CN112847741B

CN112847741B - Overturning die and method for preparing inorganic composite material section

Info

Publication number: CN112847741B
Application number: CN202110025468.6A
Authority: CN
Inventors: 崔崇; 许欣; 崔晓昱
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2022-08-09
Anticipated expiration: 2041-01-08
Also published as: CN112847741A

Abstract

The invention belongs to the field of preparation of inorganic composite material profiles, and particularly relates to a turnover die and a turnover method for preparing an inorganic composite material profile. The mold is of a cuboid structure and comprises two forming plates, four forming plate end baffles and a turnover structure; the end part baffle of the forming plate is positioned at two sides of the end part of the forming plate, and the turnover mechanism is positioned at the center of the bottom of the forming plate; the forming plate and the end baffle thereof are provided with fastening devices for forming an end sealing area; the upper part of the forming plate is provided with a redundant material extrusion port for extruding redundant materials and air, so that the compactness of the test piece is improved; the lower part of the forming plate is provided with an inclined angle for the stored material on the surface to slide off when the mold is in an open position, so as to prevent the mold from being influenced to be closed. The method provided by the invention can be used for designing and arranging the turnover structure, so that the problem that the formed part has a large defect due to material blockage caused by too narrow web plates of the die can be effectively avoided, and the operation is simple and convenient.

Description

Overturning die and method for preparing inorganic composite material section

Technical Field

The invention belongs to the field of preparation of inorganic composite material profiles, and particularly relates to a turnover die and a turnover method for preparing an inorganic composite material profile.

Background

The section bar is an object with a certain geometric shape, which is made of iron or steel and materials with certain strength and toughness through the processes of rolling, extruding, casting and the like. The section bar mainly has the following problems that the manufacturing process is complex, the corrosion of steel can cause the reduction of the bearing capacity and the reduction of the ductility of a steel-concrete combined structure, the steel is not favorable for being used in coastal areas and in a hard environment, and simultaneously, the steel has heavier dead weight and increases the load.

Reactive Powder Concrete (RPC) is a new cement-based composite material proposed first by french people p.richard in the spring meeting of american society for concrete society in 1994, following High-strength concrete (HSC) and High-performance concrete (HPC). The novel cement-based composite material is prepared based on the closest packing theory, the principles of adding fine aggregate and steel fiber, high-temperature pressurizing maintenance and the like, has the characteristics of high strength, high volume stability, low permeability and the like, and is widely applied to bridges, houses, tunnels, ocean engineering and the likeRepairing and reinforcing engineering field. RPC as a novel cement-based composite material has the compressive strength 4 times that of common concrete and the fracture energy more than 10KJ/m ² The RPC material is basically similar to metal aluminum, in addition, the porosity of the RPC material is low, the structure is compact, the durability of the material is far better than that of common concrete, in addition, the self weight of a structure made of the RPC material is equivalent to that of a steel structure, the strength can be comparable to that of the steel structure, the manufacturing cost is only 1/3 of the steel structure, the RPC material has higher advantages in the aspects of economy and environmental protection, and the RPC material conforms to the green, energy-saving and environmental-friendly production concept proposed in recent years in China.

Therefore, a member having superior durability can be obtained by using the ultra-high permeation resistance of RPC and the high stability of the constituent materials. Meanwhile, the stress member with smaller structural section size is prepared by utilizing the ultrahigh strength and the high toughness of the material, so that the safety and the service life of a structure can be greatly improved under the severe working condition, and the purposes of simple construction and maintenance cost reduction are achieved.

The RPC is cast to form the main forming mode of the prefabricated part, the shape is generally regular cuboid or cube, and the I-shaped web plate is narrow in thickness, so that the material is easily blocked during forming, and the material cannot reach the bottom, and the formed part has large defects. Therefore, the pouring forming die of the RPC I-shaped section bar needs to be designed to be of an overturning structure.

Disclosure of Invention

The invention aims to provide a turnover die and a method for preparing an inorganic composite material section, which provide section die design guidance for large-scale engineering application and preparation of ultrahigh-strength reactive powder concrete.

