CN111335636A - 3D construction method of net-shaped reinforced concrete curved roof structure - Google Patents

Abstract

The invention discloses a 3D construction method of a net-shaped reinforced concrete curved surface roof structure, and belongs to the technical field of 3D construction methods. The invention comprises the following construction steps: step one, designing a scheme; step two, establishing a curved surface model; step three, 3D printing concrete configuration; printing a concrete curved surface support body; installing a positioning pin key and a support rib; step six, assembling and weaving a bottom bidirectional fiber reinforced mesh; printing and molding the bottom curved surface concrete body; step eight, grouping and weaving an upper bidirectional fiber reinforcing mesh; printing and molding the concrete body with the curved surface at the upper part; step ten, sealing edges and closing the noodles. The 3D construction method of the net-shaped reinforced concrete curved surface roof structure provided by the invention can meet the construction of a curved surface shell roof, does not need formwork support, saves manpower, material resources and material resources, is safe and reliable in construction, has higher precision control, and meets the development trend of green intelligent construction and the industrialization requirement.

Description

A 3D construction method of mesh reinforced concrete curved roof structure

technical field

The invention relates to a reinforced concrete 3D building space curved roof structure and method, and belongs to the technical field of curved roof 3D building methods.

Background technique

At present, the expression techniques in the field of architectural design, from flat roofs to sloping roofs to rebuild special-shaped roofs, especially curved roofs with flowing water shapes are more and more used in building roof modeling, such as the use of light steel structures, membrane structures, concrete structures, etc. . The advantage of using concrete to build a roof is that it has good thermal insulation performance and integrity, but its disadvantage is that its construction is relatively difficult. Due to the relatively complex geometric characteristics of the surface, the construction of the cast-in-place concrete surface has difficulties in template lofting, forming, assembling and supporting. Similarly, due to the single-curvature or hyperbolicity of the surface, there are many difficulties in curve modeling, curve lofting, binding installation, and connection construction in reinforcement construction. In terms of pouring concrete, in view of the streamline of the curved surface and the relatively large tangential slope, unexpected difficulties have been brought to the concrete placement, pouring, vibrating, construction and maintenance.

In the prior art, the advantage of 3D printing concrete is that it does not require a formwork and can adapt to complex changes in architectural shapes. 3D printing has the advantages of intelligent manufacturing, but its limitation lies in the conflict between 3D printing and the need to configure steel bars in traditional reinforced concrete structures.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a 3D construction method for a reticulated reinforced concrete curved roof structure, which solves the problem of conflict between 3D printing and traditional reinforced concrete structures that need to configure steel bars.

The present invention is realized through the following technical solutions: a 3D construction method for a reticulated reinforced concrete curved roof structure adopts 3D printing of a concrete support body to form a structural bottom plate and a support body, and then adopts an intelligent reinforcement method, that is, a manipulator and a digital model are used. The reinforcement mesh is made by means of information control, and the bidirectional fiber reinforcement in the longitude and latitude directions at the bottom of the structure is woven to form a bidirectional curved reinforcement mesh; then the bottom surface concrete is formed by 3D printing; then the upper longitude and latitude bidirectional fiber reinforcement is arranged; The upper curved concrete is formed by printing the concrete; finally, the reinforced concrete curved roof is formed.

Further, a 3D construction method for a reticulated reinforced concrete curved roof structure includes the following construction steps:

Step 1, scheme design; including: outline identification according to design drawings; determination of busbars, poles, grids; split surfaces to determine layered boundaries and intersection areas; 3D printing of concrete configuration and testing; material properties and weaving of mesh reinforcement program.

Step 2: Build a surface model; build a model according to REVIT (ie, BIM building information modeling software), simulate and check the combination between the overall surface and the layered surface, optimize the meshing and weaving process of the mesh reinforcement, and determine the positioning pin Reasonable position of keys and support ribs, optimized printing process, orientation, printing thickness layers and conflict checking of working time.

