3D printing recycled concrete prefabricated floor slab structure and construction method thereof

Abstract

The invention discloses a 3D printing recycled concrete prefabricated floor slab structure which comprises a prefabricated floor slab which is a recycled concrete prefabricated slab composed of a recycled concrete slab body poured in a recycled concrete pouring area and reinforcing meshes longitudinally and transversely arranged in the recycled concrete slab body. The recycled concrete plate body is formed by printing layer by layer through 3D printing equipment. The invention further discloses a construction method of the 3D printing recycled concrete prefabricated floor slab structure. 3D printing, recycled concrete and prefabricated floor slabs are combined, the problem of construction waste pollution can be solved, the current advanced technology and construction method can be combined, the environment-friendly, innovative and economical development concepts are met, and the method has good application prospects and can be widely applied to the technical field of construction engineering construction.

Description

Technical Field

[0001] The present invention relates to the technical field of building engineering construction, and in particular to a 3D printed recycled concrete prefabricated floor slab structure and a construction method thereof. Background Art

[0002] 3D printing (3DP) is a type of rapid prototyping technology, also known as additive manufacturing. It is a technology that uses 3D model files as the basis, uses powdered metal or plastic and other bondable materials to construct objects by printing layer by layer. Concrete 3D printing is a new application technology that combines 3D printing technology with concrete material technology. In the actual construction printing process of concrete 3D printing, the graphic design model of the building is converted into three-dimensional information. Through the set printing path, the material with short setting time, fast strength development and good thixotropy is extruded from the nozzle, and stacked layer by layer to form a cumulative shape.

[0003] Recycled concrete refers to the new concrete made by crushing, cleaning, grading, mixing with grading in a certain proportion, partially or completely replacing natural aggregates such as sand and gravel (mainly coarse aggregate), and then adding cement, water, etc. The use of recycled concrete is not only beneficial to environmental protection, but also helps to promote sustainable development, reduce construction costs, improve building quality, and expand the scope of application. It is one of the important development directions of building materials in the future. At the same time, studies have shown that recycled coarse aggregate can be successfully used in 3D printed concrete to achieve economic benefits and improve shrinkage cracking resistance. The use of recycled concrete aggregate (RCA) to prepare 3D printed recycled coarse aggregate concrete (3DPRAC) can not only reduce the amount of cement and natural aggregate, reduce the cost of raw materials, but also reduce carbon footprint. This has been regarded as one of the most promising methods to achieve sustainable development of digital manufacturing of concrete.

[0004] Precast reinforced concrete floor slabs refer to reinforced concrete floor slabs that are prefabricated outside the component prefabrication factory or construction site and then transported to the construction site for installation. As an efficient, green and economical form of floor slabs, precast floor slabs have many advantages such as reducing construction time, improving work safety, reducing waste and reducing carbon emissions.

[0005] In view of this, a 3D printed recycled concrete prefabricated floor slab structure and a construction method thereof are proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a 3D printed recycled concrete prefabricated floor structure and a construction method thereof based on the above-mentioned background technology, so that it combines 3D printing, recycled concrete, and prefabricated floor slabs, which can not only solve the problem of construction waste pollution, but also combine the current advanced technology and construction methods, conform to the development concept of environmental protection, innovation, and economy, and have good application prospects.

[0007] The present invention provides a 3D printed recycled concrete prefabricated floor structure, comprising a prefabricated floor, wherein the prefabricated floor is a recycled concrete prefabricated slab composed of a recycled concrete slab body cast in a recycled concrete casting area and steel meshes arranged vertically and horizontally in the recycled concrete slab body, and the recycled concrete slab body is printed layer by layer by a 3D printing device.

[0008] In the above technical solution, the pouring directions of the two adjacent layers of recycled concrete in the recycled concrete slab printed layer by layer by the 3D printing equipment are perpendicular to each other.

[0009] In the above technical solution, the steel mesh includes a plurality of truss steel bar groups arranged along the length direction of the recycled concrete slab and a plurality of width direction steel bars connecting the truss steel bar groups and arranged along the width direction of the recycled concrete slab.

[0010] In the above technical solution, the truss steel bar group includes a plurality of upper chord steel bars arranged along the length direction of the recycled concrete slab and located at the top of the recycled concrete slab, and lower chord steel bars symmetrically arranged at the bottom of the recycled concrete slab are arranged on both sides of each upper chord steel bar, and web bars are arranged between each upper chord steel bar and the two lower chord steel bars symmetrically arranged therewith; the width direction steel bars include top width direction steel bars connected to the upper chord steel bars and bottom width direction steel bars connected to the lower chord steel bars, and the top width direction steel bars correspond to the bottom width direction steel bars one by one, and each bottom width direction steel bar is located directly below the corresponding top width direction steel bar.

