A precast thermal insulation and decoration integrated exterior wall panel back beating forming process

Abstract

The application discloses a precast thermal insulation and decoration integrated outer wall panel reverse forming process and belongs to the technical field of building engineering. The application realizes accurate positioning and sealing of a decorative panel through a mold with zoned negative pressure adsorption and trapezoidal sealing ribs, cooperates with first gradient concrete pouring of semi-coagulation state regulation, so that array type hemispherical dimples on the lower surface of the thermal insulation panel are filled with concrete in the pressing process, a three-dimensional mechanical interlocking interface without penetrating anchoring structure is formed, then non-penetrating elastic positioning batten is used to limit the displacement of the thermal insulation panel and directly pour second gradient concrete, combined with a phase directional vibration process, the interface embedding compactness and structural layer uniformity are respectively strengthened, and finally, temperature deformation stress is reduced through three-stage gradient temperature control maintenance. The process can simultaneously improve the interface shear strength, thermal insulation performance and forming precision and improve long-term weather resistance.

Description

Technical Field

[0001] This invention relates to the field of building engineering technology, and in particular to a reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels. Background Technology

[0002] With the rapid development of building industrialization and green energy-saving buildings, prefabricated integrated insulation and decoration exterior wall panels have become an important development direction for prefabricated building envelope systems due to their advantages such as integrating structure, insulation, and decoration, factory prefabrication, and on-site assembly. The reverse molding process is one of the mainstream production processes for this type of wall panel. Its basic method is to pre-lay the decorative surface layer (or decorative panel) on the bottom of the mold, then pour concrete, lay the insulation layer, and perform a second pour in sequence, so that each layer is formed into an integral wall panel in the mold in one go. This process can effectively ensure the adhesion reliability of the decorative surface and the structural layer, reduce on-site wet work, and improve the production accuracy of components.

[0003] In the prior art, document CN108858665A discloses "a production process for ceramic tile veneer reverse molding exterior wall panels / hanging panels". The reverse molding process involves laying ceramic tiles with pre-installed back bolts after applying a release agent, and then sequentially casting the outer leaf wall, laying the insulation board, and casting the inner leaf wall, so that the structure, decoration, and insulation of the wall panel are integrated into the molding process. At the same time, the back bolts on the back of the ceramic tile are cast together with the inner leaf wall and the outer leaf wall, which improves the structural strength of the ceramic tile veneer.

[0004] The document CN119737005A discloses "A precast concrete exterior wall with reverse-insulation decorative panel and its preparation and application methods." The precast concrete exterior wall with reverse-insulation decorative panel of the present invention integrates insulation, decoration and structure, is industrially produced, and has controllable product quality. It reduces the problems of long construction period, serious pollution and poor economy caused by separate construction of structural layer, insulation layer and decorative layer on site. Its preparation process is simple and has high production efficiency. Its application method reduces the amount of formwork used during on-site installation, which is economical. The waterproof structure is simple and has a good waterproof effect.

[0005] In summary, while existing technologies achieve integrated molding of structure, decoration, and insulation through reverse-molding processes, effectively improving the structural strength and durability of the finishing layer and reducing on-site layered construction steps, industrialized production ensures controllable product quality and good economic efficiency, and the waterproof structure design is simple and reliable, existing technologies still suffer from problems such as a single interlayer bonding mechanism. Conventional planar bonding and penetrating anchors are prone to debonding under temperature cycling and generate significant thermal bridges. Furthermore, the quality control of the decorative surface layer is poor, cement slurry is prone to leakage and contamination, the decorative panel is prone to slippage during vibration, and the insulation layer is prone to floating and shifting due to the buoyancy of concrete, resulting in uneven protective layer thickness. Cold joints are formed between two pours, affecting the overall mechanical properties. At the same time, the corners are prone to cracking and chipping due to sudden changes in modulus, and long-term weather resistance is insufficient. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels, so as to solve the problems mentioned in the background art.

