JP3784401B1 - Ribbed floor slab, ribbed floor slab manufacturing apparatus, and ribbed floor slab manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED To provide a ribbed floor slab that can be manufactured easily and with high quality, a ribbed floor slab manufacturing apparatus, and a ribbed floor slab manufacturing method.
SOLUTION: This is a manufacturing apparatus for a ribbed slab in which a floor slab part 1a and a plurality of rib parts 1b projecting from the floor slab part 1a are integrally formed of a cement-based mixed material.
The mold surface of the rib mold 34 that forms the side surface of the rib portion 1b and the bottom surface of the floor slab portion 1a is made of a material that is easier to deform than the mold surface of the bottom surface mold frame 31 that forms the lower end surface of the rib portion 1b. Is formed.
[Selection] Figure 2

Description

  The present invention relates to a floor slab spanned over a bridge, an artificial ground, a pier, etc., a floor slab used as a floor slab for forming a floor surface of a building, an apparatus for producing a ribbed floor slab, and a ribbed floor It relates to the production method of the plate.

  Conventionally, a method of constructing a floor slab by connecting a plurality of I-type and T-type precast girders in the lateral direction and placing concrete on the upper surface to form an upper structure of a bridge is known (Patent Document 1). , 2 etc.).

  In this method, I-type and T-type precast girders are manufactured with high quality by using prestressed concrete or the like in a controlled place such as a factory or an on-site production yard.

  Then, the precast girder transported to the site is assembled, and concrete is placed on the top surface of the site.

  Various joining structures are applied to integrate the precast girder and the floor slab formed of cast-in-place concrete.

On the other hand, a pre-stressed prestressed concrete slab in which a floor slab part and a plurality of rib parts are integrated is known as a floor slab for construction.
Japanese Patent Laid-Open No. 2002-21023 JP 2003-213623 A JP 59-49912 A

  However, since the floor slab constructed by such a conventional method includes a portion that is manufactured with high quality control and a portion that is not so, it is difficult to keep the overall quality high.

  Further, since the rib portion and the floor slab portion are manufactured separately, the joining structure for integrating them becomes complicated, and the labor and cost for manufacturing tend to increase.

  Furthermore, the pre-tensioned floor slab has the advantage of low manufacturing costs, but it is difficult to introduce pre-stress in two directions, and Patent Document 3 discloses that pre-stress is introduced in one direction. ing.

  Also, when a ribbed floor slab is manufactured by filling a steel mold with a cement-based mixed material with large self-shrinkage, a tensile stress is applied to the cement-based mixed material because the convex formwork restrains shrinkage deformation. There is a risk that tensile cracks may occur.

  On the other hand, conventional precast floor slabs using concrete are applied to slab floor slabs for jacket-structure piers using steel frames and steel pipes, slab floor slabs for artificial ground for marine structures, slab floor slabs for bridges, etc. The main structure of the substructure such as the jacket structure pier is determined by the seismic load, so if the weight of the slab floor slab is large, a large cross section is required for the jacket structure, the main girder of the bridge and the pier foundation, and the construction cost increases. There is a problem of doing.

  Accordingly, the present invention provides a ribbed floor slab that can be manufactured in a light weight and high quality, a manufacturing apparatus for the ribbed floor slab, and a method for manufacturing the ribbed floor slab using the manufacturing apparatus. It is said.

  In order to achieve the above object, the present invention provides a floor slab portion and a plurality of rib portions protruding from the floor slab portion, which are integrally formed of a cement-based mixed material, and the extending direction and the orthogonal direction of the rib portion. It is a floored slab with prestress introduced in the direction.

Here, as the cementitious mix materials, compressive strength 150 N / mm ² or more, flexural tensile strength 25 N / mm ² or more, fiber-reinforced cement-based split Tensile strength with 10 N / mm ² or more mechanical properties mixed material Can be used.

  Further, a floor slab part and a ribbed floor slab production apparatus in which a plurality of rib parts projecting from the floor slab part are integrally formed of a cement-based mixed material, the side face of the rib part and the floor slab part And a ribbed floor slab manufacturing apparatus in which the mold surface of the rib mold for forming the bottom surface of the rib is formed of a material that is more easily deformable than the mold surface of the bottom mold for forming the lower end surface of the rib portion. It is characterized by.