Step 3, 3D printing concrete configuration; according to the structural performance requirements, determine the strength of 3D printing concrete, test its working performance, extrusion performance, rheological performance, forming performance, mechanical performance parameters, and determine a reasonable printing direction, printing stroke, printing Thickness, Lamination Thickness, Duration, Interval.

Step 4: Print the concrete surface support body; the printing adopts a Z-shaped or S-shaped path, from the low end to the high end, the two sides are advanced symmetrically, and the intersection area is set at the inflection point of the surface; the printing thickness is 15-20mm, and the printing head is a broad kiss The rectangular mouth with notches is suitable for the streamline direction of the mesh ribs; the printing duration is 90-120min, the thickness of the interlayer stacking does not exceed 200mm, and the interlayer interval time does not exceed 90min; the printing surface support body 7d can achieve the supporting effect, Meet the subsequent construction requirements.

Step 5: Install the positioning pins and support ribs; when printing the concrete curved surface support body, within the 300mm range around the curved surface and within the 300mm bandwidth range of the ridge line, the positioning keys and support ribs are arranged at equal intervals to form bidirectional fibers for subsequent assembly. Reinforcement mesh erection tension positioning key.

Step 6: Assemble the bottom bidirectional fiber reinforced mesh; after the strength of the concrete surface support body meets the requirements, that is, when the minimum strength of the 3D printed concrete cured under the same conditions is not less than 50MPa, the bidirectional reinforced mesh is assembled and installed; The distance between them meets the design requirements, the distance in the latitude direction is 200-250mm, and the distance in the longitude direction is 250-300mm; the networking process and control elements are from low-end to high-end, first in the short direction and then in the long direction, first in the latitude direction, then in the longitude direction.

Step 7: Print and form the bottom curved concrete body; the bottom two-way fiber reinforcement mesh is installed, and the conformity of the grid size, spacing, interlayer position, longitude and latitude directions is checked, and concealed acceptance and recording are carried out. After meeting the requirements, carry out The printing construction of the bottom curved concrete body; the layered printing thickness is 10-20mm, the printing width is 1-1.1 times the spacing of the fiber mesh reinforcement grid, and the printing head is a wide kiss with a concave notch, which is suitable for the streamline direction of the mesh reinforcement. ; The printing duration is 90-120min, the stacking thickness between the printing layers is not more than 200mm, and the interval time between layers is not more than 90min.

Step 8: Assemble the upper two-way fiber reinforcement mesh; when the strength of the curved concrete body at the bottom reaches 75% of the design strength and is not lower than 50MPa, the upper two-way fiber reinforcement mesh is carried out; the spacing of the reinforcement mesh meets the design requirements, and the latitude direction The spacing is 200-250mm, and the spacing in the longitude direction is 250-300mm; the networking process and control elements are from low-end to high-end, first in the short direction and then in the long direction, first in the latitude direction, and then in the longitude direction; the network reinforcement adopts positioning pins and supports Ribs perform surface conformity correction.

Step 9, print and form the upper curved concrete body; after the upper two-way fiber reinforcement mesh is concealed and accepted, the printing construction of the upper curved concrete body is carried out. For the printing of the upper curved concrete body, the positioning ribs arranged on the curved surface are used to control the printing elevation; The layer thickness is 10-15mm, the printing duration is 90-120min, the stacking thickness between printing layers is not more than 150mm, and the interlayer interval time is not more than 90min.

Step 10, edge sealing and surface closing; edge sealing is the interactive processing of the pins and the perimeter, and surface closing is to maintain and repair the general quality defects that appear in the printing, and use the same proportion of cement mortar to repair.

The reticulated reinforced concrete curved roof structure includes, from bottom to top, a 3D printed concrete curved support body, a bottom longitude and latitude bidirectional fiber reinforced mesh, a 3D printed bottom curved concrete body, and an upper longitude and latitude direction bidirectional Fiber reinforcement mesh, 3D printed upper curved concrete body, and auxiliary construction measures, positioning pins, and supporting mesh reinforcement. The 3D printed concrete surface support body is a single-curved or hyperbolic concrete shell.