[0007] Technical solution: A reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels, comprising the following steps: S1. A steel reverse mold with partitioned negative pressure adsorption chamber and edge trapezoidal sealing ribs is used to lay the prefabricated decorative thin panels one by one on the bottom surface of the mold. The partitioned negative pressure adsorption chamber applies negative pressure to each decorative panel independently to fix it, so that the side of the decorative panel and the edge sealing rib are squeezed and adhered to form a sealing structure. The joint of the decorative panel is pre-filled with flexible silicone sealant of the same color. S2. Pour the first grade of fine stone high-performance concrete into the mold, with a pouring thickness controlled at 20mm. After pouring, use a low-frequency plate vibrator to remove surface air bubbles. Control the ambient temperature at 18~22℃ and the relative humidity at ≥60%. Cure for 1.5~2.5h until the concrete penetration resistance reaches 3~5MPa in a plastic semi-hardening state. S3. Hoist the insulation board with an array of hemispherical pits pre-processed on the lower surface to the top of the mold. Press the insulation board vertically into the semi-cured first-gradient concrete at a uniform speed using a hydraulic pressing device. The pressing speed is controlled at 5 mm / s and the pressing depth is controlled at 10~12 mm. After pressing, place a non-penetrating elastic positioning strip on the upper surface of the insulation board. The bottom protrusion of the strip is embedded in the preset shallow groove on the upper surface of the insulation board, and both ends are engaged in the positioning grooves on the side wall of the mold. S4. Directly pour the second-gradient coarse aggregate structural concrete to the total thickness of the designed slab. Use phase-separated directional vibration technology. First, start the high-frequency vertical vibrator at the bottom of the mold, set the frequency to 120Hz and the amplitude to 0.8mm, and vibrate for 15~20s in a single area. After a 30s interval, start the upper lateral vibrator, set the frequency to 80Hz and the amplitude to 1.2mm, and vibrate for 20~25s in a single area. S5. After pouring, the material is sent to a curing kiln for three-stage gradient temperature control curing. After curing, the negative pressure adsorption and positioning strip are removed, and the prefabricated integrated thermal insulation and decoration exterior wall panel is demolded.

[0008] Preferably, in step S1, the flatness of the bottom surface of the steel reverse die is ≤0.2mm / m; the edge sealing ribs are made of EPDM rubber, with a cross-section that is narrower at the top and wider at the bottom, 8mm wide at the bottom and 5mm wide at the top, and the height matches the thickness of the precast decorative thin plate; the negative pressure value applied independently to each zone of the negative pressure adsorption chamber is stably maintained at -0.06~-0.08MPa; the filling depth of the precast decorative thin plate splice joint with the same color flexible silicone sealant is 3~5mm, and the sealant surface is flush with the decorative surface.

[0009] Preferably, in step S2, the coarse aggregate particle size of the first gradient fine-stone high-performance concrete is 5~10mm, and the cementitious material dosage is 380~420kg / m³. 3 Add 0.05%~0.1% sodium gluconate retarder by mass of cementitious material, control the initial slump to 80~100mm; control the thickness deviation within ±2mm; after vibration and degassing with a low-frequency plate vibrator, cure for 1.5~2.5h in an environment with a temperature of 18~22℃ and relative humidity ≥60%.

[0010] Preferably, in step S3, the array of hemispherical recesses pre-processed on the lower surface of the insulation board has a diameter of 25mm, a depth of 10mm, a center-to-center spacing of 120mm, and is arranged in a staggered, quincunx pattern; the hydraulic pressing device has a pressing speed of 5mm / s and a pressing depth of 10~12mm; the non-penetrating elastic positioning strip is made of high-density polypropylene, with an inverted T-shaped cross-section, a total height of 25mm, a top width of 30mm, and a bottom protrusion height of 5mm and a width of 30mm; the upper surface of the insulation board has a shallow groove pre-set to match the bottom protrusion of the strip, with a groove depth of 4~5mm and a groove width of 32mm; the positioning strips are arranged at 400mm intervals along the length of the board, and the depth of the two ends inserted into the positioning grooves on the side wall of the mold is 10mm.

[0011] Preferably, in step S4, the coarse aggregate particle size of the second gradient coarse aggregate structural concrete is 10~20mm, and the cementitious material dosage is 320~360kg / m³. 3 The slump is controlled at 120~140mm; the frequency of the high-frequency vertical vibrator at the bottom of the mold is 120Hz, the amplitude is 0.8mm, and the vibration time for a single area is 15~20s; the frequency of the upper lateral vibrator is 80Hz, the amplitude is 1.2mm, and the vibration time for a single area is 20~25s; the start interval between the two types of vibrators is 30s.

[0012] Preferably, in step S5, the three-stage gradient temperature control curing is divided into a static stage, a heating stage, and a cooling stage: the static stage has a kiln temperature of 28~32℃ and a relative humidity of ≥92%, and a static time of 4h; the heating stage raises the temperature uniformly to 53~57℃ at a rate of 4~6℃ / h, and maintains the temperature for 8h; the cooling stage lowers the temperature uniformly to 25℃ at a rate of 2~3℃ / h.

[0013] Preferably, after the insulation board is pressed into place, the semi-cured first-gradient concrete is filled into all the hemispherical pits on the lower surface of the insulation board, and the side of the insulation board is in contact with the positioning block inside the mold.

[0014] Preferably, after curing, the negative pressure adsorption at the bottom of the mold is released first, then the positioning slots on the side wall of the mold and the elastic positioning strips on the upper surface of the insulation board are removed, and then the demolding operation is carried out.

