JP5073697B2 - Concrete biological curing and concrete curing structure - Google Patents

Description

  The present invention relates to a concrete curing structure and a concrete curing structure that can be applied to lining concrete of a tunnel wall surface and wall concrete such as a building or a shaft.

  By aging the concrete for a predetermined period after placing, the hydration reaction is promoted, and cracking due to drying or external force is prevented. Until now, in mountain tunnels and shield tunnels, the inside of the tunnel was kept hot and humid, and therefore, lining concrete was generally not cured after demolding. However, in recent years, a variety of lining concrete curing structures and curing methods have been developed, because if tunnels are sufficiently ventilated after tunnel penetration or due to improvements in equipment functions, etc., the properties of hardened concrete will be adversely affected. Has been.

  For example, in order to cure arched lining concrete with a simple structure reliably and at low cost, a curing material having a shape suitable for the inner peripheral surface of the lining concrete is formed of foamed polystyrene, and is adjacent to the end face of each foamed polystyrene. There is known a lining concrete curing structure in which irregularities that engage with foamed polystyrene are provided and arranged in an arch shape so that the air tube can be held in an arch shape as a supporting material (see Patent Document 1).

  Also, when covering the surface of the arch-shaped lining concrete with a sheet, a plurality of angle members having a curved surface along the tunnel arch and a carriage for sheet curing are used as supporting works, and cushions are provided at both ends of the sheet on the wife side. A curing method for lining concrete is known in which a sheet is arranged on the surface of the lining concrete without leaving an attachment mark by pressing it against the concrete surface with an angle material through the material (see Patent Document 2). ).

JP 2006-328869 A JP 2007-239320 A

  However, in the lining concrete curing structure described in Patent Document 1, the air tube is fixed on both sides of the ground in the tunnel, or the air tube is expanded along the arch shape so that the curing material can be built. It is expected that there will be difficulties in construction.

  Moreover, since the method of curing the lining concrete described in Patent Document 2 requires a large cart that supports the angle material, a large number of carts are necessary to perform long-term curing in tunnel construction. Cost.

  The present invention has been made in view of such a background, and an object thereof is to provide a concrete curing structure and a concrete curing structure capable of curing concrete that is easy to construct and efficient at a low cost. To do.

  In order to solve the above problems, the first invention is a concrete curing (2) that is arranged along a concrete wall surface (23a) and that connects a plurality of curing units (3) in the vertical direction, The curing unit (3) is attached to the entire surface of the frame (4) in such a manner that the wrap allowance (9a) extends from at least one of the upper and lower sides of the frame (4) provided with connecting portions (7, 8) at both upper and lower ends And a cured curing sheet (9).

  According to the present invention, since the concrete curing unit can be formed at a desired height by connecting the curing units in the vertical direction, the construction is easy. In addition, since the wrapping cost of the curing sheet extends from at least one curing unit at the connection portion of each curing unit, the entire concrete wall surface is covered, and local temperature reduction of the exposed portion is not caused. .

  Moreover, 2nd invention is a concrete biological body (2) which concerns on 1st invention, A curing sheet | seat (9) is a bubble buffering material, It is characterized by the above-mentioned.

  According to the present invention, by using the bubble cushioning material as the curing sheet, it is possible to reduce the cost and reduce the cost of the concrete curing unit and to enhance the heat insulation effect of the concrete wall surface.

  The third aspect of the present invention is the concrete biological body (2) according to the first aspect, wherein the water retention means (10) provided at a predetermined height position on the concrete wall surface (23a) side of the curing sheet (9) is provided. It is further provided with a feature.

  According to the present invention, by providing the water retaining means at a predetermined height position, the water vapor evaporated from the concrete is condensed on the surface of the concrete wall side of the curing sheet and does not flow down to the lower end of the concrete curing body. Since the water is retained, the entire concrete wall can be kept at high humidity.

  Moreover, 4th invention is a concrete member (2) based on 3rd invention. WHEREIN: The water retention means (10) is provided substantially horizontal, The pipe member (12) in which the slit (12a) was formed in the upper surface ) And a nonwoven fabric (11) inserted into the pipe member (12) through the slit (12a) at the lower end thereof.