Further, in the third step, 3D printing concrete configuration, including support 3D printing concrete, bottom surface 3D printing concrete, and upper surface 3D printing concrete, requires that the minimum compressive strength of concrete is not less than 80MPa, and the tensile strength is not less than 8.7MPa , the corresponding minimum strength is not less than 50MPa, and the tensile strength is not less than 5.5MPa under the same conditions for curing for 7d.

Further, in the fourth step, the concrete curved surface support is printed, and the width of the printing nozzle is 1-2 times the size of the reinforcement mesh in the latitude or longitude direction, and the reinforcement mesh is not less than 200mm; the printing intersection area is set at the inflection point of the curved surface, that is, the roof baseline. The highest is in the range of 300mm at the lowest 1/3-1/4, the printing layer thickness error does not exceed (-2mm, +2mm), and the cumulative thickness error does not exceed 5mm.

Further, in the step 5, install the positioning pin key and the support bar; the positioning pin key adopts the end steel bar with the anchoring end, the HPB300 steel bar with a diameter of not less than 20mm, the spacing is 200-300mm, and the bottom part is inserted into the concrete body. Less than 50mm, the exposed length is not less than 500mm, and a section with anchoring plate or anchoring head is exposed, with a thread buckle and a fixing ring in the middle; the fixing rib or supporting rib is a ladder-shaped rib, which fixes the position of the woven steel mesh and adjusts the height of the steel mesh.

Further, in the sixth step, the bottom bidirectional fiber reinforcement mesh is assembled, and the bidirectional reinforcement mesh is made of fiber reinforcement or prestressed galvanized steel wire, the tensile strength is not less than 1350MPa, and the elongation rate is not less than 30%.

Further, in the seventh step, the bottom curved concrete body is printed, using 3D printing concrete mixed with fibers, its designed compressive strength is not less than 80MPa, its tensile strength is not less than 7.8MPa, and the printing layer thickness error is not more than ( -5mm, +2mm), the cumulative thickness error does not exceed 5mm.

Further, in the eighth step, the upper two-way fiber reinforcement mesh is assembled, and the spacing error of the mesh reinforcement does not exceed (-5mm, +5mm), grid size deviation ±6mm, node height difference ±5mm, node position deviation ±5mm, Use laser level and theodolite for point checking.

Further, in the ninth step, the upper curved concrete body is printed and formed, using 3D printing concrete mixed with fibers, its designed compressive strength is not less than 80MPa, its tensile strength is not less than 7.8MPa, and the printing layer thickness error is not more than ( -2mm, +2mm), the cumulative thickness error does not exceed 5mm, after printing, use spray and cover film maintenance.

The beneficial effects of the present invention are as follows: the technical principle and idea of the present invention is to split the curved concrete roof into 3-layer curved surfaces through bidirectional flexible reinforcement of longitude and latitude, and construct by 3D intelligent printing. Longitude and latitude two-way flexible reinforcement solves the problems of lofting, processing, binding installation, connection and anchoring of reinforced concrete large-diameter hot-rolled steel bars; curved surface 3D intelligent printing and construction, through revit3d modeling, it solves the problems of interlayer bonding, complex surface modeling, template, reinforcement , Concrete construction technical problems. Especially in the construction of curved formwork, the technical problems of formwork lofting, forming, processing, installation, support and so on. At the same time, it also solves technical problems such as large slope and large elevation angle of curved concrete, distribution, pouring, vibrating and forming in concrete construction.

