JP4889056B2 - Concrete curing sheet and curing method - Google Patents

Description

  The present invention relates to a concrete curing technique.

  For example, as one of the tunnel lining methods, a centle (movable formwork made of steel that can be foldable) installed movably in an excavated tunnel is used, and the gap between the tunnel inner wall surface and the centle is used. After placing the lining concrete, move the centle to the place adjacent to the place where the lining concrete is placed, and cover the gap between the inner wall of the tunnel and the centle. There is known a method in which the concrete is repeatedly placed.

  In addition, if the curing of the laid concrete is insufficient, the lining concrete will crack or collapse, so it is important how well the lining concrete can be cured. It is an important matter.

For example, as a technique for curing an arched lining concrete in a tunnel, there is a technique described in Patent Document 1.
This is, as shown in FIG. 5 of Patent Document 1, arched balloons 2 and 2 on both sides that delimit predetermined places in the arched secondary lining concrete 1 in a mountain tunnel, The sealing sheet 3 that seals between the balloons 2 and 2 on both sides, and the air formed in the space formed between the inner wall surface 1a of the secondary lining concrete 1 and the balloons 2 and 2 and the sealing sheet 3 on both sides. An air layer between the inner wall surface 1a of the secondary lining concrete 1 and the balloons 2 and 2 and the sealing sheet 3 on both sides of the secondary lining concrete 1 to keep the inside warm. The next lining concrete 1 is initially cured.

  However, such a curing method using a balloon requires relatively expensive balloons 2 and 2 in order to hold the sealing sheet 3 in an arch shape, and also requires a steel base (not shown). It becomes indispensable, leading to an increase in size and complexity of equipment, and an increase in cost.

  In addition, since the number of balloons that can be prepared is limited, work efficiency is poor, and curing cannot be performed efficiently. As a result, concrete placement is also limited due to waiting for balloons (curing), etc. There was a concern that the construction period would be longer.

  For this reason, in Patent Document 1, a polystyrene foam material having a predetermined size formed so as to have a surface along the inner wall surface of the tunnel is used as a curing material, and a plurality of polystyrene foam materials having a predetermined size are used in series. A new curing technique is proposed in which the back side of the expanded polystyrene material is held by an arched air tube.

JP 2006-328869 A

  However, the one proposed in Patent Document 1 also requires a relatively expensive air tube, and the foamed polystyrene material is also expensive, and the foamed polystyrene material needs to be formed so as to have a surface shape along the tunnel inner wall surface. There is a fact that it is difficult to reduce costs.

  In addition, since it is a method of connecting a plurality of foamed polystyrene materials of a predetermined size, the work efficiency is poor, and there are also problems such as a decrease in the moisture retention level and the heat insulation level between adjacent foamed polystyrene materials, and sufficient curing may not be possible. There is also.

  The present invention has been made in view of such conventional circumstances, and an object of the present invention is to provide a concrete curing method and a concrete curing sheet capable of curing concrete well while having a simple, inexpensive and lightweight configuration. .

Concrete curing method according to the present invention,
A concrete curing method for curing a concrete by mounting a resin sheet having a plurality of air enclosing portions on a concrete surface ,
The plurality of air enclosing portions of the resin sheet have different diameters .

Concrete curing method according to the present invention,
A concrete curing method for curing a concrete by mounting a resin sheet having a plurality of air enclosing portions on a concrete surface,
The plurality of air enclosing portions of the resin sheet are configured by a plurality of layers and have different diameters between the plurality of layers.

In the present invention, the diameter of the plurality of air enclosures in the layer close to the concrete surface may be smaller than the diameter of the plurality of air enclosures in the layer far from the concrete surface.

In this invention, the air enclosure part of another resin sheet is arrange | positioned in the clearance gap between the air enclosure parts of one resin sheet, It can be characterized by the above-mentioned.

In the present invention, the attachment to the concrete surface can be characterized by being attached using an adhesive.