[0015] Beneficial effects: By pressing and embedding the semi-solidified first-gradient concrete with the array of hemispherical pits on the lower surface of the insulation board, a three-dimensional mechanical interlocking interface with a non-penetrating anchoring structure is formed, eliminating the thermal bridging effect at its source and significantly improving the interface's shear resistance. Simultaneously, a mold system with zoned negative pressure adsorption and trapezoidal sealing ribs achieves independent high-precision positioning and gap sealing of the decorative panel, preventing cement slurry leakage and ensuring the quality of the decorative surface layer. The non-penetrating elastic positioning strip and phase-separated directional vibration process work synergistically to effectively constrain the upward and lateral displacement of the insulation board during concrete pouring, while also enhancing the interface's interlocking density and the uniformity of the structural layers, ensuring a high degree of consistency between the insulation layer's position and the concrete protective layer's thickness. Finally, a three-stage gradient temperature-controlled curing system gradually releases temperature deformation stress, mitigating the risk of cracking at the edges and corners due to sudden changes in modulus. This process simultaneously improves interface bonding reliability, dimensional accuracy, and long-term weather resistance, meeting the industrialized and efficient production needs of prefabricated building envelope systems, and possesses significant comprehensive technical advantages. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0017] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1

[0019] A reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels includes: A steel reverse-molding mold with partitioned negative pressure adsorption chambers and edge trapezoidal sealing ribs is used, with a bottom surface flatness of ≤0.2mm / m. The edge sealing ribs are made of EPDM rubber, with a trapezoidal cross-section that is narrower at the top and wider at the bottom, 8mm wide at the bottom and 5mm wide at the top, and a height matching the thickness of the prefabricated decorative panels. The prefabricated decorative panels are laid flat on the bottom surface of the mold one by one. Negative pressure is applied independently to each decorative panel through the partitioned negative pressure adsorption chambers, and the negative pressure value is maintained stably at -0.06MPa, achieving independent adsorption and fixation of each panel, so that the sides of the decorative panels are squeezed and adhered to the edge sealing ribs to form a sealed structure. The joints of the prefabricated decorative panels are pre-filled with flexible silicone sealant of the same color, with a filling depth of 3mm, and the sealant surface is flush with the decorative surface.

[0020] First-grade fine-aggregate high-performance concrete is poured into the mold. The coarse aggregate particle size of this concrete is 5~10mm, and the cementitious material dosage is 380kg / m³. 3 Add 0.05% sodium gluconate retarder by weight of cementitious material, and control the initial slump to 80mm; control the pouring thickness to 20mm, with thickness deviation within ±2mm. After pouring, use a low-frequency plate vibrator to gently vibrate and remove surface air bubbles, then control the ambient temperature at 18℃ and relative humidity at ≥60% for 1.5h, until the concrete penetration resistance reaches a plastic semi-setting state of 3MPa.

[0021] An insulation board with an array of hemispherical recesses pre-processed on its lower surface is hoisted onto the mold. The hemispherical recesses are 25mm in diameter, 10mm deep, and spaced 120mm apart, arranged in a staggered, quincunx pattern. A hydraulic pressing device is used to press the insulation board vertically and uniformly into the semi-cured first-gradient concrete at a controlled speed of 5mm / s and a controlled depth of 10mm. After pressing, the semi-cured first-gradient concrete fills all the hemispherical recesses on the lower surface of the insulation board, and the side of the insulation board is aligned with the positioning blocks inside the mold. After pressing, a non-penetrating elastic positioning strip is placed on the upper surface of the insulation board. The positioning strip is made of high-density polypropylene, with an inverted T-shaped cross section, a total height of 25mm, a top width of 30mm, and a bottom protrusion height of 5mm and a width of 30mm. A shallow groove with a depth of 4mm and a width of 32mm is pre-set on the upper surface of the insulation board to match the bottom protrusion of the positioning strip. The positioning strip is arranged at 400mm intervals along the length of the board, with the bottom protrusion embedded in the shallow groove and both ends inserted into the positioning grooves on the side wall of the mold to a depth of 10mm, completely restricting the upward floating and lateral displacement of the insulation board.

[0022] The second-gradient coarse aggregate structural concrete is poured directly to the total thickness of the designed slab. The coarse aggregate particle size of this concrete is 10~20mm, and the cementitious material dosage is 320kg / m³. 3The slump is controlled at 120mm. A phase-separated directional vibration process is adopted: first, the high-frequency vertical vibrator at the bottom of the mold is started, with a frequency of 120Hz and an amplitude of 0.8mm, and a single-area vibration time of 15s to enhance the compactness of the interface interlocking protrusions; after a 30s interval, the upper lateral vibrator is started, with a frequency of 80Hz and an amplitude of 1.2mm, and a single-area vibration time of 20s to ensure that the concrete of the structural layer is uniform and dense.

[0023] After pouring, the material is placed in a curing kiln for three-stage gradient temperature control curing: During the settling stage, the kiln temperature is 28℃, relative humidity ≥92%, and the settling time is 4 hours; during the heating stage, the temperature is uniformly increased to 53℃ at a rate of 4℃ / h and maintained at this constant temperature for 8 hours; during the cooling stage, the temperature is uniformly decreased to 25℃ at a rate of 2℃ / h. After curing, the negative pressure adsorption at the bottom of the mold is released, then the positioning grooves on the side wall of the mold and the elastic positioning strips on the upper surface of the insulation board are removed. Demolding is then performed to obtain the prefabricated integrated insulation and decoration exterior wall panel.