  According to this invention, the water that flows down due to condensation on the surface of the curing sheet is absorbed by the nonwoven fabric, and even if an amount of water exceeding the water retention amount of the nonwoven fabric flows down, it is introduced into the pipe member through the slit and stored. Is done. Even when the humidity of the space due to the curing sheet and the concrete wall surface decreases, the water in the pipe member is sucked into the nonwoven fabric by the capillary phenomenon and vaporizes, so that the space due to the concrete wall surface and the curing sheet is always high in humidity. To be kept.

  Moreover, 5th invention is arrange | positioned along the arch-shaped lining concrete wall surface (23a) in a tunnel (21) in the concrete biological body (2) which concerns on 1st-4th invention, A frame (4 ) Is made of a vinyl chloride pipe, and the curing unit (3) is pre-bent with a radius of curvature larger than the radius of curvature of the lining concrete wall (23a).

  According to the present invention, when the concrete wall surface has an arch shape, the elastic vinyl chloride pipe is used as the frame body, and the frame body has a radius of curvature larger than that of the lining concrete wall surface. The frame itself can function as a supporting work for bringing the curing sheet into contact with the arch surface, the gap between the concrete wall surface and the curing sheet can be reduced, and the heat retention and moisture retention can be improved.

  The sixth invention is a concrete curing structure (1) in which a plurality of concrete curing bodies (2) according to the first to fifth inventions are arranged adjacent to each other in the horizontal direction, and the curing sheet (9) The frame (4) is attached to the frame (4) in such a manner that the wrap margin (9b) extends from at least one side in the horizontal direction.

  According to this invention, for example, even when applied to the side wall of a joint groove where the horizontal length of the concrete wall surface is large or the lining concrete of the tunnel, the width of the concrete curing (curing unit) is made easy to handle, It can be extended as appropriate.

  According to the present invention, concrete can be cured easily and efficiently at low cost.

It is a perspective view of the concrete curing structure for tunnels. It is a principal part perspective view of the concrete biological body for tunnels shown in FIG. It is a perspective view of a concrete curing unit. It is sectional drawing of the connection part of a concrete curing unit. It is explanatory drawing which shows the measurement position of an effect confirmation test. It is a graph which shows the temperature of each age in an effect confirmation test. It is a graph which shows the temperature change of each measuring point in an effect confirmation test. It is a graph which shows the change of the temperature in a curing sheet and a mine in an effect confirmation test, and humidity.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the concrete curing structure 1 for a tunnel according to the embodiment is used as a curing structure for lining concrete 23 in a tunnel 21 having an arch-shaped cross section such as a mountain tunnel excavated in a natural mountain 20. The The lining concrete 23 is constructed inside the sprayed concrete 22 sprayed on the natural ground 20. The concrete curing structure 1 is disposed along the arch-shaped wall surface 23 a of the lining concrete 23. The concrete curing structure 1 is formed by dividing a plurality of arch-shaped concrete curing bodies 2 along the arch-shaped wall surface 23a of the lining concrete 23, which are divided in the tunnel axis direction. It is the length in the tunnel axis direction. A plurality of concrete curing structures 1 are prepared and are sequentially extended in the face direction in accordance with the demolding of the lining concrete 23. Then, when a predetermined curing period has elapsed, the concrete curing structure 1 is sequentially removed from the wellhead side and reused so as to be installed on the face side again.

  As shown in FIG. 2, each concrete curing unit 2 is configured by connecting a plurality of concrete curing units 3 in the circumferential direction of the arch (vertical direction in the wall portion), and at the left and right lower ends when viewed in the tunnel axial direction. Is connected to a bar jack 13 for height adjustment. The bar jack 13 functions not only for height adjustment but also as pressing means for pressing the concrete nourishing body 2 against the concrete wall surface 23a. The concrete living body 2 has a width (length in the tunnel axis direction) that can stand by itself in an assembled state, and is 1.5 m in this embodiment. Therefore, it is possible to extend or remove the concrete nourishment 2 to a necessary length without having to assemble or disassemble one span of the lining concrete 23 at a time.

