermoplastic mold required for subsequent applications, thus achieving recycling.

[0018] Furthermore: the heater of the injection machine is an automatic thermostatic heater or a non-automatic thermostatic heater coupled with a temperature sensor.

[0019] Furthermore: the thermoplastic mold is used to reserve construction holes or pits.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] The thermoplastic molds used in this invention are very convenient to manufacture and dismantle. Simply heat the mold after the concrete has fully set to soften it, remove the old mold, and then fabricate a new one. This not only ensures precise and easy-to-control dismantling time but also has no impact on the quality of pre-reserved construction holes or pits, or the surrounding concrete surface. Furthermore, the thermoplastic molds can be made on-site or prefabricated in a factory, and prefabricated components can be easily modified on-site, offering high flexibility and convenience.

[0022] The thermoplastic mold used in this invention can be repeatedly shaped and recycled after being heated, thereby effectively avoiding resource waste and repeated production. At the same time, it can reduce waste building materials, reduce environmental risks, and save energy and protect the environment.

[0023] The thermoplastic mold used in this invention is very convenient to manufacture, install and dismantle, and has the advantages of strong versatility, high turnover rate and good molding effect. It can effectively improve work efficiency and quality, save labor and resource costs, and effectively ensure the quality of building construction. It is advanced, practical and economical, and is suitable for widespread application in projects with reserved construction holes or pits. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the method for pre-reserving construction holes using a thermoplastic mold according to the present invention.

[0025] Figure 2 This is a schematic diagram of the method for pre-reserving construction pits using thermoplastic molds as described in this invention.

[0026] Reference numerals: 1-Thermoplastic mold; 2-PTC heater; 3-Softened thermoplastic material; 4-Cutting tool; 5-Final set concrete; 6-Pre-reserved construction hole; 7-Recycled thermoplastic material; 8-Injection molding machine; 9-Hopper; 10-Heater; 11-Screw; 12-Shaping mold; 13-Pre-reserved construction pit. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting the present invention. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present invention.

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0029] like Figures 1 to 2As shown, a method for pre-reserving construction holes or grooves using a thermoplastic mold includes the following steps:

[0030] S1: Prepare thermoplastic mold 1;

[0031] S2: Place the thermoplastic mold 1 in the reserved position in the building structure to be constructed;

[0032] S3: After fixing the thermoplastic mold 1, pour concrete;

[0033] S4: After the concrete has solidified to form the final set concrete 5, the thermoplastic mold 1 is heated and softened.

[0034] S5: Remove and recycle the softened thermoplastic material 3 for future recycling.

[0035] The thermoplastic mold 1 is made of thermoplastic plastic with a softening temperature range of 80℃-300℃, including common materials such as polyethylene and nylon, as well as newer materials such as starch-based bioplastics. Thermoplastic plastics have good tensile, flexural, compressive, and impact resistance, and can be used alone as structural materials. Simultaneously, the softening temperature range of 80℃-300℃ allows it to withstand the exothermic reaction of concrete without the required heating temperature to adversely affect the quality of the concrete. The thermoplastic mold 1 is made of rigid thermoplastic plastic and can be molded as a single piece or assembled from multiple parts. It can be prefabricated in a factory or fabricated on-site, offering high flexibility and convenience.

[0036] After the concrete has fully set, the thermoplastic mold 1 is softened by a PTC heater 2 through contact or non-contact heating at a constant temperature. The heating temperature is controlled above the softening point but not exceeding the melting point. The mold can be softened in sections or as a whole. After softening, the thermoplastic mold 1 can be removed by cutting along the seam, cutting in sections, or cutting in layers. The removed thermoplastic material can be retrieved for recycling. This method not only ensures precise and easy-to-control removal time but also simplifies the operation, making removal extremely easy without affecting the quality of the reserved construction holes 6 or reserved construction pits 13 and the surrounding concrete surface.

[0037] PTC heaters are heating devices designed using the constant-temperature heating characteristics of PTC thermistors. The principle behind constant-temperature heating PTC thermistors is that after being energized, the PTC thermistor self-heats, causing its resistance to enter a transition region. The surface temperature of the PTC thermistor then remains constant, depending only on its Curie temperature and the applied voltage, and is essentially independent of the ambient temperature. Therefore, PTC heaters possess significant advantages unmatched by traditional heating elements, including constant-temperature heating, no open flame, high heat conversion efficiency, minimal influence from power supply voltage, and a long natural lifespan.

[0038] Specifically, PTC heaters are classified into three types according to their conduction method:

[0039] (1) PTC heater with heat conduction. Its characteristic is that the heat generated by the PTC element is transferred to the object being heated through a multi-layer heat transfer structure, such as an electrode plate (conductive and heat transfer), an insulation layer (electrical insulation and heat transfer), and a heat-conducting heat storage plate (some also have heat-conducting adhesive) mounted on the surface of the PTC heating element.

[0040] (2) Hot air convection type PTC heater. Its characteristics are that the generated hot air is used for convection heat transfer, the output power is large, and the blow-out air temperature and output heat can be automatically adjusted.

[0041] (3) PTC heaters with infrared radiation. The characteristic of this type of heater is that it uses the heat rapidly emitted from the surface of a PTC element or heat-conducting plate to directly or indirectly excite the far-infrared coating or far-infrared material in contact with its surface to radiate infrared rays, thus forming a PTC ceramic infrared radiation heater.

