JP2515895B2 - Curing method for housing foundation concrete - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for curing concrete when constructing a foundation of a house, which enables curing at a construction site, shortens curing time, and concrete. It is intended to strengthen the.

[Prior Art] Conventionally, as a concrete curing method, a method of naturally curing concrete placed in a mold or a concrete placed in a mold is put into an autoclave or the like, and steam is introduced into the concrete. Then there is a method of heating and curing.

The latter method is a method performed to accelerate the rotation of the mold and improve productivity, and is performed in a factory to obtain a concrete product based on preset standards.

By the way, when constructing the foundation of a house, it is necessary to cure concrete at the construction site, and the former method is exclusively used.

Specifically, conventionally, a root cutting hole was formed at the construction site, a mold was installed in this root cutting hole, after concrete was placed in the mold, natural curing was performed for a predetermined time to cure the concrete, The foundation of the house is constructed by removing the formwork after curing.

[Problems to be Solved by the Invention] However, the conventional concrete curing work at the construction site requires a very long curing period of about 3 days even at room temperature, and the formwork is used during this period. Therefore, there was a problem that the rotation of the formwork was very bad and inefficient. Also, under low temperature conditions, the curing time will be longer, so when working in cold regions,
The work in winter and morning and evening is very inefficient, so that there is a problem that the condition of curing must be changed each time according to the environment of the construction site (region, time, etc.).

The present invention has been made in view of the above circumstances, and can be implemented at a construction site, and the environment (region, time, etc.)
It is an object of the present invention to provide a method for curing concrete for a house foundation, which can efficiently perform concrete curing in a short period of time regardless of the above.

[Means for Solving the Problem] The present invention is to install a formwork, place concrete in the formwork, and then install a conduit extending from a steam generator disposed outside the formwork of the formwork. Circulate along the inner surface, then cover the entire formwork with a curing sheet to form a curing house, send the steam generated by the steam generation device into the curing house through the conduit, and keep the temperature in the curing house approximately Adjust for a certain period and continue for a predetermined time,
The solution was to cure and cure the concrete.

[Operation] According to the method for curing concrete for a housing foundation of the present invention, after concrete is placed in the formwork, the conduit extending from the steam generator is circulated along the inner surface of the formwork,
Next, by covering the entire formwork with a curing sheet to form a curing house, it is possible to form a steam curing space even at the construction site, so it is possible to perform steam curing of concrete by a simple method, and also during the curing period. It can be shortened significantly. Further, the steam generated by the steam generator is sent into the curing house through the conduit, and the temperature in the curing house is kept substantially constant for a predetermined time, so that the heat of the steam passing through the conduit causes the curing house. The inside is uniformly heated, the temperature distribution inside the curing house becomes uniform, and the curing and hardening of concrete is uniformly performed.

[Embodiment] An embodiment of a method for curing a concrete for a house foundation according to the present invention will be described in detail in the order of steps with reference to FIGS. 1 to 3.

1. Root cutting process First, the root cutting hole 1 is formed by deeply digging a desired position where the foundation of the construction site is built.

2. Formwork installation process Place 2 stones, rubble, etc. in the root cutting hole 1 to fix the bottom surface of the root cutting hole 1, and then install the formwork 3 for the cloth foundation.
In the present embodiment, a step of forming the footing portion of the foundation and the column base portion separately is adopted. First, a flat plate-shaped frame is assembled and concrete is placed to form the footing portion 4a, and then the second portion is formed. As shown in the figure, the formwork 3 for the column base portion 4b is installed on the footing portion 4a. Also here, the formwork 3 ...
As the above, it is of course possible to use a structure in which the foundation footing portion 4a and the column base portion 4b can be integrally molded when the mold is assembled.

3. Concrete pouring process Concrete 4 is poured into the formwork 3. While the concrete 4 is still uncured, anchor bolts may be placed at predetermined positions in the concrete 4 from above the formwork 3 ...
Set 10 mag.