[0024] Example 2

[0025] A reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels includes: A steel reverse-molding mold with partitioned negative pressure adsorption chambers and edge trapezoidal sealing ribs is used, with a bottom surface flatness of ≤0.2mm / m. The edge sealing ribs are made of EPDM rubber, with a trapezoidal cross-section that is narrower at the top and wider at the bottom, 8mm wide at the bottom and 5mm wide at the top, and a height matching the thickness of the prefabricated decorative panels. The prefabricated decorative panels are laid flat on the bottom surface of the mold one by one, and negative pressure is applied independently to each decorative panel through the partitioned negative pressure adsorption chambers. The negative pressure value is maintained stably at -0.07MPa, achieving independent adsorption and fixation of each panel, so that the sides of the decorative panels are squeezed and adhered to the edge sealing ribs to form a sealed structure. The joints of the prefabricated decorative panels are pre-filled with flexible silicone sealant of the same color, with a filling depth of 4mm, and the sealant surface is flush with the decorative surface.

[0026] First-grade fine-aggregate high-performance concrete is poured into the mold. The coarse aggregate particle size of this concrete is 5~10mm, and the cementitious material dosage is 400kg / m³. 3 Add 0.075% sodium gluconate retarder by weight of cementitious material, and control the initial slump at 90mm; control the pouring thickness at 20mm, with thickness deviation within ±2mm. After pouring, use a low-frequency plate vibrator to gently vibrate and remove surface air bubbles, then control the ambient temperature at 20℃ and relative humidity at ≥60% for 2.0h, until the concrete penetration resistance reaches a plastic semi-setting state of 4MPa.

[0027] An insulation board with an array of hemispherical recesses pre-processed on its lower surface is hoisted onto the mold. The hemispherical recesses are 25mm in diameter, 10mm deep, and spaced 120mm apart, arranged in a staggered, quincunx pattern. A hydraulic pressing device is used to press the insulation board vertically and uniformly into the semi-cured first-gradient concrete at a controlled speed of 5mm / s and a controlled depth of 11mm. After pressing, the semi-cured first-gradient concrete fills all the hemispherical recesses on the lower surface of the insulation board, and the side of the insulation board is aligned with the positioning blocks inside the mold. After pressing, a non-penetrating elastic positioning strip is placed on the upper surface of the insulation board. The positioning strip is made of high-density polypropylene, with an inverted T-shaped cross-section, a total height of 25mm, a top width of 30mm, and a bottom protrusion height of 5mm and a width of 30mm. A shallow groove with a depth of 4.5mm and a width of 32mm is pre-set on the upper surface of the insulation board to match the bottom protrusion of the strip. The positioning strips are arranged at 400mm intervals along the length of the board, with the bottom protrusion embedded in the shallow groove and both ends inserted into the positioning grooves on the side wall of the mold to a depth of 10mm, completely restricting the upward floating and lateral displacement of the insulation board.

[0028] The second-gradient coarse aggregate structural concrete is poured directly to the total design thickness of the slab. The coarse aggregate particle size of this concrete is 10~20mm, and the cementitious material dosage is 340kg / m³. 3 The slump is controlled at 130mm. A phase-separated directional vibration process is adopted: first, the high-frequency vertical vibrator at the bottom of the mold is started, with a frequency of 120Hz and an amplitude of 0.8mm, and a single-area vibration time of 18s to enhance the compactness of the interface interlocking protrusions; after a 30s interval, the upper lateral vibrator is started, with a frequency of 80Hz and an amplitude of 1.2mm, and a single-area vibration time of 22s to ensure that the concrete of the structural layer is uniform and dense.

[0029] After pouring, the material is placed in a curing kiln for three-stage gradient temperature control curing: During the settling stage, the kiln temperature is 30℃, relative humidity ≥92%, and the settling time is 4 hours; during the heating stage, the temperature is uniformly increased to 55℃ at a rate of 5℃ / h and maintained at this constant temperature for 8 hours; during the cooling stage, the temperature is uniformly decreased to 25℃ at a rate of 2.5℃ / h. After curing, the negative pressure adsorption at the bottom of the mold is released, then the positioning grooves on the side wall of the mold and the elastic positioning strips on the upper surface of the insulation board are removed. Demolding is then performed to obtain the prefabricated integrated insulation and decoration exterior wall panel.

[0030] Example 3

[0031] A reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels includes: A steel reverse-molding mold with partitioned negative pressure adsorption chambers and edge trapezoidal sealing ribs is used, with a bottom surface flatness of ≤0.2mm / m. The edge sealing ribs are made of EPDM rubber, with a trapezoidal cross-section that is narrower at the top and wider at the bottom, 8mm wide at the bottom and 5mm wide at the top, and a height matching the thickness of the prefabricated decorative panels. The prefabricated decorative panels are laid flat on the bottom surface of the mold one by one. Negative pressure is applied independently to each decorative panel through the partitioned negative pressure adsorption chambers, and the negative pressure value is maintained stably at -0.08MPa, achieving independent adsorption and fixation of each panel, so that the sides of the decorative panels are squeezed and adhered to the edge sealing ribs to form a sealed structure. The joints of the prefabricated decorative panels are pre-filled with flexible silicone sealant of the same color, with a filling depth of 5mm, and the sealant surface is flush with the decorative surface.