The technical solution for realizing the purpose of the invention is as follows: a turnover die for preparing inorganic composite material profiles comprises an end baffle, a forming plate and a turnover mechanism;

the forming plates comprise two forming plates, wherein cavities are arranged in the two forming plates, the cavities after the two forming plates are assembled are consistent with the shape of the section bar, the two end parts of the two forming plates are sealed through the two end part baffle plates respectively, and the bottoms of the two forming plates are connected through the turnover mechanism.

Further, after the two molding plates are closed, a surplus material extruding opening with the width of 2-3mm is reserved between the upper parts of the two molding plates, inclined planes are arranged on the adjacent planes of the upper parts of the two molding plates, and the included angle alpha between each inclined plane and the horizontal plane is 60-75 degrees;

after the die is closed, the lower parts of the two forming plates are contacted, the adjacent surfaces of the lower parts of the two forming plates are provided with inclined surfaces, and the included angle beta between each inclined surface and the horizontal plane is 60-75 degrees.

Furthermore, the whole end part baffle is a rectangular plate, and the upper end part and the lower end part of the surface of each end part baffle at each end of the forming plate, which is contacted with the two end part baffles, are provided with inclined surfaces;

the upper part and the side surfaces far away from each other of the end baffle plate are provided with fastening devices, the forming plate is provided with a fastening device matched with the fastening device on the end baffle plate, and the fastening device of the end baffle plate is connected with the fastening device on the forming plate to realize fastening and sealing;

and the two end baffles at each end of the forming plate are provided with fastening devices, and the fastening devices of the two end baffles are connected to realize fastening and sealing.

Furthermore, the fastening devices arranged on the end baffle and the forming plate are lug parts with threaded holes, the lug parts between the end baffle and the forming plate are fastened and sealed through bolt connection, and the lug parts of the two end baffle plates at one end of the forming plate are fastened and sealed through bolt connection.

Furthermore, the turnover mechanism is a hinge assembly, two hinges of the hinge assembly are respectively connected with the forming plate, and the two hinges are hinged.

Furthermore, the die cavity of the forming plate is in a half shape of the axis of the web plate of the I-shaped section.

A method for preparing an inorganic composite material profile by using the die comprises the following steps:

step (1): installing a mould, and fixing the end baffles (1) and the forming plates (2) by bolts according to the positions of the four end baffles (1) and the forming plates (2) corresponding to the fastening devices (4);

step (2): the turnover mechanism (3) is arranged at the bottom of the forming plate (2), and the forming plate (2) is flatly laid by rotating the forming plate (2) towards two sides;

and (3): pouring the prepared slurry into a cavity of a forming plate (2) to enable the central part of the slurry to be higher than the edge of the forming plate by 4-10mm, and carrying out vibration forming;

and (4): rotating the forming plate (2), approaching the forming plate (2) from two sides to the middle position, and folding the forming plate;

and (5): penetrating a bolt through a fastening device extrusion die of the end baffle (1), extruding redundant slurry and air from a redundant material extrusion opening (6) at the upper part, and screwing the bolt;

and (6): and (4) demolding after standing for 24 hours, drawing out the cylinder in the bottom turnover mechanism (3) during demolding, separating the two side forming plates (2) towards two sides, and taking out the I-shaped concrete section (8).

Further, the method also comprises the following steps:

and (7): placing the section bar (8) in water for natural curing for 24 hours, and keeping the water temperature at normal temperature;

and (8): taking out the section bar (8), and placing the section bar in a hot water curing box for curing for 24 hours at 90 ℃;

and (9): and (3) placing the section (8) in an autoclave for high-temperature autoclave curing, taking out and wiping, and removing burrs to obtain a finished product of the RPC section.

