JPS6154906A - Manufacture of concrete block - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to underground conduits (box culverts, etc.) or open conduits,
This invention relates to a method for manufacturing various concrete blocks used for constructing fire prevention water tanks, public ditches, underground passages, prefabricated garages, etc.

[Prior Art] Large concrete block products such as the box culvert A shown in Fig. 7 are usually manufactured by pouring concrete into a framed formwork as shown in Figs. 5 and 6. It is. To explain this, on the bottom formwork 1,
Outer formwork 2 corresponding to the dimensions and shape of the intended culvert A
Assemble the inner formwork 3 to form the required formwork, and first
As shown in the figure, after pouring concrete K into the bottom form l and sufficiently filling the part of the formwork that meets the bottom of the block with concrete K, insert the outer formwork from above the formwork as shown by the arrow in the figure. Concrete is successively poured into the gap between inner formwork 2 and inner formwork 3 while applying vibration as necessary, until the inside of the formwork is completely filled with concrete (K) as shown in Fig. 6.

[Problems to be Solved by the Invention] However, according to such a conventional manufacturing method, as the concrete K placed in the grasping frame is compacted, concrete is deposited in the portion corresponding to the bottom inner surface BI of the block. The air and moisture contained in the concrete collect as air bubbles and water bubbles, and as the concrete breathes, a large amount of excess moisture rises to the surface with laitance and concentrates in this area.
This results in the inconvenience that water tends to accumulate between the inner formwork 3 and the inner formwork 3. For this reason, in the block (culver) A) manufactured by this type of conventional method, as shown in Figure 7, the bottom inner surface BI becomes porous with traces of air bubbles, or as a result of water puddles. Surface defects S such as crater-like dents inevitably occur. and,
Products with such surface defects S not only impair their aesthetic appearance, but also have problems in their use as concrete blocks, such as in terms of abrasion strength and external resistance to frost damage. Since the performance required for the part is significantly reduced, it is necessary to add troublesome repair work such as lining the surface with mortar in a separate process.

Means for Solving Problem C] The present invention was made for the purpose of solving such problems in the production of concrete blocks and providing a method that can produce sound block products without repair work. To this end, the present invention provides an air vent that communicates with the inner surface of the inner form via ventilation holes when concrete is poured into a form to produce a concrete block. A hollow frame having a chamber inside and a filter cloth stretched on its inner surface is arranged, and the air chamber of the hollow inner form is configured to operate using compressed air supplied by a compressor. It is characterized in that the concrete in the formwork is cured by suctioning with an ejector while sucking the concrete surface in contact with the hollow inner formwork.

[Effect] That is, 1. In the manufacturing method of the invention, 1) a hollow frame provided with a necessary suction mechanism such as an air chamber is placed in a portion of the inner form forming the bottom inner surface of the block that is likely to cause surface defects S;
This hollow inner formwork suctions the concrete surface in contact with the inner formwork, and sequentially removes air bubbles, water bubbles, excess moisture, and other components such as laitance separated from the cement. In one method of the present invention, the concrete within the formwork is allowed to harden.

It is sufficient to use an air ejector configured to operate using compressed air supplied by a compressor as a suction means for suctioning the concrete surface in contact with the inner formwork through the hollow inner formwork. It has the characteristic that its construction is simple.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. This embodiment shows an example of construction of a large box culver (A) shown in FIG. 7, similar to the conventional example.

First, for each predetermined bottom form, an outer form 2 and an inner form 3 are prepared, and these are assembled to constitute a required form. At this time, the inner formwork 3 is constructed so that a part for molding the bottom of the block and a part for molding other parts are formed separately in advance and can be assembled detachably. The part that molds the inner surface of the bottom part is removed to form the opening 4 and then installed. In this state, as shown in Fig. 1, concrete K is poured into the bottom mold n-1 of formwork l, and as in the past, concrete K is poured only into the part of the formwork that overlaps with the bottom of the block. Make sure to fill it thoroughly.

Next, a hollow frame 5 that performs a suction action as will be described in detail below is placed in the opening 4 of the inner mold 3, that is, in the part where the bottom inner surface of the block is to be molded.