[0011] In the above technical solution, each web reinforcement is arranged in a wave-shaped structure, the wave crest of the web reinforcement is connected to the corresponding upper chord reinforcement, and the wave trough of the web reinforcement is connected to the corresponding lower chord reinforcement.

[0012] In the above technical solution, top span direction steel bars are respectively provided between two adjacent truss steel bar groups and on both sides of the recycled concrete slab. The top span direction steel bars are equal in height to the upper chord steel bars. A corresponding bottom span direction steel bar is provided directly below each top span direction steel bar. The top span direction steel bars are connected to the top width direction steel bars, and the bottom span direction steel bars are connected to the bottom width direction steel bars.

[0013] In the above technical solution, a number of vertically arranged hanging point vertical bars are provided at the bottom of the intersection of the top span direction steel bars and the top width direction steel bars on both sides of the recycled concrete slab, and the top ends of the hanging point vertical bars are consolidated with the top width direction steel bars, and the bottom ends are consolidated with the bottom width direction steel bars.

[0014] In the above technical solution, concrete supports as side supports are respectively provided at the bottom of both ends of each recycled concrete precast panel, and the end of the recycled concrete precast panel is placed on the edge of the top of the concrete support as the side support. The overlap length L between the recycled concrete precast panel and the top of the concrete support as the side support is 10 mm. The upper chord steel bars and the two ends of the top span direction steel bars of the recycled concrete precast panel extend out of the two ends of the recycled concrete panel body and bend downward, and the lower chord steel bars and the two ends of the bottom span direction steel bars of the recycled concrete precast panel extend out of the recycled concrete panel body. At both ends of the earth slab body, the horizontal lengths of the lower chord steel bars and the bottom span direction steel bars are shorter than the horizontal lengths of the upper chord steel bars and the top span direction steel bars. The top of the concrete support serving as the side support is provided with an ordinary concrete structure that wraps the ends of the upper chord steel bars and the lower chord steel bars as well as the ends of the top span direction steel bars and the bottom span direction steel bars. Concrete supports serving as intermediate supports are provided at the bottoms of the adjacent ends of the two recycled concrete precast panels along the same axis. The ends of the two recycled concrete precast panels are respectively placed on the top of the concrete support serving as the intermediate support on both sides. The lap length L between the recycled concrete precast panel and the top of the concrete support as the middle support is 10 mm. The upper chord steel bars and the top span direction steel bars and the lower chord steel bars and the bottom span direction steel bars of the two recycled concrete precast panels extend into the top of the concrete support as the middle support respectively. The upper chord steel bars, the top span direction steel bars, the lower chord steel bars, and the bottom span direction steel bars corresponding to the two recycled concrete precast panels are arranged in an overlapping structure. The top of the concrete support as the middle support is provided with a structure for connecting the ends of the upper chord steel bars and the lower chord steel bars and the top The ordinary concrete structure in which the top span direction steel bars and the bottom span direction steel bars are wrapped; the top width direction steel bars corresponding to the two adjacent recycled concrete precast panels on the side are bent and connected, and the adjacent sides of the two recycled concrete precast panels are respectively provided with inclined cuts, and the two cuts together form a wedge-shaped groove, and the horizontal ends and bent parts of the two top width direction steel bars are located in the wedge-shaped groove, and the top span direction steel bars and the top of the vertical bars of the hanging points on the sides of the two recycled concrete precast panels are all located in the wedge-shaped groove, and the wedge-shaped groove is provided with a fine stone concrete structure for filling it.

[0015] In the above technical solution, the length of the lower chord steel bars and the bottom span direction steel bars of each recycled concrete precast panel extending into the concrete support as the side support is the larger value between 5 times the steel bar diameter d and 100 cm and should extend beyond the support center line of the concrete support, the horizontal length of the upper chord steel bars and the top span direction steel bars of the recycled concrete precast panel extending into the concrete support as the side support is not less than 0.4 times the basic anchorage length Lab of the tensile steel bars and the downward bending length is 15 times the steel bar diameter d; the lower chord steel bars and the bottom span direction steel bars of each recycled concrete precast panel extending into the concrete support as the middle support is not less than 0.4 times the basic anchorage length Lab of the tensile steel bars and the downward bending length is 15 times the steel bar diameter d. The length of the support is the larger value between 5 times the diameter of the steel bar d and 100 cm and should extend beyond the center line of the concrete support. The horizontal length of the upper chord steel bars and the top span direction steel bars of the recycled concrete precast slab extending into the concrete support serving as the intermediate support shall not be less than 0.4 times the basic anchorage length Lab of the tensile steel bars and the downward bending length shall be 15 times the diameter of the steel bar d; the downward bending length of the top width direction steel bars of the two adjacent recycled concrete precast slabs on the side is 1 / 4 of the thickness of the recycled concrete precast slabs h, and the depth of the wedge-shaped grooves of the two recycled concrete precast slabs is 1 / 2 of the thickness of the recycled concrete precast slabs h.