The resin curing sheet according to the present invention is a resin sheet having a plurality of air enclosing portions, wherein the plurality of air enclosing portions of the resin sheet have different diameters.

The resin curing resin sheet according to the present invention is:
A resin sheet having a plurality of air enclosing portions, wherein the plurality of air enclosing portions of the resin sheet are configured by a plurality of layers and have different diameters between the plurality of layers.

In the present invention, the diameter of the plurality of air enclosures in the layer close to the concrete surface may be smaller than the diameter of the plurality of air enclosures in the layer far from the concrete surface.

In this invention, the air enclosure part of another resin sheet is arrange | positioned in the clearance gap between the air enclosure parts of one resin sheet, It can be characterized by the above-mentioned.

In the present invention, the front and back surfaces of the resin sheet may be flat.

In the present invention, an adhesive mainly composed of a polyvinyl alcohol-based adhesive is applied to one of the front and back surfaces of the resin sheet, and a release paper is attached to the applied surface. Can do.

In the present invention, the release paper may be wound in a roll shape so as to be on the outside.

  According to the present invention, it is possible to provide a concrete curing method and a concrete curing sheet that are capable of curing concrete well with a simple, inexpensive, and lightweight configuration.

It is sectional drawing which shows roughly the whole lining concrete curing structure in the tunnel which concerns on one Embodiment of this invention. It is sectional drawing which shows the cross-section of the curing sheet (LHT) which concerns on embodiment same as the above. It is a top view for demonstrating the bubble part of the curing sheet (LHT) which concerns on embodiment same as the above, (A) is a top view of the 2nd layer resin film, (B) is the 3rd layer resin film FIG. It is the table shown compared with the other curing method about the temperature gradient inside a concrete section to the outside air temperature change at the time of curing using the curing sheet (LHT) according to the above embodiment and the possibility of cracking . It is the table which showed the heat transfer coefficient at the time of using the curing sheet (LHT) concerning embodiment same as the above compared with the heat transfer coefficient material in other curing methods. It is the table shown compared with the other curing method about the temperature gradient inside a concrete section with respect to the curing days at the time of curing using the curing sheet (LHT) concerning an embodiment same as the above. It is the time chart which showed the mode of the concrete surface part temperature change with respect to the curing days at the time of curing using the curing sheet (LHT) according to the embodiment as compared with other curing methods. It is the time chart which showed the mode of change of the concrete surface humidity with respect to the curing days at the time of curing using the curing sheet (LHT) according to the embodiment as compared with other curing methods. It is a table | surface which shows the relationship between the fall rate of the humidity of the concrete under curing, and a crack generation probability.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

  FIG. 1 is a sectional view schematically showing a lining concrete curing structure in a tunnel according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a sectional structure of a curing sheet used in the curing structure. 3 (A) and 3 (B) are plan views for explaining a bubble portion of the curing sheet.

Here, in order to construct a highly durable and dense tunnel lining concrete, sufficient curing during construction is required.
When sufficient curing is performed, the durability of the concrete can be improved, and cracks and the like can be suppressed, and a concrete wall excellent in strength and beauty can be provided.

Concrete in which strength is expressed by a cement hydration reaction accompanied by heat generation is affected by outside air through a heat transfer boundary with outside air on the surface portion.
In other words, in the curing concrete, thermal strain occurs due to the temperature difference between the surface (relatively low temperature) and the interior (relatively high temperature), and tensile stress (internal restraint stress) is generated on the concrete surface. Cracks and the like starting from are likely to occur.

  The present inventors conducted various research experiments. As a result, in the lining concrete (thickness t = about 30 cm), as shown in FIG. The temperature increases when the outside air temperature falls below 0 ° C.

  When the concrete that has generated heat due to the hydration reaction is cooled and further dried, the concrete shrinks, and when the shrinkage is constrained to the outside (for example, the non-land surface of the sprayed concrete surface of the lining concrete) Tensile stress (external restraint stress) is generated on the concrete surface, and cracks or the like starting from the surface side are likely to occur.