It is integrally combined with the inner formwork 3. After this integration, as shown in Fig. 2, concrete is poured sequentially from the gap between the outer formwork 2 and the inner formwork 3 as shown by the arrows, and then into the formwork as shown in Fig. 3. Fill the concrete completely with the concrete.

The hollow inner formwork 5 has a configuration and a mounting structure as shown in FIG. 4. This hollow inner formwork 5 has a double structure in which the outer plate 5& and the inner plate 5b are fastened together with a port 7.7 with a spacing setting nut 6.6 in between. It has an air chamber 8. Then, this hollow inner formwork 5 has ventilation holes 9.9... bored in the inner plate 5b in a staggered manner by heating for a predetermined period of time, and the ventilation holes 9.
．． 9. The air chamber 8 is communicated with the inner surface through the fist, and the filter cloth l is placed on the inner surface (molding surface) where the vents 9, 9, . . . are opened.

I am trying to set it up. This filter cloth 1
0 is when the hollow inner formwork 5 sucks the concrete surface;
The permeability or water permeability of the fibers is selected so as to prevent the passage of aggregates and cement useful components, and selectively allow only those to be removed, such as air bubbles, water, and laitance, to pass through.

This hollow inner formwork 5 has flange parts 11.11 extending to the inclined molding surfaces on both sides thereof slidably connected to flange parts 12.12 extending corresponding to the facing parts of the inner formwork 3,
Ports 13 and 13 are screwed and connected to the lower ends of both sides of the inner formwork 3 in a freely removable manner.

On the other hand, to explain the suction mechanism attached to the hollow inner formwork 5, it penetrates the outer plate 5a and connects its lower end to the inner plate 5.
The suction pipe 14 is screwed into the socket 15 and erected in the hollow inner formwork 5f in a state where it is brought close to the hollow inner formwork 5f. This suction pipe 14 communicates with the air chamber 8 via a vertical slit 16 provided at its lower end located within the air chamber 8, and its upper end is connected to the upper end. The negative pressure suction part 17c of the air ejector 17 is opened and communicated with the air chamber 8 of the hollow inner formwork 5 from the ejector 17 through the suction pipe 14.

The air ejector 17 is a general-purpose one that includes an injection nozzle 18 that creates the negative pressure suction section 17c, and has a JFF control system that allows a driving flow (-next flow) to flow into one end of the air ejector 17.
17a has a connecting portion 17b at the other end through which a mixed flow of air in the driving flow and moisture etc. (secondary flow) sucked out from the suction tube 14 flows out. A pipe 20 for introducing compressed air supplied by a two-way compressor 19 normally provided at the construction site is connected to the connection part 17a of the air ejector 17, and the compressed air from the compressor 19 is used to air the air. The ejector 17 is configured to operate. On the other hand, in the connection part 17b,
A drainage pipe 21 is connected, and the mixed flow of air and moisture is led out of the mold, and is discharged through an end 22 to collect extracted moisture and the like in a container 23. In addition, 24 in the figure is a control valve interposed in the connection part 17a of the introduction pipe 20, and 25 is a negative pressure suction part 17.
A meter indicating the gauge pressure of c is shown.

To explain the manufacturing method of a block using a formwork formed by arranging the hollow inner formwork 5 having a suction function with such a configuration at a predetermined position, after setting the hollow inner formwork 5 as shown in m2r54. The air ejector 17 is operated for a predetermined period of time during the vibratory casting or curing of the concrete, so that the air chamber 8 of the hollow inner formwork 5 is continuously sucked through the suction pipe 14. Then, this hollow inner formwork 5 is
The inner surface that communicates with the air chamber 8 through the vents 9, 9, etc. is suctioned, and the concrete surface that is in contact with it through the filter cloth 10, that is.

Bottom inner surface of the block B I fI: There will be continuous suction. Therefore, according to this construction method, air bubbles and water bubbles that collect on the inner surface BI of the bottom of the block are successively suctioned and removed, and only harmful components such as excess moisture and separated laitance that float to the surface are removed by the filter. They are selectively suctioned and extracted through the cloth 10, and these are extracted from each vent 9, air chamber 8, suction pipe 14. The air is discharged to an external container 23 or the like via the air ejector 17 and the drain pipe 21.

