A folded UHPC exterior wall panel and its manufacturing process

Abstract

This application relates to the field of prefabricated building technology, specifically disclosing a folded UHPC exterior wall panel and its manufacturing process. The folded UHPC exterior wall panel provided in this application includes UHPC concrete and an insulation board; the insulation board includes irregularly shaped insulation boards; the manufacturing process of the aforementioned folded UHPC exterior wall panel includes the following steps: cleaning and installing the mold, preparing UHPC concrete, primary pouring, laying the insulation board, sealing with expanding foam, secondary pouring, and curing; the mold includes a folded bottom mold. This application can obtain a lightweight, high compressive strength, good impact resistance, and excellent thermal insulation performance folded UHPC exterior wall panel, which can meet specific prefabricated building requirements.

Description

Technical Field

[0001] This application relates to the field of prefabricated building technology, specifically to a folded UHPC exterior wall panel and its manufacturing process. Background Technology

[0002] With the rapid development of construction technology, prefabricated buildings have attracted widespread attention due to their flexibility and versatility. Prefabricated buildings refer to buildings where components and accessories are manufactured in large quantities in factories, transported to the construction site, and assembled on-site using reliable connection methods. Compared to other building manufacturing technologies, prefabricated buildings eliminate the complex and slow process of on-site pouring, thus offering advantages such as faster construction speed, lower production costs, and a wider variety of styles.

[0003] Exterior wall cladding is one of the main components of prefabricated buildings. Its main functions are thermal insulation, water resistance, freeze-thaw resistance, carbonization prevention, and meeting the requirements of architectural aesthetics and decoration. Currently, the manufacturing of exterior wall cladding is mainly divided into two types: one is made using a single material, and the other is made using composite materials. Exterior wall cladding made using a single material has relatively limited performance and cannot meet multiple building requirements simultaneously, thus limiting its application. On the other hand, exterior wall cladding made of multi-layer composite materials has disadvantages such as poor physical properties, poor thermal insulation performance, and heavy weight, which greatly affects the building quality and construction efficiency of prefabricated buildings.

[0004] Therefore, there is an urgent need to provide a high-performance exterior wall panel to meet the requirements of prefabricated buildings. Summary of the Invention

[0005] In order to improve the performance of exterior wall cladding, especially to enhance its physical properties and meet the requirements of prefabricated buildings, this application provides a folded UHPC exterior wall cladding and its manufacturing process.

[0006] In the first aspect, this application provides a folded UHPC exterior wall panel, which adopts the following technical solution:

[0007] A folded UHPC exterior wall panel, comprising UHPC concrete and an insulation board; the insulation board includes irregularly shaped insulation boards.

[0008] This application provides a large-size folded UHPC exterior wall panel with self-insulating effect. Compared with exterior wall panels in related technologies, this folded UHPC exterior wall panel has the characteristics of high folded dimensional accuracy, light weight, good physical properties, and excellent thermal insulation performance.

[0009] Furthermore, the insulation board is laid inside the UHPC concrete; the insulation board is a silica insulation board.

[0010] In this application, the insulation board is laid inside the folded UHPC exterior wall panel, which can not only ensure the decorative effect of the concrete exterior wall, but also improve the waterproof and thermal insulation performance of the wall panel itself. At the same time, it will also reduce the overall weight of the folded UHPC exterior wall panel, which will facilitate efficient subsequent installation. The use of silica insulation board as the insulation material of the folded UHPC exterior wall panel has the advantages of good flame retardancy, high temperature resistance, no deformation, and stability and reliability.

[0011] Secondly, this application provides a manufacturing process for a folded UHPC exterior wall panel, employing the following technical solution:

[0012] A manufacturing process for a folded UHPC exterior wall panel includes the following steps: cleaning and installing the mold, preparing UHPC concrete, primary pouring, laying insulation board, sealing with expanding foam, secondary pouring, and curing; the mold includes a folded bottom mold.

