JP3515102B2 - Formwork holding bracket - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate made of a steel plate such as a mold spacing metal fitting and a stepped mold spacing metal fitting having at least one portion for holding a mold. In particular, the present invention relates to a mold holding metal fitting of a type in which a base, a locking portion, and the like protruding outside a concrete foundation are cut and removed after concrete is poured. 2. Description of the Related Art As shown in FIG. 1, a form-spacing holding member 11, which is an example of this type of form-holding member, has a long plate-shaped base portion 12 and stands upright at both ends in the longitudinal direction. A pair of locking pieces 13, and a pair of positioning projections 14, which are locking pieces erected opposite to each other at a predetermined distance from the locking piece 13 at the base 12, It is formed by subjecting a normal steel plate to press working, punching, and the like. Then, as shown in FIG. 2, for example, a nail is driven into a mounting hole 12 a provided in the base 12, and the nail is fixed to the base G. The base formwork 16 is fitted and arranged to be vertically opposed to each other. Further, the bending groove 13a of the locking piece 13 is bent inward to fix the basic form 16 so that the form spacing metal fitting 11 can hold each basic form 16 at a predetermined interval. [0003] Further, in the form spacing metal fitting 11, a bent groove 12 b is provided in the base 12 at a position outside the positioning projection 14, and after the concrete is cast, it is exposed to the outside of the concrete foundation K to perform work. It is possible to cut and remove a part of the base 11 which obstructs the operation. Then, in a state where the foundation form 16 is erected on both sides of the form spacing metal fitting 11, concrete is poured between the forms, and after drying, the form is removed and the concrete foundation K is formed. Thereafter, the base 12 protruding outside the concrete foundation K is bent by the bending groove 12b and cut and removed. [0004] This type of mold holding metal fitting is used in large quantities in forming a concrete foundation, and is often embedded or disposable in concrete, so that it is necessary to be inexpensive. Normal steel plates are used. However, there is a concern that the form holding metal fittings may be rusted by being buried in the ground, thereby lowering the durability of the concrete foundation. In order to prevent such rust, a form holding metal fitting is formed using a steel plate whose surface is coated with inexpensive zinc or the like. However, as a result of press working, punching, and the like being performed on the steel sheet to form the mold holding metal, there is a problem that the steel base is exposed on the surface of the steel sheet after the processing, and rust is generated from the exposed portion. [0005] On the other hand, after forming a frame holding metal by press working and punching, zinc plating or the like is performed on the surface thereof. However, since plating must be performed for each individual product, there is a problem in that the cost of the mold holding bracket is increased. Further, even if plating is performed after the formation of the metal fittings, the mold space holding metal fittings 11 themselves are covered with a zinc plating layer or the like.
The steel material is exposed at the cut portion by the bent groove 12b, and rust is generated from the cut portion while being left in the ground. Therefore, corrosion progresses while the form spacing metal fitting 11 is left in the ground for a long time, and as a result,
The durability of the concrete foundation may be impaired. Further, in order to cope with the occurrence of such rust, it is sufficient to form the form holding metal fittings from stainless steel. However, there is a problem that the price is several times more than the price of the metal plate metal fittings. is there. As a plating applied to a steel sheet, ZAM (manufactured by Nissin Steel Co., Ltd.) containing zinc (Zn), aluminum (Al) and magnesium (Mg), which has been recently developed, is known. As the composition ratio of ZAM,
Molten Zn-Al-Mg consisting of aluminum 6% by weight, magnesium 3% by weight, balance being zinc and unavoidable impurities
It is a plating layer. When a steel sheet having a plating layer using ZAM is cut, a steel base is exposed on the cut surface, but zinc, aluminum, and magnesium are dissolved from the plating layer by the plating layer being wetted by rain, dew, or the like. There is a property that a dense magnesium-containing zinc-based protective coating covers the exposed end face of the steel sheet. This prevents the progress of corrosion of the steel sheet. The inventor of the present invention pays attention to such excellent corrosion resistance of ZAM, and is formed by subjecting a steel plate to press working, punching, and the like, and is exposed to the outside of a concrete foundation after placing concrete. ZAM is applied to the plating layer of the form-holding bracket made of ordinary steel plate whose base is cut off.
