TECHNICAL FIELD

This invention relates to the field of construction, namely, methods for manufacturing solid building blocks with various geometric characteristics using removable molds.

BACKGROUND OF THE INVENTION

There are known methods for producing concrete products that are widely used around the world: for example, semi-dry compaction (based on the application of external pressure at the time of production) and concrete casting in a mold (natural crystallization process). Casting in a mold makes it possible to obtain precise high- strength concrete structures with internal reinforcing elements. At the same time, full-fledged crystals are formed in the process and the concrete can gain optimal strength properties.

A METHOD OF CASTING CONCRETE FOR THE MANUFACTURE OF CONCRETE PRODUCTS is known, according to Russian Federation Patent No. 2268141 published 10.07.2006, in which concrete is poured into at least one mold made from a material that can be sealed by compression, and then split; and that mold contains an upper half and a lower half, and the lower half contains an imprint of a part of the product, and the upper half contains a complementary part of the product and a sprue channel, consisting of one or more gravity casting sprues and one or more air outlets, or alternatively, the lower half contains an imprint of a part of the product and a sprue channel consisting of one or more siphon casting sprues, and the upper half contains a complementary part of the product and one or more air outlets.

A METHOD OF FORMING a CONCRETE BLOCK, is known, according to Russian Federation invention Patent No. 2197376 published 27.01.2003, which entails laying a mixture for the base in a mold, laying a dry mixture for the outer layer in the mold, simultaneously pressing the mixtures for the base and the mixture for the outer layer together with compacting force, by which pressure is exerted on the mixture for the base and on the mixture for the outer layer during the pressing process.

A METHOD FOR MANUFACTURING CONCRETE PRODUCTS is known, according to Russian Federation Patent No. 2243882 published 10.01.2005, in which the concrete mixture is maintained at a specific temperature and humidity level, while the concrete mixture is laid into the mold and tamped down, layer by layer. The disadvantages of producing concrete products using this method include low productivity and difficulty in automating processes.

Other shortcomings include very weak ability to customize the shape, lower strength (there is no full-fledged crystal formation), virtually no possibility to integrate tensile reinforcing elements, low precision of the resulting blocks’ dimensions, and a lack of sufficient replicability/stability of shape and strength characteristics.

When developing a method for producing concrete blocks, it is necessary to find a technological process that will ensure consistency when mass producing high-strength cast blocks with complex and variable geometric characteristics. A METHOD OF MANUFACTURING BUILDING BLOCKS WITH PRECISE DIMENSIONS is known, according to Russian Federation Patent No. 2046037 C1, published 20.10.1995, which consists in assembling the parts of a mold, sealing the mold’s internal cavity on all sides, setting the form of the mold’s internal surface, and feeding a molding compound into the sealed cavity, after which the resulting block is extracted by separating the parts of the mold. The source specified above describes a method according to which a large concrete block with a bottom and four enclosing sides is made using a removable molding core with a hard mirrored coating, four corner struts or corner elements, at least four molding wall panels, as well as removable external formwork walls. On the enclosing walls of the solid block in the areas opposite the wall molding panels, the slats protruding inside are solidly concreted and when the mold’s core is assembled, the molding wall panels are drawn together to a distance greater than the size of the protrusion of the slat, and then the corner struts are pulled in to a distance less than the difference between the protrusion of the cantilever plank and the distance to which the molding wall panels are drawn together. The disadvantages of this method include very weak ability to customize the shape, lower strength (there is no full-fledged crystal formation), virtually no possibility to integrate tensile reinforcing elements, low precision of the resulting block’s dimensions, and a lack of sufficient replicability/stability of shape and strength characteristics. When developing a method for producing concrete blocks, it is necessary to find a technological process that will ensure consistency when mass producing high-strength cast blocks with complex and variable geometric characteristics.

SUMMARY OF THE INVENTION

The technological problem is eliminating these shortcomings. The technological result of the invention lies in raising the quality of large concrete blocks with improved strength characteristics and consist geometric characteristics in mass production, and also in reducing the number of voids in the body of concrete products and increasing compressive strength by holding the concrete mixture inside the mold under pressure.

