JP2015063871A - Curing protective sheet, and curing protective device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing protective sheet and a curing protective device, for performing suitable curing by preventing cracking of concrete while preventing water from directly splashing on concrete.SOLUTION: In a curing protective sheet 11 used for curing of concrete 2 put in a form 1, a water retention part 13 comprises a part in which a waterproof sheet 15 with no air permeability, a water retention layer 14 made of a water-retentive material, and a part of a base material sheet 12 serving as a substrate for the water retention layer 14 are stacked in this order on the base material sheet 12 with air permeability. Moisture can be retained by the water retention part 13, and remarkable fluctuations in temperature and humidity within the curing protective sheet 11 can be suppressed.

Description

  The present invention relates to a curing protection sheet and a curing protection device that are necessary for curing in the summer mainly of concrete put in a formwork.

  Generally, concrete needs to be cured until it is fully cured after being driven. This is because the quality of curing greatly affects the properties of the concrete after curing. However, during curing of concrete, moisture in the concrete evaporates and cracks enter the concrete due to the increase in sunlight and outside air temperature. In detail, concrete curing is a heat source generated by the hydration reaction of the concrete, and is naturally dried and solidified. The moisture in the inside is very easy to evaporate, drying is promoted, a partially non-uniform dry state, and cracking is likely to occur.

  For this reason, an effective curing support means is required in order to prevent cracks in concrete due to sunlight in the summer. As conventional curing assistance means, for example, means by watering as described in JP-A-11-324327 (Patent Document 1) and JP-A-2000-179155 (Patent Document 2) has been performed. . However, the former sprinkling means is merely intended to automatically sprinkle the required amount of water every set time, and it is difficult to evenly sprinkle the water, especially near the faucet. The water pressure tends to change at a distant place, and there remains a problem that it is difficult to expect effective and uniform watering.

  In the latter case, it is a moisture imparting mechanism used in a specified method called slip foam method, between the concrete surface exposed as the sliding form used in the method rises and the windbreak hood. Because it is a moisture application mechanism that is sprayed, it cannot be applied to general curing concrete, and the problem that water distribution is difficult to be achieved with the spray-type moisture application still remains. .

  Furthermore, a curing system described in Japanese Patent Application Laid-Open No. 2000-264756 (Patent Document 3) that promotes curing by heating concrete using low-temperature and low-pressure steam has also been proposed. Inhalation, heating the air and returning it to the curing space requires precise temperature control, which is time consuming, requires a large device, and is cumbersome and expensive to install at the curing site. It was difficult to adopt.

  While these techniques exist, it has also been found that applying water directly to concrete is less favorable for concrete curing.

JP-A-11-324327 JP 2000-179155 A JP 2000-264756 A

  Therefore, the present invention provides a curing protection sheet and a curing protection device for preventing cracking of concrete and preventing the cracking of the concrete while preventing water from being directly applied to the concrete.

In order to achieve the above object, the present invention is configured as follows.
A curing protection sheet used for curing concrete placed in a mold, provided with a water-retaining part on a breathable base sheet, and the water-retaining part is composed of a non-breathable waterproof sheet and a water-retaining layer made of a water-retaining material. And the curing protection sheet which comprises the part which laminated | stacked in this order the said base material sheet used as the foundation | substrate of a water retention layer is provided.

Since the breathable base sheet is used, the inside and the outside covered with the curing protection sheet can be vented, and the temperature and humidity on both sides of the curing protection sheet can be made not significantly different. Therefore, it can prevent that the inside covered with the curing protection sheet becomes abnormally high temperature or high humidity.
And since the water retention part was provided, if water is sprinkled on the water retention part, moisture can be retained, and the rise in temperature around the water retention part can be suppressed by absorption of heat of vaporization caused by evaporation of the moisture. In particular, the water retaining portion has a breathable waterproof sheet, a water retaining layer made of a water retaining material, and a laminated structure in which a part of the base sheet serving as a base of the water retaining layer is laminated in this order. Water can be absorbed from a certain substrate sheet side, moisture can be retained by the water retaining layer, and a waterproof sheet having no air permeability can prevent moisture from leaking through the waterproof sheet. Therefore, since the waterproof sheet side is not submerged, it is possible to prevent water from being applied to the concrete and to suppress the temperature rise inside the curing protection sheet.