  As shown in FIG. 3, each concrete curing unit 3 is about 2 m high (length in the arch circumferential direction). The concrete curing unit 3 includes a rectangular frame 4 made of a vinyl chloride pipe and a curing sheet 9 that has a rectangular shape larger than the frame 4. The frame 4 connects the two arch members 6 bent with a radius of curvature larger than the radius of curvature of the inner peripheral surface (wall surface 23 a) of the lining concrete 23, and the upper and lower ends of the two arch members 6. It consists of two linear width stop members and 5u and 5l. Each member is connected by cheese 7, and joint pipe 8 extending downward is attached to lower cheese 7.

  Curing sheet 9 is a vinyl foam cushioning material in which a large number of air bubbles are provided in the sheet, and is not only excellent in shock absorption, but also lightweight and excellent in workability, and has excellent water resistance, moisture retention, and heat insulation. In addition, it is available at a lower price than a general curing sheet. As the bubble cushioning material, commercially available products such as bubble wrap (registered trademark), air cap (registered trademark), and air cell mat (registered trademark) can be used. Moreover, concrete curing performance, handleability, and durability can be further enhanced by using a foam cushioning material in which sheets are provided on both sides of the foam, or by superposing a plurality of foam cushioning materials.

  As shown in FIGS. 3 and 4, the curing sheet 9 is affixed to the frame body 4 with a vinyl tape or an adhesive, and the concrete curing is adjacent in the lateral direction from one end edge in the left-right direction (tunnel axis direction). The wrap allowance 9b for 2 extends, and the entire surface of the frame body 4 is covered in such a manner that the wrap allowance 9a for the concrete curing unit 3 adjacent below extends from the lower end edge.

  On the side of the concrete wall 23 a near the lower end of the curing sheet 9, a water retention unit 10 for holding water that flows down along the curing sheet 9 is provided. The water retention unit 10 is composed of a water absorbing body 11 disposed along the lower width stop member 5l, and a water retention pipe 12 having a slit 12a formed on the upper surface thereof and exhibiting a C-shaped cross section. Are integrally joined to the curing sheet 9. The water absorbent body 11 may be any material having water absorbency, and in this embodiment, a nonwoven fabric is used, and the lower end thereof is attached to the water retention pipe 12 in such a manner that the lower end is inserted into the slit 12a.

  Therefore, the water that has flowed down along the surface of the curing sheet 9 on the concrete wall surface 23 a side is absorbed by the water absorbing body 11 and guided into the water retaining pipe 12. Both ends of the water retention pipe 12 are closed by caps 12 b so that the water guided by the water absorbing body 11 is stored in the water retention pipe 12. In this embodiment, a water retention unit 10 is installed in each concrete curing unit 3, but every other water retention unit 10 is provided for the concrete curing unit 3, or a plurality of concrete curing units 3 are provided with a plurality of water retention units 10. A water retention unit 10 may be provided.

  When installing each concrete curing body 2, stick jacks 13 are arranged at the left and right ends of the tunnel ground, and the concrete curing unit 3 is sequentially built using an aerial work vehicle or a movable formwork scaffold. After the left and right concrete curing units 3 are connected at the top, the concrete curing unit 2 may be lifted by the bar jack 13 and brought into full contact with the arched concrete wall surface 23a. Thus, since the concrete curing unit 3 is lightweight and does not require a dedicated carriage, the construction is easy, and the material cost and installation dismantling cost are low.

  The frame body 4 is formed with a predetermined width, so that the concrete nourishment 2 can be self-supporting. The frame body 4 is made of an elastic vinyl chloride pipe and the radius of curvature of the arch member 6 is covered. Since the radius of curvature of the wall surface 23a of the engineered concrete 23 is made larger, the frame 4 itself functions as a support work for bringing the curing sheet 9 into contact with the arch surface, and the gap between the concrete wall surface 23a and the curing sheet 9 is formed. Get smaller. Thereby, the heat retention performance and moisture retention performance of the concrete nourishment 2 are increasing. And the concrete curing structure 1 can also be extended to suitable length according to the placement span of the lining concrete 23. FIG.