[0032] First-grade fine-aggregate high-performance concrete is poured into the mold. The coarse aggregate particle size of this concrete is 5~10mm, and the cementitious material dosage is 420kg / m³. 3 Add 0.1% sodium gluconate retarder by weight of cementitious material, and control the initial slump to 100mm; control the pouring thickness to 20mm, with thickness deviation within ±2mm. After pouring, use a low-frequency plate vibrator to gently vibrate and remove surface air bubbles, then control the ambient temperature at 22℃ and relative humidity at ≥60% for 2.5h, until the concrete penetration resistance reaches a plastic semi-setting state of 5MPa.

[0033] An insulation board with an array of hemispherical recesses pre-processed on its lower surface is hoisted onto the mold. The hemispherical recesses are 25mm in diameter, 10mm deep, and spaced 120mm apart, arranged in a staggered, quincunx pattern. A hydraulic pressing device is used to uniformly and vertically press the insulation board into the semi-cured first-gradient concrete at a controlled speed of 5mm / s and a controlled depth of 12mm. After pressing, the semi-cured first-gradient concrete fills all the hemispherical recesses on the lower surface of the insulation board, and the side of the insulation board is aligned with the positioning blocks inside the mold. After pressing, a non-penetrating elastic positioning strip is placed on the upper surface of the insulation board. The positioning strip is made of high-density polypropylene, with an inverted T-shaped cross section, a total height of 25mm, a top width of 30mm, and a bottom protrusion height of 5mm and a width of 30mm. A shallow groove with a depth of 5mm and a width of 32mm is pre-set on the upper surface of the insulation board to match the bottom protrusion of the positioning strip. The positioning strip is arranged at 400mm intervals along the length of the board, with the bottom protrusion embedded in the shallow groove and both ends inserted into the positioning grooves on the side wall of the mold to a depth of 10mm, completely restricting the upward floating and lateral displacement of the insulation board.

[0034] The second-gradient coarse aggregate structural concrete is poured directly to the total thickness of the designed slab. The coarse aggregate particle size of this concrete is 10~20mm, and the cementitious material dosage is 360kg / m³. 3The slump is controlled at 140mm. A phase-separated directional vibration process is adopted: first, the high-frequency vertical vibrator at the bottom of the mold is started, with a frequency of 120Hz and an amplitude of 0.8mm, and a single-area vibration time of 20s to enhance the compactness of the interface interlocking protrusions; after a 30s interval, the upper lateral vibrator is started, with a frequency of 80Hz and an amplitude of 1.2mm, and a single-area vibration time of 25s to ensure that the concrete of the structural layer is uniform and dense.

[0035] After pouring, the material is placed in a curing kiln for three-stage gradient temperature control curing: During the settling stage, the kiln temperature is 32℃, relative humidity ≥92%, and the settling time is 4 hours; during the heating stage, the temperature is uniformly increased to 57℃ at a rate of 6℃ / h and maintained at this constant temperature for 8 hours; during the cooling stage, the temperature is uniformly decreased to 25℃ at a rate of 3℃ / h. After curing, the negative pressure adsorption at the bottom of the mold is released, then the positioning grooves on the side wall of the mold and the elastic positioning strips on the upper surface of the insulation board are removed. Demolding is then performed to obtain the prefabricated integrated insulation and decoration exterior wall panel.

[0036] Comparative Example 1 The difference between Comparative Example 1 and Examples 1-3 is that Comparative Example 1 (refer to the prior art document CN108858665A) uses a ceramic tile veneer reverse molding process to prepare the sample, including the following steps: Template pretreatment: First, clean the template thoroughly, then apply the release agent evenly to the template. Avoid missing any spots or accumulating liquid during application to ensure the release effect and not affect the later decoration of the concrete surface.

[0037] Mold assembly and ceramic tile installation: The mold uses a table mold plus side molds, with the side molds fixed to the bottom mold. Masking tape is placed on the side of the side molds near the ceramic tile, and a rubber sheet is placed between the ceramic tile and the bottom mold. The pre-installed back bolts are used to lay the processed ceramic tile on the bottom mold. During the laying process, joint control devices are used to ensure uniform joints. After laying, the ceramic tile is leveled. After leveling, the joints between the ceramic tiles are filled with sealant to a depth of 5mm, and silicone sealant is applied to the side where the ceramic tile meets the masking tape. When making L-shaped wall panels, the vertical ceramic tiles are fixed with anti-tipping clamps that are detachably connected to the side mold. The joints between the vertical and horizontal ceramic tiles are filled with PE rods and sealant.