  Here, a part of the bottom formwork is formed by small pieces that can be separated from each other by moving in the vertical direction, and the bottom formwork and the lower end face of the ribbed floor slab are separated by pressing the small pieces. A demolding device can be provided.

  In addition, a part of the upper end surface of the bottom formwork or the rib formwork of the ribbed slab manufacturing apparatus is formed by a plug body that can be separated from the other by moving in the vertical direction. Can be shaped to expand upward.

  Furthermore, in the manufacturing apparatus for the ribbed floor slab, a tension material to be disposed in the extending direction of the rib portion is accommodated in a main direction end face mold for forming an end surface in the extending direction of the rib portion of the ribbed floor slab. A slit can be provided, and a shielding member can be disposed in the gap between the slits around the tendon.

  Here, the side mold for molding the side surface of the rib portion of the ribbed floor slab in the direction orthogonal to the extending direction is provided with a slit that accommodates the tension material disposed in the extending orthogonal direction of the rib portion, A shielding member can also be disposed in the gap between the surrounding slits.

  In addition, a part of the bottom mold of the ribbed slab manufacturing apparatus is formed by a partial support plate that can be separated from the others by vertical movement, and the partial support plate can slide. The support portion can be provided below the support portion.

  And the manufacturing method of the floor slab with the rib according to the present invention comprises assembling the manufacturing apparatus for the ribbed floor slab according to any one of the above, and disposing the tension material in the extending direction and the extending orthogonal direction of the rib portion. Tension is applied, and the inside of the mold is filled with a cement-based mixed material, and after the cement-based mixed material reaches a predetermined strength, the rib mold and the bottom mold are removed.

  In the present invention configured as described above, the floor slab portion and the plurality of rib portions are integrally formed of a cement-based mixed material such as concrete, and prestress is introduced in the extending direction and the orthogonal direction of the rib portion. Has been.

  For this reason, a floor slab with no joints can be easily manufactured. Moreover, since this production can be performed in a controlled place such as a factory or a field production yard, it can be produced with high quality.

  Furthermore, since prestress is introduced in two directions, the member cross section can be reduced and the weight can be reduced.

  In particular, by using the fiber-reinforced cement-based mixed material as the cement-based mixed material, the thickness of the member can be made very thin, so that a lightweight, highly durable and high-quality ribbed slab is manufactured. Can do.

  In addition, during the curing of the cement-based mixed material, the mold surface of the rib mold is formed of rubber or styrene foam so that it can be more easily deformed than the mold surface of the bottom mold formed of a steel plate or the like. Even if self-shrinkage occurs, the rib mold does not follow and does not restrain the self-shrinkage, so that a tensile force is not generated in the cement-based mixed material and cracks are not generated.

  Furthermore, after the cementitious mixed material is hardened, when the small piece forming a part of the bottom surface formwork is pushed by the demolding device, a gap is formed around the small piece and air flows.

  For this reason, a mold can be easily demolded without generating a vacuum state between the lower end surface of the ribbed floor slab and the bottom mold.

  Further, if a part of the upper end surface of the bottom formwork or the rib formwork is used as a plug, and the plug is widened upward, the bottom formwork or the rib formwork is removed at the time of demolding. When descending downward, a gap is formed around the plug body left attached to the lower end surface of the ribbed floor slab, and air can flow in to prevent the generation of a vacuum state.

  Furthermore, by providing a slit in the main direction end face mold that molds the end face in the extending direction of the rib portion to accommodate the tension material to be arranged in the extending direction of the rib portion, a large number of tension materials can be accurately positioned. It can be installed easily.

  Here, by providing slits also in the side surface formwork in the case where the tension members are arranged in the direction perpendicular to the extending direction of the rib portions, a plurality of tension members can be accurately and easily installed in two directions.

  Further, a part of the bottom mold is formed by a partial support plate that can be separated from the other by moving in the vertical direction, and is supported from below by a sliding support portion so that the partial support plate can slide.

  In this state, when prestress is introduced by the pretension method in the extending direction of the rib portion, the floor slab with ribs moves without being restrained on the sliding support portion, and the other bottom formwork does not move. Left in the position.

  For this reason, it is possible to reduce the preparation work for manufacturing another ribbed floor slab using this bottom formwork, and to repeat the production of a ribbed floor slab that efficiently introduces prestress in two directions. it can.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a cut perspective view of a floor slab 1 with ribs that is bridged over a bridge, artificial ground, pier, or the like, or that forms a floor surface of a building.