[0016] The present invention also provides a 3D printed recycled concrete prefabricated floor construction method, which has the following steps: the first step, the design stage: complete the design work including concrete supports, recycled concrete pouring areas, web bars, lower chord bars, upper chord bars, top span direction bars, top width direction bars, bottom span direction bars, bottom width direction bars, and hanging point vertical bars, select the specifications and dimensions of each component according to the project situation, and select the recycled concrete material according to the requirements of the 3D printing equipment; the second step, the prefabrication stage: complete the mold platform, oil stains and concrete residue cleaning, mold release agent brushing, marking positioning, mold assembly work, according to the design requirements Each component is assembled in place on the formwork, and the specifications, positions, spacings and quantities of the steel bars are checked and accepted according to the drawings. The recycled concrete is poured using 3D printing equipment to complete the prefabrication of the recycled concrete precast panels. The third step, the construction phase, is to use hoisting equipment to hoist the recycled concrete precast panels to the construction plane, adjust the positions of the recycled concrete precast panels and place them on concrete supports. After all the recycled concrete precast panels are in place, ordinary concrete is poured to complete the construction and installation of the recycled concrete precast panels at the side supports and the middle supports. Fine stone concrete is poured one by one at the junction of adjacent and parallel recycled concrete precast panels to complete the construction of the overall floor slab of a working area.

[0017] The 3D printed recycled concrete prefabricated floor structure and construction method thereof of the present invention have the following beneficial effects: 1. The use of recycled concrete is economical and environmentally friendly, while solving the problem of shortage of building materials; 2. The use of 3D printing technology does not require a template, and the printer works continuously, saving processes, materials, costs, and shortening construction time. At the same time, it has a high degree of refinement, and has advantages in customization and design capabilities.

[0018] 3. Compared with cast-in-place floors, prefabricated floors have the advantages of stable quality, improved construction efficiency, and reduced construction period.

[0019] 4. The use of truss steel reinforcement layout and perpendicular pouring directions layer by layer enhances the overall stress-bearing performance and stability of the floor slab.

[0020] 5. Reserve hanging holes to facilitate installation and positioning and improve construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the overall structure of the 3D printed recycled concrete prefabricated floor structure of the present invention; Figure 2 for Figure 1 Schematic diagram of the structure at the middle section 1-1; Figure 3 for Figure 1 A schematic diagram of the structure at the middle section 2-2; Figure 4 for Figure 1 The structural diagram at the middle section 3-3; Figure 5 A top view of the structure of the edge support and its surrounding area in Example 1 of the 3D printed recycled concrete prefabricated floor structure of the present invention; Figure 6 This is a structural cross-sectional view of the side support and its surrounding area in Example 1 of the 3D printed recycled concrete prefabricated floor structure of the present invention; Figure 7 This is a structural cross-sectional view of two recycled concrete prefabricated slabs in side-by-side arrangement in Embodiment 1 of the 3D printed recycled concrete prefabricated floor slab structure of the present invention; Figure 8 A top view of the structure of the middle support and its surrounding area in Embodiment 2 of the 3D printed recycled concrete prefabricated floor structure of the present invention; Fig. 9 This is a structural cross-sectional view of the middle support and its surrounding area in Example 2 of the 3D printed recycled concrete prefabricated floor structure of the present invention; Fig.10 This is a schematic diagram of the overall process of the 3D printed recycled concrete prefabricated floor construction method of the present invention; Fig.11 This is a schematic diagram of the installation construction of the recycled concrete precast slab at the concrete support serving as the side support in step three of the 3D printed recycled concrete precast floor slab construction method of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the embodiments should not be construed as limiting the present invention.

[0023] See also Figures 1 to 9 The 3D printed recycled concrete prefabricated floor structure of the present invention includes a prefabricated floor, wherein the prefabricated floor is a recycled concrete 11 prefabricated board composed of a recycled concrete 11 board body cast in a recycled concrete casting area 2 and a steel mesh arranged vertically and horizontally in the recycled concrete 11 board body, and the recycled concrete 11 board body is printed layer by layer by a 3D printing device.