  A hose holder for fixing the water supply hose can be provided on the surface of the water holding portion on the base sheet side. Since the hose holder for fixing the water supply hose is provided on the surface of the water holding part on the base sheet side, the water supply hose can be fixed to the water holding part, and water can be effectively poured into the water holding layer of the water holding part. . Moreover, since a hose holder becomes a mark and the position of a water holding part is known, a curing protection sheet can be appropriately arranged on a mold.

  A sheet fixing portion for fixing the base sheet to the ground or the like can be provided at the end of the base sheet. For example, by providing a sheet fixing portion such as eyelets, the curing protection sheet can be fixed to the ground or the like even when the wind is strong, and fluttering can be suppressed.

Furthermore, a curing protection device comprising such a curing protection sheet, a water supply hose, and a flow rate detection device capable of measuring the amount of water flowing to the water supply hose is provided.
Because it includes a curing protection sheet, a water supply hose, and a flow rate detection device that can measure the amount of water flowing to the water supply hose, when the curing protection sheet is placed according to the length and spread of the formwork that differs depending on the site Moreover, it is possible to manage and control the effective water supply amount according to the situation.

  According to the curing protection sheet and the curing protection device of the present invention, it is possible to prevent problems such as cracking of concrete due to excessive temperature rise during summer concrete curing. Moreover, according to the curing protection sheet and the curing protection device of the present invention, the design and aesthetics of the concrete surface are not impaired.

It is a partially notched perspective view which shows the use condition of the curing protection sheet at the time of construction. It is a top view of a curing protection sheet. It is the SA-SA sectional view taken on the line of FIG. It is the SB-SB sectional view taken on the line of FIG. It is sectional drawing equivalent to FIG. 3 of the example of a change. It is the SC-SC sectional view taken on the line of FIG. It is sectional drawing equivalent to FIG. 6 of the example of a change. It is a schematic diagram which shows an example of a curing protection apparatus. It is a longitudinal cross-sectional view which shows the use condition of the curing protection sheet at the time of construction.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing a state in which concrete 2 which needs to be cured in a mold 1 is covered with a curing protection sheet 11 in order to produce a foundation of a building. FIG. 2 shows this curing protection sheet. 11 is a plan view.

As shown in FIG. 1, the curing protection sheet 11 is a sheet that covers the mold 1 in order to protect the concrete 2 struck onto the mold 1 until it is suitably solidified. The water-retaining part 13 is provided along the central longitudinal direction, which is a part of the base sheet 12 having air permeability and having a rectangular shape.
As shown in FIG. 3, the water retention part 13 is configured by a part in which a water retention layer 14 made of a water retention material and a waterproof sheet 15 having no air permeability are laminated on a base sheet 12. On the other hand, both end portions of the curing protection sheet 11 other than the water retention part 13 are constituted by a base sheet 12 as shown in FIG.

  A hose holder 17 for fixing the water supply hose 19 with a hook-and-loop fastener or the like is provided on the surface of the water retention unit 13 on the base sheet 12 side. Further, at the four corners and the long side end portions which are the end portions of the curing protection sheet 11, sheet fixing portions 18 with eyelets or the like are provided so that the curing protection sheet 11 can be fixed to the ground.

  The material used for the base material sheet 12 is preferably light-shielding so that sunlight does not directly reach the concrete, and a breathable mesh or the like that prevents the interior covered with the sheet from becoming too hot. A sheet is used. Such breathable sheets include mesh-like high-density polyethylene resin sheets such as the so-called “shade cloth”, and meshes made by welding polyvinyl chloride or polyurethane cloth to a polyester base cloth. A sheet-like sheet can be exemplified.