Therefore, in the box culvert A manufactured by this method, there are no surface defects such as pores or dents that occur in conventional products on the bottom inner surface BI, and a flat and beautiful molded surface can be obtained in that area. It is.

Moreover, according to such a manufacturing method, boxcar/<
- The bottom of the block A is subjected to a large compaction effect due to continuous suction treatment from its inner surface, resulting in properties similar to those of pressed concrete. f slope T, and harmful laitance is also extracted, so it is difficult to mold and
= It is very convenient in terms of development, and when this type of block product is used, the durability performance such as abrasion resistance and frost damage resistance will be dramatically improved.

The manufacturing method of the present invention does not require a vacuum pump or other troublesome auxiliary equipment unlike known vacuum concrete construction methods, and can be used as a driving power source for impact wrenches and other equipment at construction sites of this type. It is possible to perform the necessary suction work with the compressed air of the air compressor that is operated!It is characterized by the fact that the construction is easy and can be carried out at low cost.This is one of the features of the present invention. The suction treatment is carried out only on the inner surface of the bottom of the concrete block placed in the formwork, and since the pressure from the side of the block is applied to the bottom of the force test, even a relatively small suction force is sufficient. This is because it has the ability to extract and remove air bubbles and moisture.

The above description has been made using the box culvert A shown in FIG. Needless to say, the present invention can be similarly applied to the manufacture of various large block products.

In addition, in carrying out the present invention, the hollow inner mold 6-5
internal structure and assembly/mounting structure to the inner formwork 3.

Furthermore, the specific structure such as the connection structure of the suction pipe 14 to the air chamber 8 is of course not limited to that of the embodiment shown in the drawings, but may be modified in various ways according to various conditions such as the type of frame and convenience of handling. It is possible. Furthermore, the internal structure of the air ejector 17 does not matter as long as it exhibits the necessary suction action.

[Effects of the Invention] As described above, according to the manufacturing method of the present invention, a large concrete block can be produced in the desired molded state in which one surface is flat without generating surface defects on the inner surface of the bottom, which is different from conventional methods. This eliminates the need for any troublesome repair work.

Furthermore, in the case of the concrete obtained by this method, the properties of the concrete at the bottom part subjected to the suction action are improved, and after hardening, it is possible to give a favorable effect of improving various properties such as strength to this bottom part. and.

This method utilizes compressed air from a compressor to operate an air ejector that performs the necessary suction action, so it is easy to install.

[Brief explanation of drawings]

Figures 1, 2, and 3 are cross-sectional views showing the manufacturing process of a concrete block according to an embodiment of the present invention, and Figure 4 is a schematic diagram showing details of the hollow inner formwork used therein. It is a partial view. FIGS. 5 and 6 are cross-sectional views showing the conventional manufacturing process. FIG. 7, FIG. 8, FIG. 9, and FIG. 10 are perspective views showing specific examples of the shape of concrete blocks to which the present invention is applied. 1.2.3φ・Fist form 1...Bottom form 2...Outer form 3...Inner form 4...Opening 5...Hollow inner form 5a...Outer plate 5b...Inner plate 61, Nut 7.13...Life bolt 8...Air chamber °9...Vent lO, War, Filter cloth 11.12...Flange part 14...Suction pipe 15 Socket 17...-Air ejector 17a, 17b***Connection L7c...Negative pressure suction part 18...Injection nozzle 19...e Air compressor 2011-Fist pipe No. 21...Drain pipe 22... ...End part 23...Container 24...Control palf 25@, φ meter

Claims (1)

[Claims] When pouring concrete into a formwork to produce a concrete block, the inner formwork that forms the bottom inner surface of the block must have an air chamber inside that communicates with the inner surface of the block through a vent. A hollow frame with a filter cloth stretched on its inner surface is arranged, and the air chamber in the hollow inner form frame is sucked by an air ejector configured to operate using compressed air supplied by a compressor. A method for manufacturing a concrete block, characterized in that the concrete inside is cured while sucking the concrete surface in contact with the hollow inner formwork.