Exposing concrete to pressure using this technology makes it possible to obtain concrete products of significantly higher quality with improved strength characteristics, based on the normative documents EN 13369, EN 206-1 and GOST 13015-2012, with the characteristics of concrete surfaces of categories A1 , in which the depth of concrete chipping on the surface of the product is less than 2 mm or absent, and there is no shrinkage or other cracks on the surface due to processing.

Manufacturing building blocks with highly precise dimensions, the parts of a mold are assembled, the mold’s internal cavity is sealed, the form of the mold’s internal surface is set, a liquid mixture is fed into the mold capable of solidifying inside the mold’s internal cavity, the resulting product is removed from the mold after it has reached sufficient strength by separating the parts of the mold. The parts of the mold consist of a bottom plate mounted on an assembly table, side plates installed on the bottom plate at right angles with their end surfaces positioned around its perimeter, as well as a top plate laid on top of the end surfaces of the side plates opposite the end surfaces in contact with the bottom plate, while at least one mold part contains at least one shaping surface. A liquid mixture capable of solidification is poured into the sealed cavity of the mold, with the volume of the mixture poured greater than the volume of the material of the final product in a range from 0.1 to 99 percent, preferably from 1 to 65 percent, more preferably from 5 to 15 percent, and most preferably 10 percent. A pressure of at least 9 kPa is applied to the liquid mixture capable of solidifying inside the mold by inserting at least one plunger into the mold and fixing it in place until the product gains sufficient strength to extract.

The casting mold contains at least one channel, the shape of whose cross-section relative to its axis passing through the centers of the base of the channel in its central part is selected from a group consisting of a circle, oval, square, rectangle, triangle, trapezoid, or their combinations. This channel is intended for inserting plunger, whose immersion will subject the liquid mixture inside the sealed cavity of the mold to the required pressure. Then the mixture hardens and, after gaining sufficient strength to extract, the resulting product is removed by separating the parts of the mold.

The plunger that is used to create pressure during the solidification of the product is made in the form of a threaded screw or smooth rod, with the shape of the plunger’s cross-section relative to its axis passing through the centers of the base of the plunger in its central part selected from a group consisting of a circle, oval, square, rectangle, triangle, trapezoid, or their combinations, while its immersion depth, which is defined as the distance the plunger is inserted between the projection of a plane perpendicular to the axis of the channel passing through the centers of the channel base in its central part and the surface of the plunger in contact with the mixture inside the sealed cavity of the mold, is 1 to 983 mm, preferably from 50 to 500 mm, more preferably from 75 to 250 mm, and most preferably 100 mm.

When using this method, at least one of the shaping surfaces is made with a complex texture containing protruding elements. The mold’s parts are designed in such a way that, when assembling them, it is possible to place inserts inside the space formed by the mold, which are designed to fasten the resulting products to each other and reinforce them.

At least one of the casting mold’s parts consists of two components, of which the first contains the form of the surface of the product and the second serves as a structural element for the casting mold, with the first component attached to the surface of the second by means of a detachable connection.

The side plates standing between the surfaces of the bottom and top plates of the casting mold are prevented from moving by elements on their surfaces executed in the form of interacting protrusions on one surface and depressions on the other.

The liquid mixture capable of solidification in the mold is kept under pressure until it has gained strength sufficient to be extracted under natural conditions, while heat is released as a result of the exothermic reaction of the mixture’s components with water. The product does not require further processing after removal from the mold.

The temperature of the liquid mixture poured into the assembled mold is at least in the range from 1 to 90 degrees Centigrade, preferably from 20 to 80 degrees, more preferably from 40 to 70 degrees, and most preferably 60 degrees.

The technological result is also achieved by the fact that, in this method of manufacturing building blocks with highly precise dimensions, the parts of the mold consist of a bottom plate mounted on an assembly table, side plates installed on the bottom plate at right angles with their end surfaces positioned around its perimeter, as well as a top plate that, after the liquid is poured, is inserted into the internal space between the side plates of the mold in such a way that the plane of the top plate in contact with the liquid mixture capable of solidifying is below the upper ends of the side plates in contact with the bottom plate, while at least one part of the mold contains at least one shaping surface.