4. Concrete Steam Curing Process (Arrangement of Steam Conduit) In concrete steam curing, the steam generator 7 is first arranged near the formwork 3 ... Assembled as shown in FIG. A flexible hose is connected to the steam generator 7 to form a conduit 8 for sending the steam generated by the steam generator 7. The conduit 8 is circulated along the inside of the molds 3 so as to surround the molds 3 and the tip end thereof is arranged so as to face the inside of the curing house. At the location where it intersects with the molds 3 ..., the conduit 8 may be arranged in an arch shape so as to get over the molds 3. By arranging the conduits 8 in this way, in the subsequent curing step, the heat of the steam passing through the conduits 8 efficiently and uniformly heats the inside of the curing house 6 (described later) to locally heat or heat the curing house 6. The occurrence of a temperature distribution that is not present is prevented.

(Formation of Curing House) As shown in FIG. 1, a curing house 6 is formed by covering the entire formwork of a detached house with a curing sheet 5 of a size that covers the entire formwork. As the training sheet 5, a plastic sheet such as polyethylene is preferably used, but as long as it has heat insulating properties and is flexible and large enough to cover the entire mold, this Other than can be used.

(Temperature increase) The steam generator 7 is turned on to generate steam, which is supplied into the conduit 8, and is sent out from the tip portion thereof into the curing house 6 through the conduit 8. At this time, the temperature rise rate (temperature rising rate) in the curing house 6 is adjusted by the temperature at which steam is generated, the steam supply amount, and the like. The temperature rising rate is not particularly limited as long as the air or water inside the concrete 4 does not expand rapidly and the strength of the concrete 4 is not reduced.

(Steam curing) When the temperature inside the curing house 6 reaches the upper limit set temperature, the conditions such as the steam supply amount are changed to adjust the temperature inside the curing house to be almost constant, and this temperature is maintained for a predetermined time. Then, the concrete 4 is cured. It is said that the upper limit set temperature is usually about 60 to 70 ° C, and the duration of each is about 3 to 4 hours, but the curing and hardening of concrete 4 is sufficiently advanced, and each physical property of the concrete foundation obtained after curing is good. Other conditions may be used as long as the conditions (strength, elongation, drying shrinkage, etc.) are sufficiently satisfied. It is also possible to set the upper limit temperature in two ways and change the condition after a predetermined time to perform two-stage curing.

(Cooling down) Stop the steam supply and lower the temperature. The temperature may be lowered naturally or forcibly, but the conditions are such that the rate of temperature reduction is such that cracking of the concrete 4 due to a sudden temperature difference does not occur.

(Removal of Curing Sheet) When the temperature inside the curing house 6 drops to about room temperature, the curing sheet 5 is removed.

5. Demolding process After confirming that the concrete 4 has hardened, remove the molds 3 ...

According to such a method, when constructing the foundation of the house, the steam curing of the concrete 4 can be easily carried out at the construction site, the curing time is greatly shortened, and the rotation efficiency of the formwork 3 ... Is improved. In addition to the above, the obtained concrete foundation also has sufficiently high strength and can exhibit an excellent curing effect.

In this embodiment, the conduit 8 from the steam generator 7
After putting the inside of the mold 3 ...
Although the example covered with the above is described, for example, when the size of the foundation to be steam-cured (the entire form) is small, the curing sheet 5 is first covered on the form 3 to form the curing house 6. However, after this, the conduit 8 may be put in the curing house 6 to supply the steam.

[Example] Regarding the method for curing concrete for a housing foundation described above, the cloth foundation of a detached house is steam-cured, and the time from placing concrete foundation to starting erection is within a fixed time (within 24 hours) throughout the year. We confirmed that it could be completed.

First, at the actual construction site, make a root cutting hole in the place where the foundation is to be built, lay a cobblestone in it to harden the bottom of the root cutting hole, install the cloth foundation formwork on it, and in this formwork Concrete was placed on the ground (see Fig. 4).