[0013] The manufacturing process of the folded UHPC exterior wall panel provided in this application uses a folded bottom mold and an irregularly shaped insulation board. Therefore, the manufacturing method is simple and the manufacturing cost is low. The resulting folded UHPC exterior wall panel has high dimensional accuracy, is lightweight, has good physical properties, and excellent thermal insulation performance, so it can be used to construct buildings with specific structures.

[0014] Preferably, the specific steps for preparing UHPC concrete are as follows: adding gel material and quartz sand into a mixer and stirring at 2-5 r / min for 0.5-2 min; then adding water-reducing agent, retarder and 70-80% of the total water and stirring at 5-10 r / min for 1-2 min; finally adding fiber and 20-30% of the total water and stirring at 1-2 r / min for 2-3 min to obtain UHPC concrete; wherein the fiber is selected from steel fiber, short alkali-resistant glass fiber, polyoxymethylene fiber and polypropylene fiber.

[0015] In this application, by controlling the mixing speed and mixing time of each material in the UHPC concrete within the above-mentioned range, the cement in the UHPC concrete can be completely hydrated and fully mixed with water-reducing agent, retarder, fiber, etc., thereby obtaining a UHPC concrete with good fluidity and uniform dispersion. This UHPC concrete can fully meet the construction requirements of subsequent pouring.

[0016] In this application, the UHPC concrete needs to be left to stand for 1-2 minutes after preparation.

[0017] Because UHPC concrete generates a large number of air bubbles during its preparation, these bubbles can affect the surface smoothness, compressive strength, and impact resistance of the folded UHPC exterior wall cladding. Therefore, UHPC concrete needs to be allowed to stand after preparation. If the standing time is too short, the air bubbles in the UHPC concrete cannot be completely eliminated; if the standing time is too long, the fluidity of the UHPC concrete deteriorates, affecting subsequent pouring. Therefore, this application controls the standing time of the UHPC concrete to between 1-2 minutes, which allows for the full elimination of air bubbles and ensures smooth pouring into the mold, thereby significantly improving the surface smoothness and physical properties of the folded UHPC exterior wall cladding.

[0018] Preferably, the mold needs to be cleaned and installed before the first pouring; the specific steps of the first pouring are: to spread UHPC concrete evenly and continuously from the center of the mold, with a pouring time of ≤20min.

[0019] In this application, the concrete placement and pouring process needs to start from the longitudinal centerline of the mold and be uniform and continuous to effectively prevent the UHPC concrete from piling up and avoid segregation. Therefore, this application controls the placement time within the above range to prevent the material from solidifying and segregating when stored in the silo for a long time, while ensuring that the upper layer of concrete is placed in time before the lower layer of concrete has initially set.

[0020] Preferably, the specific steps for laying the insulation board are as follows: using prefabricated positioning blocks to position the rib width in the mold, and then laying the insulation board; then placing a steel plate on the insulation board, and using positioning fixtures to press and fix the steel plate; the irregularly shaped insulation board is laid on the folded part of the bottom mold.

[0021] The manufacturing process of the folded UHPC exterior wall cladding provided in this application includes laying insulation boards. The insulation boards are compacted using steel plates and then positioned and fixed using positioning fixtures. This prevents the insulation boards from shifting or floating during subsequent pouring and placement, ensuring that the insulation boards are completely and accurately fixed in specific positions within the folded UHPC exterior wall cladding. In this application, the insulation boards are pre-cut into the required shapes and sizes according to the mold dimensions to obtain irregularly shaped insulation boards. The shape and size of these irregularly shaped insulation boards are precisely suited for direct laying on the folded sections of the mold, resulting in folded UHPC exterior wall cladding with high dimensional accuracy in the folded sections.

[0022] Preferably, the specific steps of the foam sealing are as follows: sealing all the joints in the mold with foam.

[0023] This application utilizes expanding foam to seal all joints of the folded UHPC exterior wall panel, which effectively prevents leakage of UHPC concrete, avoids the formation of honeycomb pitting on the finished folded UHPC exterior wall panel, improves the surface smoothness of the folded UHPC exterior wall panel, and enhances the compressive strength of the folded UHPC exterior wall panel.