The volume of the liquid mixture capable of solidification that is poured into the sealed cavity of the mold is greater than the volume of the material of the final product in a range from 0.1 to 99 percent, preferably from 1 to 65 percent, more preferably from 5 to 15, percent and most preferably 10 percent.

A pressure of at least 9 kPa is applied to the liquid composition capable of solidifying inside the mold by introducing at least one plunger and fixing it in place until the product gains sufficient strength to extract. The casting mold contains at least one channel, the shape of whose cross-section, relative to its axis passing through the centers of the channel base in its central part, is selected from a group consisting of a circle, oval, square, rectangle, triangle, trapezoid, or their combinations. This channel is intended for inserting a plunger, whose immersion will subject the liquid mixture inside the sealed cavity of the mold to the required pressure.

When the liquid mixture capable of solidification has hardened to the point that it has gained sufficient strength to extract, the resulting product is removed by separating the parts of the mold.

BRIEF DESCRIPTION OF THE DRAWINGS

The essence of the proposed invention is illustrated by the drawings and description of the preferred variants of embodiment with references to the accompanying drawings: Figure 1 is a general view of an example of this invention - an assembled mold, where (1) is a bottom plate, (3) is a top plate, (2) is a side plate, and (4) is a plunger.

Figure 2 shows an assembled mold with a plunger (4) fixed in the lower position, where (1) is a bottom plate, (3) is a top plate, and (2) is a side plate.

Figure 3 shows an exploded view of a mold with a plunger (4) fixed in the lower position, where (1) is a bottom plate, (3) is a top plate, and (2) is a side plate,

Figure 4 is a view of a side plate (2) with two shaping surfaces (5).

Figure 5 is a view of a side plate (2) with an attached shaping surface (5).

Figure 6 shows a side plate (2) with a separate shaping surface (5). To increase accuracy when positioning the shaping surface on the side plate, both components are made with mortise-tenon type connecting elements (6). There are also mortise-tenon type connecting elements on the upper and lower ends of the side plates (7) for positioning and mounting the side plates relative to the bottom and top plates. The parts of the side plates are designed to be separable so that the side plates’ shaping surfaces can be replaced if a block with a different surface is required.

Figure 7 shows a bottom plate (1) with a shaping surface (5). There are mortise-tenon type connecting elements on the upper plane of the base of the bottom plate (7) for positioning and mounting the side plates on the bottom plate. The parts of the bottom plate are designed to be separable so that its shaping surface can be replaced if a block with a different bottom surface is required. Figure 8 is an exploded view of a bottom plate (1) with a shaping surface (5). To improve accuracy when positioning the shaping surface on the bottom plate, both components have mortise-tenon type connecting elements (6). The mortise-tenon type connecting elements on the upper plane of the base of the bottom plate (7) are for positioning and mounting the side plates on the bottom plate.

Figure 9 shows a top plate (3) with a shaping surface (5). There are mortise-tenon type connecting elements on the lower plane of the top plate (7) for positioning and mounting the top plate on the side plates. The parts of the top plate are designed to be separable so that its shaping surface can be replaced if a block with a different top surface is required.

Figure 10 is an exploded view of a top plate (1) with a shaping surface (5). To improve accuracy when positioning the shaping surface on the top plate, both components have mortise-tenon type connecting elements (6). The mortise-tenon type connecting elements on the lower plane of the top plate (7) are for positioning and mounting the top plate on the side plates.

Figure 11 shows an exploded view of a mold.

Figure 12 shows a variation for assembling a mold, where the side plates (2) are installed on the bottom plate (1), and the top plate (3) is inserted into the resulting cavity along with a plunger (4). Figure 13 is an exploded view of a mold, where the side plates (2) are installed on the bottom plate (1), and the top plate (3) is inserted into the resulting cavity along with a plunger (4).

Figure 14 is a general view of a variation of a mold, where (1) is a bottom plate, (3) is a top plate, (2) is a side plate, (4) is a plunger, and (9) is a special clamp.

Figure 15 is an exploded view of a mold, where (1) is a bottom plate, (3) is a top plate, (2) is a side plate, (4) is a plunger, (5) is a shaping surface, (7) are mortise-tenon type connecting elements, (8) is a channel in the mold’s top plate for pouring the liquid mixture, and (9) is a special clamp.