Compared with the existing curved roof construction technology, the present invention does not require complicated template splicing, processing, and installation, and does not require a high-support formwork bracket system, and saves a large number of processes such as hot-rolled steel bar processing, bending, hoisting, connection, and support. It saves the cost of construction measures, safety and environmental protection, saves a lot of manpower, material resources and financial resources, and the construction is safe, reliable, environmentally friendly and green, which greatly improves work efficiency. The 3D construction method of the reticulated reinforced concrete curved roof structure conforms to the industrial construction mode of digital construction and green construction, and the environmental and ecological benefits are relatively obvious.

Description of drawings

The present invention will be further described below according to the accompanying drawings and embodiments.

Fig. 1 is the flow chart of the 3D construction method of the present invention

FIG. 2 is a schematic structural diagram of the reticulated reinforced concrete curved roof structure of the present invention;

FIG. 3 is a plan view of the curved grid bars of the reticulated reinforced concrete curved roof structure of the present invention.

In the figure, 1-3D printed concrete support; 2-bottom two-way curved steel mesh; 3-bottom curved concrete; 4-upper two-way curved steel mesh; 5-upper curved concrete; 6-positioning pin key; 7-supporting rib.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the authorized specification.

The 3D construction method of the reticulated reinforced concrete curved roof structure disclosed in the embodiment of the present invention has the following technical scheme: a 3D printed concrete support body is used to form a structural bottom plate and a support body; Directional bidirectional fiber reinforcement to form a bidirectional curved steel mesh; 3D printing is used to form the bottom curved concrete; the upper longitude and latitude direction bidirectional fiber reinforcement is arranged; 3D printed concrete is used to form the upper curved concrete; finally, a reinforced concrete curved roof is formed.

A reticulated reinforced concrete curved roof structure, the structural features of which are: from bottom to top, a 3D printed concrete curved surface support body 1, a bottom longitude direction and a latitude direction bidirectional fiber reinforcement mesh 2, and a 3D printed bottom curved concrete body 3 , the upper longitude direction and latitude direction bidirectional fiber steel mesh 4, 3D printing to form the upper curved concrete body 5. Auxiliary construction measures locating pin keys 6 and supporting grid reinforcement bars 7 are also included. The 3D printed concrete surface support body is a single-curved or hyperbolic concrete shell.

As shown in Figure 1-Figure 3, taking the elliptical surface as an example, the radius of the ellipse is 12m, and the height of the arch is 5.68m. A 3D construction method for a reticulated reinforced concrete curved roof structure, the construction steps are as follows:

Step 1: Scheme design. The main contents to be defined in scheme design include: outline identification according to design drawings; determination of busbars and poles; split surfaces to determine layer boundaries and intersection areas; 3D printing of concrete configuration and testing; mesh reinforcement material properties and weaving procedures.

The second step is to build a surface model. Build a model according to REVIT, simulate and check the combination between the overall surface and the layered surface, optimize the meshing and weaving process of the mesh reinforcement, determine the reasonable positions of the positioning pins and support ribs, and optimize the printing process, orientation, and printing thickness. Conflict checking of layers and working hours.

Step three, 3D printing the concrete configuration. According to the structural performance requirements, determine the strength of the 3D printed concrete, test its working performance, extrusion performance, rheological properties, forming properties, mechanical properties and other parameters, and determine its reasonable printing direction, printing stroke, printing thickness, stacking thickness, continuous time, interval.

The fourth step is to print the concrete surface support. The printing adopts a Z-shaped or S-shaped path, from the low end to the high end, the two sides are advanced symmetrically, and the intersection area is set at the inflection point of the surface. The printing thickness is 17mm, and the print head is a broad kiss with a concave notch, which adapts to the streamline direction of the mesh ribs. The printing duration is 90min, the stacking thickness between printing layers does not exceed 200mm, and the interval time between layers does not exceed 90min. Printing the curved support body 7d can achieve a supporting function and meet the construction requirements of the subsequent process.

Step 5: Install positioning pins and support ribs. When printing the concrete surface support body, within the range of 300mm around the surface and within the 300mm bandwidth of the ridge line, the positioning keys and support ribs are arranged at equal intervals, and the tension positioning keys are erected for the subsequent assembly of the bidirectional fiber reinforcement mesh.