  In order to reduce the tensile stress generated by these “internal restraint stress” and “external restraint stress” and suppress the occurrence of cracks, etc., (1) the concrete temperature is lowered slowly, (2) the concrete section It is important to reduce the temperature difference in the interior (temperature difference between the concrete surface and the inner part), but it is considered that these can be achieved by appropriately heat-treating the concrete.

In addition, concrete does not undergo a sufficient hydration reaction if water is insufficient at the young age, and external constraining stress increases when the surface dries.
Therefore, when curing concrete, it is necessary to perform moisture retention curing (curing in a sealed state to retain moisture or curing in a humidified state) that keeps the concrete surface in a sufficiently wet state.

  The inventor of the present invention has developed a concrete curing technique that can achieve both heat curing and moisture curing effectively while repeating a variety of research experiments and having a simple and low-cost configuration.

  The concrete curing technology according to the present invention is a resin curing sheet, for example, by sticking the resin curing sheet to the surface of the lining concrete after decentration of the centle with an adhesive, thereby maintaining a heat retaining effect and a high humidity state (so-called wet state). Moisturizing effect that can be produced.

  For example, as shown in FIGS. 3A and 3B, the curing sheet according to the present invention can exhibit a high heat retention effect and a moisture retention effect during concrete curing. It can be set as the sheet | seat made from the polyethylene which has several air enclosure parts called the bubble buffer sheet | seat, bubble sheet | seat, air cushion, or bubble wrap sheet | seat (trademark) etc. which are utilized widely for packing.

  In addition, since a bubble sheet is resin, it is excellent in moisture retention, and since it has several air enclosure part (bubble), it is excellent in heat insulation and excellent in heat retention. Further, when such a bubble sheet is used as a curing sheet, it is inexpensive, easily available, and lightweight and easy to handle.

  Further, in the present invention, the air bubble sheet for curing is adhered to the surface of the concrete with an adhesive. For example, the adhesive is used for curing at a work site (for example, a lining concrete construction site in a tunnel). It can be applied to the adhesive surface of the bubble sheet with concrete. Alternatively, an adhesive is applied to the adhesive surface of the air bubble sheet for curing in advance, and release paper is affixed to prevent the adhesion performance from deteriorating due to dust adhering to the application surface. It is also possible to attach the curing sheet to the concrete surface while peeling the release paper at the lining concrete construction site in the tunnel (for example, etc.).

  If the curing sheet is adhered to the concrete surface with an adhesive as in the present invention, a relatively large facility such as a conventional balloon can be dispensed with, and the cost can be greatly reduced. It is possible to improve the work efficiency.

  In addition, the present inventors have conducted various experimental studies and know the structure of the air bubble sheet for curing that can further improve the heat retaining property and the moisture retaining property.

  The air bubble sheet for curing made of polyethylene having a plurality of air enclosing portions according to the present embodiment (hereinafter sometimes referred to as LHT. LHT (trademark): Lining Concrete Humidity / Thermal Sheet) 100 is as shown in FIG. Further, it can be composed of a plurality of layers.

  In the LHT 100 according to the present invention, the surface portion in contact with the outside air is used as the first layer sheet, and this is constituted by the transparent film 101 made of polyethylene.

The second layer sheet is a layer closer to the concrete surface side than the first layer, and is composed of a transparent film 102 made of polyethylene having a plurality of air-sealed portions (bubble portions) 102A having a relatively large diameter arranged in a plane. Can do. For example, as shown in FIG. 2 and FIG. 3 (A), the size of the air enclosing portion (bubble portion) 102A is, for example, a particle size of 20 mm, a vertical and horizontal arrangement pitch of 12 mm, and a particle height (H) of 8 mm can do.
However, the particle size, the arrangement pitch, the particle height, and the like can be changed as appropriate, and the air sealing portion (bubble portion) 102A having a different particle size in the same layer can also be used.