Figure 16 shows the assembly of a variation of the invention. The bottom plate (1) is installed on an assembly table. There are special clamps (9) mounted on the mold’s bottom plate. To insert the reinforcing studs of the future block into the mold, a special ‘rig’ is used, which temporarily holds the reinforcing studs in place until all four side plates have been installed in the mold.

Figure 17 shows the installation of the mold’s shaping surface on the bottom plate. The shaping surface (5) is installed on the bottom plate (1) to form the surface of the bottom of the product. Optimally, the shaping surface (5) is fixed in place on the bottom plate by magnets. To increase accuracy when positioning the shaping surface on the bottom plate, both components have mortise-tenon type connecting elements (6). Figure 18 shows the assembly of a side plate and a shaping surface. The optimal method is to attach the shaping surface (5) to the side plate (2) using threaded fasteners (10). To increase accuracy when positioning the shaping surface on the plates of the mold, both components have mortise-tenon type connecting elements (6).

Figure 19 shows a side plate (2) assembled with a shaping surface (5). Figure 20 shows side plates (2) with shaping surfaces (5) being installed on a bottom plate (1) with a shaping surface (5). The side plates are put in place sequentially. The bottom plate (1) and the side plates (2) have mortise-tenon connecting elements (7) at the places where they are joined for positioning them relative to one another. Figure 21 shows the mold’s side plates (2) with shaping surfaces (5) mounted on a bottom plate (1) with a shaping surface (5).

Figure 22 shows a shaping surface (5) being installed on a top plate (3) using threaded fasteners (10), which is the optimal method.

Figure 23 shows a shaping surface (5) installed on a top plate (3).

Figure 24 shows a top plate (3) with a shaping surface (5) being mounted on side plates (2).

Figure 25 is a view of an assembled mold, where (1) is the bottom plate, (2) is a side plate, and (3) is the top plate Figure 26 shows the top and bottom plates (3 & 1) being pulled together by special clamps (9), thereby fixing the side plates (2) in place. The mold thereby acquires the strength necessary to withstand the pressure it will be subjected to.

Figure 27 shows an automatic dispenser injecting a liquid mixture into channels in the mold’s top plate under pressure. (8) serves as a channel for a plunger. Each product has an exact specific norm for the volume-weight of the supplied mixture. The mixture is injected preheated, optimally at 80 degrees Celsius. Figure 28 shows plungers (4) being installed in the mold’s top plate (3). They are alternately screwed into the top plate (3).

Figure 29 shows plungers (4) fully inserted into the top plate (3), thereby creating the pressure required in the mold cavity to properly manufacture the product.

Figure 30 shows plungers (4) being removed from the mold’s top plate (3).

Figure 31 shows the mold without plungers (4).

In Figure 32, the clamps (9) have been loosened and the top plate is being removed.

In Figure 33 the product (11), along with the side plates (2), is lifted vertically in a direction perpendicular to the surface of the bottom plate (1).

Figure 34 shows the removed side plates with the nearly finished product (11) inside. The side plates (2) are alternately separated from the product (11).

Figure 35 shows the mold’s side plates separated from the nearly finished product (11).

EXAMPLES Version 1 of the Invention

Step 1. Begin assembly. In Fig. 11, the mold’s bottom plate (1) containing one shaping surface (5) is installed on the assembly table. It has special mortise-tenon type connecting elements (7) for positioning and mounting the mold’s side plates. The fasteners of the future product are inserted into the mold with the help of a special ‘rig’, which temporarily holds them in place until all the mold’s side plates are installed. Step 2. Installation of the mold’s side plates (2) on mold’s bottom plate (1). In Figure 11, the side plates (2) with shaping surfaces (5) are sequentially positioned and mounted on a bottom plate (1) with a shaping surface (5), with the help of mortise-tenon type connecting elements (7).