[0042] Accordingly, the placement of PTC heaters can be divided into two categories based on their heat conduction method: contact and non-contact. PTC heaters using heat conduction are placed in contact, while those using hot air convection and infrared radiation are placed in non-contact. Specifically, for heat conduction PTC heaters, by manufacturing constant-temperature heating PTC thermistors into various shapes and specifications, such as common circular, rectangular, strip, ring, and honeycomb porous shapes, and combining them with metal components, various forms of high-power PTC heaters are formed. This allows for better contact and heat conduction between the heat conduction PTC heater 2 and the thermoplastic mold 1.

[0043] The removal methods for thermoplastic molds after softening by heat include removal by cutting along the seam, removal by cutting in sections, and removal by cutting in layers, mainly depending on the type of reserved location and the length of the cutting tool 4. Specifically, for reserved construction holes 6, when the length of the cutting tool 4 is greater than or equal to the thickness of the reserved construction hole 6, removal by cutting along the seam can be used; when the length of the cutting tool 4 is less than the thickness of the reserved construction hole 6, removal by cutting in sections combined with removal in layers can be used; for reserved construction pits 13, removal by cutting in sections combined with removal in layers is usually required.

[0044] The dismantled molds can be recycled and reshaped, enabling multiple engineering applications and achieving a very high recycling rate. Specifically, this includes the following two methods:

[0045] The first method: Transfer the dismantled thermoplastic material to the hopper 9 of the injection molding machine 8 for recycling;

[0046] The second method involves transferring the dismantled thermoplastic material to a gas or liquid below its softening point temperature to cool and solidify it until a hard outer shell appears. The material is then temporarily stored in a storage device. When it needs to be recycled, the thermoplastic material with the hard outer shell is placed in the hopper 9 of the injection molding machine 8.

[0047] The first method enables on-site reshaping and prefabrication of the thermoplastic mold 1; the second method does not require the injection molding machine 8 to be equipped on the construction site, but only requires the cooled and shaped thermoplastic material to be temporarily stored in the storage device; the storage device is not special in performance, and a variety of materials can be selected, the most common of which is PVC bucket, etc., so it is suitable for construction sites under various conditions.

[0048] The injection molding machine 8 uses a heater 10 to raise the temperature inside the barrel to a level higher than the melting point of the recycled thermoplastic material 7 but not exceeding the decomposition temperature. The recycled thermoplastic material 7 is in a fluid state and is then extruded into the shaping mold 12 by the screw 11. It is then cooled and shaped into the thermoplastic mold 1 required for subsequent use, thus achieving recycling.

[0049] The heater 10 of the injection machine 8 is an automatic thermostatic heater or a non-automatic thermostatic heater coupled with a temperature sensor.

[0050] The thermoplastic mold 1 is used to reserve construction holes 6 or construction pits 13. There are no special requirements for the shape and size of the mold used to reserve construction holes 6 or construction pits 13. In terms of shape, it can be round, square or other special shapes, while the size is mainly adapted to the needs of the project. It can be integrally molded or assembled from multiple parts.

[0051] Based on the description and drawings of this invention, those skilled in the art can easily manufacture or use the method of pre-reserving construction holes or grooves using a thermoplastic mold, and can achieve the positive effects described in this invention.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for pre-reserving construction holes or grooves using a thermoplastic mold, characterized in that: Includes the following steps: S1: Prepare the thermoplastic mold; S2: Place the thermoplastic mold in the reserved position in the building structure to be constructed; S3: After fixing the thermoplastic mold, pour the concrete; S4: After the concrete has hardened, the thermoplastic mold is softened by heat. S5: Remove and recycle the softened thermoplastic material for future reuse; The thermoplastic mold is a rigid molding material; the thermoplastic mold is used to reserve construction holes or pits; In step S5, after the thermoplastic mold softens due to heat, it can be dismantled by cutting along the seam, cutting in sections, or cutting in layers, and the dismantled thermoplastic material can be retrieved for recycling. The method for retrieving and recycling dismantled thermoplastic materials is to transfer the dismantled thermoplastic materials to the hopper of the injection molding machine for recycling, or to transfer them to a gas or liquid below the softening point temperature to cool and solidify until a hard outer shell appears, and then store them temporarily in a storage device. When recycling is required, the thermoplastic material with a hard outer shell is placed in the hopper of the injection molding machine. The injection molding machine uses a heater to ensure that the temperature inside the barrel is higher than the melting point of the thermoplastic material but not higher than its decomposition temperature. Once the thermoplastic material is in a fluid state, it is extruded into a shaping mold by a screw, cooled and shaped into the thermoplastic mold required for subsequent use, thus enabling recycling.

2. The method for pre-reserving construction holes or grooves using a thermoplastic mold according to claim 1, characterized in that: The thermoplastic mold is made of thermoplastic plastic with a softening temperature range of 80℃-300℃.

3. The method for pre-reserving construction holes or grooves using a thermoplastic mold according to claim 2, characterized in that: The thermoplastic mold can be integrally formed or composed of multiple parts, and can be prefabricated in the factory or made on-site.

4. The method for pre-reserving construction holes or grooves using a thermoplastic mold according to claim 1, characterized in that: In step S4, after the concrete has set, the thermoplastic mold is softened by a PTC heater through contact or non-contact heating at a constant temperature. The heating temperature is controlled to be higher than the softening point of the thermoplastic material but not exceeding the melting point of the thermoplastic material. The thermoplastic mold can be softened by heating in sections or as a whole.

5. The method for pre-reserving construction holes or grooves using a thermoplastic mold according to claim 1, characterized in that: The heater of the injection machine is either an automatic thermostatic heater or a non-automatic thermostatic heater coupled with a temperature sensor.

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