Tried to apply. As a result, it was confirmed that the progress of corrosion from the cut surface of the form-holding metal fitting was prevented and the durability of the concrete foundation was enhanced, and the present inventor has arrived at the present invention. [0008] That is, the present invention provides:
In order to solve the above-mentioned problem, corrosion does not progress inside the exposed portion of the steel base such as a pressed portion, a punched portion or the like of a steel plate, and the long-term durability of the concrete foundation is secured. It is an object of the present invention to provide a mold holding metal fitting which can be used. [0009] In order to achieve the above object, the structural features of the invention according to claim 1 include an elongated base portion,
At least one end of the base and at least one pair of locking pieces that are vertically erected integrally with the base at positions facing the one end and face each other, and are fitted and arranged between the pair of locking pieces. In a formwork metal fitting made of ordinary steel sheet which holds a frame and forms a concrete foundation by the moldwork, a 6% by weight of aluminum, 3% by weight of magnesium, and the balance consisting of zinc and inevitable impurities are formed on the surface of the ordinary steel sheet. Zn-
An Al-Mg plating layer is formed, and further, a base groove or a locking piece that can cut a protruding portion of the base or the locking piece that protrudes outside from the concrete foundation formed using the formwork. It has been established in. As a composition ratio of zinc, aluminum and magnesium, 91% of zinc
Aluminum 6% -magnesium 3% is preferable, but the composition ratio may slightly fluctuate. [0010] In the first aspect of the present invention, the form is fitted between the pair of locking pieces of the form holding metal fitting, concrete is poured between the forms, and after the concrete is dried. The concrete foundation is formed by removing the formwork. Here, the form-holding metal fitting is formed by subjecting a normal steel plate to press working, punching, or the like, and the steel base is exposed at the cut portion after the working. Also,
Since the projecting part of the formwork bracket that protrudes from the concrete foundation interferes with work, etc., provide a bent groove,
It may be cut and removed in the bending groove, thereby exposing the steel base to the cut portion. However, a molten Zn-Al-Mg plating layer composed of 6% by weight of aluminum, 3% by weight of magnesium, and the balance of zinc and unavoidable impurities is formed on the surface of the steel material of the mold holding metal from the beginning.
Therefore, when the molten Zn—Al—Mg plating layer is wetted by rain, dew, or the like, zinc, aluminum, and magnesium dissolve out of the plating layer, and the exposed surface of the steel substrate is covered with the dense magnesium-containing zinc-based protective coating. .
This prevents the progress of corrosion from the exposed surface of the steel base. The cost of forming the hot-dip Zn—Al—Mg plating layer is equivalent to that of ordinary hot-dip galvanizing, etc., and the plated metal frame holding metal is significantly larger than the stainless steel metal frame holding metal. Will be cheaper. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the above-described mold spacing support metal 11 which is an example of a mold supporting jig. The structure of the mold spacing metal fitting 11 is as described above, and the molten Zn—Al—Mg having a composition ratio of 6% by weight of aluminum, 3% by weight of magnesium, and the balance of zinc and unavoidable impurities is formed on the entire surface.
It is formed by subjecting a steel plate on which a plating layer is formed to press working, punching, and the like. Then, as shown in FIG. 2, in a state where the foundation formwork 16 is erected on both sides of the formwork spacing metal fitting 11, concrete is poured into the formwork, the formwork is removed after drying, and the concrete foundation is removed. K is formed. Thereafter, the base 12 and the locking piece 13 projecting to the outside of the concrete foundation K are bent into the bent groove 12.