[0024] The steel mesh includes a plurality of truss steel bar groups arranged along the length direction of the recycled concrete 11 slab body and a plurality of width direction steel bars connecting the truss steel bar groups and arranged along the width direction of the recycled concrete 11 slab body.

[0025] The truss steel bar group includes a plurality of upper chord steel bars 5 arranged along the length direction of the recycled concrete 11 slab and located at the top of the recycled concrete 11 slab, and lower chord steel bars 4 symmetrically arranged at the bottom of the recycled concrete 11 slab are arranged on both sides of each upper chord steel bar 5, and a web steel bar 3 is arranged between each upper chord steel bar 5 and two lower chord steel bars 4 symmetrically arranged therewith. In one or more embodiments, each web steel bar 3 is arranged in a wave-shaped structure, and the crest of the web steel bar 3 is connected to the corresponding upper chord steel bar 5, and the trough of the web steel bar 3 is connected to the corresponding lower chord steel bar 4. The width direction steel bars include top width direction steel bars 7 connected to the upper chord steel bars 5 and bottom width direction steel bars 9 connected to the lower chord steel bars 4, and the top width direction steel bars 7 correspond to the bottom width direction steel bars 9 one by one, and each bottom width direction steel bar 9 is located directly below the corresponding top width direction steel bar 7.

[0026] Top span direction steel bars 6 are respectively provided between two adjacent truss steel bar groups and on both sides of the recycled concrete 11 slab. The top span direction steel bars 6 are equal in height to the upper chord steel bars 5. A corresponding bottom span direction steel bar 8 is provided directly below each top span direction steel bar 6. The top span direction steel bars 6 are connected to the top width direction steel bars 7, and the bottom span direction steel bars 8 are connected to the bottom width direction steel bars 9.

[0027] Example 1 like Figures 1 to 4The embodiment 1 of a 3D printed recycled concrete prefabricated floor structure of the present invention shown includes a concrete support 1, a recycled concrete pouring area 2, a web bar reinforcement 3, a lower chord reinforcement 4, an upper chord reinforcement 5, a top span direction reinforcement 6, a top width direction reinforcement 7, a bottom span direction reinforcement 8, a bottom width direction reinforcement 9, a hanging point vertical reinforcement 10, a recycled concrete 11 slab body, a common concrete 12 structure and a fine stone concrete 13 structure. In this embodiment, the concrete support 1 is an edge support.

[0028] According to the above scheme, the concrete support 1 can be a concrete beam or a concrete wall. In order to meet the anchorage length of the steel bar at the concrete support 1, the width of the concrete beam or the concrete wall is selected according to the design requirements.

[0029] According to the above scheme, the recycled concrete pouring area 2 is the area where the 3D printing equipment prints the recycled concrete 11. The plane size of this area is the size of the recycled concrete 11 precast board determined according to the specific design, and the area height is the thickness of the recycled concrete 11 precast board. The recycled concrete 11 precast board is designed according to the module to facilitate construction. The 3D printing equipment is used in this area to densely pour the recycled concrete 11 to ensure the overall working performance of the recycled concrete 11 precast board.

[0030] See also Figures 5 and 6 , each recycled concrete 11 precast panel has a concrete support 1 as an edge support at both ends and at the bottom, the end of the recycled concrete 11 precast panel is placed on the edge of one side of the top of the concrete support 1 as the edge support, the overlap length L between the recycled concrete 11 precast panel and the top of the concrete support 1 as the edge support is 10mm, the ends of the upper chord steel bar 5 and the top span direction steel bar 6 of the recycled concrete 11 precast panel respectively extend out of the two ends of the recycled concrete 11 panel and bend downward, the ends of the lower chord steel bar 4 and the bottom span direction steel bar 8 of the recycled concrete 11 precast panel respectively extend out of the two ends of the recycled concrete 11 panel, the horizontal lengths of the two ends of the lower chord steel bar 4 and the bottom span direction steel bar 8 are shorter than the horizontal lengths of the two ends of the upper chord steel bar 5 and the top span direction steel bar 6, and the top of the concrete support 1 as the edge support is provided with an ordinary concrete 12 structure that wraps the ends of the upper chord steel bar 5 and the lower chord steel bar 4 as well as the ends of the top span direction steel bar 6 and the bottom span direction steel bar 8.

