JPS6037262B2 - Manufacturing method of hollow concrete slag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a concrete flat plate having a hollow portion (hereinafter referred to as "hollow concrete slab").

Hollow concrete slabs are widely used for floors, ceilings, walls, roofs, etc. in building construction.

This slab is also used in bridges, ports, piers and other structures. Slabs used in this manner are generally reinforced with tendons of various types, such as steel strands or bamboo. In general, ``producing hollow concrete slabs requires huge concrete pouring machines;
Requires large investment of capital. The aim of the invention is to provide a method for producing hollow concrete slabs that does not require large pouring machines or capital investments and is competitive with products produced by these machines. Put simply,
The method for manufacturing hollow concrete slabs of the present invention includes the step of preforming an assembly consisting of a plurality of concrete channels having mutually parallel longitudinally extending cross sections approximately in the shape; The step of pouring concrete and forming the base layer; make sure that the hollow portion formed inside the channel forming the assembly is open downward, and that the lower green ends of both legs of the channel are at least as wide as above. contacting the basal layer and holding one or more of the assemblies in place on the basal layer with no gap between the lower edge and the basal layer; The concrete constituting the groove hardens to a certain extent, so that even if concrete is poured around the channel, the concrete will not penetrate into the longitudinally extending hollow portion formed by the channel and the base layer. A step of curing until the concrete is filled between and around the upper memory sections to a height that covers the upper surface of the channel sections with a predetermined thickness; Then, all of the concrete is completely cured. The concrete slab is cured until the concrete slab is completed.

The manufacturing method of the present invention uses an assembly consisting of a plurality of channel members that can be easily manufactured using a simple formwork as described above, and is used to manufacture a hollow concrete slab. Each groove is held in place on a concrete base layer cast in the formwork to allow some of the base layer concrete to harden, and then concrete is poured around the channel to form a concrete slab. A hollow section defined within the profile has the advantage that the desired shape can be reliably maintained.

A second aspect of the present invention relates to a method for manufacturing a large number of hollow concrete slabs at once as described above, in which an assembly consisting of a plurality of concrete channel members having a cross section extending in a mutually parallel longitudinal direction and having a shape of approximately Step of forming a plurality of pieces; Step of pouring concrete to a predetermined depth in an appropriate formwork and thereby forming a base layer: The hollow portion formed inside the channel members constituting the above assembly faces downward. The plurality of assemblies are attached to the plurality of assemblies such that the lower edges of the legs of the channels are in contact with at least the base layer and there is no gap between the lower edges and the base layer. longitudinally aligned in the formwork, i.e. the channels of adjacent assemblies are aligned longitudinally in a line with as few gaps as possible between them, and at a predetermined position on the base layer; The step of holding the concrete constituting the base layer to a certain extent, so that even if concrete is poured around the channel, the longitudinal length formed by the channel and the base layer is A step of curing until the concrete does not penetrate into the hollow portion extending in the direction; Filling concrete between and around the channel members to a height that covers the upper surface of the channel members to a predetermined thickness. A stage of curing until all the concrete is completely hardened to complete a longitudinally long concrete slab assembly; and after removing the formwork from the concrete slab assembly, the concrete slab assembly is lengthened to a predetermined length. and cutting the plurality of concrete slabs into predetermined lengths to produce a plurality of concrete slabs.

The present invention will be further described below with reference to the drawings.

The method according to the present invention is used for manufacturing synthetic hollow concrete slabs 1, which have a relatively high moment of inertia despite having a relatively low weight per unit area, and are resistant to loads and scale sections. It has a fairly large resistance to force.