The third layer sheet is a layer closer to the concrete surface side than the second layer, and is composed of a transparent film 103 made of polyethylene having a plurality of air-sealed portions (bubble portions) 103A having a relatively small diameter arranged in a plane. Can do. For example, as shown in FIG. 2 and FIG. 3 (B), the size of the air enclosing part (bubble part) 103A is such that the particle diameter is 10 mm, the vertical and horizontal arrangement pitch is 12 mm, and the particle height (H) is 3.5 mm. Can be adopted.
However, the particle size, the arrangement pitch, the particle height, and the like can be changed as appropriate, and the air sealing portion (bubble portion) 103A having a different particle size or the like can be provided in the same layer.

  The fourth layer sheet is a layer that is in contact with the concrete surface while being in contact with the third layer, and is composed of a transparent film 104 made of polyethylene.

  The film (sheet) 101 to 104 of each layer has a width of about 1.2 m and a length of about 20 to 25 m, and the layers 101 to 104 are stacked and bonded to each other to have a thickness of about 11.5 mm. It can be handled as a single sheet, which is wound into a roll.

  In this way, by making the fourth layer film 104 in contact with the concrete surface a flat film, the entire surface can be brought into close contact with the concrete surface without any gaps, and moisture retention during curing can be made at a high level. It is possible to provide a finished surface having a good appearance with little unevenness on the surface. In addition, the adhesiveness applied to the concrete surface can be maximized.

  Furthermore, by making the first layer film 101 in contact with the outside air a flat film, when sticking the LHT 100 to the concrete surface, a broom-like tool or a spatula-like tool is used to increase the degree of adhesion. Since there is nothing to catch even if the surface of the LHT100 is scratched, the LHT100 can be smoothly and satisfactorily adhered to the concrete surface, and the surface of the concrete has irregularities and the like while maintaining a high level of heat retention and moisture retention. It is possible to provide a finished surface with a small and uniform appearance.

  In addition, the LHT 100 according to the present embodiment is obtained by superposing a resin sheet having a relatively large air enclosing portion (bubble portion) and a resin sheet having a relatively small air enclosing portion (bubble portion). Therefore, since it becomes a result which covers the clearance gap between adjacent large air enclosure parts (bubble part) by the small air enclosure part (bubble part), it comes to be able to improve the heat retention during curing. Yes.

  In addition, although the resin-made sheet | seat which has the air enclosure part (bubble part) of the same size or a near size can also be piled up, in that case, the clearance gap between the air enclosure part (bubble part) which adjoins one curing sheet | seat It is preferable to adjust the overlapping position of the curing sheet so that the air sealing part (bubble part) of the other curing sheet comes to the position covering the surface.

  Here, although LHT100 which concerns on this Embodiment is stuck on the concrete surface with an adhesive agent, as the adhesive agent, a synthetic resin adhesive agent can be used, for example. As the synthetic resin adhesive, for example, a polyvinyl alcohol adhesive such as a highly hydrophilic polyvinyl alcohol aqueous solution can be employed.

  In addition, when using the polyvinyl alcohol aqueous solution, 50 to 70% (volume) of water is added to the stock solution 10 ± 1% (volume), and the viscosity becomes 1000 ± 100 (mPa · s) and Ph = 5 to 6. Such adjustment is preferable from the viewpoint of improving the releasability when the LHT 100 is peeled off from the concrete surface which has been cured while maintaining good adhesiveness. Furthermore, it is also possible to meet demands such as dust and the like not adhering to the adhesive after peeling so that the concrete surface is not soiled and not being peeled off even if there is a wind.

