JP6275998B2 - Concrete wet curing equipment - Google Patents

Description

  The present invention relates to a wet curing apparatus used for curing concrete.

  The concrete structure is required to exhibit a predetermined strength and durability after the concrete is hardened. In the case of blast furnace cement type B for increasing the surface strength and densification, the concrete structure is wet for 7 to 12 days after placing. It is required to keep the state (this period is to keep the concrete surface moist without using a formwork, a curing sheet, etc., depending on conditions such as the type of cement and the outside temperature).

  As a specific curing method, in the case of the upper surface of a structure having a large area such as a basic slab, it is covered with a curing mat (nonwoven fabric, etc.) in addition to submerged curing (stores about 5-10 cm of water). Yes, this provision is strictly observed.

  On the other hand, in the case of the side of a structure that is large in the vertical direction, such as side walls and piers, it cannot be submerged. Therefore, after removing the formwork, in the summer, seal curing (a plastic sheet is applied to the wall to dry the concrete surface). In addition, in the winter, heat retention + sealing curing (a bubble cushioning sheet (registered trademark bubble wrap) is attached to the wall to suppress the drying of the concrete surface and at the same time suppress the heat dissipation) Yes, the wet state cannot be reliably maintained.

  On the other hand, as a formwork method for constructing RC tower-like structures such as piers, silos, chimneys, tanks or skyscraper cores, concrete is continuously cast while sliding the formwork panels upward. There are many known slip-form methods.

  This slip form method has a remarkable construction feature that it can be applied quickly, but on the other hand, the surface of the placed concrete will be exposed to the outside air after a few hours, so that it is sufficiently wet-cured. Had the problem of not being able to do.

  Such a problem is that moisture evaporates from the concrete surface at the early age stage, the hydration reaction does not proceed sufficiently and the original strength does not come out, and cracking due to drying shrinkage is likely to occur. Carbon, chlorine ions, rainwater, and the like enter the concrete and cause a situation in which the corrosion of the reinforcing bar progresses early through neutralization of the concrete or directly.

Patent Document 1 below relates to a concrete surface curing device mainly used in a slip foam method, and can improve the quality of concrete by reliably moist curing the concrete surface without reducing the rapid workability of the slip foam method. It has been proposed as possible.
JP 2000-179155 A

  As shown in FIG. 7, the curing device 1 for the concrete surface 8 is provided with a sprayer 3 as a moisture applying mechanism in the vicinity of the lower edge of the sliding mold 2, and the sprayer is connected to a water supply hose 4 and a water supply pump. The water supply hose 4, the water supply pump, and the water supply tank are sequentially connected to a water supply tank (not shown) via (not shown), and function as a water supply mechanism for supplying water to the sprayer 3 as needed.

  On the other hand, the windshield hood 7 is separately attached along the lower edge of the sliding mold 2, and the position of the sprayer 3 and the spray direction are such that the mist from the sprayer is raised by the windshield hood 7 and the sliding mold 2. Accordingly, it is appropriately adjusted so as to be sprayed between the exposed concrete surface 8.

  The concrete surface curing device 1 is a sprayer 3 attached in the vicinity of the lower edge of the sliding mold 2 when the concrete 9 is placed while raising the sliding mold 2 continuously or intermittently by the slip form method. A mist is sprayed through and the moisture is given to the concrete surface 8 that appears sequentially from the bottom of the sliding formwork.

  In the figure, reference numeral 10 denotes a reinforcing bar, which enables prevention of cracking due to drying shrinkage and suppression of crack width. This avoids a situation in which carbon dioxide, chlorine ions, rainwater, or the like enters the concrete 9 through the cracks, and the corrosion of the reinforcing bar 10 progresses through neutralization of the concrete or directly. It becomes possible.

The following Patent Document 2 describes a method for curing a concrete body that has been cast and formed, after removing a formwork for forming a concrete body, a fiber material and a porous material embedded in the fiber material on the surface of the concrete body A curing sheet having a porous drain pipe is provided so that the fiber material is in contact with the surface of the concrete body and the porous drain pipe is substantially horizontal, and water is supplied to the porous drain pipe. It is what you do.
Japanese Patent Laid-Open No. 10-46816

  According to Patent Document 2, when water is supplied to the porous drain tube, the water released from the drain tube is diffused and held between the fiber materials by capillary action. The curing sheet provided with the fiber material and the porous drain pipe embedded in the fiber material is covered so as to cover the surface of the concrete body, and the fiber material is in contact with the surface of the concrete body. Thus, the surface of the concrete body can always be kept wet.