[0024] Preferably, the specific steps of the secondary concrete pouring are as follows: first, UHPC concrete is poured into the folded part of the bottom formwork; then, it is poured upwards in sequence until all the reinforcing bars and embedded parts are poured, thereby obtaining the folded UHPC exterior wall panel precast body.

[0025] The UHPC exterior wall panel obtained in this application is a folded type. Therefore, during the manufacturing process, the folded part of the bottom mold must be poured first to avoid the UHPC concrete from damaging the positioning fixtures in the mold, causing the ribs to be non-vertical, and thus affecting the structural performance of the folded UHPC exterior wall panel.

[0026] Preferably, the curing includes natural curing and high-temperature curing; the specific steps of natural curing are as follows: cover the folded UHPC exterior wall panel prefabricated body with tarpaulin, and then cure it for 22-48 hours under the conditions of temperature 5-40℃ and humidity ≤60%. The mold can be removed to obtain the folded UHPC exterior wall panel molded body.

[0027] In this application, curing the precast folded UHPC exterior wall panel obtained after casting under natural conditions can promote the full hydration of cement in UHPC concrete and accelerate the hardening of the precast folded UHPC exterior wall panel, thereby obtaining a folded UHPC exterior wall panel with excellent physical strength.

[0028] Preferably, the specific steps of the high-temperature steam curing are as follows: hoist the folded UHPC exterior wall panel molding body, and then steam cure it at 80-100℃ for 24-50 hours to obtain the folded UHPC exterior wall panel.

[0029] In this application, the folded UHPC exterior wall panel is steam-cured at 80-100℃ for 24-50 hours, which can effectively prevent shrinkage, cracking and other adverse phenomena from occurring in the later use of the folded UHPC exterior wall panel, improve the performance of the folded UHPC exterior wall panel and increase its physical strength.

[0030] Preferably, a mold release agent application step is required between the mold cleaning and installation step and the first material pouring step, i.e., applying a mold release agent to the mold surface; the mold release agent is a water-based mold release agent.

[0031] In this application, applying a release agent to the mold surface facilitates the subsequent demolding of the UHPC exterior wall panel. Furthermore, the use of a non-toxic, odorless, and film-forming water-based release agent ensures that the obtained UHPC exterior wall panel has a clean, smooth, and pollution-free surface. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of the manufacturing process of the folded UHPC exterior wall panel provided in this application. Detailed Implementation

[0033] This application provides a folded UHPC exterior wall panel, which includes UHPC concrete and insulation board; the UHPC concrete includes the following components: gel material, quartz sand, water-reducing agent, retarder, steel fiber and water.

[0034] The manufacturing process of the above-mentioned folded UHPC exterior wall cladding panels specifically includes the following steps:

[0035] (1) Preparation of UHPC concrete: Add gel material and quartz sand to a mixer and stir at 2-5 r / min for 0.5-2 min; then add water-reducing agent, retarder and 70-80% of the total water and stir at 5-10 r / min for 1-2 min; finally add steel fiber and 20-30% of the total water and stir at 1-2 r / min for 2-3 min, then let stand for 1-2 min to obtain UHPC concrete.

[0036] (2) Mold cleaning and installation: Clean the bottom mold, side mold and / or frame mold, etc.; then install the bottom mold to support it firmly and level it with a level; then install the side mold on the bottom mold with fastening bolts; in addition, when the folded UHPC exterior wall panel has a window opening, a frame mold that matches the window size should also be installed. The area formed by the bottom mold, side mold and frame mold is the forming area of ​​the folded UHPC exterior wall panel; wherein, the mold includes the folded bottom mold.

[0037] (3) Apply release agent: Apply water-based release agent to the surface of the mold.

[0038] (4) Rebar cutting: Cut the rebar according to the size requirements, with a size deviation of ≤5mm, and place it in the forming area of ​​the folded UHPC exterior wall panel.

[0039] (5) One-time concrete placement and pouring: Use a concrete placing machine to evenly and continuously place UHPC concrete from the longitudinal center line of the mold. The placement time is ≤20min. During the placement process, use a scraper to assist in leveling. If the edges and corners are uneven, add material to fill them in time.

