Concrete-forming additive device and concrete structure

Abstract

[Problem] To provide a concrete-forming additive device and a concrete structure that make it possible to facilitate user convenience. [Solution] A concrete-forming additive device 10 is added to unhardened concrete, and has a rod-shaped portion 11 which is formed in a rod shape and which has formed at one end and the other end thereof dilated portions 12, 13 having a thickness greater than that of the rod-shaped portion. The concrete-forming additive device 10 generates tensile strength by overlapping with another concrete-forming additive device within a range where one concrete-forming additive device constrains concrete. In a concrete structure 1, the concrete-forming additive device 10 is added to unhardened concrete.

Description

Concrete forming additive equipment and concrete structure

[0001] The present invention relates to a concrete-forming additive tool used for concrete, and a concrete structure made of concrete.

[0002] Concrete is generally prepared by mixing cement, water, coarse aggregate (crushed stone or gravel), and fine aggregate (sand), which is then solidified through the hydration reaction between the water and cement. Concrete is widely used as a building material.

[0003] Concrete has the drawback of having a very low tensile strength, approximately 1 / 10 to 1 / 13 of its compressive strength. To compensate for this drawback, it is common to arrange reinforcing bars in a matrix pattern vertically and horizontally within the concrete. However, a new coarse aggregate, a roughly tetrahedral metallic coarse aggregate, has been proposed as a new coarse aggregate that can improve not only compressive strength but also tensile strength (Patent Document 1). Because of its roughly tetrahedral outer shape, this coarse aggregate exhibits an anchoring effect in mortar, making it possible to improve tensile strength and shear strength compared to conventional coarse aggregates.

[0004] Furthermore, in order to improve the adhesion between metallic coarse aggregate and mortar, a coarse aggregate has been proposed in which a fine wire of 20 count or more is passed through the metallic coarse aggregate body so that the wire can be easily wound around the coarse aggregate body (Patent Document 2). With this coarse aggregate, the wire is wound around the coarse aggregate body during stirring of the fresh concrete, and the mortar is captured by the wound wire, so that the coarse aggregate and mortar move together, which has the advantage of making the coarse aggregate less likely to settle in the fresh concrete and improving the dispersibility of the coarse aggregate.

[0005] However, in the case of metallic coarse aggregate as described in Patent Document 1, the tensile strength of the coarse aggregate itself is too strong compared to the strength of the mortar portion of the concrete, so the interface between the coarse aggregate and the mortar peels off, causing the mortar portion to break, and there are cases in which the coarse aggregate cannot contribute to further improving the tensile strength of the concrete.

[0006] As described in Patent Document 2, winding a wire around the metal coarse aggregate body can improve the adhesion between the coarse aggregate and mortar, but since the way the wire is wound around the coarse aggregate body is not consistent, there is a risk of variation in tensile strength.

[0007] In response to this, a coarse aggregate made of metal mesh material shaped into hollow spheres has been proposed in order to further improve the adhesion between the mortar and the coarse aggregate, prevent fracture of the mortar, and improve the tensile strength of the concrete (Patent Document 3).

[0008] Patent No. 6485932 Patent No. 6532073 Patent No. 6667886

[0009] However, the coarse aggregate described in Patent Document 3 is made by processing and shaping a metal mesh material, which results in high material costs. On the other hand, coarse aggregate is typically used in large quantities, occupying approximately 70% of the volume of concrete, so it is necessary to make it available at a lower cost.

[0010] SUMMARY OF THE INVENTION The present invention provides a concrete-forming additive tool and a concrete structure that can be convenient for users.

[0011] The concrete-forming additive of the present invention is an additive that is added to concrete before it hardens, and is characterized in that one additive overlaps another in the area where one additive restrains the concrete, thereby generating tensile strength.

[0012] In addition, the concrete forming additive tool of the present invention is an additive tool for concrete formation that is added to concrete before it hardens, and is characterized in that it has a rod-shaped portion formed into one end and the other end of which has an enlarged portion that is thicker than the rod-shaped portion.

[0013] Furthermore, the concrete forming additive tool of the present invention is an additive tool for concrete formation that is added to concrete before it hardens, and is characterized in that three rod-shaped portions are formed at one end and the other end with bulges that are thicker than the three rod-shaped portions, the three rod-shaped portions are arranged in different directions from each other, and the middle portions of the three rod-shaped portions are connected and fixed together.