In Patent Document 1, fog or water is sprayed on the surface of weak concrete having a uniaxial compressive strength of about 0.06 N / mm ² exposed within several hours after placing. If water droplets on the concrete surface flow down, the cement on the surface may flow out. In that case, the concrete surface is not finished precisely and becomes a sandy rough surface.

  In addition, hydration reaction proceeds when concrete comes into contact with water. Since the hydration reaction proceeds with the time kept in a wet state, the effect is further enhanced by performing a long-time wet curing (at least 2 weeks or more). Since the sliding formwork in the slip form method of Patent Document 1 rises at a speed of 5 to 6 m / day, and the windbreak hood rises together with the formwork, if the windbreak hood is short, it will leave the curing surface immediately. .

  Therefore, when building by the slip form method, unless it is a windbreak hood which reaches the lower end of a structure, for example, the wet curing for 2 weeks cannot be ensured.

  In addition to this, the sprayed water flows down due to condensation or is diffused into the atmosphere from the lower end of the windbreak hood, so that a large amount of water is used to maintain the humidity.

  In Patent Document 2, it is quite difficult to diffuse and hold water released from the drain pipe between the fiber materials of the curing sheet, and when constituted by a highly absorbent fiber or a fiber material carrying a highly absorbent resin. It will be expensive. Furthermore, it is necessary to devise a method for preventing the dissipation of water from the curing sheet due to direct sunlight or wind, and it is necessary to attach a film for preventing moisture dissipation to the outer surface of the fiber material.

  The object of the present invention is to eliminate the inconvenience of the conventional example, and to easily keep the concrete surface in a wet state. Even if water flows on the concrete surface, there is no fear of the mortar flowing out of the surface. It is an object of the present invention to provide a concrete wet curing apparatus that can be easily installed and is easy to manage.

In order to achieve the above object, the present invention according to claim 1 uses the lower end of the slide mold as a bracket attached to the upper part of the range to be cured after the slide mold is removed or moved to the upper part, or instead of the bracket. The spray nozzle and the water supply pipe are disposed above the concrete curing surface, the water retention sheet is suspended without being in close contact with the concrete curing surface, the surplus water recovery basin is disposed below, and the outside of the water retention sheet in a position away 30~40cm from curing surface of the concrete surface hanging plastic sheet is placed, outward supplied from the water supply pipe and the closed space formed by surrounding a plastic sheet of water in the water retaining sheet, then spray The gist is to continue spraying from the nozzle.

  According to the first aspect of the present invention, the enclosed space surrounded by the vinyl sheet becomes an important element, and the outer surface is enclosed by the vinyl sheet to cure the concrete surface, so that the sealed space is sprayed. By releasing (mist), moisture curing can be realized with less moisture, and the start of curing is likely to roughen the concrete surface because the strength is fully developed after demolding (4th to 5th day of casting) Nor.

  Furthermore, by surrounding the outside with a vinyl sheet to form a closed space, humidity can be easily maintained and a wet state can be easily maintained.

  Also, spraying (mist) is released from the upper part, which is a closed space with a vinyl sheet, and the humidity is measured at the lower part, thereby making operation management relatively easy.

  In addition to the above action, wet curing can be realized by releasing spray (mist) into the sealed space, and there is a water retention sheet (towel fabric or nonwoven fabric with reinforcing fibers) in the vicinity of the concrete surface, so the concrete surface is moistened. It can be easily kept in a state. In addition, since the wet curing is started after demolding (after 4 to 5 days after casting), there is no worry of the mortar flowing out of the surface even if water flows on the concrete surface.

  The curing period can be easily adjusted simply by changing the length of the water retaining sheet (towel fabric or nonwoven fabric with reinforcing fibers) and the vinyl sheet. (For example, if a towel cloth having a length of 3 rods, a nonwoven fabric containing reinforcing fibers, or a vinyl sheet is used, the wet period of 3 rods can be cured.)

  Since there is no need to attach a water retaining sheet (towel fabric or non-woven fabric with reinforcing fibers) or vinyl sheet to the concrete surface, it can be applied to structures with uneven surfaces and concrete structures with different sizes at the top and bottom. .