  Here, the detailed experimental research result about the heat retention characteristic of LHT100 which concerns on this Embodiment is shown.

i) Heat transfer rate To confirm the heat-retaining effect, for the curing of lining concrete (thickness t = 30cm), (1) When there is no curing (no curing material) (when curing with lining concrete surface exposed) (2) When using a resin curing sheet (LHT100: thickness t = 11.5 mm) having a plurality of air enclosures (bubbles) according to the present embodiment, (3) Q mat (trademark) ( When using a two-layer curing material: NETIS KT-980368-A, which is a moisturizing and curing sheet using acrylic fibers, and a heat-insulating mat in which glass wool is sealed with a special film, (4) Control panel (concrete panel: When covering and curing with water-resistant lauan veneer material (thickness 9 mm) used as a formwork material when placing concrete, the following four cases were compared.

η = 1 / (1 / β + Σ (d _Fi / λ _Fi ))

η: Modified heat transfer coefficient (W / m ² ° C)
β: Heat transfer coefficient of the surface in contact with outside air (W / m ² ° C)
Generally 12-14 (W / m ² ° C)
d _Fi : thickness of curing material (m)
λ _Fi : Thermal conductivity of curing material (W / m ² ° C)

  As shown in FIG. 5, the corrected thermal conductivity η of the LHT 100 according to the present embodiment is (1) about 30% of η when there is no curing material, and (3) η when a Q mat is used. (4) About 50% of the case using the panel material, and it was confirmed that there was a higher heat retention effect than (1), (3) and (4).

ii) Regarding the temperature gradient in the lining concrete section As a result of the three-dimensional FEM temperature analysis, the temperature difference (maximum value) in the lining concrete section is (1) 2) When LHT100 according to the present embodiment is used, it was confirmed that the temperature was reduced to 4.87 ° C. corresponding to 48% of the case without (1) no curing material (marked with * in FIG. 6) See).

  In addition, as shown in FIG. 6, the lining concrete surface temperature (t1) calculated as the underground air temperature (outside air temperature) = 0 ° C. also decreases as the curing days elapse, and (1) curing material When there is nothing, the outside air temperature is about + 1 ° C. (2) When the LHT100 according to the present embodiment is used, the lining concrete surface temperature (t1) is maintained at a high temperature around the outside air temperature + 3 ° C. It is understood that it is possible.

  In addition, although the mode of the lining concrete surface temperature with respect to curing days is shown in FIG. 7, when the resin curing sheet (LHT100) based on this Embodiment of (2) is utilized from FIG. (1) In the case of no curing material, it is understood that the temperature is maintained at a high temperature for a long period of time with less temperature change compared to the case of using (4) a panel.

  From the above i) and ii), the curing using the resin curing sheet (LHT100) having a plurality of air enclosing portions (bubble portions) according to the present embodiment is caused by the internal restraining force and the external restraining force. It is possible to provide a concrete structure excellent in strength and aesthetics in which stress can be reduced and cracks are suppressed.

  For example, in the lining concrete of the tunnel arch, tensile stress is likely to occur on the inner peripheral surface of the tunnel arch due to internal restraining force and external restraining force, and cracks starting from the inner wall surface of the tunnel are likely to occur. According to the curing method using the curing sheet according to the present embodiment, it is possible to reduce the tensile stress generated on the inner peripheral surface of the tunnel arch portion, and thus, cracks and the like are suppressed, and the tunnel structure is excellent in strength and aesthetics. Things can be provided.

  Subsequently, detailed experimental research results on the moisture retention characteristics of the LHT 100 according to the present embodiment will be described.

I) Measurement result of surface humidity of lining concrete FIG. 8 shows the measurement result of measuring the surface humidity of lining concrete that changes with age. In addition, (1) When there is no curing (no curing material) (when curing by lining the surface of the lining concrete), the mold is removed at the age of 1 day, and (2) when the LHT 100 according to the present embodiment is used. Was demolded at a material age of 1 day, and immediately after that, the curing sheet according to the present embodiment was attached to the lining concrete surface.