  Moreover, although the water retention material used for the water retention layer 14 includes fibers and foamed resins such as polyester and nylon having water retention properties, it is preferable to use a nonwoven fabric composed of polyester fibers or a nonwoven fabric composed of nylon fibers. it can.

  As the waterproof sheet 15, a resin sheet having no air permeability can be used. For example, a synthetic resin made of polyethylene or polyvinyl chloride is laminated on a base fabric made of polyester fiber, such as a sheet commonly called "tarporin". Sheet.

The end portion of the water retaining portion 13 joins the base sheet 12, the water retaining layer 14 and the waterproof sheet 15 by thermocompression bonding, bonding with an adhesive, sewing, etc. The material sheet 12 and the waterproof sheet 15 may be combined. In particular, the center 11a of the short side end portion of the curing protection sheet 11 is a portion that rides on the mold 1, and if moisture leaks from this portion, the concrete 2 may be directly covered with moisture, and therefore shown in FIG. Thus, it is a preferable modification that the water retaining layer 14 is confined inside and the base sheet 12 and the waterproof sheet 15 are fixed.
As shown in FIG. 6, the boundary between the water retaining portion 13 and the other portions is not limited to the case where the end of the water retaining layer 14 is peeled off and the three layers are fixed, as shown in FIG. The base sheet 12 and the waterproof sheet 15 can be fixed to each other, but when the curing protection sheet 11 is placed on the mold 1, it is difficult to leak moisture inside the base sheet 12 and The embodiment shown in FIG. 7 in which the waterproof sheet 15 is fixed is preferable.

The size of the curing protection sheet 11 is not particularly determined because the size of the formwork also changes depending on the size of the building, but for the convenience of handling, the length is about 2 m to 10 m, and the width is a gap. It is preferably about 1 to 8 m so as to be covered with the mold so as not to appear.
Moreover, the thickness of the curing protection sheet 11 is preferably such that the base sheet 11 does not easily rise in the wind and does not become heavy in work, and is about 0.2 mm to 2.0 mm. The thickness of the water retention layer 14 is It is preferably about 5 mm to 25 mm so that an appropriate amount of water can be retained, while the sheet does not bend and damage the concrete surface by retaining a large amount of water. Furthermore, if the waterproof sheet 15 is too thick, it drips or becomes heavy from the end thereof, and if it is too thin, the waterproof sheet 15 is easily damaged and easily perforated. Therefore, the thickness is preferably about 0.2 mm to 0.5 mm.

  The water supply hose 19 is preferably made of, for example, a material having good compatibility in which a recycled raw material of rubber and polyethylene are blended, and a hose having a porous structure in which water oozes from the outer surface of the hose (“Sheper hose (trade name)”) is used. be able to. It may be sprayed in the form of a fountain or sprayed, but if it is a hose in which water gradually oozes from the outer surface of the hose as sweat oozes out from the body, water can be effectively supplied to the water retaining part 13 preferable. Water supply from the water supply hose 19 can control the water supply amount and time with a timer.

  FIG. 8 shows an example of a curing protection device (watering system) 20 using the watering hose 19 (the description of the curing protection sheet 11 is omitted). A timer 21 and a pressure hose 22 are connected to a water source (faucet), and the pressure hose 22 is further branched in three directions through a four-port branch 23. A water supply hose 19 is connected to the tip of the pressure hose 22 via a coupler 24 at the branched end. Further, by providing the coupler 25, it is possible to connect a plurality of water supply hoses 19 if necessary. A stop valve 26 is provided at the tip. Moreover, it is preferable to provide the flowmeter 27 in a part of piping connected with such a pressure | voltage resistant hose 22 and the water supply hose 19. FIG. Specifically, by providing a flow meter 27 as a flow rate detector near the front position of the four-port branch 23 and in the vicinity of the tip of each branch destination, the difference in water amount between the upstream portion of the pipe and the downstream portion of the branch destination is reduced. It is possible to grasp and control the amount of water supply. A water pressure meter or the like may be provided instead of the flow meter to control the amount of water supplied from the viewpoint of water pressure.