  Installation of a water retaining sheet (towel fabric or non-woven fabric with reinforcing fibers), vinyl sheet, and spray nozzle piping can be easily performed if a bracket is installed. Also, the bracket can be easily installed by using the bolt of the separator P-con part.

  The gist of the present invention described in claim 2 is that the upper part of the vinyl sheet is connected and fixed to the curing surface of the concrete, and the lower end part is placed in a surplus water collecting trough.

  According to the second aspect of the present invention, the water that has flowed down as condensed water flows along the vinyl sheet, and can be reliably recovered by the lower excess water recovery tank.

  The gist of the present invention described in claim 3 is that when the amount of water collected in the surplus water recovery tank is large, it is recycled for curing.

  According to the third aspect of the present invention, the moisture curing is basically performed by discharging spray (mist) into the sealed space. However, since the surplus water is circulated and used, the amount of water used can be extremely reduced.

  The gist of the present invention described in claim 4 is to maintain the humidity between the vinyl sheet and the water retaining sheet at 90 to 100%, and to increase the spray amount from the spray nozzle when the humidity is lower than that. .

  According to this invention of Claim 4, the humidity between a concrete curing surface and a water retention sheet | seat is kept at 90-100% by discharge | releasing spray (mist) from the upper part used as the closed space with a vinyl sheet. The amount of spray from the spray nozzle can be reduced.

  The gist of the present invention described in claim 5 is that the water-retaining sheet is a towel cloth or a nonwoven fabric containing reinforcing fibers.

  According to the fifth aspect of the present invention, particularly in the case of towel cloth, it can be carried out at low cost by using a material that is extremely easily available. It is also possible to reuse used towel cloth.

  As described above, the concrete wet curing apparatus of the present invention is easy to keep the concrete surface in a moist state, and even if water flows on the concrete surface, there is no fear of the mortar content flowing out of the surface. As a result, it is easy to install and easy to manage. Furthermore, even a structure with an uneven surface, or a structure with a different size between the upper part and the lower part can be applied without problems.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a detailed longitudinal side view showing an embodiment of a concrete wet curing apparatus of the present invention, FIG. 2 is a sectional view showing an installation state, and 11 in the figure is a side wall of a concrete structure such as an oil storage tank or a bridge. In the figure, 12 is a slide formwork, and 13 is a scaffold incorporated in the formwork.

  After the mold 12 is removed or moved to the upper part, the bracket 14 is attached to the upper part of the range to be cured using a P-con bolt of a separator (not shown).

  A pipe with a spray nozzle is disposed as the spray nozzle 15 in parallel with the wall surface of the side wall 11 using the bracket 14 and connected to a water supply pump.

A towel cloth as a water retaining sheet 17 is suspended and installed without being brought into close contact with the curing surface of the concrete surface 16. The water retaining sheet 17 can also be attached using the bracket 14. In addition to the towel cloth, a nonwoven fabric containing reinforcing fibers, a sponge, a water-swellable fiber sheet, and the like can be used as the water retaining sheet 17.

  As shown in FIG. 6, a water supply pipe (perforated polyethylene pipe) 20 is sewn into the upper end of the towel cloth, which is the water retaining sheet 17, and connected to a water supply pump. The lower end of the water retention sheet 17 was placed in an excess water recovery bowl 18 which is a U-shaped groove.

  The surplus water recovery rod 18 may be attached to the lower end of the water retention sheet 17 and hung together with the water retention sheet 17, or may be attached to the side wall 11 separately from the water retention sheet 17.

A vinyl sheet 19 is hung and installed outside the water retaining sheet 17 at a position 30 to 40 cm away from the curing surface of the concrete surface 16. The vinyl sheet 19 is also suspended by the bracket 14, the upper part is horizontally developed along with the bracket 14, the end thereof is brought into close contact with the concrete surface 16, and is suspended from the end of the bracket 14 as it is to hold the water retention. Parallel to the sheet 17, the lower part is narrowed down to the concrete surface 16 side, and the lower end is put into the surplus water recovery rod 18.

  The vinyl sheet 19 is a vinyl chloride sheet, a polyethylene sheet, a polypropylene sheet, other synthetic resin sheets, a rubber sheet, or the like, and any material may be used as long as it is impermeable.

  Next, the usage will be described. Water is supplied from the water supply pipe 20, and the water retention sheet (towel cloth) 17 is wetted from the upper end to the lower end. Supply water twice a day.

  Thereafter, spraying (mist) from the spray nozzle 15 is continued.