  FIG. 8 shows the change in the humidity of the lining concrete surface relative to the number of days of curing. Compared to the case of (1) without the curing material, the LHT 100 according to the present embodiment of (2) is applied to the surface of the lining concrete. It is understood that a high humidity is maintained when sticking to.

  As shown in FIG. 8, when there is no curing material of (1), the moisture content decreases rapidly after placing due to the promotion of vaporization by the concrete hydration reaction, and thereafter the mine humidity gradually increases as the curing days progress. (Humidity of outside air) tends to be equal to 65%. In addition, when there is no curing material of (1), the minimum humidity is 45% (immediately after demolding).

  On the other hand, when the LHT 100 according to the present embodiment of (2) is attached to the lining concrete surface as a curing material, the resin films 101 to 104 constituting the LHT 100 have no property of absorbing moisture, Since there are almost no openings or gaps through which water evaporates, there is very little reduction in the amount of water due to the concrete hydration reaction, and it can be maintained at a high humidity of about 98% even after the curing days. It is confirmed. In addition, when LHT100 which concerns on this Embodiment of (2) is stuck on the lining concrete surface, minimum humidity is 95% (just after demolding).

II) Correlation between surface humidity of cracked concrete and crack (crack) occurrence rate Obtain the amount of strain generated for each humidity to determine the possibility of cracking due to the decrease in humidity (backside of the cracked concrete (ground side) ) Was constrained, and the analysis was attempted by comparing this with the allowable tensile stress of concrete.
As a result, as shown in FIG. 9, when the humidity of the lining concrete surface becomes 50% or less, the crack generation rate is expected to increase.

  From the above I) and II), when the LHT 100 according to the present embodiment of (2) is attached to the lining concrete surface, the lining concrete surface humidity (about 50%) at which cracking is a concern is increased. Since the exceedingly high humidity state (wet state) of about 95% can be maintained for a long period of time, it is possible to provide a concrete structure excellent in strength and aesthetic appearance with little occurrence of cracks and the like.

  Here, advantages other than the heat retaining effect and the moisturizing effect during curing of the resin curing sheet (LHT100) having a plurality of air enclosures (bubbles) according to the present embodiment will be described. Since the above-mentioned Q mat (3) is difficult to adopt in terms of cost, it is compared with a conventional balloon curing system using a balloon.

Advantage 1: There is no limitation on the curing period.
In other words, when high-cost and large-scale equipment such as a balloon curing system is required, the number of balloons that can be prepared and the length that can be cured at one time will be limited. There is an advantage that there is no such limitation because a curing sheet that is easily available at low cost is used and cured by sticking it to the concrete surface with an adhesive.

In the case of a balloon curing system, curing at one site can only be performed for a maximum of about one week (system length = 31.0 m), and it is necessary to move the system for curing the next site.
When LHT100 according to the present embodiment is used = the longest period is unlimited (it is possible even from the time immediately after the decent frame to the completion date)

  Advantage 2: It can be easily attached (attached) to concrete, removed (peeled) from concrete, and reattached.

Advantage 3: Diversion and reuse are possible. Furthermore, the cost is low even without diversion or reuse. The direct construction cost was estimated as the tunnel extension (1 km) and the tunnel cross-section circumference (20 m).
For example,
Balloon curing system = about 15 million yen / 1000m
In the case of LHT100 according to the present embodiment = about 1,200,000 yen / 1000 m (use of new products)
= About 6.9 million yen / 1000m (1 reuse)
= About 5.9 million yen / 1000m (2 times reuse)

Advantage 4: There is no need to worry about the preparation period and preparation cost for building a curing system.
For example,
Balloon curing system = “2 days x (6 people + machine)” for system assembly and “2 days x (6 people + machine)” for disassembly, and the total cost is about 1 million yen. Requires about 4 days.
On the other hand, when it cures using LHT100 concerning this embodiment, the expense and work period for these preparations are unnecessary.