In addition, mild steel reinforcement and/or prestressed tendons (steel elements placed in concrete for reinforcement)
It also has the advantage of being able to add By the way, in the conventional method, individual relatively thin concrete channel members 2 as shown in FIG. 1 were used to manufacture the slab 1. This channel member 2 is preformed using a suitable mold 3 as shown in FIG. Generally, the channel 2 is made of concrete of the same composition as the concrete used to make the slurp, but this concrete can be of a different type if desired. When shaping the channel 2, a string ring 4 made of a suitable wire is partially implanted into the channel 2 for convenient subsequent handling. The channel profile 2 is formed well before it is incorporated into the slab 1, so that the channel is sufficiently hardened so that there is little damage during handling.
The curing time of this channel member 2 is generally set not to exceed 2 hours. By the way, concrete slabs are generally manufactured to a width such that two or more channel members 2 are arranged side by side with an increased interval in the lateral direction. Therefore, in the past, it took a long time to arrange such channel members 2 at predetermined positions in the formwork, but FIG. [Four channels of shape 2
An assembly 5 consisting of:

Although not shown in this figure, the assembly 6 is formed as an integral continuous body using a suitably shaped mold. Thus, in the illustrated embodiment, a pair of laterally extending longitudinally spaced continuous rods 6 are cast into the web of the channel 2 forming the assembly. It is preferred that the rods 6 project outwardly beyond the outer ends of both sides of the channel 2 of the assembly 5 for reasons explained below. This rod 6 is preferably made of metal and maintains the channel 2 in the desired positional relationship. Furthermore, this will provide a convenient means for handling the assembly 5 in a damage-free manner after the channels have sufficiently cured. Haru S
It also acts as a lateral reinforcement of the slab 1 when the slab is completed, increasing its strength against lateral stresses. Slab 1 is a suitable rectangular side plate 7 and bottom plate 8
It is created using a formwork consisting of.

Like the inner surface of the base plate 8, the inner surface of the side plates 7 is coated with a suitable mold release agent. After coating the side panels 7 and the base 8 with a release agent, - the concrete is poured approximately horizontally into the formwork to form a relatively thin base layer 9;

The channels 2 are then arranged with the legs or flanges facing downwards in the mold over the base layer 9, as schematically shown in FIG. Means for supporting the channel shape, in the illustrated embodiment recesses engaging the ends of the bar 6, are intended to "support the ends of the bar 6 to prevent the channel 2 from sinking too deeply into the base layer 9 of concrete. This recess is shown in Figures 4 and 6.
As shown in the figure, the depth at which the lower green end of the groove-shaped flange provided on the side plate 7 of the formwork penetrates into the base layer 9 is adjusted. The lower edge of the flange of the channel must be at least in contact with the base layer 9 over its entire length, preferably slightly wedge-shaped into the base layer. Although not shown, the concrete may be vibrated to obtain the required sinking depth. After the assembly 5 is properly positioned on the base layer 9 of concrete, the base layer concrete is now allowed to cure to a suitable hardness, and then the concrete is molded in order to form the upper layer 11 thereon. Fill inside.

When filling the lateral gaps between the channel members 2 with concrete, care must be taken to ensure good adhesion to the base layer. The bottom green of the flange of Mizogatamura 2 and the base layer 9 are at least in contact with each other so that there is no gap between them, so while pouring concrete to form the upper layer 11, the tip of the flange This prevents concrete from flowing into the hollow area inside the channel. The concrete channel 2 does not float in the concrete that is later poured to surround it.
It becomes a structural part of the slab 1, and structurally becomes a member that resists various stresses by integrating with the concrete poured around it. FIG. 5 shows the slab after the top layer 11 has been cast to approximately the level of the upper end of the side plate 7 of the formwork and the upper surface of the channel web has been covered to the required depth. After a suitable curing time has elapsed, the side plates 7 of the formwork are removed from the slab to complete the slab. As can be seen from FIG. 5, the groove shapes 2, when incorporated into the slab 1, form an immovable core, whereby the slab 1 consists of laterally spaced, longitudinally extending, usually rectangular It is provided with a hollow portion, that is, a passage turtle 2.