  Since the foam cushioning material is used for the curing sheet 9 and the water retention unit 10 is provided at an appropriate height position, even if water vapor evaporated from the concrete condenses and flows down along the surface of the curing sheet 9, the concrete curing is performed. Water is retained by the water retention unit 10 without flowing down to the lower end of the body 2. And even when the humidity of the space by the curing sheet 9 and the concrete wall surface 23a is lowered, the water stored in the water retaining pipe 12 is sucked into the nonwoven fabric by the capillary phenomenon and vaporized, so that the concrete wall surface 23a The space with the curing sheet 9 is always kept at high humidity.

  Moreover, since each concrete curing unit 3 is provided with wrap allowances 9a and 9b for the curing sheet 9 in one of the lower side and the left and right direction (tunnel axis direction), the connecting portion between the concrete curing units 3 and the concrete curing unit are provided. Also in the connection part of the bodies 2, the concrete wall surface 23a is covered with the curing sheet 9, and a local temperature drop and humidity fall are prevented.

  Furthermore, according to the concrete curing structure 1 having such a configuration, since the entire wall surface 23a of the lining concrete 23 is covered with the curing sheet 9, the impact on the concrete by materials and equipment is reduced, and high-quality concrete is obtained. Can do.

  Next, the effect of the concrete curing structure 1 will be described. In the tunnel 21 shown in FIG. 5, the present inventors made various measurements depending on whether the concrete curing structure 1 was assembled immediately after demolding the lining concrete 23 and concrete curing was performed, and when concrete curing was not performed. Went. The results are shown in FIGS. In addition, in this effect confirmation test, the concrete curing structure 1 of the form which does not attach the water holding body 10 and the nonwoven fabric 11 is used.

  The measuring part was a leg part of the lining concrete 23, and each measuring instrument was arranged at the position shown in the enlarged view of part A in FIG. Specifically, the thermometer 31 is 80 mm or 230 mm from the concrete surface between the inside of the tunnel 21, the curing sheet, that is, between the curing sheet 9 and the wall surface 23 a of the lining concrete 23 (hereinafter abbreviated as a concrete surface). It installed in seven places, 380mm, 530mm, and 730mm. Moreover, the hygrometer 32 was installed in two places in the tunnel of the tunnel 21 and a curing sheet. The 80 mm, 230 mm, and 380 mm measuring points from the concrete surface are inside the lining concrete 23, the 530 mm measuring point from the concrete surface is inside the sprayed concrete 22, and the 730 mm measuring point from the concrete surface is , Inside of natural ground 20.

  FIG. 6 is a graph showing the temperature at each measurement point for each age, (A) shows the measurement results with concrete curing, and (B) shows the measurement results without concrete curing. As shown in the figure, in the case where the curing of (A) is performed, the temperature of all the measuring points from the inside of the sheet to the sprayed concrete 22 is not performing the curing of (B) as the age is younger. You can see that it is expensive compared to things. That is, it can be seen that the lining concrete 23 of the arch leg is kept warm by the concrete curing structure 1. In addition, the temperature difference between the concrete surface and the interior of the one that is cured (A) is smaller than that of the one that is not cured (B), and the temperature stress is reduced. Recognize.

  FIG. 7 is a graph showing the temperature change at each measurement point, (A) shows the measurement result with concrete curing, and (B) shows the measurement result without concrete curing. As shown in the figure, in the case of curing (A), the temperature of all the stations except the underground temperature is always kept higher than that of the point not curing (B). . In particular, the concrete surface temperature (0 mm) when the curing of (B) is not performed is as low as the underground temperature, and is fluctuating with changes in the underground temperature, but the curing of (A) is performed. It can be seen that the concrete surface temperature (0 mm) in this case is very high as compared with the underground temperature, and gradually changes as the material age increases without fluctuation as shown in (B). This means that the wall surface 23a of the lining concrete 23 is most easily affected by changes in the underground temperature, and in (A), the influence is mitigated by the concrete curing structure 1. This also shows that the lining concrete 23 of the arch leg is kept warm by the concrete curing structure 1.

