JPH0729290B2 - Curing method for concrete secondary products - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curing method for filling and molding a secondary concrete product in a mold.

[0002]

2. Description of the Related Art Conventionally, in a concrete secondary product manufacturing plant, raw concrete is put into a mold while being vibrated by a low-frequency vibrator or a high-frequency vibrator, and after the completion of the filling and molding, the mold is placed in a curing room. Or the mold is covered with a shielding sheet, and the atmospheric temperature in the curing chamber or the space containing the protective sheet is raised to 60 to 85 ° C. at atmospheric pressure with steam to accelerate and cure concrete.

However, in both the method of covering the mold with the shielding sheet and the method of housing in the curing room, steam is blown into a large space, so that a large amount of heat is required and a large amount of heat is lost. Further, a large temperature difference (10 to 60 ° C.) occurs between the surface portion and the inside of the secondary concrete product due to the variation in the temperature in the space and the difference in the thickness and volume inside the mold.

Due to this temperature difference, although the hardening acceleration of concrete is within the same form, the strength required for demolding reaches 100% at the place of the minimum thickness, but at the place of the maximum thickness. Then, it may reach only 20 to 60%. For this reason, the strength becomes insufficient, and cracks, cracks, breakage, etc. occur at the time of demolding. In the season when the outside temperature is low, hair cracks occur more frequently due to the temperature difference between the surface and the inside.

As a preventive measure against these problems, hardening is generally accelerated by prolonging the curing time. However, since this requires a larger amount of heat, the curing cost is increased and the production efficiency is significantly impaired. It also results in continuing to apply excessive heat to the already hardened part, which greatly impairs the quality of the secondary concrete product.

On the other hand, Japanese Patent Publication No. 61-6029 and Japanese Examined Patent Publication No. 2-15518 disclose a method of curing a secondary concrete product by filling a hollow mold with a heat generating substance such as steam. .

However, in these methods, since the heat-generating substance is uniformly supplied without considering the difference in the thickness or volume inside the mold, a temperature difference occurs between the surface portion and the inside of the concrete, and depending on the part of the product. It is unavoidable that there is a difference in the degree of hardening acceleration, the strength is partially insufficient, and the risk of cracks occurring during demolding cannot be neglected. Also, the problem of energy loss has not been sufficiently solved by these methods.

[0008]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention Therefore, an object of the present invention is to supply the minimum necessary heat-generating substance or heating medium to the space of the double structure of the mold according to the thickness and volume of the target site. By doing so, it is to provide a method for curing secondary concrete products that improves the curing efficiency, saves energy, and secures the required strength.

[0009]

[Means for Solving Problems] In the method for curing a concrete secondary product of the invention of wood, one of the standing wall portion, the flat surface portion, the diagonal portion and the other portion contacting with concrete of the mold for molding the concrete secondary product is used. Part or all has a double structure that forms a single space or a plurality of independent spaces, and fills the space with a heating material or a heating agent, or a heating medium such as high-pressure steam, hot air, warm air, heated water or oil. Curing function to give heat for hardening to concrete from one side or both sides in contact with concrete by circulating or retaining The mold is equipped with, and each part where the thickness and volume of the concrete secondary product are different
In order to cure the minutes evenly within the same time,
The adjustment was changed according to the different member cross sections of the secondary product.
Promote concrete by giving the minimum necessary amount of heat to the space
To cure .

[0010]

[Operation] In this method of curing secondary concrete products,
The formwork is constructed of a single body corresponding to the shape of the target product, or a plurality of formwork parts 2, 3, 4, 5, 13
It is configured by dividing into. Forming a single body or a plurality of form parts 2, 3, 4, 5, 13 has a single space 11 by forming a part having a double structure in contact with concrete.
Alternatively, a plurality of spaces are formed.

The supply of the heat generating substance and the heating medium to each space 11 is adjusted in accordance with the thickness, volume, and volume of each part of the mold or the product to be molded by the mold part. The heating of the concrete made from one side or both sides is preferably a temperature difference between the surface part and the inside (the difference between the A point temperature and the B point temperature of the circle in Fig. 3 and the difference between the C point temperature and the D point temperature of the circle. ) Is performed within 3 hours so that the same temperature (60 to 80 ° C.) is reached.

After crossing the temperature rise curve of the product surface and the temperature rise curve of the inside of the product, the product 1 is left as it is for 0 to 120 minutes depending on the thickness of the product, etc. Good strength is secured, and it is released from the mold without causing cracks or damage.

[0013]

In the illustrated embodiment, the concrete secondary product 1 is a U-shaped gutter block, and the formwork is two left and right formwork parts forming the upper half of the outer surface of the standing wall of the product 1. 2, two left and right formwork parts 12 forming the lower half of the outer surface of the upright wall, a formwork part 4 forming the upper part of the inner side surface of the upright wall part, and a main part of the upright wall part. It is divided into two left and right formwork parts 3 forming the inner side surface and the upper surface of the bottom wall part, and a formwork part 5 forming the lower surface of the bottom wall part of the product 1.

