JP2000094428A - Method for placing concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economical concrete placing method, by which a cement is favorably hardened and an early demolding work become possible even in summer or ion winter. SOLUTION: Form panels 2 and 4 are box-shaped members having respectively internal spaces. Over the whole regions of form surfaces 2a and 4a, a plurality of fine pores communicating with the internal spaces are formed. On the rear surfaces 2b, feed holes 24 communicating with the internal spaces are provided. Just before the placement of a concrete C, the supplying of a concrete accelerator from a fluid supplying system into the internal spaces is started. In this case, through the flowing-in of the concrete accelerator from the internal spaces through the fine pores inside form surfaces, the hardening of the concrete C on a surface side is hastened as compared with that on an interior side. Thus, since the surface side of the concrete hardens eariler that its interior, an effective means is realized when the early demolding work of the form panels 2 and 4 or the reduction of the side pressure of concrete applying to the form panels 2 and 4 by the placing of high fluid concrete is intended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a concrete placing method.

[0002]

2. Description of the Related Art In a concrete casting method in which at least a pair of form panels are placed with their form surfaces facing each other and concrete is cast between the form surfaces to construct a concrete structure, a concrete construction method is used in summer or summer. If the cement hydration reaction in concrete does not proceed well in winter, the properties of concrete may be impaired.

[0003] That is, if the concrete temperature drops significantly in the severe winter, the hydration reaction of the concrete becomes insufficient, the development of strength is delayed, and the peeling of the concrete surface occurs when the form panel is peeled off. Sometimes.
In addition, when the surface of the concrete dries early due to the heat of hydration of the cement in the middle of the summer, or when the concrete becomes hot, the manifestation of strength is poor,
The surface of the concrete may become rough.

[0004]

Therefore, it is conceivable to cover the concrete pouring position with a large tent or the like and to make the cement hydration reaction an optimal temperature environment even in summer or winter. Therefore, there is a problem in terms of elongation of construction period and construction cost.

On the other hand, in order to reduce the frictional force of concrete acting on the form panel when the form panel is peeled off, a concrete hardening accelerator may be used.
Although it is only necessary to accelerate the hardening of the concrete surface side only, conventionally, a concrete hardening accelerator is supplied to the entire area of concrete to accelerate the hardening of the entire concrete, so a large amount of concrete hardening accelerator is required .

[0006] In the case of concrete using sulfur, when the temperature of the form panel is low, the concrete cools and hardens during the filling of the concrete, and the concrete may not be filled to every corner of the form panel. . Also,
When sulfur concrete is cooled and hardened, depending on the cooling rate, the crystal form of the sulfur after hardening is different, including when it becomes amorphous, so that concrete that does not exhibit the desired performance is manufactured. There is.

[0007] Further, in order to prevent early drying of the concrete surface due to the heat of hydration of the cement in the middle of the hot summer, watering curing may be performed. There was a problem in terms of reuse.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to eliminate the need for preparation such as covering a casting position with a large tent or the like, and to prevent the cement hydration reaction even in summer or winter. The second purpose is to greatly reduce the amount of concrete hardening accelerator and watering for curing, and the third purpose is to fill concrete using sulfur to the details of the formwork. It is an object of the present invention to provide a concrete placing method capable of producing sulfur concrete having a predetermined crystal form.

[0009]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, at least a pair of form panels are arranged with their form surfaces facing each other, and concrete is placed between the form surfaces. Concrete to be cast or cast concrete between the formwork surface of the formwork panel arranged so as to face the ground or the rock surface and the ground or the rock surface to construct a concrete structure. In the casting method, a number of pores are formed in the form panel to open toward the form surface, and depending on the environment at the time of concrete placement, a liquid concrete hardening accelerator, hot water and This is a method in which any of the cold water is sent out and flows out of the mold surface through the fine holes.

[0010] The above-mentioned environment at the time of casting concrete includes a severe winter when the hydration reaction of the concrete tends to be insufficient, a hot season when the surface of the concrete tends to dry early due to the hydration heat of the cement, and a mold. It refers to the environment when it is desired to reduce the frictional force acting on concrete when the frame panel is peeled off.