[0040] (6) Laying insulation boards: Cut the insulation material into the required shape and size; then use the three types of pre-made I-shaped, L-shaped and T-shaped positioning blocks to position the rib width in the mold according to the preset position; after all the positioning is completed, lay the insulation boards, and the joints of the insulation boards should be tight; then place the steel plate on the insulation board and use the positioning fixture to press and fix the steel plate; the irregularly shaped insulation board is laid on the folded part of the bottom mold.

[0041] (7) Install embedded parts: Place the embedded parts according to the set position and fix them with special fixing devices.

[0042] (8) Foam sealing: After all installation and fixing are completed, seal all joints in the mold with foam.

[0043] (9) Secondary pouring: First, pour UHPC concrete into the folded part of the bottom formwork; then pour it upwards in sequence until all the reinforcing bars and embedded parts are poured, thereby obtaining the folded UHPC exterior wall panel precast body.

[0044] (10) Natural curing: After the secondary material pouring is completed, the folded UHPC exterior wall panel prefabricated body is covered with tarpaulin and then cured for 22-48 hours under the conditions of temperature 5-40℃ and humidity ≤60%. The mold can be removed to obtain the folded UHPC exterior wall panel molded body.

[0045] (11) High-temperature steam curing: The folded UHPC exterior wall panel is hoisted and then steam-cured at 80-100℃ for 24-50 hours to obtain the folded UHPC exterior wall panel.

[0046] In the specific embodiments of this application, the gel material was purchased from Dalian Gerunte Building Materials Co., Ltd.; the quartz sand was purchased from Lingshou County Chuanqing Mineral Products Co., Ltd.; the water-reducing agent and retarder were purchased from Jiangsu Subote New Materials Co., Ltd.; the steel fiber was purchased from Yunnan Yuntianhua Co., Ltd.; the water-based release agent was purchased from Hunan Jinhuada Building Materials Co., Ltd.; and the remaining raw materials, reagents, solvents, etc., can all be obtained commercially.

[0047] The present application will be further described in detail below with reference to preparation examples, embodiments, accompanying drawings, and performance testing.

[0048] Preparation Example

[0049] The preparation example provides a UHPC concrete. The amounts of each component in this UHPC concrete are as follows: 1100 kg of gel material, 1100 kg of quartz sand, 12 kg of water-reducing agent, 0.8 kg of retarder, 180 kg of steel fiber, and 100 kg of water.

[0050] The preparation method of the above-mentioned UHPC concrete is as follows:

[0051] Add the gel material and quartz sand to the mixer and stir at 3 r / min for 1 min; then add the water-reducing agent, retarder and 70% of the total water and stir at 8 r / min for 2 min; finally add the steel fiber and 30% of the total water and stir at 1 r / min for 2 min, then let it stand for 2 min to obtain UHPC concrete.

[0052] Example

[0053] Example 1

[0054] Example 1 provides a manufacturing process for a folded UHPC exterior wall panel.

[0055] The manufacturing process of the above-mentioned folded UHPC exterior wall cladding panels specifically includes the following steps:

[0056] (1) Preparation of UHPC concrete: UHPC concrete was prepared according to the preparation example.

[0057] (2) Mold cleaning and installation: Clean the bottom mold, side mold and frame mold, etc.; install the bottom mold to support it firmly and level it with a level; then install the side mold on the bottom mold with fastening bolts. The area formed by the bottom mold, side mold and frame mold is the forming area of ​​the folded UHPC exterior wall panel; wherein, the mold includes the folded bottom mold.

[0058] (3) Apply release agent: Apply water-based release agent to the surface of the mold.

[0059] (4) Rebar cutting: Cut the rebar according to the size requirements, with a size deviation of ≤5mm, and place it in the forming area of ​​the folded UHPC exterior wall panel.

[0060] (5) One-time pouring: Use a concrete placing machine to evenly and continuously pour the UHPC concrete provided in Example 1 from the longitudinal center line of the mold. The pouring time is 15 minutes. During the pouring process, use a scraper to assist in leveling. If the edges and corners are uneven, add material to fill them in time.