  The ribbed floor slab 1 includes a floor slab portion 1a that forms a floor surface on the upper surface, a plurality of rib portions 1b that protrude downward from the lower surface of the floor slab portion 1a, and a ribbed floor slab as a rib portion. It is mainly composed of side wall portions 1c and 1c provided on one side edge.

  Such ribbed floor slab 1 is manufactured to a predetermined length, and a plurality of ribbed floor slabs 1 are connected in the extending direction (main direction) of the rib portion 1b to form a long girder structure.

  Further, a tension material 2A directed in the main direction is disposed on the rib portions 1b and 1c, and prestress is introduced in the main direction of the floor slab 1 with ribs by the tension material 2A.

  Further, the tension material 2B directed in the direction perpendicular to the extending direction (sub-direction) of the rib portion 1b is disposed on the floor slab portion 1a, and prestress is introduced in the sub-direction of the floor slab 1 with ribs.

  Such a floor slab 1 with ribs can be manufactured by placing a cement-based mixed material such as concrete, but it is particularly preferable to manufacture using a fiber-reinforced cement-based mixed material with ultra-high strength.

  This fiber reinforced cementitious mixed material mixes metal fibers into a cementitious matrix obtained by mixing a composition containing cement, aggregate particles, pozzolanic reactive particles, and a dispersant with water. To make.

  Here, an aggregate material such as cinnabar having a maximum particle size of 3.0 mm or less, preferably 2.5 mm or less is used for the aggregate particles. Further, as the pozzolanic reaction particles, those having a particle size of 15 μm or less are used. For example, silica fume or the like is used as a highly active pozzolanic reaction particle having a particle size of 0.01 to 0.5 μm, and fly ash or blast furnace slag is used as a low activity pozzolanic reaction particle having a particle size of 0.1 to 15 μm. To do. These pozzolanic reactive particles having different activities can be mixed or used alone. Further, at least one type of the dispersant is used in order to improve fluidity.

For the metal fiber, for example, a steel fiber having a diameter of about 0.1 to 0.3 mm and a length of about 10 to 30 mm and a tensile yield stress of 2600 to 2800 N / mm ² is used. Further, this steel fiber is mixed in an amount of about 1 to 4% of the total volume of the fiber-reinforced cementitious mixed material to be produced.

A member formed of the above-mentioned fiber-reinforced cement-based mixed material manufactured with such a blend has a compressive strength of 150 to 200 N / mm ² , a bending tensile strength of 25 to 45 N / mm ² , and a split tensile strength of 10 to 25 N. / Mm ² , water permeability is 4.0 × 10 ⁻¹⁷ cm / sec, salt diffusion coefficient is 0.0019 cm ² / year, and elastic modulus is 50 to 55 GPa.

  FIG. 2 shows a cut perspective view of the mold 3 used for manufacturing the floor slab 1 with ribs.

  The mold 3 includes a rectangular plate-shaped bottom mold 31 that forms the lower end surface of the rib portion 1, and quadrangular prism-shaped rib molds 34 that are juxtaposed on the bottom mold 31 at intervals in the sub-direction. ,..., And a main direction end face mold 32 erected on the outer edge of the bottom mold 31 in order to mold the end face in the extending direction of the rib portion 1b (FIG. 2 is a cutaway view and one is not shown). And side surface molds 33, 33 erected on the outer edge of the bottom surface mold frame 31 in order to mold the side surface in the direction perpendicular to the extending direction of the rib portion 1 b.

  The bottom mold 31 is made of a highly rigid member such as a steel plate, and the supporting frame 4 disposed below the bottom mold 31 supports the weight of the mold 3 and the ribbed floor slab 1 formed therein.

  The rib form 34 is formed of a material that is more easily deformable than a steel material such as rubber, polystyrene foam, or synthetic resin material.

  During the primary curing of cement-based mixed materials, self-shrinkage tends to occur and attempts to deform. However, if a rigid formwork such as a conventional steel plate is used, the convex formwork constrains shrinkage deformation. A tensile stress is generated in the mixed material, and a tensile crack is generated. On the other hand, if the rib formwork 34 is formed of a material that is easily deformable, the restraint during such contraction deformation can be relaxed, and the occurrence of tensile cracks can be prevented.