[0038] Rebar cage fabrication and installation: The rebars are straightened using a cold-drawing method. The cold-drawing rate of HPB300 grade rebars is no more than 4%, and the cold-drawing rate of HRB35, HRB400, and RRB400 grade rebars is no more than 1%. After straightening, the rebars are cut and bent to form a rebar cage. The rebar cage is then hoisted into a mold. Protective pads are arranged in a quincunx pattern at the bottom of the rebar cage, with a spacing of 600mm between adjacent protective pads. After the rebar cage is tied and fixed, the holes where the rebars protrude from the mold are sealed tightly.

[0039] Pre-embedded parts positioning and installation: Fix the connecting sleeve on the template and the reinforcing cage. After positioning the pre-embedded parts, install the simple tooling together with the pre-embedded parts on the mold and fix it on the platform mold with bolts. When installing the embedded nut, apply grease to the threads in advance to protect them and ensure that all kinds of pre-embedded parts are installed firmly and in accurate positions.

[0040] Concrete pouring for the outer leaf wall: Mix concrete according to the design ratio, and the mixing time shall not be less than 90 seconds; pour concrete for the outer leaf wall, avoiding the position of the embedded parts during pouring and vibration, and after pouring, the upper surface of the concrete and the upper edge of the side formwork shall be kept on the same plane. The thickness of the concrete for the outer leaf wall is 50mm; after pouring, quickly smooth the concrete surface.

[0041] Insulation board laying and connection: Lay the insulation boards in a timely manner and level them to ensure that the assembly is completed before the initial setting of the concrete; use connectors to assemble and connect the insulation boards, and tie the connectors to the steel bars of the outer leaf wall.

[0042] Concrete pouring for inner leaf walls: Mix concrete according to the design ratio, and the mixing time shall not be less than 90 seconds; pour and vibrate the concrete for the inner leaf walls, and the thickness of the concrete pouring for the inner leaf walls shall be 200 mm.

[0043] Surface shaping and polishing: First, use a scraper to level the concrete surface. After removing all the embedded parts, proceed with the rough troweling, leveling and polishing processes to process the concrete surface, controlling the flatness of the concrete surface to be within 3mm. After all polishing processes are completed, let it stand for 2 hours.

[0044] Steam curing and demolding: Cover the concrete surface with plastic film for steam curing; before steam curing, let it stand until there are no indentations when pressed by hand. The steam curing process is controlled by heating at 15℃ / hour, holding at a constant temperature for 6-8 hours, and cooling down at 15℃ / hour. When demolding, the temperature difference between the component and the ambient temperature should not exceed 15℃; demolding is carried out after the compressive strength of the concrete test block reaches 20MPa.

[0045] Comparative Example 2 The difference between Comparative Example 2 and Examples 1-3 is that Comparative Example 2 (refer to the prior art document CN119737005A) uses the preparation process of precast concrete exterior walls with insulated decorative panels to prepare the sample, including the following steps: Decorative panel side template assembly: Assemble the first template of the thermal insulation decorative panel into a large rectangular frame on the mold table. The height of the rectangular frame is consistent with the thickness of the thermal insulation decorative panel.

[0046] Insulation and decorative panel installation and tie-fit installation: Arrange the insulation and decorative panels in reverse and lay them within the rectangular frame, starting from the lower left corner of the frame; after each insulation and decorative panel is laid, install tie-fits at the horizontal and vertical joints of adjacent panels. The upper flange of the tie-fit should be flush with the groove reserved in the finishing layer, the middle flange should be wedged between the insulation layers to control the width of the panel joints, and the lower flange should extend into the concrete layer for anchoring; install them one by one until all insulation and decorative panels are laid.

[0047] Tie rod hole fixture setup: Insert the tie rod hole fixture at the designated position in the vertical seam. The fixture is made of PVC20 pipe. Before installation, enlarge the hole at the corresponding position by 18mm, and the depth should be consistent with the thickness of the insulation board in the insulation decorative panel. After the fixture is inserted, the bottom of it passes directly through the insulation decorative panel and is close to the formwork surface. The fixture in the concrete section is fixed with tie wire to the reinforcing bar.

[0048] Sealing treatment of board joints: Seal the first horizontal and first vertical joints between the insulation and decorative boards. Apply a layer of structural adhesive evenly to the joint and then apply sealant paper. At the location of tie rods, apply an additional layer of sealant paper with the same cross-sectional shape as the tie rod, and apply a layer of sealant to the gap formed by the sealant paper and the tie rod. At the location of the tie rod hole fixture, apply an additional layer of sealant paper through the fixture, and apply a layer of sealant to the gap formed by the sealant paper and the fixture to ensure that there is no leakage of grout in any part.

[0049] Concrete side formwork assembly: Draw the outline of the precast concrete on the insulation board, and lay a ring of waterproof membrane along the outline, with half of the width of the waterproof membrane inside the outline and half outside the outline; then assemble the second formwork of the precast concrete to form a small rectangular frame that is close to the upper part of the insulation board.