These mold parts 2, 3, 4, 5, 12
Has a hollow double structure over the entire width and height, and a single space 11 is formed in each mold part. One or a plurality of heating medium inlets 3 and outlets 14 are provided in each mold portion so as to communicate with the space 11. In the space 11 of the mold parts 2, 3, 12 having a relatively large inner volume, distribution pipes 8, 9, 10 are installed inside in order to enhance the curing effect. , 9 and 10 are connected. Each distribution pipe is provided with a heating medium blowing hole on the peripheral side wall.

As a mode of supplying heat for accelerating hardening of concrete, a method of filling the space 11 with a heating material or a heating agent,
High pressure steam, hot air, warm air, a method of circulating or retaining a heating medium such as heated water or oil, a method of heating or heating a heating substance such as water or oil filled in the space 11 by electric heating or another method, etc. It is selected appropriately. By making the inlet port 13 and the outlet port 14 have the same diameter or making one of them smaller than the other, it is possible to change the flow rate and the retention state of the heating medium.

The size of the space 11 of the double structure of the mold and the mold part is appropriately determined according to the shape, size, weight, etc. of the product, the heating area, the temperature of the heating medium or the exothermic substance, the usage amount of the heating medium, etc. It is determined. Further, the outer cover material of the double structure on the side in contact with the outside air is made of a single material such as a steel plate or a composite material, but various heat retaining treatments can be applied to minimize the heating effect and energy loss. Moreover, in order to improve the flowability of the heating medium in the space, the reinforcing horizontal ribs and vertical ribs of the mold can be provided with a required number of through holes to the extent that the reinforcing action is not impaired.

In order to minimize the loss of the heating medium such as the discharged steam, the heating medium can be fed again to the inlet and reused. In addition, the discharged heating medium can be connected to an adjacent mold part to reuse the residual heat. This reuse can also be done between multiple forms. Further, in order to further enhance the curing effect, a shielding sheet can be used together.

The curing temperature is adjusted by manually or automatically controlling the supply amount of the heating medium. One of the methods is to install a control device in the pipe that injects the heating medium into the space of the double structure of the formwork, connect sensors such as a flow meter and a thermometer to the control device, and measure the outside air temperature and concrete mixing. Adjust the heating medium into each space until the temperature of the surface and the center of each part becomes equal to the preset value depending on the temperature, the thickness and volume of each part of the product, and then the surface and the center. There is a method of maintaining the same temperature for 0 to 120 minutes after the temperature of the parts becomes equal.

The heating of the concrete injection opening of the formwork is performed by an opening / closing method or another effective method. After the mold oil (releasing agent) applied to the mold is dried by preheating the mold, the concrete is filled into the mold and molded, the air bubbles on the product surface are greatly reduced, and a better quality concrete Secondary products can be manufactured.

[0020]

As described above, in the method for curing a concrete secondary product of the present invention, a part or all of the standing wall portion or the flat portion of the molding frame, the diagonal portion, or any other portion in contact with the concrete, It has a double structure that forms a single space or a plurality of independent spaces, limits the supply partner of the heat-generating substance or heating medium to the space, and the thickness of the concrete secondary product or
Evenly cure each part with different volume within the same time
Adjustments according to the thickness and volume of each part to be heated.
The minimum required amount of heat is added to the space,
Accelerate by heating concrete from one or both sides in contact
Because it is cured, it is possible to greatly improve the curing efficiency and save energy, and since there is no temperature difference between the surface and the inside of the product, there is no fear of hair cracks or damage, and secondary concrete of high quality The product can be manufactured efficiently.

In addition, since this curing method can be carried out immediately by partially modifying the mold by the conventional filling and molding method, the capital investment for the mold can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a mold for molding a concrete secondary product used for carrying out the method of the present invention.

FIG. 2 is a vertical sectional view of the mold.

FIG. 3 is a vertical cross-sectional view of a concrete secondary product molded by the mold.

[Explanation of symbols]

 1 Concrete secondary product 2 Formwork 3 Formwork part 4 Formwork part 5 Formwork part 6 Lifter 7 Lifter 8 Distribution pipe 9 Distribution pipe 10 Distribution pipe 11 Space for supplying heating medium 12 Formwork part 13 inlet 14 outlet

Claims (1)

[Claims] 1. A double structure in which a part or all of a standing wall portion, a flat surface portion, an oblique portion, and other portions in contact with concrete of a mold for molding a secondary concrete product form a single space or a plurality of independent spaces. The structure is such that the space is filled with a heat-generating material or a heat-generating agent, high-pressure steam, hot air, warm air, or a heating medium such as heated water or oil is circulated or retained, or the space is filled with water or oil. By heating or heating an exothermic substance by electric heating or some other method, the formwork is provided with a curing function of giving heat for hardening acceleration to concrete from one or both sides in contact with concrete.
Within the same time, each part with different thickness and volume of the secondary product
The minimum required heat, adjusted and adjusted according to the thickness and volume of each part of the concrete secondary product to ensure uniform hardening.
A method for curing a secondary concrete product, which comprises accelerating curing by giving an amount to the space .