The steel material is exposed at the cut surface of the base 12 by being cut and removed by bending at b. In addition, the form spacing metal fitting 11
Is formed by subjecting a normal steel plate to press working, punching, and the like, and the steel base is also exposed at the cut portion after the working. However, since the form spacing metal fitting 11 is covered with the molten Zn—Al—Mg plating layer,
The molten Zn—Al—Mg plating layer is wetted by rain, dew, and the like, so that zinc, aluminum, and magnesium dissolve out of the plating layer, and the exposed surface of the steel base has a high corrosion-resistant dense magnesium-containing zinc-based protection. Covered with a coating.
Therefore, the progress of corrosion from the exposed surface of the base material of the steel base 12 is prevented. As a result, even if the form spacing metal fitting 11 is left in the ground for a long time, the corrosion does not progress, the durability of the concrete foundation is secured for a long time, and the housing provided on the concrete foundation is provided. And the like, the reliability of the building is improved. The cost of forming the hot-dip Zn—Al—Mg plating layer is equivalent to that of ordinary hot-dip galvanizing or the like. And become significantly cheaper. Therefore, the burden on the cost due to the use of the molten Zn—Al—Mg plating layer is very small. FIG. 3 shows another example of a formwork holding fixture, a stepped formwork spacing holding jig (hereinafter referred to as a "step") which is a formwork holding fixture used for stacking and fixing a mold in two stages. (Referred to as a separator) is shown in a perspective view. The step separator 21 has a long plate-shaped base 22 having a predetermined width, and a rectangular end portion protruding at one end in the width direction at both ends and the center in the longitudinal direction at right angles to the base 22. Pieces 23a, 23
b and the intermediate locking piece 23c, and an end member having the same shape protruding in the opposite direction to the end locking pieces 23a, 23b and the intermediate locking piece 23c at the other end in the width direction with the base 22 interposed therebetween. Stop pieces 25a, 25b and intermediate locking piece 25c are provided integrally. The end locking pieces 23a, 23b and the intermediate locking piece 23c are rectangular plates, and the length of the intermediate locking piece 23c in the longitudinal direction is longer than that of the end locking pieces 23a, 23b. Between the end locking pieces 23a and 23b and the intermediate locking piece 23c, there are formed frame insertion portions 24a and 24b which are spaces for inserting the lower or upper mold frames 17 and 18.
Also, between the end locking pieces 25a, 25b and the intermediate locking piece 25c, a form fitting portion 26 for fitting the forms 17, 18 is formed.
a, 26b. The base portion 22 is provided with bent grooves 22a and 22b extending between both ends in the width direction at both ends in the longitudinal direction of the intermediate locking pieces 23c and 25c. This step separator 21 has the above-mentioned molten Zn-Al-Mg
Pressing, punching and the like are performed on the steel sheet on which the plating layer is formed. The use state of the step separator 21 will be described. As shown in FIG. 4, the form spacing metal fitting 11 is placed on the base concrete G with the vertical and horizontal reinforcing bars 28 interposed therebetween, and is fixed by driving a nail into a mounting hole of the base 12. A pair of lower molds 17 are respectively inserted and erected between a pair of locking pieces 13 erected on the base 12 of the mold space holding bracket 11 and the positioning projections 34. A pair of lower molds 17 is provided with a step separator 21.