[0050] Rebar tying: Tie vertical and horizontal reinforcing bars within a small rectangular frame, and tie the end of the tie piece that extends into the concrete to the reinforcing bar for fixation.

[0051] Concrete pouring and curing: Pour concrete into the mold, and cure it according to conventional procedures after pouring.

[0052] Demolding and Finished Product Warehousing: After curing, demolding is carried out, and the finished products are put into storage after inspection.

[0053] To illustrate the finished products using the present invention, tests were conducted on the finished products prepared in Examples 1-3 and Comparative Examples 1-2. The test methods are as follows: Interface shear strength test: Referring to the relevant specifications for interface performance testing of precast concrete sandwich insulated wall panels, the finished wall panels were cut into standard specimens of 100mm×100mm, each specimen containing the complete interface between the concrete layer and the insulation layer; a microcomputer-controlled electronic universal testing machine was used for shear loading, with the loading rate set to 5mm / min, and the maximum load at which the interface delamination failure occurred was recorded, and the interface shear strength was calculated; 5 parallel specimens were prepared for each group, and the test results were taken as the arithmetic mean.

[0054] Insulation layer position deviation test: After the finished product is demolded, 9 test points are evenly selected on the surface of each wall panel. The total thickness of the panel, the thickness of the upper structural concrete layer and the thickness of the lower decorative bonding layer are measured by an ultrasonic concrete thickness gauge. The actual spatial position of the insulation layer is calculated. The upward deviation and lateral offset deviation of the insulation layer relative to the design position are calculated. The maximum deviation value among the 9 test points is taken as the test result of the sample.

[0055] Test of cement slurry seepage defect rate of decorative surface: After demolding, the entire surface of the decorative surface is visually inspected under natural light. The total area of ​​the area with cement slurry seepage pollution is counted by combining image area measurement tools. The proportion of the area with cement slurry seepage pollution to the total area of ​​the entire decorative surface is calculated, which is the cement slurry seepage defect rate of the decorative surface. The number of independent cement slurry seepage defect points on a single board is recorded at the same time.

[0056] Concrete cover thickness deviation test: In accordance with the testing requirements in GB50204 "Code for Acceptance of Construction Quality of Concrete Structures", a steel reinforcement cover tester was used to select 12 measuring points evenly on the upper surface of the slab to measure the actual cover thickness of the concrete in the structural layer. The maximum positive deviation and the maximum negative deviation between the measured value and the design value were counted respectively, and the sum of the absolute values ​​of the two was used as the cover thickness deviation index to reflect the uniformity of the cover thickness.

[0057] Test of bond strength retention rate after freeze-thaw cycles: Referring to the rapid freeze-thaw test method in the "Technical Standard for External Wall Insulation Engineering" JGJ144, the interface bonding standard sample was placed in a freeze-thaw test chamber, and the temperature cycle range was set from -20℃ to 20℃. The duration of each cycle was 8 hours, and a total of 50 freeze-thaw cycles were performed. After the cycle, the interfacial tensile bond strength of the sample was tested and compared with the initial bond strength before freeze-thaw. The bond strength retention rate was calculated to evaluate the long-term weather resistance of the board.

[0058] The test results are shown in the table below:

[0059] As can be seen from the comparison of the embodiments and comparative examples, the present invention constructs a three-dimensional array interlocking interface through semi-solid embedded pressing, combined with a synergistic molding process of phase-separated directional vibration and non-penetrating elastic positioning, and a three-stage gradient temperature-controlled curing mechanism, which can simultaneously improve the interlayer bonding strength, molding dimensional accuracy, and long-term weather resistance of the wall panel. The three-dimensional mechanical interlocking structure effectively strengthens the interface shear resistance and eliminates continuous thermal bridges, the zoned sealing system blocks the seepage of grout into the decorative surface from the source, phase-separated vibration and positioning strips jointly ensure the uniformity of the insulation layer position and protective layer thickness, and gradient curing alleviates internal residual stress and reduces the risk of corner cracking. It can balance high interface bonding reliability, high molding accuracy, and long-term service durability, and is more suitable for the industrial production and engineering application needs of prefabricated building envelope systems.