[0061] (6) Laying insulation boards: Cut the insulation material into the required shape and size; then use the three types of pre-made I-shaped, L-shaped and T-shaped positioning blocks to position the rib width in the mold according to the preset position; after all the positioning is completed, lay the insulation boards, and the joints of the insulation boards should be tight; then place the steel plate on the insulation board and use the positioning fixture to press and fix the steel plate; the irregularly shaped insulation board is laid on the folded part of the bottom mold.

[0062] (7) Install embedded parts: Place the embedded parts according to the set position and fix them with special fixing devices.

[0063] (8) Foam sealing: After all installation and fixing are completed, seal all joints in the mold with foam.

[0064] (9) Secondary pouring: First, pour UHPC concrete into the folded part of the bottom formwork; then pour it upwards in sequence until all the reinforcing bars and embedded parts are poured, thereby obtaining the folded UHPC exterior wall panel precast body.

[0065] (10) Natural curing: After the secondary material pouring is completed, the folded UHPC exterior wall panel prefabricated body is covered with tarpaulin and then cured for 35 hours at a temperature of 20℃ and a humidity of 50%. The mold is then removed to obtain the folded UHPC exterior wall panel molded body.

[0066] (11) High-temperature steam curing: The folded UHPC exterior wall panel is hoisted and then steam-cured at 95℃ for 40 hours to obtain a folded UHPC exterior wall panel of 3m×3m×0.4m.

[0067] Example 2

[0068] Example 2 provides a manufacturing process for a folded UHPC exterior wall panel.

[0069] The difference between the above embodiment and Embodiment 1 is that the material is poured in one step.

[0070] In the manufacturing process of the folded UHPC exterior wall panel provided in Example 2, the material placement time for a single material pouring is 20 minutes.

[0071] Example 3

[0072] Example 3 provides a manufacturing process for a folded UHPC exterior wall panel.

[0073] The difference between the above embodiments and Embodiment 1 is that the natural maintenance steps are used.

[0074] The specific steps for natural curing of the folded UHPC exterior wall panel provided in Example 3 are as follows: After the secondary material pouring is completed, the precast folded UHPC exterior wall panel is covered with a tarpaulin and then cured for 22 hours at a temperature of 40°C and a humidity of 50%. The mold is then removed to obtain the folded UHPC exterior wall panel.

[0075] Example 4

[0076] Example 4 provides a manufacturing process for a folded UHPC exterior wall panel.

[0077] The difference between the above embodiments and Embodiment 1 is that the natural maintenance steps are used.

[0078] The specific steps for natural curing of the folded UHPC exterior wall panel provided in Example 4 are as follows: After the secondary material pouring is completed, the precast folded UHPC exterior wall panel is covered with a tarpaulin and then cured for 50 hours at a temperature of 20°C and a humidity of 60%. The mold is then removed to obtain the folded UHPC exterior wall panel.

[0079] Example 5

[0080] Example 5 provides a manufacturing process for a folded UHPC exterior wall panel.

[0081] The difference between the above embodiments and Embodiment 1 is that the natural maintenance steps are used.

[0082] The specific steps for natural curing of the folded UHPC exterior wall panel provided in Example 5 are as follows: After the secondary material pouring is completed, the precast folded UHPC exterior wall panel is covered with a tarpaulin and then cured for 55 hours at a temperature of 0°C and a humidity of 50%. The mold is then removed to obtain the folded UHPC exterior wall panel.

[0083] Example 6

[0084] Example 6 provides a manufacturing process for a folded UHPC exterior wall panel.

[0085] The difference between the above embodiments and Embodiment 1 is the high-temperature curing step.

[0086] The specific steps for high-temperature steam curing of the folded UHPC exterior wall panel provided in Example 6 are as follows: the folded UHPC exterior wall panel molding body is hoisted and then steam-cured at 80°C for 50 hours to obtain the folded UHPC exterior wall panel.

[0087] Example 7

[0088] Example 7 provides a manufacturing process for a folded UHPC exterior wall panel.