Step 3. Installation of the mold’s top plate (3) on the mold’s side plates (2) with shaping surfaces (5). In Fig. 11 , the top plate (3) is positioned and mounted on side plates (2) with shaping surfaces (5), with the help of mortise-tenon type connecting elements (7). Step 4. Injecting the liquid mixture into the mold. In Fig. 11, an automatic dispenser injects a liquid mixture into channels in the mold’s top plate (8) under pressure. Each product has an exact specific norm for the volume-weight of the supplied mixture. The mixture is injected preheated, most preferably at 80 degrees Celsius. Step 5. In Figure 11 , plungers (4) are installed in the mold’s top plate (3). In the next operation, the plungers are screwed into the mold to failure, sinking approximately 100 mm. The plungers (4) subject the liquid mixture inside the mold to pressure, optimally, to 10 MPa. The plungers displace volume inside the mold by compressing air bubbles in the concrete mixture. Statistically, mixed concrete usually contains about 10% voids.

Stage 6. Hardening. The product is kept under pressure for two hours, as it gains initial strength. To do this, the mold containing the product moves through a curing tunnel. The increased temperature and moisture act upon the mixture inside the mold, creating a steaming effect as the product hardens, since moisture cannot displace space inside the mold. This significantly accelerates crystallization in the mixture. Step 7. Disassembling the mold. In Fig. 11 , the plungers (4) are removed from the assembled mold.

Step 8. Disassembling the mold. In Fig. 11, the mold’s top plate (3) is removed and sent for cleaning. Step 9. Disassembling the mold. In Fig. 11, the mold’s side plates (2) along with the product are removed from the mold’s bottom plate. To do this, the bottom plate is temporarily fixed in place, and the mold’s side plates along with the product are lifted vertically in a direction perpendicular to the surface of the bottom plate. Then, the mold’s bottom plate is sent for cleaning.

Stage 10. Disassembling the mold. In Fig. 11, the mold’s side plates (2) are separated from the nearly finished product in turn. When being removed, the movement is strictly perpendicular to the surface of the product. The mold’s side plates are sent for cleaning.

Version 2 of the Invention

Step 1. Begin assembly. In Fig. 16, the bottom plate (1) is installed on an assembly table. Special clamps (9) can be mounted on the mold’s bottom plate. To insert the reinforcing studs of the future block into the mold, a special ‘rig’ is used, which temporarily fixes the reinforcing studs in place until all four side plates have been installed in the mold.

Step 2. Assembly of the mold’s bottom plate and a shaping surface. In Fig. 17, the shaping surface (5) is installed on the bottom plate (1) to form the surface of the bottom of the product. Optimally, the shaping surface (5) is fixed in place on the bottom plate by magnets. To increase accuracy when positioning the shaping surface on the bottom plate, both components have mortise-tenon type connecting elements (6).

Step 3. Assembly of the mold’s side plates (2) and their shaping surfaces (5). In Fig. 18, the shaping surfaces (5) are attached to the side plates (2) by threaded fasteners (10), which is the optimal method. To increase accuracy when positioning the shaping surface on the plates of the mold, both components have mortise-tenon type connecting elements (6). Fig. 19 shows a side plate (2) assembled with its shaping surface (5). Step 4. Installing side plates with shaping surfaces on a bottom plate with a shaping surface. Fig. 20 shows side plates (2) with shaping surfaces (5) being installed on a bottom plate (1) with a shaping surface (5). The side plates are put in place sequentially. Both the bottom plate (1) and the side plates (2) have mortise-tenon connecting elements (7) at the places where they are joined for positioning them relative to each other. In Fig. 21, the mold’s side plates (2) with shaping surfaces (5) are mounted on a bottom plate (1) with a shaping surface.

Step 5. Assembly of a top plate with a shaping surface. Fig. 22 shows a shaping surface (5) being installed on a top plate (3) using threaded fasteners (10), which is the optimal method. To increase accuracy when positioning the shaping surface on the top plate, both components have mortise-tenon type connecting elements (6). The parts of the top plate are designed to be separatable so that the top plate’s shaping surface can be replaced if a block with a different top surface is required. Fig. 23 shows a shaping surface (5) installed on a top plate (3). Step 6. Installing a top plate with shaping surfaces on side plates. Fig. 24 shows a top plate (1) with a shaping surface (5) being mounted on side plates (2). Fig. 25 shows the assembled mold, where (1) is a bottom plate, (2) is a side plate, and (3) is a top plate. Fig. 26 shows the top and bottom plates (3 & 1) being pulled together by special clamps (9), thereby fixing the side plates (2) in place. The mold thus acquires the strength necessary to withstand the pressure it will be subjected to.