  FIG. 3 shows sectional views of three types of rib molds 34, 35 and 36.

  FIG. 3A shows a solid rib form 34 made of an easily deformable elastic material such as rubber.

  Such a rib mold 34 is provided with a presser plate 5a at the upper end of a through-hole 34a opened in the vertical direction, through which a bolt 5 or the like is passed, screwed into a screw hole provided in the bottom mold 31, and the bottom surface. It is fixed to the bottom mold 31 with an adhesive applied to the bottom.

  Thus, if it forms solidly, material cost will become high, but since the peeling resistance at the time of demolding becomes high, the frequency | count of diversion of a formwork can be increased.

  FIG. 3B shows a hollow rib mold 35 made of an easily deformable elastic material such as rubber. Such a rib mold 35 is formed by passing a bolt 5 or the like through a through-hole 35a opened in the vertical direction and screwing it into a screw hole provided in the bottom mold 31 and using an adhesive applied to the bottom surface. 31 is fixed.

  If it is made hollow in this way, the amount of material used can be reduced and the mold can be easily removed because it can be easily deformed at the time of mold removal.

  Further, FIG. 3 (c) shows a rib form 36 composed of a steel plate part 36b for retaining the inner shape and a rubber part 36a coated on the surface thereof. The steel plate portion 36b is formed by bending a plate material into a trapezoidal shape, and its lower end is fixed to the bottom surface mold 31 by welding or the like.

  The rubber portion 36b is arranged as an easily deformable elastic material, and can be replaced with a foamed polystyrene or a synthetic resin material as in the other examples.

  Thus, the number of diversions can be increased by providing the steel plate portion 36b having high rigidity and not easily broken. Further, the rubber portion 36b on the surface that is easily deformed can be easily repaired by fixing the rubber portion 36b with an adhesive so as to be replaceable.

  Further, as shown in FIG. 4, the main-direction end face formwork 32 is provided with slits 32a,... As many as the number of rib portions 1b,. Oriented tendons 2A,... Are arranged.

  The slit 32a has a role of a gauge for placing the pretensioning tension material 2A at an accurate position. The slit 32a performs planar alignment of the tension material 2A and shields the slit 32a. Alignment in the height direction is performed by the members 6A,.

  As shown in FIG. 5, the shielding member 6A has a semi-cylindrical depression into which the tension material 2A is fitted. By arranging the shielding members 6A and 6A above and below the tension material 2A, the tension member 2A The gap between the surrounding slits 32a can be shielded to prevent leakage of the cementitious mixed material placed inside.

  This shielding member 6A can be made of steel, wood, synthetic resin, hard rubber, or the like, and has a size that crosses three slits 32a,... As shown in FIG.

  This shielding member 6A is attached to the upper and lower sides of the tension material 2A that has been subjected to initial tension and loosened. From the lowermost shielding member 6A to the guide grooves 62 and 62 provided on the outer surface of the main-direction end form frame 32. The wedges 61,... Are inserted into the gaps between the guide grooves 62, 62 and the shielding members 6A,.

  FIG. 6 shows a perspective view in which a shielding member 6B having a different form from the above is arranged in the slit 32a. Although the shielding member 6A described above has a form in which the shielding part is divided into upper and lower parts, the shielding member 6B has a form in which the shielding part is divided into left and right parts.

  The tension members 2A,... Are placed in semicylindrical depressions provided at intervals in the vertical direction of the shielding member 6B, the other shielding member 6B is aligned from the opposite side, and the slit 32a is in that state. If it is inserted, the gap of the slit 32a around the tendon 2A can be shielded to prevent leakage of the cementitious mixed material placed inside.

  In this manner, the tension members 2A and 2B can be easily and accurately arranged in the slits 32a and 33a of the main-direction end face mold 32 and the side face mold 33 from above.

  The ribbed floor slab 1 of the present embodiment introduces prestress in two directions by a pretension method.

  This pre-tension method is one of the methods to introduce pre-stress into a member molded with cement-based mixed material, and cement-based mixed material such as concrete is filled around pre-tensioned tension material such as PC steel wire. When the tension of the tension material is released after the predetermined strength is exhibited, the tension material contracts, and accordingly, prestress is introduced into the cement-based mixed material by the transmission of the adhesive force around the tension material. is there.