This reduces the weight of the slab. When the slab 1 is used as a structural member of a building, this hollow portion, that is, a passage, can be used as a passage for electrical wiring pipes, heating ducts, pipes, electric wires, and other members. If within 2 hours after the assembly of the channel 2 has been formed, the channel has not fully set and the base layer 9 of the concrete poured around the channel 9 may be particularly damp if damp. And the adhesive strength to the channel member 2 is improved. However, it is not critical that the channel 2 and the concrete poured adjacent thereto are bonded. Because channel member 2
This is because it has desired structural properties even in the unbonded state. Even if there is no adhesion between the channel material 2 and the concrete poured between them, there is a relatively large surface with high frictional resistance between the channel material and the poured concrete, so that It is thought that it is difficult for slips to occur between the two. However, if necessary, mechanical hooking means may be provided on the sides of the channel 2. That is, it is preferable to provide a number of recesses, such as grooves 13, spaced apart in the longitudinal direction (FIG. 13), and further mechanically fix the channel members 14 to the concrete poured therebetween. . The method of the present invention requires equipment for lifting and moving the assembly 5 as well as the finished slab.

Equipment for pouring concrete is also required at the site where the assembly 5 of channels 2 as well as the slab is manufactured. However, the method of the present invention does not require the large and expensive machinery typically used to make conventional concrete slabs. FIG. 7 shows an assembly consisting of a plurality of channel members 2 as shown in FIG. FIG. 3 is a plan view of a state in which solid bodies 5 are arranged.

When producing such a long-span concrete slab assembly, the length of the slab 1 is determined by the spacing of the laterally extending weir plates 15 inserted into the formwork 16. Alternatively, the concrete slab assembly can be formed continuously without inserting the weir, and then the concrete slab assembly can be cut or sawed to the required length. FIG. 8 is a plan view of another embodiment of the arrangement of an assembly consisting of channels 2 of a sprue for manufacturing a long span concrete slab assembly IJ. The concrete slab assembly manufactured in this manner can be cut into a predetermined length to produce a plurality of concrete slabs, or can be used as it is as one long span concrete slab without being cut. In that case, the gaps 17 located between the longitudinally aligned channels 2 are injected to form the upper layer 11, unless a continuous hollow or passageway 12 for electrical wiring pipes etc. is required. It is not a big problem even if the concrete falls and blocks the passage or dams it up. Furthermore, even if only a relatively large amount of concrete falls from the gap 17 into the area of the passage 12,
As a result, the passage can be used as is for passing members such as electrical wiring pipes. In order to minimize the fall of concrete from the gap 17 when pouring the upper layer 11,
Adjacent ends of the channel 2 can be provided with relatively thin longitudinally projecting portions 18 . It extends horizontally over the entire width of the passageway or hollow section 12. Projecting portions 18 at both ends of the longitudinally aligned channels 2 are generally provided, as shown in FIG. 9, in order to prevent concrete from falling into the gaps 17 when pouring the upper layer 11. Bring to a butt or a state close to a butt. As a result, the passage 12 continues through the gap 17, and the resulting long passage can be used for electrical wiring pipes, etc. The method of the invention also contemplates including within the slab 1 optionally longitudinally extending metal reinforcing bars 19.

The reinforcing bars 19 are generally placed in the concrete that is poured between adjacent groove shapes 2 and at the bottom of the groove shapes, as shown in FIG. The reinforcing bars 19 consist of mild steel reinforcing bars or prestressed strands or steel rods. FIG. 11 shows an example of the use of a concrete slab manufactured by the method of the present invention.

A large number of slabs 1 are layered in parallel as shown to form a floor or deck. The hollow portion in the slab, ie, the portions at both ends of the passage 12, can be closed with mortar if there is no need to pass parts such as electrical wiring pipes. 1st
Figure 2 shows another example of how to join adjacent concrete slabs. Longitudinal heel-shaped protrusions 21 provided at the bottom of both sides of the slab are placed adjacent to each other in an abutting relationship. The adjacent slabs 1 are
A cavity 22 for filling with grout is formed directly above these heel-shaped protrusions 21. This space 22 is shown in Figures 4 and 5.
As shown in the figure, it is formed by longitudinally extending protrusions 23 provided centrally inwardly on both sides of the side plates 7 of the formwork. Adjacent slabs forming the floor or deck are connected and fixed by filling the cavities 22 with a suitable grout 24. Further, referring to FIG. 12, during or after forming the slabs 1, the ends of the aligned fins 6 of adjacent slabs 1 are exposed and strained so that their upper surfaces are exposed, and the corresponding trailing fins 25 are applied. The aligned rods 6 are shown straddled and welded to their respective ends.