According to a second aspect of the present invention, at least a pair of form panels are arranged such that their form surfaces face each other, concrete is cast between the form surfaces, or they face the ground or rock surface. In a concrete casting method in which concrete is cast between the formwork surface of the formwork panel and the ground or the rock surface, and the concrete structure is constructed, temperature control means is provided on the formwork panel. Built-in,
The method is to heat or cool the formwork surface to a predetermined temperature by the temperature control means according to the environment at the time of concrete casting.

According to a third aspect of the present invention, in the concrete placing method according to the second aspect, the temperature control means circulates in the form panel by setting a fluid such as water or oil to a predetermined temperature. This is a construction method using a fluid circulation device.

Further, the invention described in claim 4 is the same as the claim 2.
In the concrete placing method described in the above, the temperature control means for heating the form surface to a predetermined temperature is constituted by an electric heating element such as a nichrome wire or a ribbon heater disposed on the back side of the form surface. is there.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show members according to a concrete placing method according to a first embodiment of the present invention. The present embodiment includes a pair of form panels 2, 4 whose form surfaces 2a, 4a face each other in parallel.

As shown in FIG. 2, the form panel 2 is a box-shaped member having an internal space 20. A plurality of pores 22 communicating with the internal space 20 are formed over the entire form surface 2a. I have. A supply port 24 communicating with the internal space 20 is provided on the back surface 2b, and the liquid concrete hardening accelerator L supplied from the fluid supply device 26 is fed into the internal space 20 via the supply port 24. It is supposed to be. Although not shown, a control valve for controlling the supply of the concrete hardening accelerator L, controlling the pressure, and the like is provided in a supply path between the supply port 24 and the fluid supply device 26. Further, a nonwoven fabric 28 having fine cloth holes is stuck over the entire area of the mold surface 2a. Although the form panel 4 is formed in the same shape, the form panels 2 and 4 may be used without attaching the nonwoven fabric 28 described above.

In this embodiment, the concrete C
Immediately before or during or after the casting, the supply of the concrete hardening accelerator L from the fluid supply device 26 to the internal space 20 is started by operating the control valve. Then, when the concrete hardening accelerator L flows into the inside of the mold surfaces 2a, 4a, hardening on the surface side is promoted as compared with the inside of the concrete C.

As described above, since the surface side of the concrete C hardens before the inside, it is desired to realize the early demolding work of the form panels 2 and 4 or by casting the high form concrete. This is an effective means when it is desired to reduce the lateral pressure of concrete acting on the panels 2 and 4.

Further, since the concrete hardening accelerator L is not supplied to the entire area of the concrete C as in the prior art, the consumption of the concrete hardening accelerator L is greatly reduced, and therefore an economical concrete placing method is provided. Can be.

As a second embodiment, there is a method in which hot water H is supplied from the fluid supply device 26 during a severe cold season. In this embodiment, after the concrete C is cast, the supply of the hot water H from the fluid supply device 26 to the internal space 20 is started by operating the control valve. At this time, the warm water H that has flowed from the internal space 20 through the pores 22 to the inside of the mold surfaces 2a and 4a is heated to an ambient temperature such that the cement hydration reaction proceeds favorably throughout the concrete C. Since the temperature is raised to the optimum environmental temperature, the hydration reaction of the surface of the concrete C is sufficiently performed. Therefore, when removing the form panels 2 and 4, defects such as peeling of the surface of the concrete C can be suppressed. In addition, there is no need for a large tent for covering the concrete casting position, so there is no problem in terms of construction period and construction cost. In addition, an appropriate amount of hot water H is supplied from the form panels 2 and 4 to the concrete C. Therefore, there is no problem in the vicinity of the hot water H (curing water) and in the recovery and reuse of the curing water.

Further, as a third embodiment, there is a method of supplying cold water W from the fluid supply device 26 in the middle of a hot summer. In this embodiment, after the concrete C is cast, supply of the cold water W from the fluid supply device 26 to the internal space 20 is started by operating the control valve. At this time, the cold water W flowing from the internal space 20 through the pores 22 to the inside of the mold surfaces 2a and 4a is heated to an ambient temperature such that the cement hydration reaction proceeds well throughout the concrete C. Since the temperature is lowered to the optimum environmental temperature, the hydration reaction of the surface of the concrete C is sufficiently performed. Therefore, even when shearing friction occurs between the mold surfaces 2a and 4a when removing the mold panels 2 and 4,
Defects such as peeling of the surface of the concrete C can be suppressed. Further, similarly to the above-described second embodiment, there is no problem in terms of construction period and construction cost because a large tent or the like is not required.
There is no problem in the recovery and reuse of curing water.