[0031] See also Figure 7The top width direction steel bars 7 corresponding to the two adjacent recycled concrete 11 precast panels on the side are bent and connected, and the adjacent sides of the two recycled concrete 11 precast panels are respectively provided with inclined cuts, and the two cuts together form a wedge-shaped groove, and the horizontal ends and bent parts of the two top width direction steel bars 7 are located in the wedge-shaped groove, and the top span direction steel bars 6 and the top of the hanging point vertical bars 10 on the sides of the two recycled concrete 11 precast panels are all located in the wedge-shaped groove, and the wedge-shaped groove is provided with a fine stone concrete 13 structure to fill it.

[0032] See also Figures 5 to 7 According to the above scheme, the web reinforcement 3, the lower chord reinforcement 4, and the upper chord reinforcement 5 are designed according to the design requirements of the assembled composite floor. Among them, the length of the lower chord reinforcement 4 end of each recycled concrete 11 precast plate extending into the concrete support 1 as the side support is the larger value between 5 times the reinforcement diameter d and 100mm and should extend through the support centerline 14 of the concrete support 1. The horizontal length of the upper chord reinforcement 5 end of the recycled concrete 11 precast plate extending into the concrete support 1 as the side support is not less than 0.4 times the basic anchorage length Lab of the tensile reinforcement and the downward bending length is 15 times the reinforcement diameter d. The anchorage length requirements are met to ensure the connection strength at the concrete support 1.

[0033] According to the above scheme, the top span direction steel bars 6, top width direction steel bars 7, bottom span direction steel bars 8, and bottom width direction steel bars 9 are all selected according to the stress conditions of the floor slab. Among them, the length of the top span direction steel bars 6 of the recycled concrete 11 precast slab extending into the concrete support 1 as the side support is not less than 0.4 times the basic anchoring length Lab of the tensile steel bar and the downward bending length is 15 times the steel bar diameter d, the downward bending length of the top width direction steel bars 7 of the two adjacent recycled concrete 11 precast slabs on the side is 1 / 4 of the recycled concrete 11 precast slab thickness h, and the depth of the wedge-shaped grooves of the two recycled concrete 11 precast slabs is 1 / 2 of the recycled concrete 11 precast slab thickness h. The length of the bottom span direction steel bars 8 of the recycled concrete 11 precast slab extending into the concrete support 1 as the side support is the larger value between 5 times the steel bar diameter d and 100mm and should extend over the support center line 14 of the concrete support 1. Considering that the mechanical properties of recycled concrete 11 are worse than those of ordinary concrete 12, reinforcement treatment is performed during the design of the reinforcement, such as increasing the diameter of the reinforcement by one level.

[0034] According to the above scheme, the vertical reinforcement 10 of the hanging point is located below the top span direction reinforcement 6 of the outermost side of each recycled concrete 11 board, and the upper and lower ends of the vertical reinforcement 10 of the hanging point are respectively welded to the top width direction reinforcement 7 and the bottom width direction reinforcement 9. The position of the vertical reinforcement 10 of the hanging point is determined according to the span of the recycled concrete 11 precast board, ensuring reasonable force and convenient construction when the recycled concrete 11 precast board is lifted at the hanging point.

[0035] According to the above scheme, the recycled concrete 11 is a concrete that meets the construction gradation of the 3D printing equipment. The 3D printing equipment has certain requirements for printing materials, and the appropriate gradation of the recycled concrete 11 is an important guarantee for the normal operation of the 3D printing equipment.

[0036] According to the above scheme, the printing and pouring direction of the recycled concrete 11 changes layer by layer, so that the printing and pouring directions of the upper and lower layers are perpendicular. The mutually perpendicular pouring directions make the grip between the recycled concrete 11 and various steel bars tighter, thereby enhancing the overall force-bearing performance and stability of the floor slab.

[0037] According to the above scheme, both the ordinary concrete 12 and the fine stone concrete 13 meet the requirements of the design specifications and are selected according to the design needs. Ordinary concrete 12 is used to connect the node connection area of ​​the concrete support 1 as the side support to form an ordinary concrete 12 structure to ensure the firmness of the connection at the node of the concrete support 1. The fine stone concrete 13 has a small aggregate particle size and is used for the wedge-shaped groove at the joint of the two recycled concrete 11 precast panels, so that the interface is flat and the connection is guaranteed.

[0038] According to the above solution, the overlap size of the recycled concrete 11 precast panel at the concrete support 1 serving as the edge support is 10 mm.