The usage of the curing protection sheet 11 is shown below (see FIG. 9). After the concrete 2 is struck onto the mold 1, the curing protection sheet 11 is covered so as to cover the entire mold 1 so that the water retaining portion 13 is positioned on the upper part of the mold 1. At this time, the waterproof sheet 15 side of the water retaining portion 13 is set to the mold side, and the base sheet 12 side is exposed on the surface.
If a water supply hose 19 is arranged and fixed to a hose holder 17 provided in the water holding part 13, and water is regularly supplied to the water supply hose 19, the water oozed from the water supply hose 19 is permeable to the base material. The sheet 12 passes through the water retention layer 14 and is stored in the water retention layer 14. Since the water retaining layer 14 is blocked by the waterproof sheet 15, water does not flow out to the mold 1 side. Therefore, it is possible to prevent water droplets from falling on the concrete 2 and maintain the design, smoothness, and aesthetics of the surface of the concrete 2.

On the other hand, the water supplied in excess of the water retention amount of the water retention layer 14 is transmitted along the surface of the base sheet 12 and flows down to the ground while lowering the surface temperature.
During the time when the water supply hose 19 is not supplied with water, the water stored in the water retention layer 14 prevents a sudden temperature rise due to changes in the outside air temperature or heat generation during concrete hardening. That is, when the stored water evaporates through the base sheet 12, it takes away latent heat of vaporization and suppresses the temperature rise around the water retaining portion 13 so that the temperature of the space surrounded by the mold 1 and the waterproof sheet 15 does not rise too much. Can be. In addition, since the inside and outside air enters and exits through the air-permeable base sheet 12 in the interior covered with the curing protection sheet 11, it is difficult for heat to accumulate, and rapid fluctuations in humidity can be reduced.

The hose holder 17 provided on the base material sheet 12 side of the water retention part 13 can keep the water supply hose 19 at the upper part of the mold 1, and suitably supply water from the water supply hose 19 to the water retention layer 14. It is a role. In addition, the hose holder 17 also serves as a mark indicating the position of the holding portion 13 and assists in properly arranging the curing protection sheet 11 on the mold 1.
The sheet fixing portion 18 provided at the side edge portion or corner portion of the curing protection sheet 11 is formed by making a hole in the sheet with eyelets or the like, and using a fixing / holding means to the ground such as a peg. It can be fixed to the ground or tied to a fixed object by providing a knot or the like. Thereby, the curing protection sheet 11 can be prevented from being easily lifted by the wind, and the worker can be prevented from catching the end of the curing protection sheet 11 with his / her foot.

  In addition, it is preferable that the supply amount of water is controlled to the extent. For that purpose, the amount of water evaporation is predicted from the temperature and humidity, the concrete temperature, and the wind speed. On the other hand, the flow meter 27 measures the outflow amount of water from the water supply hose 19 that reaches each end when predetermined water is supplied from the water source. Then, the number of times of water supply, the water supply time, and the flow rate are determined so that water can be supplied as much as the predicted amount of water evaporation, and the opening degree of the faucet is adjusted based on that, and the timer 21 is set. Thus, the amount of water supply can be controlled.

The present invention will be further described below by showing experimental examples.
(1) Production of Curing Protection Sheet (11) For the base sheet (12), a shade sheet made of polyethylene resin, a PET nonwoven fabric with a thickness of 20 mm as the water retaining part (13), and PVC as the waterproof sheet (15) Each type of turbolin was used. In addition, the water supply hose (19) was made of a porous material and water was oozed out (Unihose, “Sheper Hose (trade name)”). The overall dimensions of the curing protection sheet (11) are 4000 mm in the length direction and 1800 mm in the width direction, with a width of 600 mm in the center of the width direction, and the base sheet (12), the water retaining layer (14) and the waterproof sheet (15). A water retention part (13) having a three-layer structure was provided. On the other hand, the width of 600 mm at both ends of the water retention part (13) is a one-layer configuration of only the base sheet (12). Further, a hose holder (17) using a hook-and-loop fastener was provided on the surface of the water retention part (13) on the base sheet (12) side.