FIGS. 3 and 4 show a fourth embodiment according to the present invention. In the form panel 2 of the present embodiment, a heating element (electric heating element) 32 such as a nichrome wire or a ribbon heater that generates heat by energization with a power supply is provided on an inner wall 34a that is a back surface of the mold surface 2a of the internal space 30. It has a simple configuration. A temperature sensor 34 for detecting the temperature of the mold surface 2a is provided at the center of the inner wall 30a. When the measured temperature detected by the temperature sensor 34 is equal to or lower than a predetermined value, the temperature controller (not shown) energizes the heating element 32, and stops energizing the heating element 32 when the measured temperature exceeds the predetermined value. . Also,
One form panel 4 also has the same configuration.

According to the concrete casting method including the form panels 2 and 4 having the above-described structure, immediately before the concrete C is poured, the power supply to the heating element 32 is started by the operation of the temperature control unit, thereby forming the form. The temperature is raised so that the surface 2a reaches a predetermined temperature. Thereby, the cast concrete C is heated from the surface side near the form panel 2 side, and the hydration reaction is promoted, so that high-quality concrete C can be formed in a short time.

Further, even in a severe cold season, the form panels 2, 4
If the concrete is not sufficiently heated, the concrete property will not be of high quality, and this method is optimal for sulfur concrete. In other words, even if sulfur concrete is poured between the form panels 2 and 4, the sulfur is heated from the surface near the form panel 2 side and the sulfur is kept in a molten state. Defects, such as generation of voids, are spread over every corner of the surfaces 2a, 4a.

FIG. 5 shows a mold panel 2 according to a fifth embodiment of the present invention, which is formed in a box shape having an internal space 60 and has a back surface 2b on which a fluid is provided. A supply port 62 and a fluid discharge port 64 are provided. Then, cold water or cooled oil is fed from the fluid supply port 62 and circulates through the internal space 60, and then the fluid discharge port 6
4 and has a simple configuration.

When a concrete structure is constructed using the apparatus having the above-described structure, cold water or cooled oil circulating through the internal space 60 cools the formwork panel 2 so that the entire area of the poured concrete can be satisfactorily cemented. Since the surrounding temperature is lowered to the optimal environmental temperature so that the sum reaction proceeds, the hydration reaction of the concrete surface can be reliably performed.

When warm water or heated oil is fed from the fluid supply port 62 and circulates through the internal space 60 and then flows out from the fluid discharge port 64, the form panels 2, 4 can be sufficiently provided even in a severe cold season. Since it is heated, for example, even if sulfur concrete is cast between the form panels 2 and 4, the sulfur concrete is heated from the surface near the form panel 2 side and is surely filled with sulfur concrete, and the desired performance is obtained. It is possible to produce sulfur concrete that has been demonstrated.

In each of the above embodiments, a pair of form panels 2 whose form surfaces 2a, 4a are opposed to each other in parallel.
Although the method of constructing a concrete structure in 4 has been described, concrete is cast between the formwork surface 2a of the formwork panel 2 arranged so as to face the ground or the bedrock surface and the ground or the bedrock surface. Even when the present invention is applied to a method of constructing a concrete structure, a similar effect can be obtained.

[0028]

As described above, according to the concrete casting method according to the first aspect, when the form panel is to be quickly removed from the mold or when the high-flowable concrete is cast, the concrete acting on the form panel is formed. When it is desired to reduce the lateral pressure of the concrete, the concrete hardening accelerator is sent out from the fluid supply device. Thereby, when the concrete hardening accelerator flows into the inside of the formwork surface, the hardening of the surface side is promoted as compared with the inside of the concrete, so that the lateral pressure of the concrete is reduced. Further, since the concrete hardening accelerator is not supplied to the whole area of the concrete as in the related art, the consumption of the concrete hardening accelerator is greatly reduced, so that the concrete placing method is economical. Also, when hot water flows out from the fluid supply device into the inside of the form during the severe cold season, the surrounding temperature is raised to the optimal environmental temperature so that the cement hydration reaction proceeds well throughout the concrete. In addition, the hydration reaction of the concrete surface can be sufficiently performed. In addition, when cold water flows out from the fluid supply device to the inside of the formwork during the hot summer, the surrounding temperature is reduced to the optimal environmental temperature so that the cement hydration reaction proceeds well throughout the concrete. In addition, the hydration reaction of the concrete surface can be sufficiently performed.