Step 6: Assemble the bottom two-way fiber reinforcement mesh. After the strength of the concrete surface support body meets the requirements, that is, when the minimum strength of the 3D printed concrete cured under the same conditions is not less than 50MPa, the two-way reinforcement mesh can be networked and installed. The spacing of the network meets the design requirements, the spacing in the latitude direction is 200mm, and the spacing in the longitude direction is 250mm. The networking process and control elements are from low-end to high-end, first in the short direction and then in the long direction, first in the latitude direction, then in the longitude direction.

Step 7, print and form the bottom curved concrete body. After the installation of the bottom two-way fiber reinforced mesh is completed, the surface conformity of the grid size, spacing, interlayer position, longitude and latitude directions is reviewed, and concealed acceptance and recording are carried out. After meeting the requirements, the bottom surface surface concrete body can be printed. Construction. The bottom curved concrete body is printed, and the 3D printing concrete used is 3D printing concrete mixed with fibers, and its designed compressive strength is not less than 80MPa, and its tensile strength is not less than 7.8MPa. The layered printing thickness is 10-20mm, and the printing width is 1-1.1 times the spacing of the fiber mesh reinforcement grid. The printing duration is 90-120min, the stacking thickness between printing layers does not exceed 200mm, and the interval time between layers does not exceed 90min.

Step 8: Assemble the upper two-way fiber reinforcement mesh. When the strength of the bottom curved concrete body reaches 75% of the design strength and is not less than 50MPa, the network work of the upper two-way fiber reinforcement can be carried out. The spacing of the steel mesh meets the design requirements, the spacing in the latitude direction is 200-250mm, and the spacing in the longitude direction is 250-300mm. The networking process and control elements are from low-end to high-end, first in the short direction and then in the long direction, first in the latitude direction, then in the longitude direction. The meshing reinforcement adopts positioning pins and support ribs to correct the surface conformity. The spacing, grid size, node height difference, and position of the mesh reinforcement bars meet the requirements, and laser level and theodolite are used for point checking.

Step 9, printing and forming the upper curved concrete body. After the concealed acceptance of the upper two-way fiber reinforced mesh is qualified, the printing construction of the upper curved concrete body is carried out. For the printing of the upper curved concrete body, the positioning ribs arranged on the curved surface are used to control the printing elevation. The printing layer thickness is 10-15mm, the printing duration is 90-120min, the stacking thickness between printing layers is not more than 150mm, and the interlayer interval time is not more than 90min. After printing, use spray and cover film curing.

Step ten, edge and finish. Edge sealing is the interactive processing of the pin key and the perimeter, and the closing surface is to maintain and repair the general quality defects that appear in the printing, and use the same proportion of cement mortar to repair.

The reticulated reinforced concrete curved roof structure has the following structural features: a 3D printed concrete support body is used to form a structural bottom plate and a support body; Two-way curved steel mesh; then 3D printing is used to form the bottom curved concrete; then the upper longitude and latitude direction bidirectional fiber reinforcement is arranged; then 3D printing concrete is used to form the upper curved concrete; finally, a reinforced concrete curved roof is formed.

The configuration of the 3D printed concrete in the third step includes the 3D printed concrete of the support body, the 3D printed concrete of the bottom curved surface, and the 3D printed concrete of the upper curved surface. The corresponding minimum strength of curing 7d is not less than 50MPa, and the tensile strength is not less than 5.5MPa.

The fourth step is to print the concrete surface support body, and the width of the printing nozzle is 1-2 times the size of the steel mesh in the latitude or longitude direction, and is not less than 200mm. The printing intersection area is set at the inflection point of the surface, that is, the roof baseline is within the range of 300mm at the lowest 1/3-1/4 point. The printing layer thickness error does not exceed (-2mm, +2mm), and the cumulative thickness error does not exceed 5mm.