[0039] According to the above scheme, a cut with a size of 1 / 2 of the thickness h of the recycled concrete 11 precast panels is reserved on the adjacent side of the two adjacent recycled concrete 11 precast panels along the span direction, and a hanging point is set in the cut area. The two cuts form a wedge-shaped groove. After the lifting and installation are completed, fine stone concrete 13 is poured in the wedge-shaped groove to connect the two recycled concrete 11 precast panels.

[0040] Example 2 This embodiment is basically the same as Embodiment 1, except that: like Figures 1 to 4 A 3D printed recycled concrete prefabricated floor structure shown includes a concrete support 1, a recycled concrete pouring area 2, a web reinforcement 3, a lower chord reinforcement 4, an upper chord reinforcement 5, a top span direction reinforcement 6, a top width direction reinforcement 7, a bottom span direction reinforcement 8, a bottom width direction reinforcement 9, a hanging point vertical reinforcement 10, recycled concrete 11, ordinary concrete 12 and fine stone concrete 13. The concrete support 1 is an intermediate support.

[0041] See also Figures 8 to 9, a concrete support 1 as an intermediate support is provided at the bottom of the adjacent ends of two recycled concrete 11 precast panels along the same axis, the ends of the two recycled concrete 11 precast panels are respectively placed on the edges of both sides of the top of the concrete support 1 as the intermediate support, the overlap length L between the recycled concrete 11 precast panels and the top of the concrete support 1 as the intermediate support is 10mm, the upper chord steel bars 5 and the top span direction steel bars 6 and the lower chord steel bars 4 and the bottom span direction steel bars 8 of the two recycled concrete 11 precast panels are respectively extended into the top of the concrete support 1 as the intermediate support, the upper chord steel bars 5, the top span direction steel bars 6, the lower chord steel bars 4, and the bottom span direction steel bars 8 corresponding to the two recycled concrete 11 precast panels are all arranged in an overlapping structure, and the top of the concrete support 1 as the intermediate support is provided with a common concrete 12 structure that wraps the ends of the upper chord steel bars 5 and the lower chord steel bars 4 and the ends of the top span direction steel bars 6 and the bottom span direction steel bars 8; The length of the lower chord steel bar 4 and the bottom span direction steel bar 8 of each recycled concrete 11 precast slab extending into the concrete support 1 as the intermediate support is the larger value between 5 times the steel bar diameter d and 100 cm and should extend beyond the support center line 14 of the concrete support 1. The horizontal length of the upper chord steel bar 5 and the top span direction steel bar 6 of the recycled concrete 11 precast slab extending into the concrete support 1 as the intermediate support is not less than 0.4 times the basic anchorage length Lab of the tensile steel bar and the downward bending length is 15 times the steel bar diameter d; Example 3 See also Fig.10 The specific design and construction process of the 3D printed recycled concrete prefabricated floor slab construction method of the present invention is as follows: Step 1, design stage: including concrete support 1, recycled concrete pouring area 2, web reinforcement 3, lower chord reinforcement 4, upper chord reinforcement 5, top span direction reinforcement 6, top width direction reinforcement 7, bottom span direction reinforcement 8, bottom width direction reinforcement 9, hanging point vertical reinforcement 10, all of which are designed in this stage. According to the actual situation of the project, the specifications and dimensions of each component are selected. At the same time, according to the requirements of the 3D printing equipment, the appropriate recycled concrete 11 material is selected.

[0042] Step 2, prefabrication stage: complete the work of cleaning the formwork, oil stains and concrete residues, evenly applying the release agent, marking and positioning, and assembling the mold, assemble the above components on the formwork according to the design requirements, compare and accept the steel bar specifications, positions, spacing, quantity, etc. according to the drawings, and use 3D printing equipment to cast recycled concrete 11 to complete the prefabrication of recycled concrete 11 prefabricated panels.

[0043] Step 3, construction stage: Use hoisting equipment to hoist the recycled concrete 11 precast panels to the construction plane, adjust the position of the recycled concrete 11 precast panels and place them on the concrete support 1, and after all the recycled concrete 11 precast panels are in place, pour ordinary concrete 12 to complete the construction and installation of the recycled concrete 11 precast panels at the side supports and the middle supports. Fig.11 And the work of pouring fine stone concrete 13 at the junction of adjacent parallel recycled concrete precast panels 11 is completed one by one, as shown in FIG. Figure 7 As shown, the construction of the entire floor slab of a work area is completed.

[0044] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0045] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A 3D printed recycled concrete prefabricated floor structure, comprising a prefabricated floor, characterized in that: The prefabricated floor slab is a recycled concrete (11) prefabricated slab consisting of a recycled concrete (11) slab body cast in a recycled concrete casting area (2) and steel meshes arranged vertically and horizontally in the recycled concrete (11) slab body, and the recycled concrete (11) slab body is printed layer by layer by a 3D printing device.