Advantage 5: When curing using the LHT 100 according to the present embodiment, a lightweight and easy-to-handle resin curing sheet is simply attached to the concrete surface, so that the construction is simple and low cost.
For example,
Balloon curing system = 3 people x 2 hours / (tunnel extension = 10.5m) = 2600 yen / m
When curing using a curing sheet according to the present embodiment = 2 people x 1 hour / (tunnel extension = 10.5m) = 952 yen / m

  Here, an example of the construction procedure at the time of curing concrete using the resin curing sheet (LHT100) which has the some air enclosure part (bubble part) which concerns on this Embodiment is illustrated.

《Construction procedure》
1. Preparation of necessary tools, etc. 1) Adhesive sprayer 2) Precise elasticity at the end of a handle such as a broom or a plastic spatula wiper for attaching a curing sheet (LHT100) according to the present embodiment (Equipment with a pressing part)
3) Protective eyeglasses 4) Measuring cylinder for aqueous adhesive preparation 5) Aerial work vehicle for sticking work

2. Preparation of Adhesive 1) A synthetic resin adhesive (20 kg packed) is mixed with water at a concentration of 50%, 70%, etc. according to weather conditions (the strength of wind speed in the mine after penetration).
2) Transfer the prepared adhesive to the sprayer tank.

3. Mounting (sticking) work of curing sheet (LHT100) 1) After moving the removed centle (movable formwork), set a gondola or the like of an aerial work vehicle for sticking work on the part to which LHT100 is stuck. However, it is also possible to attach the LHT 100 while moving the centle using a centle lap side scaffold without using a work vehicle.

    2) Wear protective glasses. Although the adhesive to be used is harmless, there is a possibility that it may enter the eyes etc. due to flying or the like and impede work efficiency.

    3) The curing sheet (LHT100) is wound and stored in a roll shape with the adhesive surface to the concrete surface facing up. For this reason, sticking of the curing sheet to the concrete surface can be performed by a one-push technique that is excellent in workability and finished. In the tunnel cross section, the arch portion is mounted from the lower right side of the tunnel cross section by attaching it from the lower side to the upper side of the tunnel cross section and mounting it toward the lower left side when reaching the top end. It is a method of continuously attaching the LHT 100 without disconnecting the LHT 100 halfway through to the lower left. However, the mounting method is not limited to one-pressing.

    4) About 1 m of the tip of the curing sheet (LHT100) wound in a roll shape is pulled out, and the adhesive is sprayed on the adhesive surface to the concrete surface with a sprayer. Adhesive can also be sprayed on the concrete side. Alternatively, it is possible to use the LHT 100 to which an adhesive is applied in advance.

5) The width of the curing sheet (LHT100) is 1.2m. When sticking (attaching) to the concrete line of the lining concrete when attaching (attaching) to concrete, the gap is good and the gap is good. It is possible to attach (stick) closely. However, the width of the curing sheet can be appropriately changed according to demand.
It is preferable that the adjacent LHTs 100 are overlapped with each other, or the gap between the adjacent LHTs 100 is filled with a resin tape or the like so that the moisture retaining property and the heat retaining property are maintained at a high level.

    6) At the time of attaching (attaching) the LHT 100 to the concrete or after attaching, for example, from above the first layer 101 of the attached (attached) LHT 100 with a pressing tool such as a broom or a plastic spatula. It is made to boil and the adhesiveness of LHT100 and the concrete surface is improved.

    7) After that, the operation is repeated such that the adhesive is applied every 1 m and applied (attached) every 1 m. In addition, as for the work, one person holds the roll of the curing sheet and pulls out the curing sheet, and the other person performs the work of applying the adhesive and the work of bringing the curing sheet and the concrete surface into close contact with a broom. Is efficient.