The fifth step is to install positioning pins and support ribs. The positioning pin key adopts the end steel bar with anchoring end, HPB300 steel bar with a diameter of not less than 20mm, the spacing is 200-300mm, the bottom part is inserted into the concrete body of not less than 50mm, the exposed length is not less than 500mm, and a section with anchoring plate or Anchor head with threaded clasp and retaining ring in the middle. The fixed rib or support rib is a ladder-shaped rib, and the position of the reinforced mesh is fixed and the height of the reinforced mesh is adjusted.

In the sixth step, the bottom bidirectional fiber reinforcement mesh is assembled. Two-way steel mesh, using fiber steel or prestressed galvanized steel wire, the tensile strength is not less than 1350MPa, and the elongation rate is not less than 30%.

The seventh step is to print and form the bottom curved concrete body. The 3D printed concrete incorporating fibers has a design compressive strength of not less than 80MPa and a tensile strength of not less than 7.8MPa. The printing layer thickness error does not exceed (-5mm, +2mm), and the cumulative thickness error does not exceed 5mm.

In the eighth step, the upper bidirectional fiber reinforcement mesh is assembled. The spacing error of the meshing steel bars does not exceed (-5mm, +5mm), the grid size deviation is ±6mm, the node height difference is ±5mm, and the node position deviation is ±5mm. Laser level and theodolite are used for point checking.

In the ninth step, the upper curved concrete body is printed and formed. The 3D printed concrete incorporating fibers has a design compressive strength of not less than 80MPa and a tensile strength of not less than 7.8MPa. The printing layer thickness error does not exceed (-2mm, +2mm), and the cumulative thickness error does not exceed 5mm. After printing, use spray and cover film curing.

Focus on solving the problems of formwork, support and splicing of curved reinforced concrete roofs; solve the problems of lofting, processing, binding, installation, connection and fixing of steel bars in curved reinforced concrete roof panels; Difficulties in pouring, vibrating, forming and curing.

The above are only exemplary embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. A3D construction method of a net-shaped reinforced concrete curved surface roof structure is characterized by comprising the following steps: 3D printing a concrete support body to form a structural bottom plate and the support body, and then weaving bidirectional fiber reinforcements in the longitude direction and the latitude direction of the bottom of the framework by adopting an intelligent reinforcement arrangement method to form a bidirectional curved reinforcement mesh; then 3D printing is adopted to form bottom curved surface concrete; then arranging upper longitudinal and latitudinal bidirectional fiber reinforced bars; then, forming upper curved surface concrete by adopting 3D printed concrete; finally, the concrete curved surface roof containing the ribs is formed.

2. A3D construction method of a net-shaped reinforced concrete curved surface roof structure is characterized by comprising the following steps:

the method comprises the following construction steps:

step one, designing a scheme; the method comprises the following steps: carrying out contour recognition according to a design drawing; determining a bus, a pole and a grid; splitting the curved surface, and determining a layered boundary and an intersection area; 3D printing concrete configuration and testing; material performance and weaving procedure of the mesh reinforcing steel bar;

step two, establishing a curved surface model; establishing a model according to REVIT (BIM building information model software), simulating and checking conflicts of the combination of the whole curved surface and the layered curved surface, optimizing the networking and weaving processes of the mesh-shaped reinforcing steel bars, determining the reasonable positions of the positioning pin keys and the supporting ribs, and optimizing the conflict checking of the printing process, the trend, the number of printing thickness layers and the working time;

step three, 3D printing concrete configuration; according to the structural performance requirement, determining the strength of the 3D printed concrete, testing the working performance, the extrusion performance, the rheological performance, the forming performance and the mechanical performance parameters of the 3D printed concrete, and determining the reasonable printing direction, the printing stroke, the printing thickness, the laminating thickness, the duration and the interval time;