[0014] The concrete structure of the present invention is characterized in that the concrete forming additive device according to claim 1 or 2 is added to pre-hardened concrete.

[0015] According to the present invention, it is possible to provide a concrete forming additive tool and a concrete structure that are convenient for users.

[0016] FIG. 1 is a cross-sectional view showing a concrete structure to which a concrete formation adding tool according to a first embodiment of the present invention has been added. FIG. 2 is a first explanatory view showing the effect of the concrete formation adding tool according to the first embodiment of the present invention. FIG. 3 is a second explanatory view showing the effect of the concrete formation adding tool according to the first embodiment of the present invention. FIG. 4 is a perspective view showing a concrete formation adding tool according to a second embodiment of the present invention. FIG. 5 is a perspective view showing a concrete formation adding tool according to the first, third, and fifth embodiments of the present invention. FIG. 6 is a perspective view showing a concrete formation adding tool according to the second embodiment, and sixth to eighth embodiments of the present invention. FIG. 7 is a perspective view showing a concrete formation adding tool according to the ninth to eleventh embodiments of the present invention. FIG. 8 is a perspective view showing a concrete formation adding tool according to the twelfth to fifteenth embodiments of the present invention. FIG. 9 is a perspective view showing a concrete formation adding tool according to the sixteenth and seventeenth embodiments of the present invention. FIG. 10 is a perspective view showing a concrete formation adding tool according to the eighteenth and nineteenth embodiments of the present invention.

[0017] <Embodiments> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0018] FIG. 1 is a cross-sectional view showing a concrete structure to which a concrete forming additive tool according to a first embodiment of the present invention has been added. FIG. 2 is a first explanatory diagram showing the effects of the concrete forming additive tool according to the first embodiment of the present invention. FIG. 3 is a second explanatory diagram showing the effects of the concrete forming additive tool according to the first embodiment of the present invention. FIG. 4 is a perspective view showing a concrete forming additive tool according to a second embodiment of the present invention. FIG. 5 is a perspective view showing a concrete forming additive tool according to the first, third, and fifth embodiments of the present invention. FIG. 6 is a perspective view showing a concrete forming additive tool according to the second embodiment, and sixth to eighth embodiments of the present invention. FIG. 7 is a perspective view showing a concrete forming additive tool according to the ninth to eleventh embodiments of the present invention. FIG. 8 is a perspective view showing a concrete forming additive tool according to the twelfth to fifteenth embodiments of the present invention. FIG. 9 is a perspective view showing a concrete forming additive tool according to the sixteenth and seventeenth embodiments of the present invention. FIG. 10 is a perspective view showing a concrete forming additive tool according to the eighteenth and nineteenth embodiments of the present invention.

[0019] <Configuration of the first embodiment of the present invention> As shown in FIG. 1 , the concrete structure 1 according to the first embodiment of the present invention is made by adding aggregate (coarse aggregate, fine aggregate) 3 and a concrete-forming additive tool 10 to pre-hardened concrete (cement paste, which is made by mixing cement as a binder with water), and kneading the mixture. The concrete structure 1 is made up of cement paste 2, aggregate 3, and concrete-forming additive tool 10.

[0020] The concrete forming additive tool 10 has a rod-shaped portion 11 formed in a rod shape, and teardrop-shaped swelling portions 12, 13 that are thicker than the rod-shaped portion 11 formed at one end and the other end of the rod-shaped portion 11.

[0021] The concrete forming additive tool 10 can be made of metals such as steel, aluminum alloys, and stainless steel alloys, fiber reinforced plastics such as glass fiber and carbon fiber, high strength plastics, and the like.

[0022] The concrete forming additive tool 10 can be manufactured by forging, casting, welding, punching, molding, or the like.

[0023] <When the Concrete Forming Additive 10 is Made of Metal> When the concrete forming additive 10 is made of metal, blasting (surface roughening) can be performed to strengthen cement adhesion. If rust prevention is required, plating is performed.

[0024] In one example of a specific method for manufacturing the concrete forming additive tool 10 when metal is used as the material, the rod-shaped portion 11 and the teardrop-shaped enlarged portions 12, 13 are integrally formed.

[0025] The concrete forming tool 10 of the first embodiment is used in place of crushed stone as aggregate, and has a total length of 40 mm, a rod-shaped portion 11 having a diameter of 2 mm, and bulging portions 12, 13 having a thickness of 4 mm. The bulging portions 12, 13 are formed to their thickness by press forging. When iron is used as the material, hot-dip galvanizing is performed as the overall surface treatment.