[0089] The difference between the above embodiments and Embodiment 1 is the high-temperature curing step.

[0090] The specific steps for high-temperature steam curing of the folded UHPC exterior wall panel provided in Example 7 are as follows: the folded UHPC exterior wall panel molding body is hoisted and then steam-cured at 100°C for 24 hours to obtain the folded UHPC exterior wall panel.

[0091] Example 8

[0092] Example 8 provides a manufacturing process for a folded UHPC exterior wall panel.

[0093] The difference between the above embodiments and Embodiment 1 is that the embodiment involves brushing on the release agent.

[0094] The specific steps for applying release agent to the folded UHPC exterior wall panel provided in Example 8 are as follows: apply an oil-based release agent to the surface of the mold; the oil-based release agent is MK-CR-2, purchased from Dongguan Meiya Chemical Co., Ltd.

[0095] Comparative Example

[0096] Comparative Example 1

[0097] Comparative Example 1 provides a folded UHPC exterior wall panel.

[0098] The difference between the above comparative example and Example 1 is that in the manufacturing process of the folded UHPC exterior wall panel provided in Comparative Example 1, the material placement time for one pouring is 30 minutes.

[0099] Comparative Example 2

[0100] Comparative Example 2 provides a folded UHPC exterior wall panel.

[0101] The difference between the above comparative example and Example 1 is the step of laying the insulation board.

[0102] The specific steps for laying the insulation board of the folded UHPC exterior wall panel provided in Comparative Example 2 are as follows: cut the insulation material into the required shape and size; then use the three types of pre-made positioning blocks (straight, L-shaped, and T-shaped) to position the rib width in the mold according to the preset position; after all the positioning is completed, lay the insulation board, and the joints of the insulation board should be tight; the irregularly shaped insulation board is laid on the folded part of the bottom mold.

[0103] Comparative Example 3

[0104] Comparative Example 3 provides a UHPC exterior wall panel.

[0105] (1) Prepare the mold: Clean the surface of the mold, which includes a bottom mold and side molds, and install the bottom mold on the corresponding transfer component;

[0106] (2) Cleaning the bottom mold: Use a sweeper and a sprayer to clean and spray the bearing surface of the bottom mold;

[0107] (3) Marking with a marking machine: Marking the upper surface of the bearing in step S2 with a marking machine to form a marking area for installing the side mold;

[0108] (4) Install the side mold: Install and position the side mold in the marked area, and fit it with the upper surface of the bearing to form a molding area;

[0109] (5) Install the reinforcing mesh: Place the reinforcing mesh parallel to the upper surface of the bearing in the forming area;

[0110] (6) One-time pouring: The UHPC concrete provided in Preparation Example 1 is poured into the forming area using a concrete placing machine, and then vibrated by a vibrating table to form the first casting body;

[0111] (7) Install insulation board: Lay insulation board on top of the first cast body;

[0112] (8) Install the reinforcing cage: Install the reinforcing cage, and the end of the reinforcing cage can extend out of the hole of the side formwork as the subsequent connection end; then install the connectors.

[0113] (9) Secondary concrete placement and pouring: The UHPC concrete is poured into the casting body above the first casting body and surrounded by the side mold to complete the second pouring; then the vibrating table is used to make the concrete layout of the second pouring body flat and the air bubbles are removed to form the second casting body. The steel cage and connectors are embedded in the second casting body to form the UHPC exterior wall panel precast body.

[0114] (10) Manual finishing: Grind and smooth the upper surface of the UHPC exterior wall panel prefabricated body;

[0115] (11) Pre-curing operation; Place the UHPC exterior wall panel prefabricated body into the pre-curing cellar;

[0116] (12) Machine troweling; using a troweling machine to smooth the upper surface of the UHPC exterior wall precast body;

[0117] (13) Curing operation: Place the precast exterior wall panel into the curing cellar for 8 hours of curing to obtain the UHPC exterior wall panel molded body;

[0118] (14) Mold disassembly: First, the side mold is disassembled, and then the bottom surface is disassembled. During the bottom surface disassembly, the bottom mold is first flipped and tilted at a certain angle using a flipping machine, and then the UHPCb exterior wall panel is separated from the bearing upper surface and removed using a transport device to obtain the UHPC exterior wall panel.