(2) Curing of concrete placed in the formwork Cover the formwork by applying the previous protection sheet (11) so that the waterproof sheet (15) side of the water retention part (13) is located on the upper surface of the house foundation formwork did. A water supply hose (19) was placed in the water retention part (13) and fixed with a hose holder (17). Water was supplied to the water supply hose (19) twice a day (Example 1). For comparison, an experiment was performed in which no water was supplied using this curing protection sheet (11) (Example 2). Further, an experiment was conducted in which the formwork was covered with a commercially available blue sheet and water was not supplied (Example 3). The temperature inside the mold was measured for about 24 hours. The results are shown in the following table.

Formwork internal space temperature (℃)
Curing protection sheet Curing protection sheet Blue sheet
Watering No water No water
(1) Average value 38.7 37.8 43.2
(2) Maximum temperature 50.1 61.4 60.9
(3) Minimum temperature 32.8 29.1 34.9
(2)-(3) 17.3 32.3 26.0

As shown in the table, when the curing protection sheet (11) is used, there is no significant difference in average temperature in comparison with the case where water is supplied or not, but when looking at the maximum temperature, When the water was supplied, the temperature was lowered by about 10 ° C., and the temperature difference between the maximum temperature and the minimum temperature was reduced by about 15 ° C. It can be seen that by using the curing protection sheet (11) to supply water appropriately, the temperature change in the mold (1) can be reduced and the concrete (2) is excellently cured.
In addition, when both the curing protection sheet (11) and the blue sheet are compared without water, the curing protection sheet (11) has a lower average value (average temperature) and minimum temperature (nighttime) than the blue sheet. The reason for this is that the portion of the curing protection sheet (11) other than the water retention part (13) is a breathable base sheet (12), so it is easily affected by a decrease in temperature such as at night. Conceivable. However, for concrete curing in summer, the decrease in temperature does not need to be a problem, and it is necessary to pay attention to excessive temperature rise. Therefore, the curing protection sheet (11) that can keep the temperature low on average is better than the blue sheet. Is also preferable.
Therefore, the curing protection sheet (11) is an excellent sheet for curing concrete (2), and it is not possible to use the curing protection device (20) including the watering mechanism by the watering hose (19). It can be seen that this is an excellent method for curing concrete (2).

DESCRIPTION OF SYMBOLS 1 Formwork 2 Concrete 11 Curing protection sheet 11a Short side edge center 12 Base material sheet 13 Water retention part 14 Water retention layer 15 Waterproof sheet 17 Hose holder 18 Sheet fixing part 19 Water supply hose 20 Curing protection device (watering system)
21 timer 22 pressure hose 23 4 port branch 24, 25 coupler 26 stop valve 27 flow meter

Claims (4)

Curing protection sheet used for curing concrete placed in a mold,
A water-retaining part is provided on a breathable base sheet, and the water-retaining part comprises a waterproof sheet having no breathability, a water-retaining layer made of a water-retaining material, and a part of the base sheet serving as a foundation for the water-retaining layer. Curing protection sheet composed of layers laminated in this order.   The curing protection sheet of Claim 1 which provided the hose holder which fixes a water supply hose to the surface at the side of the base material sheet of the said water retention part.   The curing protection sheet of Claim 1 or Claim 2 which provided the sheet | seat fixing | fixed part for fixing this base material sheet to the ground etc. in the edge part of the said base material sheet.   A curing protection device comprising the curing protection sheet according to any one of claims 1 to 3, a water supply hose, and a flow rate detection device capable of measuring the amount of water flowing to the water supply hose.

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