[0026] <When the Concrete Forming Additive 10 is Made of Plastic> When the concrete forming additive 10 is made of plastic such as fiber reinforced plastic or high strength plastic, it is subjected to matte treatment, blasting treatment, etc. to enhance cement adhesion.

[0027] In one example of a specific manufacturing method for the concrete forming additive tool 10 when plastic is used as the material, a plastic plate is punched out into the shape shown in Figure 1. In another example of a specific manufacturing method, a die-cast tool is poured into a mold and then removed.

[0028] In the concrete structure 1 to which the concrete-forming additive tool 10 shown in Figure 1 has been added, in addition to the bonding force between the cement paste 2 and the concrete-forming additive tool 10, the enlarged portions 12 and 13 of the concrete-forming additive tool 10 engage with the cement paste 2 and apply a compressive force in the opposite direction to the tensile force applied to the concrete structure 1, thereby obtaining concrete that is strong against tensile forces.

[0029] In contrast, as shown in Figure 2, in a conventional concrete structure 5 that does not use a concrete forming additive tool 10, the tensile force is resisted only by the bonding strength between the cement paste 2 and the aggregate (coarse aggregate, fine aggregate) 3, and therefore sufficient strength against the tensile force cannot be obtained.

[0030] In addition, in the concrete structure 7 to which the concrete forming additive tools 10a and 10b shown in Figure 3 (which are the same as the concrete forming additive tool 10 shown in Figure 1) have been added, the area 14 in which the enlarged portion 12 of one concrete forming additive tool 10a restrains the cement paste 2 overlaps with the area 14 in which the enlarged portion 13 of the other concrete forming additive tool 10b restrains the cement paste 2, thereby generating a greater tensile strength.

[0031] Therefore, the reference numeral 14 indicates the range in which the concrete resists tension force using its inherent compressive strength.

[0032] Therefore, range 14 is the range in which the cement paste 2 resists tensile force, and compressive force is generated in the cement paste 2 by the concrete forming adding tools 10a, 10b, which resists the tensile force via the concrete forming adding tools 10a, 10b.

[0033] Furthermore, the concrete forming additive tools 10, 10a, and 10b can be used as they are in the manufacturing process, including ready-mix concrete plants, transportation, pumping, and pouring (pouring into the desired location). The concrete forming additive tools 10, 10a, and 10b have increased strength due to the combined anchoring effect with other aggregates.

[0034] The size of the concrete-forming additive tool 10 is not limited to the above-mentioned size, and various sizes are applicable. For example, in mass concrete used in dams, etc., the larger the maximum diameter of the concrete-forming additive tool, the more advantageous it is. On the other hand, even if the size of the concrete-forming additive tool is microscopic, smaller than fine aggregate, by simultaneously mixing something that has the same mechanical function as in the first embodiment, the ranges of effect overlap synergistically, and higher strength concrete can be provided.

[0035] <Configuration and Operation of the First Embodiment of the Present Invention> The configuration and operation of the first embodiment of the present invention will be summarized below. Concrete-forming additives 10, 10a, and 10b are concrete-forming additives that are added to concrete before it hardens, and one concrete-forming additive overlaps another in the area where one concrete-forming additive restrains the concrete, generating tensile strength.

[0036] Here, the size of the concrete forming additive tools 10, 10a, 10b that serve as aggregates does not have to be uniform, and a composite of coarse, fine and minute aggregates will synergistically increase strength.

[0037] In this case, the concrete forming additive tools 10, 10a, 10b which are used to form coarse, fine and fine (macro to micro) aggregates are mixed together and the overlapping areas synergistically create tensile strength.

[0038] Concrete forming additives 10, 10a, 10b are coarse, fine, and minute concrete forming additives that are added to concrete before it hardens, and one concrete forming additive overlaps another in the area where the concrete is constrained, generating tensile strength from both a macroscopic and microscopic perspective.

[0039] The concrete forming additive tools 10, 10a, 10b are concrete forming additive tools that are added to concrete before it hardens, and have enlarged portions 12, 13 at one end and the other end of a rod-shaped portion 11 that is formed in a rod shape and is thicker than the rod-shaped portion.

[0040] The concrete structure 1 has a large number of concrete-forming additives 10 (such as sand and gravel) added to the pre-hardened concrete.

[0041] The concrete structure 7 is made by adding concrete forming additives 10a and 10b to the pre-hardened concrete.