Compared with the prior art, the invention has the remarkable advantages that:

this RPC section bar upset mould, simple structure, reasonable in design, convenient operation. The special opening and closing structure is novel in design, the problem that materials are blocked at the rib part of the die and cannot smoothly reach the bottom due to the special I-shaped shape is effectively solved, the forming difficulty and the demolding difficulty are reduced, the production efficiency is improved, meanwhile, a redundant material extruding opening is added at the upper part of the forming plate, so that air is discharged by extruding slurry, the compactness of a test piece is improved, the production defect of a concrete section is effectively reduced, and specific design guidance is provided for large-scale engineering application and preparation of ultrahigh-strength active powder concrete; on the premise of ensuring the strength and rigidity of the die, the material consumption is saved, the weight is reduced, and the cost is reduced.

Drawings

Fig. 1 is an exploded view of the flip-flop die of the present invention.

Fig. 2 is a front view in cross section of a forming plate of the present invention.

Fig. 3 is a three-dimensional schematic view of an end stop of the present invention.

Fig. 4 is a schematic view of the turnover mechanism of the present invention.

FIG. 5 is a schematic view of the die installation of the present invention.

Fig. 6 is a schematic view of the flip-flop mold of the present invention opening.

Fig. 7 is a schematic view of the casting of the present invention.

FIG. 8 is a schematic view of the present invention showing the closing of the flip-flop mold.

Fig. 9 is a schematic diagram of mold closing after casting of the mold of the present invention.

FIG. 10 is a schematic view of the die extrusion of the present invention.

FIG. 11 is a schematic drawing illustrating the removal of the mold of the present invention.

Fig. 12 is a schematic view of the finished profile of the present invention.

FIG. 13 is a schematic size diagram of an I-shaped section and a die used therein; wherein figure (a) is a schematic drawing of the cross-sectional dimension of an i-shaped section; (b) schematic drawing of cross-sectional dimensions of the die.

Description of reference numerals:

1-end baffle, 2-forming plate, 3-turnover mechanism, 4-first fastening device, 5-second fastening device, 6-excess material extrusion opening, 7-bolt and 8-section.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

The invention provides a design method of a mould for producing RPC (reactive powder concrete) profiles, wherein the mould is of a cuboid structure and comprises two forming plates 2, four forming plate end baffles 1 and a turnover mechanism 3 (shown in figure 1).

The forming plate 2 is divided into a left plate and a right plate, a plurality of fastening devices 4 are arranged on the forming plate, and the fastening devices are fixed through screws; the upper part of the forming plate is provided with a surplus material extruding opening 6 (shown in figure 2), the inclination angle alpha of the extruding opening is 60-75 degrees, and the distance c between the surplus material extruding openings is 2-3mm, so that the material compactness is improved by extruding air out of the material in the forming stage; the bottom of the forming plate is inclined, the inclination angle beta of the forming plate is 60-75 degrees, and the inclination angle of the bottom is set to prevent the blockage of the assembly of the mold due to the accumulation of surface materials when the mold is turned over.

The end baffle of the forming plate 2 is of a rectangular plate-shaped structure (shown in figure 3), the thickness of the end baffle is 7-9mm, and the end baffle is totally four and is respectively arranged at two sides of the end of the forming plate; all be equipped with on the 2 end baffle of profiled sheeting and the profiled sheeting 2 on the fastener that corresponds, form the end seal through screw and fastener. And an arc-shaped perforated mold closing fastening device is arranged on the outer side of the end baffle, and the arc-shaped perforated mold closing fastening device is connected with the end baffle through bolts after molding to achieve the purpose of closing the mold.

The turning structure 3 is shown in fig. 4, and is connected and fixed at the head and the tail of the bottom of the forming plate through screws, and a turning mechanism is arranged at intervals of 50 cm.

The mold assembly method is as shown in fig. 5, the mold forming plate 2 is corresponding to the fastening device 4 of the end baffle plate, the screws penetrate through the forming plate and the fastening device 4 on the end baffle plate of the forming plate to be fixed, and the turnover mechanism 3 is installed at the bottom of the two forming plates.