[0119] Performance testing

[0120] The compressive strength, impact resistance, shrinkage rate, thermal insulation performance, and outer surface of the UHPC exterior wall panels obtained in Examples 1-8 and Comparative Examples 1-3 of this application were tested.

[0121] (1) The thermal insulation performance test method refers to GB / T 13475-2008. The thermal insulation performance of the folded UHPC exterior wall panels obtained in Examples 1-8 of this application meets the requirements of GBT50176-2016 Code for Thermal Design of Civil Buildings.

[0122] (2) The compressive strength test method refers to T / CBMF37-2018; the impact resistance test method refers to GB / T30100-2013; the shrinkage test method refers to GBJ82; the surface defect test is to check whether there are surface honeycomb pitting, bubbles, cracks, unevenness and other defects on the outer surface of the UHPC exterior wall panel. The test results are shown in Table 1.

[0123] Table 1. Performance test results of the folded UHPC exterior wall panels obtained in Examples 1-8 and Comparative Examples 1-3.

[0124]

[0125]

[0126] According to the test results in Table 1, the compressive strength of the folded UHPC exterior wall panels obtained in Examples 1-8 of this application is ≥120 MPa, the impact resistance is ≥5 times, and the shrinkage rate is ≤0.06%. The compressive strength of the folded UHPC exterior wall panel obtained in Comparative Example 2 is 111 MPa, the impact resistance is 4 times, and the shrinkage rate is 0.07%. The compressive strength of the UHPC exterior wall panel obtained in Comparative Example 3 is 108 MPa, the impact resistance is 4 times (a small number of cracks appeared after the 5th impact), and the outer surface of this UHPC exterior wall panel has bubbles and a small amount of honeycomb pitting. Therefore, it can be seen that the manufacturing process of the folded UHPC exterior wall panel provided in this application can not only obtain a folded UHPC exterior wall panel, but also make the obtained folded UHPC exterior wall panel have excellent compressive strength, good impact resistance, low shrinkage rate, and basically no surface defects.

[0127] According to the test results of Examples 1-2 and Comparative Example 1, the compressive strength of the folded UHPC exterior wall cladding obtained in Examples 1-2 is 135 MPa and 125 MPa, respectively, with an impact resistance of ≥5 times and a shrinkage rate of 0.03% and 0.04%. In contrast, the compressive strength of the folded UHPC exterior wall cladding obtained in Comparative Example 1 is 108 MPa, with an impact resistance of 4 times and a shrinkage rate of 0.04%. Therefore, this application demonstrates that by controlling the single-stage pouring time in the manufacturing process of the folded UHPC exterior wall cladding to ≤20 minutes, it is possible to obtain folded UHPC exterior wall cladding with high compressive strength.

[0128] According to the test results of Examples 1 and 3-5, in Examples 1 and 3-4, the temperature was controlled between 5-40℃, the humidity was controlled at ≤60%, and the curing time was controlled between 22-48h during the natural curing process. The resulting folded UHPC exterior wall panel had a compressive strength >125Mpa, a shrinkage rate ≤0.05%, and a smooth surface without any defects. However, in Example 5, the temperature was controlled at 0℃, the humidity was controlled at 50%, and the curing time was controlled at 55h during the natural curing process. The resulting folded UHPC exterior wall panel had a compressive strength of 120Mpa, a shrinkage rate of 0.06%, and a small number of fine lines on the surface.

[0129] According to the test results of Examples 1 and 6-7, when the temperature in the high-temperature steam curing step of Examples 1 and 6-7 is controlled at 80-100℃ and the time is controlled between 24-50h, the compressive strength of the obtained folded UHPC exterior wall panels is all >130Mpa, the impact resistance is all ≥5 times, the shrinkage rate is ≤0.05%, and the surface is flat and without any defects.