[0060] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A reverse molding process for prefabricated integrated thermal insulation and decorative exterior wall panels, characterized in that, Includes the following steps: S1. A steel reverse mold with partitioned negative pressure adsorption chamber and edge trapezoidal sealing ribs is used to lay the prefabricated decorative thin panels one by one on the bottom surface of the mold. The partitioned negative pressure adsorption chamber applies negative pressure to each decorative panel independently to fix it, so that the side of the decorative panel and the edge sealing rib are squeezed and adhered to form a sealing structure. The joint of the decorative panel is pre-filled with flexible silicone sealant of the same color. S2. Pour the first grade of fine stone high-performance concrete into the mold, with a pouring thickness controlled at 20mm. After pouring, use a low-frequency plate vibrator to remove surface air bubbles. Control the ambient temperature at 18~22℃ and the relative humidity at ≥60%. Cure for 1.5~2.5h until the concrete penetration resistance reaches 3~5MPa in a plastic semi-hardening state. S3. Hoist the insulation board with an array of hemispherical pits pre-processed on the lower surface to the top of the mold. Press the insulation board vertically into the semi-cured first-gradient concrete at a uniform speed using a hydraulic pressing device. The pressing speed is controlled at 5 mm / s and the pressing depth is controlled at 10~12 mm. After pressing, place a non-penetrating elastic positioning strip on the upper surface of the insulation board. The bottom protrusion of the strip is embedded in the preset shallow groove on the upper surface of the insulation board, and both ends are engaged in the positioning grooves on the side wall of the mold. S4. Directly pour the second-gradient coarse aggregate structural concrete to the total thickness of the designed slab. Use phase-separated directional vibration technology. First, start the high-frequency vertical vibrator at the bottom of the mold, set the frequency to 120Hz and the amplitude to 0.8mm, and vibrate for 15~20s in a single area. After a 30s interval, start the upper lateral vibrator, set the frequency to 80Hz and the amplitude to 1.2mm, and vibrate for 20~25s in a single area. S5. After pouring, the material is sent to a curing kiln for three-stage gradient temperature control curing. After curing, the negative pressure adsorption and positioning strip are removed, and the prefabricated integrated thermal insulation and decoration exterior wall panel is demolded.

2. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 1, characterized in that, In step S1, the flatness of the bottom surface of the steel reverse die is ≤0.2mm / m; the edge sealing ribs are made of EPDM rubber, with a cross-section that is narrower at the top and wider at the bottom, 8mm wide at the bottom and 5mm wide at the top, and the height matches the thickness of the precast decorative thin plate; the negative pressure value applied independently to each zone of the negative pressure adsorption chamber is stably maintained at -0.06~-0.08MPa; the filling depth of the precast decorative thin plate splice joint with the same color flexible silicone sealant is 3~5mm, and the sealant surface is flush with the decorative surface.

3. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 1, characterized in that, In step S2, the coarse aggregate particle size of the first gradient fine-stone high-performance concrete is 5~10mm, and the amount of cementitious material is 380~420kg / m³. 3 Add 0.05%~0.1% sodium gluconate retarder by mass of cementitious material, control the initial slump to 80~100mm; control the thickness deviation within ±2mm; after vibration and degassing with a low-frequency plate vibrator, cure for 1.5~2.5h in an environment with a temperature of 18~22℃ and relative humidity ≥60%.

4. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 1, characterized in that, In step S3, the array of hemispherical recesses pre-processed on the lower surface of the insulation board has a diameter of 25mm, a depth of 10mm, and a center-to-center spacing of 120mm, arranged in a staggered, quincunx pattern; the hydraulic pressing device has a pressing speed of 5mm / s and a pressing depth of 10~12mm; the non-penetrating elastic positioning strip is made of high-density polypropylene, with an inverted T-shaped cross-section, a total height of 25mm, a top width of 30mm, and a bottom protrusion height of 5mm and a width of 30mm; the upper surface of the insulation board has a shallow groove pre-set to match the bottom protrusion of the positioning strip, with a groove depth of 4~5mm and a groove width of 32mm; the positioning strips are arranged at 400mm intervals along the length of the board, and the depth of the two ends inserted into the positioning grooves on the side wall of the mold is 10mm.

5. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 1, characterized in that, In step S4, the coarse aggregate particle size of the second-gradient coarse aggregate structural concrete is 10~20mm, and the cementitious material dosage is 320~360kg / m³. 3 The slump is controlled at 120~140mm; the frequency of the high-frequency vertical vibrator at the bottom of the mold is 120Hz, the amplitude is 0.8mm, and the vibration time for a single area is 15~20s; the frequency of the upper lateral vibrator is 80Hz, the amplitude is 1.2mm, and the vibration time for a single area is 20~25s; the start interval between the two types of vibrators is 30s.

6. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 1, characterized in that, In step S5, the three-stage gradient temperature control curing is divided into a static stage, a heating stage, and a cooling stage: the static stage has a kiln temperature of 28~32℃ and a relative humidity of ≥92%, and a static time of 4h; the heating stage raises the temperature at a rate of 4~6℃ / h to 53~57℃ and is kept at a constant temperature for 8h; the cooling stage lowers the temperature at a rate of 2~3℃ / h to 25℃.

7. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 4, characterized in that, After the insulation board is pressed into place, the semi-cured first-gradient concrete is filled into all the hemispherical pits on the lower surface of the insulation board, and the side of the insulation board fits into the positioning block inside the mold.

8. The reverse molding process for a prefabricated integrated thermal insulation and decorative exterior wall panel according to claim 6, characterized in that, After curing, first release the negative pressure adsorption at the bottom of the mold, then remove the positioning slots on the side wall of the mold and the elastic positioning strips on the upper surface of the insulation board, and then carry out the demolding operation.

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