JPH04108943A - Manufacturing method of cylindrical block - Google Patents

Abstract

PURPOSE:To improve strength of a cylindrical block by forming a heaped-up portion of extra concrete before the concrete becomes hard, and by removing the heaped-up concrete portion outside together with a formwork. CONSTITUTION:A formwork 14 is assembled by erecting a side plate 1 and an end plate 2 on a base stand 13 to form an outer mold and jointing and clamping the bottom frame 8 of a medium mold 5 thereon. A concrete 16 is then poured into a hollow portion 15 in the formwork 14 while being vibrated and compacted. The bottom frame 8 is removed from the formwork 14 after elapse of 10 to 20 minutes from completion of concrete pour in. A heaped-up portion 19 is formed by pouring an excessive amount of mortor 18 into the exposed portion. The bottom frame 8 is pushed in the horizontal direction to push out the heaped-up portion 19 outside of the formwork 14. Lastly the bottom frame 8 is secured to the medium mold 5 and the concrete 16 in the formwork 14 is hardened. Air bubbles and foams generated on the bottom surface portion of a medium mold 8 are then removed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for manufacturing cylindrical concrete blocks such as Bosokskalcha-1.

(Prior Art) A mold for manufacturing a cylindrical block includes a box-shaped outer mold and a cylindrical middle mold mounted in the middle of the outer mold. In a formwork in which a medium size is installed horizontally, a space is formed between the bottom of the medium size and the bottom of the outer mold, and the concrete flowing into this space (in this specification, this includes mortar) When the air, excess water, cement paste, sand, etc. contained in the
Its discharge is blocked by the bottom surface of the medium size, and large air bubbles and water bubbles are formed in the area in contact with the bottom surface of the medium size, increasing the slump value of the concrete in this area. If the concrete solidifies in this state, a layer 10 as shown in FIG. 4 will be formed on the inner surface of the molded cylindrical block, significantly degrading the quality of the product.

As one method to solve this problem, a medium-sized formwork with a ventilated bottom surface has been proposed. FIG. 3 is a diagram showing an example of such a formwork, and includes an outer mold 3 in which the side plate 1 and the end plate 2 are provided so as to be freely openable and closable, and a middle mold that is inserted into the through hole 4 of the end plate and installed horizontally. 5. Medium size 5 is
A bottom frame 8 forming the bottom surface and an opening 6 to which the bottom frame is attached
It is divided into a gate-shaped frame 7 and a gate-shaped frame 7. Cylindrical block 9
is formed by pouring concrete into a horizontal cylindrical cavity formed when the outer mold and middle mold are assembled. The middle mold 5 is removed from the molded block by removing the bottom frame 8 and squeezing the portal frame 7.

The molding surface of the bottom frame 8 is formed of a punched metal 11 provided with a large number of ventilation holes, and a fabric 12 is attached to the outside of this punched metal during molding. Air bubbles and water bubbles generated on the bottom surface of the medium mold 8 are discharged through the grain of the cloth 12 and the perforations of the punching metal 11, so that the generation of latar 10 as shown in FIG. 4 is prevented. It is.

(Problems to be Solved by the Invention) A method using a formwork having a structure as shown in FIG. 3 is considered to be the best method for preventing the formation of craters on the inner surface of a cylindrical block. 7 However, when molding is performed using a formwork with the above structure, water in the concrete in the part that contacts the bottom frame 8 is excessively removed, and a brittle layer with roughened Mi weave is formed in that part. After the area loses its fluidity, the water that has risen from below remains in the lower part of the fragile layer, causing the concrete to solidify. As a result, the surface formed by the bottom frame 8 becomes a rough surface, and craters hidden under the roughened brittle layer reduce the strength of the block, and when an impact is applied, the brittle layer collapses and creates a crater. The problem was that it appeared.

The present invention aims to solve the above problems,
The object of the present invention is to provide a method that can prevent the formation of craters and brittle layers in the lower part of horizontally mounted medium-sized blocks, and can therefore produce cylindrical blocks with high strength and excellent surface properties. There is.

(Means for Achieving the Object) The method of the present invention provides a formwork comprising an outer mold 3 and a cylindrical middle mold 5 mounted horizontally on the outer mold, the middle mold 5 being attached to the bottom surface. This is adopted for molding a cylindrical block using a mold made of a portal frame 7 having an opening 6 and a separable bottom frame 8 attached to the opening. According to the method of the present invention, before the concrete hardens, an extra concrete bulge 19 is formed in the part to be formed on the bottom surface of the medium mold 5, and the bottom frame 8 of the medium mold 5 (or the temporary bottom frame 2
3) by horizontally moving the raised part 19.
This method is characterized in that part of the concrete is removed outside the formwork 14.

The method for forming the raised portion 19 is to pour the concrete 16 into the formwork 14 and leave it for a period of time for air bubbles and water bubbles to rise, and then remove the bottom frame 8 once to remove the concrete 16 that forms at the contact area with the bottom frame 8. There are methods to fill in excess concrete 18 to fill the air bubbles and water bubbles 17,
A temporary bottom frame 23 with a recess 22 about the size of a bolt is prepared, and concrete 16 is placed in the formwork assembled using this bottom frame 23.
A method can be adopted in which the lower part of the medium mold 5 is made thicker than the thickness of the product by pouring it.

Then, while the raised portion 19 is still soft, pull out the temporary bottom frame 23 in the horizontal direction and attach the bottom frame 8, or move the bottom frame 8 in the horizontal direction and insert it into the medium size 5. As a result, excess concrete in the raised portion 19 is drawn out of the formwork 14 at the end of the bottom frame 8 or the end of the recess 22 of the temporary bottom frame 23.