The result is to provide a continuous reinforcing element across the width of the floor that is more resistant to lateral stresses applied to the structure. Grout or other suitable filler is used to fill the recess in the floor into which splice rod 25 is installed. Hollow concrete slabs are of course manufactured in various thicknesses.

Probably in the range of 10.2 to 30.5 arcs, depending on the expected shear forces and other loading conditions. Although the width of the slab 1 can be made arbitrarily, a size up to about 120 mm is preferable for ease of handling. Assuming that the scale conditions and other loading conditions require a slab thickness of 20.3 cm, the basal layer 9 will be 3.81 cm thick.
For a slab with a thickness of 20.3 mm, the channel 2 has a width of 22 mm.
5 skin, depth is 15.9c. The thickness of the web of groove shape 2 is 1.90 mm. The thickness of each flange is 2.54c at the position adjacent to the web, and the thickness is 1.
．． The lower end of 90c slopes toward the green side. thickness 2
In a slab with a 0.3 skin width of 120c, four groove-shaped villages 2 are arranged on the base layer at 6.98c intervals from each other in the lateral direction. The channel 2 in the 20.3 cm thick slab is held within the base layer 9 by a depth of 1.27 mm. When the concrete for the upper layer 11 is poured in this way and is cast over a slab 1' of thickness 20.3, the web of channel 2 is covered to a depth of about 2.54 skin. be exposed. Since the lower edge of the flange extends approximately 1.27 skins into the basal layer 9, the approximately rectangular hollow portion 12 in the slab of 20.3 arcs is approximately 12.
It has a cross-sectional dimension of 7 skins x 17.8 skins. For example, if scale loads are not a determining factor in the design, such as when the slab is used for wall construction, the thickness of the web of the channel 2 and the upper layer 11 above the web may be The sum of the thicknesses can be approximately equal to the thickness of the base layer 9. If rock loading is not an issue, this ratio is probably the best because it causes the hollow section or passageway 12 to be located approximately in the center of the top and bottom surfaces of the slab.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional precast concrete channel used in hollow concrete slabs. 2 is a partial perspective view of a formwork for forming the concrete channel of FIG. 1; FIG. FIG. 3 is a perspective view of an assembly of multiple concrete channels according to the present invention. FIG. 4 is a cross-sectional view of a formwork for making a hollow concrete slab, illustrating one stage of the method of the invention in which the assembly of FIG. 3 is placed in contact with a concrete base layer. FIG. 5 is a diagram similar to FIG. 4, but
Figure 6 shows another step in the process of pouring concrete into the formwork according to the invention; FIG. 6 is an enlarged view showing an assembly of channels supported in the formwork; FIG. FIG. 7 is a plan view of a formwork for manufacturing a relatively long span concrete slab assembly with longitudinally arranged assemblies of multiple slabs. FIG. 8 is a view similar to FIG. 7 showing a state in which adjacent channel members are arranged in a staggered relationship in the longitudinal direction. 9th
The figure is an enlarged cross-sectional view of a gap between longitudinally aligned channels. FIG. 10 is an end view of the completed concrete slab. FIG. 11 is a perspective view showing a number of slabs connected laterally in sequence to form a floor or deck. FIG. 12 is an enlarged cross-sectional view taken along line 12--12 of FIG. FIG. 13 is an enlarged perspective view of another embodiment of the channel member used in the method of the present invention. 1...Hollow concrete slab, 2...
... Channel material, 3 ... Formwork, 5 ... Assembly consisting of a plurality of groove shapes, 6 ... Connection rod, 7.
...Side plate of formwork, 8...Base of formwork, 9
... Basal layer, 10 ... Concavity, 11 ...
... Upper layer, 12 ... Hollow part, 19 ...
...Metal reinforcement. Genta・Buru・” Kota・2 Blue, 3 Komono・Puta, Ekoaki・6 Genta・Z Blue, d”ヱ,. "〇pu hakama, ZZ hole soreburu" i

Claims (1)