  FIG. 8 is a graph showing changes in temperature and humidity in the pit and in the seat. The in-seat temperature is higher than the underground temperature as the age of the lining concrete 23 is younger, and gradually approaches the underground temperature as the material age increases. This means that the concrete curing structure 1 contains heat from the hydration reaction of the lining concrete 23 in the curing sheet 9, and the lining concrete 23 is kept warm by suppressing heat dissipation to the mine. On the other hand, the in-seat humidity is always higher than the downhole humidity, and is maintained at approximately 100% after the age of 7 days. On the other hand, regardless of the age of the lining concrete 23, the mine humidity has changed between about 50% and 80%. In this effect confirmation test, it can be seen that, even if the concrete curing structure 1 does not include the water retaining body 10 and the nonwoven fabric 11, the lining concrete 23 is effectively moisturized at least in the measurement section.

  As described above, by curing the lining concrete 23 using the concrete curing structure 1 according to the embodiment, the concrete is maintained at high temperature and high humidity, and the hydration reaction of the cement is promoted. You can get a few good quality concrete.

  This is the end of the description of specific embodiments, but the present invention is not limited to these embodiments. For example, in the above embodiment, the concrete curing structure 1 is applied to the lining concrete of a mountain tunnel. However, the concrete curing structure 1 may be applied to other tunnels such as a shield tunnel. It may also be applied to other concrete structures such as joint grooves and culverts.

  For example, when the concrete curing structure according to the present invention is applied to a vertical shaft, if the vertical cross section of the vertical shaft is circular, the curved concrete curing units are sequentially connected in the horizontal direction in the same manner as in the above embodiment to form a circular concrete curing structure. Then, a bar jack may be disposed at the final connecting portion and brought into contact with the side surface of the shaft. Moreover, in this case, even if no special support is provided, the concrete nourishment is lightweight, and therefore the concrete nourishment is made to stand against gravity by the compressive force (friction force against the side of the shaft) with a bar jack ( It is also possible to keep it in the installation position). On the other hand, if the vertical cross section of the shaft is rectangular, for example, a connecting member that also serves as a length adjustment is provided at the end of each side to connect the concrete curing unit into a flat rectangular shape, or a bar jack is provided for each side. It may be used as a concrete body for each side. In this case, the frame may have a single flat shape, but if the shape is slightly curved in the horizontal direction so as to protrude toward the concrete surface side, the entire surface of the concrete nourishment can be reliably brought into contact with the concrete surface. Can do.

  Moreover, in the said embodiment, although the combination of a water retention pipe and a nonwoven fabric was used as a water retention body, it may be set as the form only of a nonwoven fabric, or it may be set as the form which uses sponge instead of a nonwoven fabric. Moreover, you may form a water holding body using a frame. In addition to these changes, changes can be made as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Concrete curing structure 2 Concrete curing body 3 Concrete curing unit 4 Frame body 7 Cheese 8 Joint pipe 9 Curing sheet 9a, 9b Wrap allowance 10 Water retention unit 11 Nonwoven fabric 12 Water retention pipe 12a Slit 23 Covering concrete 23a Wall surface

Claims (6)

A concrete health care unit that is arranged along a concrete wall surface and is formed by connecting a plurality of curing units in the vertical direction,
The curing unit has a frame having a connecting portion at both upper and lower ends, and a curing sheet attached to the entire surface of the frame so that a lapping allowance extends from at least one of the upper and lower sides. .   The concrete curing body according to claim 1, wherein the curing sheet is a foam cushioning material.   The concrete bioculture according to claim 1 or 2, further comprising water retaining means provided at a predetermined height position on the concrete wall surface side of the bubble cushioning material. The water retention means is
A pipe member provided substantially horizontally and having a slit formed on the upper surface thereof;
The concrete biological body according to claim 3, wherein the lower end thereof has a nonwoven fabric inserted into the pipe member through the slit. Arranged along the arched lining concrete wall in the tunnel,
The frame according to any one of claims 1 to 4, wherein the frame body is made of a vinyl chloride pipe, and the curing unit is previously bent with a radius of curvature larger than the radius of curvature of the lining concrete wall surface. The concrete biological body according to one item. A concrete curing structure in which a plurality of the concrete curing bodies according to claim 1 are arranged adjacent to each other in the horizontal direction,
The concrete curing structure, wherein the curing sheet is attached to the frame body in such a manner that a lapping margin extends from at least one horizontal direction of the frame body.

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