[0042] In addition, Figure 1 shows a state in which one concrete forming additive tool 10 has been added to the concrete structure 1, and Figure 3 shows a state in which two concrete forming additive tools 10a and 10b have been added to the concrete structure 1, but in fact a large number of concrete forming additive tools will be added to the concrete structures 1 and 7.

[0043] The concrete forming additives 10, 10a, 10b and concrete structures 1, 7 of the first embodiment allow for the inexpensive production of concrete that is strong against tensile forces, and also improves its compressive, shear, and bending strength (compressive strength, shear strength, and bending strength). As a result, national land resilience and infrastructure lifespans are possible, providing user convenience. This changes the common knowledge that concrete around the world is weak against tension to concrete that is strong against tension. It achieves performance superior to that of reinforced concrete by reducing or eliminating the materials and labor required for assembling rebar in reinforced concrete. Such performance contributes to national land resilience and is consistent with sustainable development.

[0044] <Configuration of the second embodiment of the present invention> As shown in Figure 4, the concrete forming additive tool 20 according to the second embodiment of the present invention is an additive tool for concrete formation to be added to pre-hardened concrete, and is made by combining three cotton-swab-shaped members 21, 22, and 23 and welding the center 30 of the rod-shaped member 11.

[0045] The three cotton-swab-shaped members 21, 22, 23 are the same as those of the metal concrete forming additive tool 10 shown in FIG. 1, and the rod-shaped portion 11 and the teardrop-shaped enlarged portions 12, 13 are integrally formed.

[0046] The three swab-shaped members 21, 22, 23 are arranged in the x, y, and z directions that are orthogonal to each other, and in this state, the center 30 of the rod-shaped portion 11 is connected and fixed by welding.

[0047] The concrete forming additive tool 20 can be made of materials other than metal, and the method of connecting the center of the rod-shaped part 11 can be adhesive, welding, fusion, etc.

[0048] The concrete forming adding tool 20 according to the second embodiment is a representative embodiment of the present invention, and is the best or nearly best embodiment.

[0049] The concrete forming additive tool 20 has teardrop-shaped arms (rod-shaped portion 11 and teardrop-shaped enlarged portions 12, 13) extending in three dimensions.

[0050] The concrete cement paste 2 sandwiched between the teardrop-shaped portions at the ends of the arms (teardrop-shaped swelling portions 12, 13) is constrained within the arms. This state exists overlapping front to back, left to right, and up and down.

[0051] The concrete structure produced using the concrete-forming additive tool 20 becomes concrete in which the binder (cement paste 2) and the entire interior are constrained. In other words, concrete that is strong against tensile forces from all directions is obtained.

[0052] The concrete forming additive tools 20 are shaped so that they do not get tangled with each other.

[0053] In the second embodiment, the concrete forming tool 20 has a maximum diameter of 40 mm, an intermediate diameter of 20 mm, and a minimum diameter of 5 mm. This is because the maximum diameter of the existing aggregate (crushed stone) is 40 mm, and this has been thoroughly studied in materials science. Furthermore, in terms of the manufacturing process, the tool can be used as is in ready-mix concrete plants, transportation, pumping, and pouring (pouring into the desired location). This configuration is familiar to concrete manufacturing and construction sites.

[0054] Furthermore, the concrete forming additive tool 20 has increased strength due to the combined anchoring effect with other aggregates.

[0055] The size of the concrete-forming additive 20 is not limited to the above-mentioned size, and various sizes are applicable. For example, in mass concrete used in dams, the larger the maximum diameter of the concrete-forming additive, the more advantageous it is. On the other hand, even if the size of the concrete-forming additive is microscopic, smaller than fine aggregate, by simultaneously mixing additives that have the same mechanical properties as those in the second embodiment, the ranges of effect overlap synergistically, and higher strength concrete can be provided.

[0056] <Configuration and Function of Second Embodiment of the Present Invention> The configuration and function of the second embodiment of the present invention will be summarized below. Concrete-forming additive tool 20 is a concrete-forming additive tool that is added to concrete before it hardens, and one concrete-forming additive tool overlaps another concrete-forming additive tool in the area where one concrete-forming additive tool restrains the concrete, generating tensile strength.

[0057] Here, the size of the concrete forming additive tool 20 that serves as the aggregate does not have to be uniform, and a composite of coarse, fine and minute aggregates will synergistically increase the strength.