printing a concrete curved surface support body; printing is carried out by adopting a Z-shaped or S-shaped path, the direction from the low end to the high end is symmetrical and pushed in from two sides, and an intersection region is arranged at the position of a curved surface inflection point; the printing thickness is 15-20mm, and the printing head is a rectangular nozzle with a wide kiss notch and is suitable for the streamline trend of the reticular rib; the printing duration is 90-120min, the stacking thickness between printing layers is not more than 200mm, and the interlayer pause time is not more than 90 min; the printing curved surface support body 7d can achieve a supporting effect and meet the construction requirements of subsequent procedures;

installing a positioning pin key and a support rib; when the concrete curved surface support body is printed, positioning keys and supporting ribs are arranged and installed at equal intervals within the range of 300mm of the periphery of the curved surface and within the range of 300mm of the bandwidth of a ridge line, and tensioning positioning keys are erected for the subsequent assembly and weaving of the bidirectional fiber reinforced bar mesh;

step six, assembling and weaving a bottom bidirectional fiber reinforced mesh; after the strength of the concrete curved surface support body meets the requirement, namely the minimum strength of the 3D printing concrete maintained under the same condition is not lower than 50MPa, carrying out networking, weaving and installing on the bidirectional reinforcing mesh; the distance of the networking meets the design requirement, the distance in the latitude direction is 200-250mm, and the distance in the longitude direction is 250-300 mm; the networking process and the control elements are from low end to high end, the short direction is firstly followed by the long direction, the latitude direction is firstly followed by the longitude direction;

printing and molding the bottom curved surface concrete body; after the bottom bidirectional fiber reinforced mesh is installed, carrying out surface conformity rechecking in the mesh size, the space, the interlayer position, the longitude direction and the latitude direction, carrying out concealed acceptance and recording, and carrying out printing construction on a bottom curved surface concrete body after the requirements are met; the layered printing thickness is 10-20mm, the printing width is 1-1.1 times of the space between the fiber mesh reinforcement grids, and the printing head is a wide kiss strip concave gap and is suitable for the streamline trend of the mesh ribs; the printing duration is 90-120min, the stacking thickness between printing layers is not more than 200mm, and the interlayer pause time is not more than 90 min;

step eight, grouping and weaving an upper bidirectional fiber reinforcing mesh; when the strength of the bottom curved surface concrete body reaches 75% of the designed strength and is not lower than 50MPa, networking the upper bidirectional fiber reinforced steel bars; the distance between the reinforcing steel bar nets meets the design requirement, the distance between the reinforcing steel bar nets in the latitude direction is 200-250mm, and the distance between the reinforcing steel bar nets in the longitude direction is 250-300 mm; the networking process and the control elements are from low end to high end, the short direction is firstly followed by the long direction, the latitude direction is firstly followed by the longitude direction; the networking steel bars adopt positioning pin keys and supporting ribs to carry out curved surface conformity correction;

printing and molding the concrete body with the curved surface at the upper part; after the upper bidirectional fiber reinforced mesh is concealed and accepted, printing construction of an upper curved surface concrete body is carried out, the upper curved surface concrete body is printed, and the printed elevation is controlled by positioning ribs arranged on the curved surface; the printing layering thickness is 10-15mm, the printing duration is 90-120min, the stacking thickness between printing layers is not more than 150mm, and the interlayer pause time is not more than 90 min;

step ten, sealing edges and closing the noodles; the edge sealing is to carry out interactive treatment on the pin key and the periphery, the surface closing is to maintain and repair general quality defects in printing, and cement mortar with the same proportion is adopted for repairing.