Therefore, according to the present invention, it is possible to suppress defects on the surface of concrete when removing the formwork panel, regardless of the environment in which concrete is cast. There is no need for a large tent to cover the location, so there is no problem in terms of construction period and construction cost.Suitable amounts of hot and cold water are supplied from the formwork panel to the concrete, thus contaminating the surroundings of the curing water. And
There is no problem in the recovery and reuse of curing water.

According to the second aspect of the present invention, the temperature control means incorporated in the form panel sets the form surface to an optimum temperature in accordance with the environment at the time of concrete casting. Even if you want to remove the mold early, to reduce the concrete lateral pressure, or even in severe winter or hot summer,
It is possible to optimally promote the hydration reaction of the cast concrete surface and suppress the defects on the concrete surface.
And even if sulfur concrete that needs heating in the severe cold season is poured, the sulfur concrete is heated from the surface side near the formwork surface and the filling can be ensured, so the surface of the cured sulfur concrete is Defects such as voids are reliably suppressed, and high-quality concrete can be formed.

According to the third aspect of the present invention, since the fluid circulating device circulates a fluid such as water or oil set at a predetermined temperature in the form panel, the same effect as in the second aspect is obtained. In addition to this, the fluid circulating device has a simple configuration, so that the cost of the temperature control means can be reduced.

Further, according to the present invention, even if sulfur concrete which needs to be heated in a severe cold season is poured, the sulfur concrete is heated from the surface side near the formwork surface to ensure the filling. Therefore, defects such as voids are reliably suppressed on the surface of the hardened sulfur concrete, and high-quality concrete can be formed. Further, since the present invention uses an electric heating element having a simple configuration, the cost of the temperature control means can be reduced as in the third aspect.

[Brief description of the drawings]

FIG. 1 is a perspective view showing members when a concrete placing method according to a first embodiment of the present invention is performed.

FIG. 2 is a diagram showing details of the first embodiment.

FIG. 3 is a view showing a form panel according to a fourth embodiment.

FIG. 4 is a view taken along line VI-VI in FIG. 3;

FIG. 5 is a view showing a form panel according to a fifth embodiment.

[Explanation of symbols]

 2, 4 Form panel 2a, 4a Form surface 20, 30, 60 Internal space 22 Pores 24 Supply port 26 Fluid supply device 32 Heating element (electric heating element) A Compressed air B Oil (oil) L Concrete hardening acceleration Agent H Hot water W Cold water

Continued on the front page (72) Inventor Jun Sakamoto 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Takefumi Shinto 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. F term (reference) 4G055 AA01 CA01 CA17 CA20

Claims (4)

[Claims] 1. A formwork panel in which at least a pair of formwork panels face each other and concrete is cast between the formwork surfaces or arranged so as to face the ground or rock surface. Concrete is cast between the formwork surface and the ground or the bedrock surface to construct a concrete structure. A hole is formed, and depending on the environment at the time of concrete placement, any one of the liquid concrete hardening accelerator, hot water and cold water is sent out from the fluid supply device, and flows out inside the formwork surface through the pore. A concrete casting method characterized by the following: 2. A formwork panel in which at least a pair of formwork panels face each other and concrete is cast between the formwork surfaces, or arranged so as to face the ground or rock surface. In a concrete placing method for placing concrete between the formwork surface and the ground or the rock surface to construct a concrete structure, a temperature control means is built in the formwork panel, and the concrete A concrete casting method, wherein the form control surface is heated or cooled to a predetermined temperature by the temperature control means according to an environment at the time of installation. 3. The concrete casting apparatus according to claim 2, wherein said temperature control means is a fluid circulating device for circulating the fluid inside said form panel by setting a fluid such as water or oil to a predetermined temperature. Construction method. 4. The temperature control means for heating the mold surface to a predetermined temperature is constituted by an electric heating element such as a nichrome wire or a ribbon heater disposed on the back side of the mold surface. The concrete casting method according to claim 2.