[0058] In this case, the concrete forming additive tools 20 that are used to form coarse, fine, and fine (macro to micro) aggregates are mixed together, and the overlapping areas synergistically create tensile strength.

[0059] The concrete forming additives 20 are coarse, fine and minute concrete forming additives that are added to concrete before it hardens, and one concrete forming additive overlaps another in the area where the concrete is constrained, generating tensile strength from both a macro and micro perspective.

[0060] The concrete forming additive tool 20 has three rod-shaped portions 11, 11, 11 formed at one end and the other end thereof with enlarged portions 12, 13 that are thicker than the three rod-shaped portions, the three rod-shaped portions being arranged in different directions from one another, and the middle portions of the three rod-shaped portions being connected and fixed together.

[0061] In the concrete structure of the second embodiment, a large number of concrete forming additives 20 (such as sand or gravel) are added to the concrete before it hardens.

[0062] The concrete forming additive tool 20 and concrete structure of the second embodiment can produce concrete that is strong against tensile force at low cost, and as a result, the strength against compression, shear, and bending (compressive strength, shear strength, and bending strength) is also improved, resulting in stronger national land and longer infrastructure lifespans, and providing convenience to users. This changes the common knowledge that concrete around the world is weak against tensile force to strong tensile force. It reduces or eliminates the materials and labor required for assembling rebar in reinforced concrete, thereby achieving performance that exceeds that of reinforced concrete. Such performance contributes to strengthening national land and is consistent with sustainable development.

[0063] <Various embodiments of concrete forming additives> Figure 5 shows a group of rod-shaped concrete forming additives, with Figure 5(a) showing a first embodiment of the concrete forming additive 10. Figure 5(b) shows a third embodiment of a hook-shaped concrete forming additive 51 with hooks formed on both ends of the rod-shaped portion. Figure 5(c) shows a fourth embodiment of a centipede-shaped concrete forming additive 52. Figure 5(d) shows a fifth embodiment of a faceted concrete forming additive 53.

[0064] Figure 6 shows a group of three-dimensional concrete forming additive tools, with Figure 6(a) showing a second embodiment of the concrete forming additive tool 20. Figure 6(b) shows a sixth embodiment of the wire brush ball-type concrete forming additive tool 54. Figure 6(c) shows a seventh embodiment of the bottle brush-type concrete forming additive tool 55. Figure 6(d) shows an eighth embodiment of the drum-type concrete forming additive tool 56.

[0065] 7A and 7B show a group of spiral concrete forming additive tools, with Fig. 7A showing a coil-type concrete forming additive tool 57 of the ninth embodiment, Fig. 7B showing a concrete forming additive tool 58 made of a shaving iron lathe-machined material of the tenth embodiment, and Fig. 7C showing a concrete forming additive tool 59 made of a thread-cutting material of the eleventh embodiment.

[0066] Figure 8 shows a group of plate-shaped concrete forming additives, with Figure 8(a) showing a washer-type concrete forming additive 60 of the twelfth embodiment, Figure 8(b) showing a flat bar-type concrete forming additive 61 of the thirteenth embodiment, Figure 8(c) showing a spring washer-type concrete forming additive 62 of the fourteenth embodiment, and Figure 8(d) showing a modified washer-type concrete forming additive 63 of the fifteenth embodiment.

[0067] 9A and 9B show a group of wire frame concrete forming additive tools, with Fig. 9A showing a wire frame wire ball type concrete forming additive tool 64 of the 16th embodiment and Fig. 9B showing a wire frame water wheel type concrete forming additive tool 65 of the 16th embodiment.

[0068] 10A and 10B show a group of curved concrete forming additives, with Fig. 10A showing an S-shaped concrete forming additive 66 according to an eighteenth embodiment, and Fig. 10B showing a fiber-assembled concrete forming additive 67 according to a nineteenth embodiment.

[0069] The concrete forming additives 51-67 of the third to nineteenth embodiments also produce concrete that is strong against tension, and as a result, the strength against compression, shear, and bending (compressive strength, shear strength, and bending strength) is also improved, resulting in stronger national land and longer infrastructure lifespans, and providing convenience to users. This changes the common knowledge that concrete around the world is weak against tension to strong tensile strength. It reduces or eliminates the materials and labor required for assembling rebar in reinforced concrete, thereby achieving performance that exceeds that of reinforced concrete. Such performance contributes to strengthening national land and is also compatible with connectable development.