3. The 3D construction method of the reticular reinforced concrete curved roof structure as claimed in claim 2, characterized in that: the reticular reinforced concrete curved roof structure sequentially comprises a 3D printed concrete curved support body (1), a bottom longitudinal direction and latitudinal direction bidirectional fiber reinforced mesh (2), a 3D printed and molded bottom curved concrete body (3), an upper longitudinal direction and latitudinal direction bidirectional fiber reinforced mesh (4) and a 3D printed and molded upper curved concrete body (5) from bottom to top, and further comprises an auxiliary construction measure positioning pin key (6) and a supporting grid reinforced bar (7);

the 3D printing concrete curved surface supporting body is a single-curved surface or double-curved surface concrete shell.

4. The 3D construction method for the net-shaped reinforced concrete curved roof structure as claimed in claim 2, wherein in the third step, 3D printing concrete configuration comprises 3D printing concrete on the support body, 3D printing concrete on the bottom curved surface and 3D printing concrete on the upper curved surface, and the concrete is required to have the compressive minimum strength not lower than 80MPa, the tensile strength not lower than 7.8MPa, the corresponding minimum strength of 7D under the same curing condition is not lower than 50MPa, and the tensile strength is not lower than 5.5 MPa.

5. The 3D construction method of the reticular reinforced concrete curved roof structure as claimed in claim 2, wherein in the fourth step, the concrete curved support body is printed, the width of the printing nozzle is 1-2 times of the mesh size of the reinforcing steel bar in the latitude or longitude direction, and the mesh size of the reinforcing steel bar is not less than 200 mm; the printing intersection area is arranged at the inflection point of the curved surface, namely the highest roof base line is positioned between the range of 300mm at the lowest position 1/3-1/4, the printing layering thickness error is not more than (-2mm, +2mm), and the accumulated thickness error is not more than 5 mm.

6. The 3D construction method of the reticular reinforced concrete curved roof structure as claimed in claim 2, wherein the fifth step is to install a positioning pin key and a support rib; the positioning pin key adopts an end reinforcing bar with an anchoring end, HPB300 reinforcing bars with the diameter not less than 20mm, the distance is 200-300mm, the bottom part is inserted into a concrete body not less than 50mm, the exposed length is not less than 500mm, a section of anchoring plate or anchoring head with the anchoring end is exposed, and a screw thread and a fixing ring are arranged in the middle; the fixed ribs or the supporting ribs are ladder-shaped ribs, the positions of the woven reinforcing mesh are fixed, and the elevation of the reinforcing mesh is adjusted.

7. The 3D construction method of the net-shaped reinforced concrete curved roof structure as claimed in claim 2, wherein in the sixth step, the bottom bidirectional fiber reinforced mesh is organized and woven, the bidirectional reinforced mesh is made of fiber reinforced steel bars or prestressed galvanized steel wires, the tensile strength is not lower than 1350MPa, and the tensile rate is not lower than 30%.

8. The 3D construction method of the net-shaped reinforced concrete curved roof structure as claimed in claim 2, wherein in the seventh step, the bottom curved concrete body is printed and molded, and the 3D printed concrete doped with fibers is adopted, so that the designed compressive strength is not lower than 80MPa, the tensile strength is not lower than 7.8MPa, the printed layered thickness error is not more than (-5mm, +2mm), and the accumulated thickness error is not more than 5 mm.

9. The 3D construction method of the reticular reinforced concrete curved roof structure as claimed in claim 2, wherein in the eighth step, the upper bidirectional fiber reinforced bar net is organized, the interval error of the networking reinforced bars is not more than (-5mm, +5mm), the grid size deviation is +/-6 mm, the node height difference is +/-5 mm, and the node position deviation is +/-5 mm, and a laser level and a theodolite are adopted for point checking.

10. The 3D construction method of the net-shaped reinforced concrete curved roof structure as claimed in claim 2, wherein in the ninth step, the upper curved concrete body is printed and molded, the 3D printed concrete doped with fibers is adopted, the designed compressive strength is not lower than 80MPa, the tensile strength is not lower than 7.8MPa, the error of the printed layered thickness is not more than (-2mm, +2mm), the accumulated thickness error is not more than 5mm, and after printing, spraying and film covering maintenance are adopted.

Images