[Claims] 1. A method for manufacturing a concrete slab having hollow portions extending in mutually parallel longitudinal directions, the method comprising a plurality of concrete channel members each extending in mutually parallel longitudinal directions and having an approximately ■-shaped cross section. The step of pre-forming the assembly; the step of pouring concrete to a predetermined depth in a suitable formwork to form the base layer; the hollow portion formed inside the channel forming the above assembly faces downward; one or more of the assemblies so that they are open and the lower edges of both legs of the channel are in contact with at least the base layer, and there is no gap between the lower edges and the base layer; Holding the three-dimensional object in place on the base layer; the concrete constituting the base layer hardens to some extent, so that even if concrete is poured around the channel, the channel and the base layer A step of curing until the concrete does not seep into the longitudinally extending hollow portion formed by the grooves; and filling the surrounding area with concrete;
and curing until all of the concrete is completely hardened to complete the concrete slab. 2. In the method of manufacturing a concrete slab according to claim 1, the step of holding the assembly in place on the base layer is performed before the assembly is sufficiently hardened. A method for manufacturing a concrete slab, wherein the concrete slab is held in a predetermined position on the base layer in the above state, whereby the channel forming the assembly and the surrounding concrete are integrally bonded. 3. In the method for manufacturing a concrete slab according to claim 1, the step of pre-forming the assembly is performed using concrete of the same composition as the concrete of the remaining part of the concrete slab to be manufactured. A method of manufacturing concrete slabs that involves forming an assembly. 4. In the method for manufacturing a concrete slab according to claim 1, the step of preforming the assembly includes connecting and fixing a plurality of channel members with a connecting rod extending in the horizontal direction;
A method for manufacturing a concrete slab, thereby increasing the resistance to stress applied in the lateral direction of the slab. 5. In the method for manufacturing a concrete slab according to claim 4, the step of connecting and fixing a plurality of channel members with connecting rods extending laterally includes the step of connecting and fixing a plurality of channel members by connecting rods such that both ends of the connecting rods constitute the assembly. connecting and fixing a plurality of channels so as to project outwardly from each outermost edge of the outermost channel of the channel formation; and positioning the assembly at a predetermined position on the base layer. manufacturing a concrete slab, wherein the step of retaining the assembly comprises retaining the assembly by engaging a protrusion of the connecting rod within a recess provided in a slab-forming form. Method. 6. The method of manufacturing a concrete slab according to claim 1, wherein the step of preforming the assembly is such that recesses are provided at longitudinally spaced intervals on the outer surface of the channel. A method for manufacturing a concrete slab, in which the assembly is formed by molding the groove, thereby strengthening the bond between the channel member and the surrounding concrete. 7. In a method for manufacturing a concrete slab having a hollow portion extending in a mutually parallel longitudinal direction, a plurality of assemblies consisting of a plurality of concrete channel members each extending in a mutually parallel longitudinal direction and having a cross section approximately in the shape of a square are prepared in advance. Forming step; Step of pouring concrete to a predetermined depth in a suitable formwork long in the longitudinal direction, thereby forming the base layer; Hollow portions formed inside the channels constituting the above assembly are a plurality of the assemblies, such that the lower edges of both legs of the channel members are in contact with at least the base layer, and there is no gap between the lower edges and the base layer; longitudinally aligned within said formwork and held in position on said base layer; the concrete constituting said base layer being allowed to harden to some extent, whereby said channel member A step of curing until the concrete does not intrude into the longitudinally extending hollow portion formed by the channel member and the base layer even if concrete is poured around the channel member; filling concrete between and around the channels to a predetermined coating height; curing until all concrete is completely cured to complete a longitudinally elongated concrete slab assembly; and after removing the formwork from the concrete slab assembly,
A method for manufacturing a concrete slab, comprising: cutting the concrete slab assembly into a predetermined length to manufacture a plurality of concrete slabs. 8. In the method for manufacturing a concrete slab according to claim 7, the step of filling concrete between and around the channel members is performed by adding a weir plate between adjacent longitudinally aligned assemblies. A method for manufacturing a concrete slab, which comprises filling concrete with an intervening material, thereby facilitating cutting of the concrete slab assembly.