4). Removal of LHT100 The adhesive used for attaching the LHT100 achieves both desired tackiness and peelability when peeled off by adjusting the polyvinyl alcohol adhesive to a predetermined concentration as described above. be able to. Therefore, the LHT 100 can be easily and cleanly peeled off from the concrete surface by simple human manual work, and the LHT 100 can be reused or diverted.

  Furthermore, since the LHT 100 uses the transparent resin films 101 to 104, the state of the concrete being cured can be visually confirmed from the outside even after being attached. Therefore, since it is possible to detect early when a problem or the like occurs, it is possible to take countermeasures at an early stage, thereby contributing to improvement of quality as a concrete structure. It is something that can be done.

  As described above, according to the concrete curing method using the resin curing sheet (LHT100) having a plurality of air enclosing portions (bubble portions) according to the present embodiment, the configuration is simple, inexpensive and lightweight. However, because it has excellent heat retention characteristics, it can reduce the tensile stress caused by internal and external restraining forces, and it can be maintained in a wet state (high humidity state) for a long period of time. It is possible to provide a concrete structure excellent in strength and aesthetics in which the above is suppressed.

  In the present embodiment, the LHT 100 is described as having four layers. However, the present invention is not limited to this, and the number of layers may be various as long as it is a resin curing sheet having a plurality of air enclosures (bubbles). It can be changed as needed.

  Further, in the present embodiment, the curing of the lining concrete in the tunnel has been described representatively, but the present invention is not limited to this, and can also be applied to the concrete curing of other concrete structures. is there.

  The embodiment described above is merely an example for explaining the present invention, and various modifications can be made without departing from the gist of the present invention.

100 Resin Curing Sheet (LHT) with Multiple Air Encapsulation Portions (Bubble Portions)
101 Resin film of the first layer 102 Resin film of the second layer 102A Air sealing part (bubble part)
103 3rd layer resin film 103A Air sealed part (bubble part)
104 4th layer resin film

Claims (12)

A concrete curing method for curing a concrete by mounting a resin sheet having a plurality of air enclosing portions on a concrete surface ,
A concrete curing method, wherein the plurality of air enclosing portions of the resin sheet have different diameters . A concrete curing method for curing a concrete by mounting a resin sheet having a plurality of air enclosing portions on a concrete surface,
  The plurality of air enclosing portions of the resin sheet are composed of a plurality of layers and have different diameters between the plurality of layers. 3. The concrete curing method according to claim 2, wherein the diameter of the plurality of air enclosures in the layer close to the concrete surface is smaller than the diameter of the plurality of air enclosures in the layer far from the concrete surface. The concrete curing method according to claim 2 or 3, wherein an air sealing portion of another resin sheet is disposed in a gap between the air sealing portions of one resin sheet. The concrete curing method according to any one of claims 1 to 4, wherein the concrete surface is attached using an adhesive. A resin sheet for concrete curing, wherein the resin sheet has a plurality of air enclosing portions, and the plurality of air enclosing portions of the resin sheet have different diameters. A resin sheet having a plurality of air enclosing portions, wherein the plurality of air enclosing portions of the resin sheet are composed of a plurality of layers and have different diameters between the plurality of layers. Resin sheet. The resin-curing sheet for concrete curing according to claim 7, wherein the diameter of the plurality of air enclosing portions of the layer close to the concrete surface is smaller than the diameter of the plurality of air enclosing portions of the layer far from the concrete surface. The resin sheet for concrete curing according to claim 7 or 8, wherein an air sealing part of another resin sheet is arranged in a gap between air sealing parts of one resin sheet. The resin sheet for concrete curing according to any one of claims 6 to 9, wherein the front and back surfaces of the resin sheet are flat. An adhesive mainly composed of a polyvinyl alcohol-based adhesive is applied to one of the front and back surfaces of the resin sheet, and a release paper is attached to the applied surface . Item 11. The resin-curing sheet for concrete curing according to any one of Items 10 . The resin sheet for concrete curing according to claim 11, wherein the release paper is wound in a roll shape so as to be on the outside.