JPH068228B2 - Curing method for hydraulic inorganic moldings - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for curing a hydraulic inorganic molded article.

(Prior art) Conventionally, molded articles containing cement (for example, roof tiles and walls)
In the case of curing by curing, first, after dehydration press molding, leave the molded product placed on a flat plate-like receiving plate made of FRP or the like and leave it for about 4 hours at an ambient temperature of 20 ° C to 30 ° C. Precuring is performed, and then the ambient temperature is 50 ° C to 60 ° C.
Primary curing is performed by leaving it in a steam chamber with a humidity of about 95% for a predetermined time. If sufficient strength is obtained at this stage, the curing process is terminated by removing it from the backing plate, but if the strength is still insufficient at this stage, secondary curing by steam curing or room temperature curing is further performed.

(Problems to be Solved by the Invention) In such a curing method, when the outside air temperature is low such as in winter, the pre-curing cannot be performed outdoors or indoors without a heating facility. It is necessary to keep the inside of the room insulated from the outside air and to heat the room to a predetermined temperature (20 ° C to 30 ° C) with a heating device such as a boiler. in this case,
If the humidity is too low, the molded product may be too dry and the final strength may not be sufficiently obtained. Therefore, appropriate humidification is also required. As described above, the pre-curing when the temperature is low has a problem that a large-scale facility (heating facility and humidifying facility) is required in addition to the primary curing.

(Means for Solving the Problems) A method for curing a hydraulic inorganic molded article according to the present invention is a hydraulic inorganic molded article formed in an appropriate shape on a receiving plate in which an internal cavity is filled with a latent heat storage agent. After the object is placed and left for a predetermined time for pre-curing, the hydraulic inorganic molded article is left on the receiving plate for a predetermined time in the steam chamber for primary curing. The hydraulic inorganic molded product is, for example, a fiber-reinforced cement composition molded into an appropriate shape by dewatering press molding.

(Function) A hydraulic inorganic molded article is placed on a receiving plate having an internal cavity filled with a latent heat storage agent, and pre-curing is performed for a predetermined time.
In this case, the ambient temperature required for precuring is 20 ° C to 30 ° C.
Since the temperature is in ° C, a hexahydrate salt of calcium chloride, for example, having a phase conversion temperature in this range is used as the heat storage agent filled in the backing plate. Thereby, the hydraulic inorganic molded product on the receiving plate can be cured in the range of 20 ° C to 30 ° C by the heat dissipation of the heat storage agent without being affected by the outside air temperature (for example, 10 ° C or less). After that, the heat storage agent is stored again by the primary curing in which the receiving plate is left in the steam chamber together with the hydraulic inorganic molded product for the primary curing, and is ready for the next new precuring.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

The drawings show the structure of a backing plate used in the curing method of the present invention.

In the figure, reference numeral 1 is a hydraulic inorganic molding, for example, a roof tile. Reference numeral 2 denotes a receiving plate on which the roof tile 1 just after the molding is placed, the upper surface of which is formed in a corrugated shape that matches the lower surface of the roof tile 1, and a cavity 2a is formed inside. The latent heat storage agent 3 is filled in the cavity 2a of the receiving plate 2.

Here, the latent heat type heat storage agent refers to a type that does not show the effect of increasing the temperature at the time of phase conversion from solid to liquid or liquid to solid and simply spends energy to change the state of the substance. As such a latent heat type heat storage agent,
Those having a phase conversion temperature of 30 ° C. to 60 ° C., for example, calcium chloride hexahydrate (phase conversion temperature: 29 ° C.), sodium sulfate decahydrate salt (32.4 ° C.), calcium nitrate tetrahydrate (43 C.), sodium acetate trihydrate (58.degree. C.), and eutectic salts thereof. In this embodiment, 5 kg of calcium chloride hexahydrate is used as the heat storage agent 3 in the cavity 2a of the receiving plate 2. Calcium chloride hexahydrate has a phase conversion temperature of 29 ° C and a latent heat of 40k.
Since it is cal / kg, this one receiving plate has a latent heat amount of 200 kcal.