[0130] According to the test results of Examples 1 and 8, the surface of the folded UHPC exterior wall panel obtained using the water-based release agent in Example 8 contained a small number of air bubbles, while the surface of the folded UHPC exterior wall panel obtained using the water-based release agent in Example 1 was smooth and without defects. Therefore, the use of a water-based release agent in the manufacturing process of the folded UHPC exterior wall panel provided in this application can further improve the surface smoothness of the folded UHPC exterior wall panel and improve its quality.

[0131] In summary, this application provides a manufacturing process for a folded UHPC exterior wall panel. This manufacturing process has the advantages of simple operation, high production efficiency, and low cost. Furthermore, the folded UHPC exterior wall panel obtained using the above manufacturing process has the advantages of being lightweight, having good physical properties, high folding dimensional accuracy, and excellent thermal insulation performance.

[0132] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A manufacturing process of a folded-face type UHPC exterior wall panel, characterized in that, The folded surface type UHPC outer wall hanging plate comprises UHPC concrete and a thermal insulation plate; the thermal insulation plate comprises a special-shaped thermal insulation plate; The manufacturing process of the folded surface type UHPC outer wall hanging plate comprises the following steps: (1) Preparation of UHPC concrete: add gel material and quartz sand into a mixer, and stir at 2-5 r / min for 0.5-2 min; then add water reducing agent, retarder and 70-80% of total water, and stir at 5-10 r / min for 1-2 min; finally, add glass fiber and 20-30% of total water into the mixture, and stir at 1-2 r / min for 2-3 min, and then stand for 1-2 min to obtain the UHPC concrete; (2) Mould cleaning and installation: clean the bottom mould, side mould and / or frame mould; then install the bottom mould to make it stable, and use a level to level it; then install the side mould on the bottom mould with fastening bolts; in addition, when the folded surface type UHPC outer wall hanging plate has a window, a frame mould matching the size of the window should also be installed, and the area formed by the bottom mould, side mould and frame mould is the forming area of the folded surface type UHPC outer wall hanging plate; wherein the mould comprises a folded surface type bottom mould; (3) Brushing of release agent: brush water-based release agent on the surface of the mould; (4) Steel bar cutting: cut the steel bar according to the size requirement, and the size deviation is ≤5 mm, and place it in the forming area of the folded surface type UHPC outer wall hanging plate; (5) First material distribution and pouring: use a material distribution machine to uniformly and continuously distribute the UHPC concrete from the longitudinal center line of the mould, and the distribution time is 15 min; during the distribution process, use a scraper to assist in leveling in time, and timely supplement and level the corners that are not flat; (6) Laying of thermal insulation plate: cut the thermal insulation material into the required shape and size; then use the three types of positioning blocks of one-letter type, L type and T type that are pre-prepared to position the rib width in the mould according to the preset position; after all the positioning is completed, lay the thermal insulation plate, and the joint of the thermal insulation plate should be tight; then place a steel plate on the thermal insulation plate, and use a positioning tool to compact and fix the steel plate; the special-shaped thermal insulation plate is laid on the folded surface part of the bottom mould; (7) Installation of embedded part: place the embedded part according to the set position, and fix and install it by using a special fixing device; (8) Foaming glue sealing: after all the installation and fixation are completed, seal the positions of all the joint seams in the mould with foaming glue; (9) Second material distribution and pouring: first, pour the UHPC concrete on the folded surface part of the bottom mould; then pour upwards in turn until the steel bar and the embedded part are fully poured, so as to obtain the folded surface type UHPC outer wall hanging plate precast body; (10) Natural curing: after the second material distribution and pouring are completed, cover the folded surface type UHPC outer wall hanging plate precast body with tarpaulin, and then cure it under the condition of temperature 20℃ and humidity 50% for 35 h, and then remove the mould to obtain the folded surface type UHPC outer wall hanging plate forming body; (11) High-temperature steam curing: hoist the folded surface type UHPC outer wall hanging plate forming body, and then steam cure it at 95℃ for 40 h, so as to obtain the folded surface type UHPC outer wall hanging plate.

Images