[0070] Furthermore, the concrete forming adding tools 51 to 67 of the third to nineteenth embodiments can be used as they are in the manufacturing process, including ready-mix concrete plants, transportation, pumping, and pouring (pouring into the desired location). The concrete forming adding tools 51 to 67 of the third to nineteenth embodiments have increased strength due to the combined anchoring effect with other aggregates.

[0071] The sizes of the concrete-forming additives 51 to 67 shown in Figures 5 to 10 can be varied. For example, in the case of mass concrete used in dams, the larger the maximum diameter of the concrete-forming additives, the more advantageous it is. On the other hand, even if the size of the concrete-forming additives is microscopic, smaller than fine aggregate, by mixing additives with similar mechanical properties at the same time, the ranges of their effects overlap synergistically, and higher-strength concrete can be provided.

[0072] The concrete forming additive tools 51 to 67 shown in FIGS. 5 to 10 do not have to be a single tool, but rather a composite of coarse, fine and fine particles, which synergistically increases the strength.

[0073] In this case, the concrete forming additive tools 51 to 67 which are used as coarse, fine and fine (macro to micro) aggregates are mixed and the overlapping areas synergistically create tensile strength.

[0074] Concrete forming additives 51 to 67 are coarse, fine and minute concrete forming additives that are added to concrete before it hardens, and one concrete forming additive overlaps another in the area where the concrete is constrained, generating tensile strength from both a macro and micro perspective.

[0075] In the concrete forming adding tools 10, 20, 51 to 67 of the first to nineteenth embodiments, iron, aluminum, stainless steel, plastic, fiber reinforced plastic, etc. can be used as the material.

[0076] The definition of aggregate in the present invention includes the concrete forming adding tools 10, 20, 51 to 67 of the first to nineteenth embodiments, coarse aggregate, fine aggregate, and aggregate in general (including fine aggregate).

[0077] In the concrete structures of the first to nineteenth embodiments, both the concrete forming adding tool and conventional aggregate are used as aggregate, but it is also possible to use only the concrete forming adding tool as aggregate.

[0078] Surface treatments that can be used include burrs, knurling, chromium chrome, hot dip plating, etc. Surface finishes such as sandpaper can also be used to increase friction and adhesion.

[0079] The probability of cracking can also be reduced by using materials such as aluminum that have a similar expansion coefficient to concrete.

[0080] A viscous adhesive may be mixed into the cement paste itself before it hardens in concrete (by mixing and kneading the adhesive).

[0081] It is also possible to place concrete-forming additives of different diameters inside capsules that dissolve in water and mix them with cement paste.

[0082] Furthermore, in the first to nineteenth embodiments of the present invention shown in FIGS. 1 to 10, the size and material of the concrete forming additive tool and the concrete structure can be changed in various ways.

[0083] In this way, the structure, connections between components, chemical substances, and the like of the present invention can be modified in various ways without departing from the spirit of the present invention.

[0084] Materials can also be freely selected, including metal, plastic, FRP, wood, etc. For example, two or more members can be combined into one, or conversely, one member can be made up of two or more separate members and connected together.

[0085] Furthermore, the first to nineteenth embodiments are merely examples of the best mode or a mode close to it at present.

[0086] 1, 5, 7 Concrete structure 2 Cement paste 3 Aggregate 6 Crushed stone 10, 20, 51 to 67 Additive tool for concrete formation 10a, 10b Additive tool for concrete formation 11 Rod-shaped portion 12, 13 Expanded portion 14 Area that uses the compressive force inherent in concrete to resist tensile force 21, 22, 23 Swab-shaped member 30 Center portion

Claims

1. A concrete forming additive that is added to pre-hardened concrete, characterized in that one concrete forming additive overlaps another concrete forming additive in the area where the concrete is restrained, generating tensile strength.

2. A concrete forming additive to be added to pre-hardened concrete, characterized in that a rod-shaped portion has an enlarged portion at one end and the other end of the rod-shaped portion, the enlarged portion being thicker than the rod-shaped portion.

3. A concrete forming additive device to be added to pre-hardened concrete, characterized in that three rod-shaped portions are formed at one end and the other end with bulges that are thicker than the three rod-shaped portions, the three rod-shaped portions are arranged in different directions, and the middle portions of the three rod-shaped portions are connected and fixed together.

4. A concrete structure characterized in that the concrete forming additive according to any one of claims 1 to 3 is added to unhardened concrete.

Images