When pouring, the forming plate and the baffle plate are rotated by 90 degrees towards two sides (as shown in figure 6), the prepared slurry is poured into a concrete forming mould, the center height of the slurry is slightly higher than that of the mould edge, as shown in figure 7, the purpose is to discharge air by extruding redundant materials during forming, and the compactness of a test piece is improved. The mold forming plate 2 is closed towards the center (see fig. 8), and the mold is pressed in a fixed manner by bolts 7 through the arc-shaped perforated clamp 5 in front of the end stop of the forming plate (see fig. 9). The excessive slurry is extruded from the extrusion port at the upper part of the forming plate (see figure 10), air is discharged by extruding the excessive material to improve the compactness of the material, and the material is easily accumulated on the surface of the bottom of the forming plate in the process of closing the forming plate of the mold to the center, so that the bottom of the forming plate is designed to be inclined to prevent the slurry from falling to the combining area of the mold to influence the combination of the mold. When the mold is removed, the mold can be separated by only pulling out the cylinder at the center of the lower hinge, and the successfully prepared RPC concrete section is taken out. (see FIG. 11).

The invention also provides a preparation method of the novel inorganic composite material RPC section, which comprises the following steps:

and (1) installing the die according to a drawing 5, and fixing the end baffle plate 1 and the forming plate 2 of the four forming plates by screws according to the positions corresponding to the fastening devices 4.

Step (2) the turnover mechanism 3 is installed at the bottom of the forming plate, and the forming plate 2 is rotated to two sides, so that the forming plate 2 is tiled (see fig. 6).

In the step (3), the RPC slurry with the compressive strength respectively reaching 200MPa, 300MPa and 400MPa after maintenance is prepared in the experiment, so that the RPC slurry can be used for preparing RPC profiles with different sizes, and the requirements of multiple directions are met, wherein the sizes of the RPC profiles and the sizes of the dies are shown in an attached table 1 and a figure 13.

And (4) pouring the prepared slurry into a concrete forming area of the mould, making the center of the slurry slightly higher than the edge of the mould, and carrying out vibration forming (see figure 7). The slurry comprises cement, silica fume, quartz powder, steel fiber and corresponding fine aggregate.

And (5) rotating the forming plate, approaching the forming plate 2 from two sides to the middle position, and folding the forming plate (see figure 8).

And (6) penetrating a bolt through the arc-shaped perforation matched die fastening device 5 at the front side of the end baffle 1 to extrude the die, extruding redundant slurry and air from an upper extruding opening, improving the compactness of the molded test piece, and screwing the bolt 7.

(see FIGS. 9-10)

And (7) demolding after standing for 24 hours, drawing out the cylinder of the bottom turnover mechanism 3 during demolding, separating the two side forming plates towards two sides, and taking out the I-shaped concrete RPC section bar 8. (see FIG. 11)

And (8) placing the section bar 8 in water for natural curing for 24 hours, and keeping the water temperature at normal temperature.

And (9) taking out the section bar 8, and placing the section bar in a hot water curing box for curing for 24 hours at 90 ℃.

And (10) placing the section bar 8 in an autoclave for high-temperature autoclave curing, taking out and drying, and removing burrs to obtain a finished product of the RPC section bar. (see FIG. 12)

Examples

Taking the preparation of an I-shaped section with the strength of 200MPa as an example, as shown in figure 13, the invention provides a production die of an RPC I-shaped section, which comprises two forming plates 2, four forming plate end baffles 1 and a turnover mechanism 3 (shown in figure 1). The forming plates 2 are fixedly connected with the corresponding fastening devices 4 of the end baffles 1 through screws, so that the four baffles 1 are respectively fixed at the ends of the two forming plates 2 to form a forming area of the I-shaped RPC concrete (as shown in FIG. 5). The turnover mechanism 3 is arranged at a position below the bottom of the forming plate, and the forming plate 2 is rotated to a horizontal position (see figure 6), namely the mold is at an open position. The slurry to be formed is then poured into the concrete forming area and the mould is placed on a vibrating table with the central portion of the slurry slightly above the edges of the mould. The rotating die merges the dies, and the excessive slurry is extruded from the excess material extrusion opening 6, and the material accumulated on the surface slides down when the lower part is in an inclined structure so as not to block the closing of the die (as shown in fig. 11). The fixing bolts penetrate through the arc-shaped through holes on the forming plate, and the die is closed by screwing the bolts (as shown in figures 8-9). Standing for 24h, and removing the mould, wherein the central column of the bottom hinge is only required to be pulled out when the mould is removed, the screws of the arc-shaped mounting mechanism are loosened, and the fastening devices at each position are opened, so that the mould can be separated from the concrete (see figure 11). The turning design has simple and convenient die operation, and the problem that a formed part has a larger defect due to material blockage caused by too narrow die webs can be effectively avoided by arranging the turning structure; meanwhile, the upper part of the forming plate is provided with a redundant extrusion port, so that air and redundant materials are discharged after the slurry is extruded, the size of a component is ensured, and the lower part of the forming plate is provided with an inclination angle to prevent the forming surface from being adhered with the materials to influence the closing of the die; and the demoulding is simple and convenient, and the production efficiency is improved.