  The mist attached to the water retaining sheet (towel cloth) 17 and the vinyl sheet 19 becomes water droplets, gradually flows down, and is collected in the surplus water collecting trough 18 installed in the lower part. When the amount of collected water is large, it is recycled as curing water such as water supply.

  The humidity between the concrete surface 16 and the water retaining sheet (towel fabric) 17 is maintained at 90 to 100%, and when it is lower than that, the spray amount is increased.

  The wet curing period will be at least 2 weeks after placement due to the relationship between the curing period and the progress of densification of the concrete surface.

  Humidity is measured in the vinyl sheet 19 with a hygrometer, and the amount of spraying or the intermittent operation interval of spraying is adjusted. These can also be automated by computer control.

  3 and 4 show a second embodiment of the present invention. In the case of a pillar structure, a wall structure, etc., in which concrete is divided into several rods by a slide mold, it is slid instead of a bracket. Using the lower end of the formwork scaffold, a water retaining sheet (towel cloth) 17, a spray nozzle 15 and a vinyl sheet 19 can be attached thereto.

  If it does in this way, this invention apparatus can move with the movement of a formwork. It is to be noted that the maintenance of humidity is facilitated by the presence of the water retaining sheet (towel cloth) 17, but if the height of the part to be cured is as low as about 3 m or less, the spray amount can be reduced even without the water retaining sheet (towel cloth) 17. Humidity can be controlled by adjustment.

  In addition, as shown in FIG. 5, when the inside surrounded by the wall has a relatively small area, a vinyl sheet 19 is stretched around the top of the placed concrete in a plane direction, and a water retaining sheet (towel is placed around the inside of the wall. The dough) 17 and the spray nozzle 15 may be arranged.

  When heating curing is required in a cold region, it is also possible to maintain the humidity and temperature by using a bubble buffer sheet as the vinyl sheet 19 and heated water instead of spraying room temperature water from the spray nozzle 15. .

1 is a detailed longitudinal side view showing a first embodiment of a concrete wet curing apparatus of the present invention. It is sectional drawing of the installation state which shows 1st Embodiment of the wet curing apparatus of concrete of this invention. It is a detailed vertical side view which shows 2nd Embodiment of the wet curing apparatus of the present invention. It is sectional drawing of the installation state which shows 2nd Embodiment of the wet curing apparatus of concrete of this invention. It is sectional drawing of the installation state which shows 3rd Embodiment of the wet curing apparatus of the concrete of this invention. It is a side view of a water retention sheet (towel cloth). It is a vertical side view which shows a prior art example.

DESCRIPTION OF SYMBOLS 1 ... Concrete curing device 2 ... Sliding formwork 3 ... Sprayer 4 ... Water supply hose 7 ... Windbreak hood 8 ... Concrete surface 9 ... Concrete 10 ... Reinforcement 11 ... Side wall 12 ... Formwork 13 ... Scaffold 14 ... Bracket 15 ... Spray nozzle 16 ... Concrete surface 17 ... Water retention sheet 18 ... Surplus water recovery tank 19 ... Vinyl sheet 20 ... Water supply piping

Claims (5)

After removing the slide formwork or moving it to the upper part, install a spray nozzle and water supply pipe above the concrete curing surface , using the bracket attached to the upper part of the curing area, or using the lower end of the slide formwork instead of the bracket. Install and suspend the water retention sheet without sticking to the concrete curing surface, provide a surplus water recovery basin below, at a position 30-40 cm away from the concrete curing surface outside the water retention sheet It installed hanging plastic sheets, outward supplied from the water supply pipe and the closed space formed by surrounding a plastic sheet of water in the water retaining sheet and then and performing continuously sprayed from the spray nozzle concrete Wet curing equipment.   The wet curing apparatus for concrete according to claim 1, wherein the vinyl sheet is connected and fixed to the curing surface of the concrete, and the lower end portion is placed in a surplus water recovery tank.   The wet curing apparatus for concrete according to claim 1 or 2, wherein when the amount of water collected in the surplus water collecting tank is large, the concrete is recycled for curing.   The wet curing of concrete according to any one of claims 1 to 3, wherein the humidity between the vinyl sheet and the water retaining sheet is maintained at 90 to 100%, and if lower than that, the spray amount from the spray nozzle is increased. apparatus.   The wet-curing apparatus for concrete according to claim 1, wherein the water-retaining sheet is a towel cloth or a nonwoven fabric containing reinforcing fibers.

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