Are fitted by fitting them in the form fitting portions 26a and 26b. A pair of upper molds 18 are inserted into the mold insertion portions 24 a and 24 b of the stepped separator 21 and are stacked on the lower mold 17. Further, the above-mentioned formwork space holding bracket 11 is attached to the upper ends of the pair of upper formworks 18 to maintain the space between both upper formworks 18. Concrete is poured between the opposing surfaces of the upper and lower molds 17 and 18 assembled in this way, and after drying, the upper and lower molds 17 and 18 are removed to form a concrete foundation K as shown in FIG. . After that, the base 22 of the step separator 21 projecting outside the concrete foundation K and the form spacing metal fitting 1
One base 11 is bent and cut and removed in the bending grooves 22a and 22b and the bending groove 12b. Thereby, the steel material is exposed at the two cut surfaces of the base 22 and the base 12. Further, the step separator 21 and the form-spacing holding fitting 11 are formed by subjecting a normal steel plate to press working, punching work, or the like, and the steel base is exposed at a cut portion after the working. However, the surfaces of the step separator 21 and the mold spacing metal fitting 11 are covered with the above-mentioned molten Zn—Al—Mg plating layer. Aluminum and magnesium elute, and the exposed surface of the steel material is covered with a dense magnesium-containing zinc-based protective coating having high corrosion resistance. Therefore, the progress of corrosion from the exposed portions of the various steel bases in the step separator 21 and the form spacing metal fitting 11 is prevented. As a result, even if the step separator 21 and the form spacing metal fitting 11 are left in the ground for a long time, corrosion does not progress, and the durability of the concrete foundation is secured for a long time. Further, the point that the burden on cost due to the use of the molten Zn—Al—Mg plating layer is very small is the same as that described in the above embodiment. In each of the above embodiments, the plating layer is a molten Zn—Al—Mg plating layer having a composition ratio of 6% by weight of aluminum, 3% by weight of magnesium, and the balance of zinc and unavoidable impurities. (Manufactured by Nissin Steel Co., Ltd.) is used, but even with a plating layer whose composition ratio is changed within a range of about several percent, the same effect can be obtained for the above corrosion prevention. Further, in each of the above embodiments, as the form holding metal, the form space holding metal and the step separator are shown, but other similar forms such as a semi-separator in which the form space holding metal is cut at an intermediate position in the longitudinal direction. The present invention can be similarly applied to them. In addition, the form holding metal fittings described in the above embodiments are merely examples, and various modifications can be made without departing from the gist of the present invention. According to the present invention, molten Zn—Al— containing 6% by weight of aluminum, 3% by weight of magnesium, and the balance of zinc and unavoidable impurities is formed on the entire surface of the mold holding metal.
Since the Mg plating layer, for example, the plating layer with the trade name ZAM, is formed, the exposed portion of the steel base such as the cut portion where the form holding metal is pressed or punched is reliably protected by the plating layer. Is done. As a result, in the present invention, the progress of corrosion of the steel base is prevented, the long-term durability of the concrete foundation is ensured, and the reliability of the building erected on the concrete foundation is enhanced. According to the present invention, the molten Zn-Al-Mg
The cost of forming the plating layer is equivalent to that of ordinary hot-dip galvanizing or the like, and there is an advantage that the burden on cost is very small.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing a form spacing metal fitting according to an embodiment of the present invention. FIG. 2 is a front view schematically showing a use state of a mold space holding bracket. FIG. 3 is a perspective view schematically showing a step separator. FIG. 4 is a front view schematically showing a use state of the step separator before placing concrete. FIG. 5 is a front view schematically showing a use state of the step separator after casting concrete. [Description of References] 11: Form spacing metal fitting, 12: Base, 12b: Bending groove, 13: Locking piece, 14: Positioning projection, 16: Form,
17 lower mold, 18 upper mold, 21 step separator, 22 base, 22a, 22b bent groove, 23a,
23b: End locking piece, 23c: Middle locking piece, 24a, 2
4b: Form insert portion, 25a, 25b: End locking piece, 25
c: Intermediate locking pieces, 26a, 26b: Form insert portions.

Claims (1)

(57) Claims 1. An elongated base, and at least one end of the base and a position opposed to the one end, which are vertically vertically integrated with the base and integrally opposed to each other. A mold holding metal fitting made of ordinary steel sheet having at least a pair of locking pieces to hold a form fitted between the pair of locking pieces, and forming a concrete foundation by the form. On the surface of the ordinary steel sheet, molten Zn-Al- containing 6% by weight of aluminum, 3% by weight of magnesium, and the balance consisting of zinc and unavoidable impurities.
An Mg plating layer is formed, and a bent groove is formed on the base or the locking piece, which can cut the protruding portion of the base or the locking piece that protrudes outside from the concrete foundation formed using the formwork. Formwork holding fittings provided on one piece.