Step 7. Pouring the mixture into the mold. In Fig. 27, the mold is placed in the fill position on a vibrating worktable. An automatic dispenser injects a liquid mixture into channels in the mold’s top plate under pressure. (8) serves as a channel for a plunger. Each product has an exact specific norm for the volume-weight of the supplied mixture. The mixture is injected preheated, optimally at 80 degrees Celsius.

Step 8. Plungers. In Fig. 28, the plungers (4) are installed in the mold’s top plate (3). They are alternately screwed into the top plate (3). In the next operation, the plungers are screwed into the mold to failure, optimally, sinking approximately 20 mm. The plungers are screwed in while the vibrating table is running. The plungers (4) subject the liquid mixture inside the mold to pressure, optimally to 10 MPa. The plungers displace volume inside the mold by compressing air bubbles in the concrete mixture. Statistically, mixed concrete usually contains about 10% voids. Concrete castings of significantly higher quality with improved strength characteristics are obtained by exposing concrete to pressure using this method.

Stage 9. Hardening. The product is kept under pressure for two hours, as it gains initial strength. To do this, the mold containing the product moves through a curing tunnel. The increased temperature and moisture act upon the mixture inside the mold, creating a steaming effect as the product hardens, since moisture cannot displace space inside the mold. This significantly accelerates crystallization in the mixture.

Stage 10. Disassembling the mold. In Fig. 30, the plungers (4) are removed from the mold’s top plate (3). Fig. 31 shows the mold without the plungers (4)

Step 11. Disassembling the mold. In Fig. 32, the clamps (9) have been loosened and the top plate is removed. The top plate is sent for cleaning.

Step 12. Disassembling the mold. In Fig. 33, the mold’s side plates (2) along with the product (11) are removed from the mold’s bottom plate (1). To do this, the bottom plate is temporarily fixed in place, and the mold’s side plates (2) along with the product (11) are lifted vertically in a direction perpendicular to the surface of the bottom plate. Then, the mold’s bottom plate is sent for cleaning.

Stage 13. Disassembling the mold. In Fig. 34 and 35, the mold’s side plates (2) are separated from the nearly finished product (11) in turn. When being removed, the movement is strictly perpendicular to the surface of the product.

INDUSTRIAL APPLICABILITY

The plunger that is used to subject the concrete mixture to pressure inside the mold while the product is hardening is inserted into the mold to a depth of up to 10 mm, with the depth of immersion defined as the distance the plunger is inserted between the projection of the plane perpendicular to the axis of the channel passing through the centers of the channel base in its central part and the surface of the plunger in contact with the composition inside the sealed mold cavity, at which a pressure of 9 kPa is created, as a result of which there is no shrinkage and there are no cracks, pits, or residue on any of the product’s surfaces due to processing. The plunger displaces volume in the mold by compressing air bubbles in the concrete mix, thus reducing their volume by 50%.

The plunger that is used to subject the concrete mixture to pressure inside the mold while the product is hardening is inserted into the mold to a depth of up to 50 mm, with the depth of immersion determined as the distance the plunger is inserted between the projection of the plane perpendicular to the axis of the channel passing through the centers of the channel base in its central part and the surface of the plunger in contact with the liquid mixture inside the sealed mold cavity, at which a pressure of 1 ,000 kPa is created, as a result of which there is no shrinkage and no cracks on any of the product’s surfaces due to processing. The plunger displaces volume in the mold by compressing air bubbles in the concrete mix, thus reducing their volume by 80%.

The plunger that is used to subject the concrete mixture to pressure inside the mold while the product is hardening is inserted into the mold to a depth of up to 500 mm, with the depth of immersion defined as the distance the plunger is inserted between the projection of the plane perpendicular to the axis of the channel passing through the centers of the channel base in its central part and the surface of the plunger in contact with the liquid mixture inside the sealed mold cavity, at which a pressure of 6 MPa is created, as a result of which there is no shrinkage and no cracks on any of the product’s surfaces due to processing. The plunger displaces volume in the mold by compressing air bubbles in the concrete mix, thus reducing their volume by 87%.