2. The 3D printed recycled concrete prefabricated floor structure according to claim 1, characterized in that: The pouring directions of the two adjacent layers of recycled concrete (11) above and below the recycled concrete (11) slab printed layer by layer by the 3D printing device are perpendicular to each other.

3. The 3D printed recycled concrete prefabricated floor structure according to claim 2, characterized in that: The steel mesh comprises a plurality of truss steel bar groups arranged along the length direction of the recycled concrete (11) slab body and a plurality of width direction steel bars connecting the truss steel bar groups and arranged along the width direction of the recycled concrete (11) slab body.

4. The 3D printed recycled concrete prefabricated floor structure according to claim 3, characterized in that: The truss steel bar group comprises a plurality of upper chord steel bars (5) arranged along the length direction of the recycled concrete (11) plate and located at the top of the recycled concrete (11) plate, each upper chord steel bar (5) is provided with lower chord steel bars (4) symmetrically arranged at the bottom of the recycled concrete (11) plate on both sides, and a web bar steel bar (3) is provided between each upper chord steel bar (5) and two lower chord steel bars (4) symmetrically arranged therewith; the width direction steel bars comprise top width direction steel bars (7) connected to the upper chord steel bars (5) and bottom width direction steel bars (9) connected to the lower chord steel bars (4), the top width direction steel bars (7) correspond to the bottom width direction steel bars (9) one by one, and each bottom width direction steel bar (9) is located directly below the corresponding top width direction steel bar (7).

5. The 3D printed recycled concrete prefabricated floor structure according to claim 4, characterized in that: Each web reinforcement (3) is arranged in a wave-shaped structure, the wave crest of the web reinforcement (3) is connected to the corresponding upper chord reinforcement (5), and the wave trough of the web reinforcement (3) is connected to the corresponding lower chord reinforcement (4).

6. The 3D printed recycled concrete prefabricated floor structure according to claim 5, characterized in that: Top span direction steel bars (6) are respectively provided between two adjacent truss steel bar groups and on both sides of the recycled concrete (11) slab body. The top span direction steel bars (6) are at the same height as the upper chord steel bars (5). A bottom span direction steel bar (8) corresponding to each top span direction steel bar (6) is provided directly below the top span direction steel bar (6). The top span direction steel bar (6) is connected to the top width direction steel bar (7), and the bottom span direction steel bar (8) is connected to the bottom width direction steel bar (9).

7. The 3D printed recycled concrete prefabricated floor structure according to claim 6, characterized in that: A plurality of vertically arranged hanging point vertical bars (10) are provided at the bottom of the intersection of the top span direction steel bars (6) and the top width direction steel bars (7) on both sides of the recycled concrete (11) slab, wherein the top ends of the hanging point vertical bars (10) are fixedly connected to the top width direction steel bars (7) and the bottom ends are fixedly connected to the bottom width direction steel bars (9).