Next, the curing method of the present invention using the receiving plate 2 having the above structure will be described.

First, the fiber-reinforced cement composition is dehydrated and press-molded to form the roof tile 1, and the roof tile 1 immediately after this molding is placed on the upper surface of the receiving plate 2, and the roof tile 1 is covered (not shown) from the front side. Perform recuperation. In this case, the precuring is performed at an ambient temperature of 20.
It is carried out by leaving it at 4 ° C to 30 ° C for 4 hours, but even when the outside temperature is low (for example, 10 ° C or less) such as in the winter, without storing it in a boiler room or the like, it can be used outdoors or in a heating facility. Leave the roof tile 1 for about 4 hours 20
Can be kept above ℃. That is, the roof tile 1 can be kept at a constant temperature for a certain period of time by utilizing the latent heat when the heat storage agent 3 filled in the receiving plate 2 undergoes a phase conversion from a liquid to a solid. However, it is assumed that the heat storage agent 3 is liquid in advance. Since the pre-curing using such a receiving plate 2 is heat transfer by surface contact with the roof tile 1, the heat transfer efficiency of heat is better than the surface heating of the roof tile 1 by air propagation as in the conventional method. . In addition, such pre-curing is necessary in order to make the calcium ion concentration in the tissue of the molded product uniform and to carry out uniform hydration. Furthermore, the roof tile 1 in an uncured state immediately after molding
When exposed to extremely low temperatures, water in the tissue may freeze and the roof tile 1 may be cracked, causing frost damage. That is valid.

In addition, as a cover for covering the roof tile 1, a synthetic resin film, a synthetic resin felt made of cloth, or the like is preferable.

When the pre-curing is completed in this way, then the primary curing is carried out with the roof tile 1 placed on the receiving plate 2. The primary training is performed by leaving the roof tiles 1 in the steam chamber at an ambient temperature of 50 ° C. to 60 ° C. and a humidity of about 95% for a predetermined time. At this time, the heat storage agent 3 that has been phase-converted from liquid to solid by precuring is heated (absorbs heat and stores heat) and is phase-converted again to solid or liquid.

If sufficient strength is obtained in this way, the roof tile 1 is taken out together with the receiving plate 2 from the steam chamber, and then the roof tile 1 is taken out from the receiving plate 2 to complete the curing. Then, the backing plate 2 taken out from the steam chamber is used again for pre-curing another roof tile 1.

In this way, the heat storage agent 3 repeats heat dissipation during precuring and heat storage during primary curing. Therefore, a new heat source for storing only the heat storage agent 3 that radiates heat in the precuring is not required.

If sufficient strength has not yet been obtained by the above-mentioned primary curing, secondary curing by steam curing or room temperature curing for a predetermined time is further performed.

In addition, although the roof tile 1 is taken as an example of the molded product in the above-described embodiment, the present invention is not limited to this, and a wall body or the like may be used.

(Effects of the Invention) As described above, according to the method for curing a hydraulic inorganic molded article according to the present invention, in precuring, even when the outside temperature is low such as in winter, a large-scale heating facility or humidifying facility can be used. The above-mentioned curing can be easily performed without needing a thing.

[Brief description of drawings]

The drawing is a vertical cross-sectional view of a backing plate used in a method for curing a hydraulic inorganic molded article according to the present invention. 1 ... Roof tile 2 ... Receiving plate 3 ... Heat storage agent

Claims (2)

[Claims] 1. A hydraulic inorganic molding having a proper shape is placed on a receiving plate having an internal cavity filled with a latent heat type heat storage agent and left for a predetermined time to perform precuring. A method for curing a hydraulic inorganic molded article, characterized in that the hydraulic inorganic molded article is left on a receiving plate in a steam chamber for a predetermined time for primary curing. 2. The method for curing a hydraulic inorganic molded article according to claim 1, wherein the hydraulic inorganic molded article is obtained by molding a fiber-reinforced cement composition into a proper shape by dehydration press molding.