TABLE 1 PRC I-shaped section bar specification table

H is height, b is leg width, d is rib thickness, t is thickness, R and R are arc chamfers, X is template thickness, and X takes 5-8mm in order to ensure that the strength of the die meets the production requirements.

¹ S＝2×(b×t)+(h-2t)×d

² M＝S×10 ^-4 ×1×2780

Claims

1. A method for preparing inorganic composite material section by using a turnover die is characterized in that the turnover die comprises an end baffle (1), a forming plate (2) and a turnover mechanism (3); the two molding plates (2) are internally provided with a cavity, the shape of the cavity formed by closing the two molding plates (2) is consistent with that of the section, the two end parts of the two molding plates (2) are respectively sealed through two end part baffles (1), and the bottoms of the two molding plates (2) are connected through a turnover mechanism (3); after the two forming plates (2) are closed, a surplus material extruding opening (6) with the width of 2-3mm is reserved between the upper parts of the two forming plates (2), inclined planes are arranged on the adjacent planes of the upper parts of the two forming plates (2), and the included angle alpha between each inclined plane and the horizontal plane is 60-75 degrees;

after die assembly, the lower parts of the two molding plates (2) are contacted, and the adjacent surfaces of the lower parts of the two molding plates (2) are provided with inclined surfaces, and the included angle beta between the inclined surfaces and the horizontal plane is 60-75 degrees;

the forming die is used for forming an I-shaped section, and the shape of a cavity of the forming plate (2) is half of the shape of the web plate of the I-shaped section as an axis; the method specifically comprises the following steps:

and (6): and (3) demolding after standing for 24 hours, drawing out the cylinder in the bottom turnover mechanism (3) during demolding, separating the forming plates (2) at the two sides to the two sides, and taking out the I-shaped concrete section (8).

2. The method for preparing an inorganic composite profile using an inverse mold as claimed in claim 1, further comprising the steps of:

3. The method for preparing inorganic composite material section bar using the turning mold as claimed in claim 2, wherein the end portion baffle (1) is a rectangular plate as a whole, and the upper and lower end portions of the surface of each end of the forming plate (2) where the two end portion baffles (1) are in contact are provided with inclined surfaces;

the upper part and the side surfaces far away from each other of the end baffle (1) are provided with fastening devices, the forming plate (2) is provided with a fastening device matched with the fastening device on the end baffle (1), and the fastening device on the end baffle (1) is connected with the fastening device on the forming plate (2) to realize fastening and sealing;

the two end baffles (1) at each end of the forming plate (2) are provided with fastening devices, and the fastening devices of the two end baffles (1) are connected to realize fastening and sealing.

4. The method for preparing the inorganic composite material profile by using the turnover die as claimed in claim 2, wherein the fastening devices arranged on the end baffle plate (1) and the forming plate (2) are lug parts with threaded holes, the lug parts between the end baffle plate (1) and the forming plate (2) are fastened and sealed by bolt connection, and the lug parts of the two end baffle plates (1) at one end of the forming plate (2) are connected by bolts (7) to realize fastening and sealing.

5. The method for preparing inorganic composite material profiles by using the turnover die as claimed in claim 3, wherein the turnover mechanism is a hinge assembly, two hinges of the hinge assembly are respectively connected with the forming plate (2), and the two hinges are hinged.