(Function) According to the above method, air and excess water rising from the concrete that has flowed into the space between the bottom surface of the middle mold 5 and the bottom surface of the outer mold 3 are removed when the raised portion 19 is removed. The surface of the block in that part is formed by the bottom frame 8 which is removed from the formwork together with the concrete in that part, and after these are removed, it is reinstalled, so that no craters or brittle layers occur, and the forming surface is smooth. will also improve.

(Embodiment) FIG. 1 is a vertical sectional view showing a first embodiment of the present invention in the order of (a) to f). First, the side plate 1 and the end plate 2 are erected on the base 13 to assemble the box-shaped outer mold 3, and the gate frame 7 of the medium size 5 is inserted into the through hole 4 of the end plate, and the gate frame 7 is expanded. Assemble the formwork 14 by fitting and fastening the bottom frame 8 into the opening 6 (
a). Next, slump value 6~
Pour concrete 16 of No. 10 while vibrating compaction.

After 10 to 20 minutes have passed after pouring is completed, air, some water, cement, and sand will gather at the bottom of the medium mold 5, causing air bubbles and water bubbles 17.
occurs, and the slump value of the concrete layer 3 to 5 degrees from the contact surface with the bottom frame 8 becomes about 12 (b). At this point, the bottom frame 8 is removed from the formwork 14 (C), and extra mortar 18 with a slump of about 12 is poured into the exposed part to fill air bubbles and water bubbles and form a raised part 19 (d). Next, the bottom frame 8 is pushed in horizontally from one end of the opening 6 of the portal frame 7 without introducing air (e). As a result, the excess raised portion 19 is pushed out to the opposite side at the tip of the bottom frame 8 and is discharged outside the formwork 14 (f). Finally, while holding down the bottom frame 8 so that it does not lift up, rub it back and forth about 20 times to blend it with the concrete surface, and then fix it to the gate frame 7.
Take care of yourself.

After curing is completed, the formwork 14 is opened and the cylindrical block 9 is removed from the mold.

FIG. 2 shows a second embodiment of the present invention, in which a temporary bottom frame 23 is used. A recess 22 is formed in the molding surface of the temporary bottom frame 23, and the bottom of the cavity 15 formed in the form 14 assembled using the bottom frame 23 has a wall thickness of the block to be molded. It becomes thicker by the depth of the recess 22 (a).

Therefore, concrete is poured into the empty space 15 with vibration compaction (b), and the bottom frame 8 is removed 10 to 20 minutes after the completion of pouring (c). Air bubbles and water bubbles 17 are generated in the raised portion 19 formed in the recess 22, and the bottom frame 2
The slump value of the concrete layer from 3 to 51 m from the contact surface with No. 3 is about 12. Therefore, as in the first embodiment, a regular bottom frame 8 without a recess is horizontally inserted into one end of the opening 6 of the portal frame 7, and the concrete in the raised portion 19 formed by the recess 22 is scraped out. ), the bottom frame 8 is rubbed back and forth on the concrete surface, fixed to the formwork, and cured to solidify the block.

(Effects of the Invention) As described above, the method of the present invention can reliably remove air bubbles and water bubbles that occur when concrete is poured into the formwork, so it is possible to remove craters, rough surfaces, and brittle surfaces on the inner surface of the cylindrical block. This method has the effect of producing a high-quality cylindrical block that is dense, has high strength, and has excellent surface properties without forming layers.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the first embodiment of the present invention in the order of steps, FIG. 2 is a longitudinal sectional view showing the second embodiment of the invention in the order of steps, and FIG. 3 is a longitudinal sectional view showing the second embodiment of the present invention in the order of steps. FIG. 4 is an exploded perspective view of the formwork, and FIG. 4 is a perspective view showing the crater of the cylindrical block. In the figure, 3: Outer mold 6: Opening 8: Bottom frame 16: Concrete 22: Recess 5: Medium mold 7: Portal frame 15: Hole 19: Swelling part 23: Temporary bottom frame

Claims (2)

[Claims] (1) Tubular medium size (5) with a separable bottom frame (8)
is mounted horizontally on the outer mold (3) to assemble the formwork (14), concrete (16) is poured into the void (15) of the formwork, and before the concrete hardens, the bottom frame (8 ) is removed, extra concrete (18) is poured into the opening after removal to form a raised part (19), and before the raised part hardens, the bottom frame (8) is horizontally inserted into a medium-sized ( 5) to push the excess concrete in the raised part (19) out of the formwork (14), then fix the bottom frame (8) to the middle mold (5) and remove the concrete inside the formwork (14). A method for producing a cylindrical block, characterized by solidifying it. (2) Temporary bottom frame (23) with a recess (22) on the molding surface
A cylindrical medium size (5) installed in place of the regular bottom frame (8).
is mounted horizontally on the outer mold (3) to assemble a formwork (14), concrete (16) is poured into the empty space (15) of the formwork, and before the concrete hardens, a temporary bottom frame is installed. (2
3), move this temporary bottom frame horizontally and remove it, or insert the bottom frame (8) horizontally into the middle mold (5) and remove the raised part (19) formed in the recess (22). )
Push out the excess concrete from the formwork (14),
After that, fix the regular bottom frame (8) to the medium size (5) and formwork (
14) A method for manufacturing a cylindrical block, characterized by solidifying the concrete inside.