8. The 3D printed recycled concrete prefabricated floor structure according to claim 7, characterized in that: Concrete supports (1) serving as side supports are respectively provided at the bottom of both ends of each recycled concrete (11) precast panel. The end of the recycled concrete (11) precast panel is placed on the edge of the top of the concrete support (1) serving as the side support. The overlap length L between the recycled concrete (11) precast panel and the top of the concrete support (1) serving as the side support is 10 mm. The upper chord steel bars (5) and the top span direction steel bars (6) of the recycled concrete (11) precast panel extend out of the two ends of the recycled concrete (11) panel and are bent downward. (11) The two ends of the lower chord steel bars (4) and the bottom span direction steel bars (8) of the precast slab extend out of the two ends of the recycled concrete (11) slab body respectively, and the horizontal lengths of the two ends of the lower chord steel bars (4) and the bottom span direction steel bars (8) are shorter than the horizontal lengths of the two ends of the upper chord steel bars (5) and the top span direction steel bars (6). The top of the concrete support (1) serving as the side support is provided with a common concrete (12) structure that wraps the ends of the upper chord steel bars (5) and the lower chord steel bars (4) and the ends of the top span direction steel bars (6) and the bottom span direction steel bars (8); Concrete supports (1) serving as intermediate supports are provided at the bottom of the adjacent ends of two recycled concrete (11) precast panels along the same axis. The ends of the two recycled concrete (11) precast panels are respectively placed on the edges of both sides of the top of the concrete support (1) serving as the intermediate support. The overlap length L between the recycled concrete (11) precast panels and the top of the concrete support (1) serving as the intermediate support is 10 mm. The upper chord steel bars (5) and the top span direction steel bars (6) of the two recycled concrete (11) precast panels and the lower chord steel bars (4) and the bottom span direction steel bars (6) are The steel bars (8) extend into the top of the concrete support (1) as the middle support respectively, and the upper chord steel bars (5), the top span direction steel bars (6), the lower chord steel bars (4), and the bottom span direction steel bars (8) corresponding to the two recycled concrete (11) precast panels are arranged in an overlapping structure, and the top of the concrete support (1) as the middle support is provided with a common concrete (12) structure that wraps the ends of the upper chord steel bars (5) and the lower chord steel bars (4) and the ends of the top span direction steel bars (6) and the bottom span direction steel bars (8); The top width direction steel bars (7) corresponding to the two adjacent recycled concrete (11) precast panels are connected after being bent, and the adjacent sides of the two recycled concrete (11) precast panels are respectively provided with inclined cutouts, and the two cutouts are combined to form a wedge-shaped groove, and the horizontal ends and bent parts of the two top width direction steel bars (7) are located in the wedge-shaped groove, and the top span direction steel bars (6) and the top of the hanging point vertical bars (10) on the sides of the two recycled concrete (11) precast panels are all located in the wedge-shaped groove, and the wedge-shaped groove is provided with a fine stone concrete (13) structure for filling it.

9. The 3D printed recycled concrete prefabricated floor structure according to claim 8, characterized in that: The length of the lower chord steel bars (4) and the bottom span direction steel bars (8) of each recycled concrete (11) precast slab extending into the concrete support (1) as the side support is the greater of 5 times the steel bar diameter d and 100 cm and should extend beyond the support center line (14) of the concrete support (1); the horizontal length of the upper chord steel bars (5) and the top span direction steel bars (6) of the recycled concrete (11) precast slab extending into the concrete support (1) as the side support is not less than 0.4 times the basic anchorage length Lab of the tensile steel bars and the downward bending length is 15 times the steel bar diameter d; The length of the lower chord steel bars (4) and the bottom span direction steel bars (8) of each recycled concrete (11) precast slab extending into the concrete support (1) as the intermediate support is the greater of 5 times the steel bar diameter d and 100 cm and should extend beyond the support center line (14) of the concrete support (1); the horizontal length of the upper chord steel bars (5) and the top span direction steel bars (6) of the recycled concrete (11) precast slab extending into the concrete support (1) as the intermediate support is not less than 0.4 times the basic anchorage length Lab of the tensile steel bars and the downward bending length is 15 times the steel bar diameter d; The length of the steel bars (7) bent downward in the width direction of the top of the two adjacent recycled concrete (11) precast panels is 1 / 4 of the thickness h of the recycled concrete (11) precast panels, and the depth of the wedge-shaped grooves of the two recycled concrete (11) precast panels is 1 / 2 of the thickness h of the recycled concrete (11) precast panels.

10. A 3D printed recycled concrete prefabricated floor construction method, characterized in that: The following steps are involved: Step 1, design stage: complete the design work including concrete support (1), recycled concrete pouring area (2), web reinforcement (3), lower chord reinforcement (4), upper chord reinforcement (5), top span direction reinforcement (6), top width direction reinforcement (7), bottom span direction reinforcement (8), bottom width direction reinforcement (9), and hanging point vertical reinforcement (10), select the specifications and dimensions of each component according to the project situation, and select the recycled concrete (11) material according to the requirements of the 3D printing equipment; Step 2, prefabrication stage: complete the work of cleaning the formwork, cleaning the oil stains and concrete residues, applying the release agent, marking and positioning, and assembling the molds. Assemble the various components on the formwork according to the design requirements, check the specifications, positions, spacing, and quantity of the steel bars according to the drawings, and use 3D printing equipment to cast the recycled concrete (11), completing the prefabrication of the recycled concrete (11) prefabricated panels; Step 3, construction phase: Use lifting equipment to lift the recycled concrete (11) precast panels to the construction plane, adjust the position of the recycled concrete (11) precast panels and place them on the concrete supports (1), pour ordinary concrete (12) after all recycled concrete (11) precast panels are in place, complete the construction and installation of the recycled concrete (11) precast panels at the side supports and the middle supports, and pour fine stone concrete (13) one by one at the intersection of adjacent parallel recycled concrete (11) precast panels to complete the construction of the entire floor slab of a working area.

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