The entire formwork was covered with a curing sheet to form a curing house. As the curing sheet, a commercially available blue sheet with a size of 80 m square was used. A steam generator was placed in the vicinity of the curing house, and a conduit extending from the steam generator was drawn into the curing house to surround the inside of the curing house, and the tip of the steam generator was arranged to face the inside of the curing house. .
Super steam heater LHO for steam generator
-125 type, the conduit extending from this device has a diameter of 220 m
A flexible bellows hose of m and 30 m in length was used.

In addition, the temperature measuring device 9 is arranged outside the curing Haku,
The six sensors connected to this temperature measuring device were pulled into the respective positions shown in FIG. 4, and the temperatures at these six positions were detected and recorded. The position shown in the figure indicates the outside air temperature, and the position indicated by indicates the base basin temperature.

The superlattent heater generator was operated to continuously raise the temperature, cure, and lower the temperature. The temperature rise rate during temperature rise is unset (free temperature rise), and the temperature condition during curing is the maximum temperature of 70
2 hours at ℃, then 1 hour at 60 ℃,
Further, the temperature lowering rate at the time of lowering the temperature was not set (free temperature lowering).

At this time, the temperature of each of the 6 points recorded in the temperature measuring device was changed to the 5th
The temperature curve as shown in the figure was drawn. As shown in the figure, it was found that the temperature at each position of ~ in the curing house follows the set temperature although there is some variation, and a large temperature distribution does not occur in the curing house. It was also found that the base basin temperature indicated by also increased sufficiently following the set temperature.

After the curing of the concrete was completed in this way, the curing sheet was removed, and the form was removed to obtain the intended concrete foundation. When the strength of the obtained concrete foundation was measured, it became clear that it reached the specified strength (180 kg).

As described above, according to this example, it was found that the curing can be performed in a short time and the concrete having sufficient quality can be obtained.

[Effects of the Invention] As described above, according to the method for curing concrete for a housing foundation of the present invention, a steam generator installed on the outside of the formwork after the formwork is installed and concrete is placed in the formwork. The further extending conduit is circulated along the inside of the mold, and then the entire mold is covered with a curing sheet to form a curing house, and steam generated by the steam generator is fed into the curing house through the conduit, Keeping the temperature inside the curing house almost constant while maintaining it for a predetermined time,
Since it cures and hardens the concrete,
At the construction site, concrete can be cured in a short time with a simple method. Therefore, since the formwork staying time is shortened, the formwork rotates better, the entire construction period for building the foundation of the house can be shortened, and the work efficiency is significantly improved. Also, according to this method, there is an effect that the concrete can be cured within a fixed time regardless of the environment (region, time, etc.) of the construction site. Further, the steam generated by the steam generator is sent into the curing house through the conduit, and the temperature in the curing house is maintained for a predetermined time while being adjusted to be substantially constant. Therefore, the heat of the steam passing through the conduit causes the curing house to heat. By uniformly heating the inside, the temperature distribution in the curing house can be made uniform, and the curing and hardening of concrete can be performed uniformly. Therefore, the strength of the obtained concrete foundation can be sufficiently increased, and an excellent curing effect can be exhibited.

[Brief description of drawings]

1 to 3 show an example of the present invention,
FIG. 1 is a perspective view showing a configuration example when a conduit extending from a steam generator is arranged in a curing house, and FIGS. 2 and 3 are cross-sectional views showing an example of a positional relationship between a mold and the conduit. FIG. 4 is a layout view of the temperature measuring device and the sensor used in the experimental example, and FIG. 5 is a graph showing a measured temperature curve in the experimental example. 3 ... Formwork, 4 ... Concrete, 5 ... Curing sheet, 6 ... Curing house, 7 ... Steam generator, 8 ... Conduit.

Claims (1)

(57) [Claims] 1. A formwork is installed and concrete is poured into the formwork, and then a conduit extending from a steam generator disposed outside the formwork is circulated along the inside of the formwork, and Cover the entire formwork with a curing sheet to form a curing house,
The housing foundation is characterized in that the steam generated by the steam generator is sent into the curing house through the conduit, and the temperature in the curing house is kept substantially constant for a predetermined time to cure and cure the concrete. For curing concrete for construction.