  FIG. 7 shows a plan view of a production yard for simultaneously producing a plurality of floor slabs 1 with ribs, and FIG. 8 shows a side view. Here, the tendons 2A and 2B are indicated by two-dot chain lines with the number omitted for the sake of simplicity.

  Moreover, the left-right direction of FIG. 7 is a main direction used as the extending direction of the rib part 1b, and an up-down direction is a sub direction.

  7 and 8, five ribbed floor slabs 1,... Are disposed, and abutments 71 for fixing the tension members 2 </ b> A disposed in the main direction on both sides thereof. 72 and 73 were installed.

  7 is a fixed abutment 71, and a fixed abutment 72 and a movable abutment 73 are installed on the right side via tension jacks 74,.

  Then, both ends of the tension member 2A are fixed to the left fixed abutment 71 and the movable abutment 73 via the fixing jig 75, and the movable abutment 73 moves away from the fixed abutment 72 when the tension jacks 74,. It is possible to move and to tension a plurality of tendons 2A,.

  A large-capacity jack having a large pushing force is used as the tension jack 74 used for tensioning the tension members 2A,.

  In addition, a pair of fixed abutments 81 and 82 are respectively installed in the sub-direction which is the vertical direction in FIG. 7 with the ribbed floor slab 1 interposed therebetween, and one end of the tension material 2B in the sub-direction is fixed by the fixing jig 84. A small tension jack 83 for monostrand is installed at the other end, fixed to the abutment 82.

  Then, the tension jacks 83,... Are operated to give tension to the tension members 2B,.

  When the number of tension members 2B in the sub-direction is large, a method of applying tension to a plurality of tension members 2B,... At a time by combining a fixed abutment, a movable abutment and a tension jack as in the main direction. Can also be applied.

  The ribbed floor slabs 1,... To which tension is applied by the tension members 2A and 2B are formed into a predetermined shape by the mold 3, and the mold 3 is supported by the support frame 4. The frame 4 is placed on a support jack 10 that can move up and down (see FIG. 8).

  A plurality of support jacks 10 are installed at intervals below the outer edge of the mold 3 in order to support the support frame 4 at a plurality of locations.

  As shown in FIG. 9 (b), a part of the bottom mold 31 is formed as a circular small piece 11a so as to be separable from other parts, and on the back surface of the small piece 11a, FIG. 9 (a) is formed. As shown in FIG. 1, the tip of a demolding jack 11 as a demolding device is attached.

  The lower part of the demolding jack 11 is fixed to the support frame 4. When the demolding jack 11 is extended, the small piece 11 a jumps out from the bottom surface mold 31.

  For this reason, when the demolding jack 11 is elongated after the ribbed floor slab 1 is formed, the ribbed floor slab 1 is lifted or the bottom surface mold 31 fixed to the support frame 4 is lowered by the reaction force. The bottom surface mold 31 is separated from the lower end surface of the floor slab 1 with ribs.

  Further, the demolding jacks 11 are installed at a plurality of locations, and hydraulic hoses are connected between the demolding jacks 11... To make the push-up load constant.

  Further, a part of the rib mold 34 or the bottom mold 31 is formed on the upper surfaces of the plug bodies 12A and 12B as shown in FIG.

  As shown in FIG. 10 (a), the plug 12A is disposed at the upper end of the air supply pipe 122 that penetrates the rib mold 34, and the head thereof is in the direction of the ribbed floor slab 1 (upward). It is formed in a frustoconical shape that spreads out.

  A sealing layer 121 such as grease or rubber packing is provided on the side surface of the plug 12A so that the cementitious mixed material filled in the mold 3 does not leak out.

  Since the upper surface of the plug 12A adheres to the filled cementitious mixed material, when the rib form 34 is separated from the ribbed floor slab 1, the periphery of the plug 12A and the air supply pipe 122 are separated. A gap is formed between the upper ends, and the air that has passed through the air supply pipe 122 flows into the lower end surface side of the ribbed floor slab 1 from the gap, thereby suppressing the occurrence of a vacuum state.

  FIG. 10B shows a view in which an air supply hole 123 is provided in the bottom mold 31 and the plug body 12B is disposed therein to form a part of the bottom mold 31. Other configurations and functions and effects Since is substantially the same as the plug 12A, description thereof is omitted.

  A plurality of such plug bodies 12A and 12B are provided at intervals so that air flows evenly into the lower end surface of the floor slab 1 with ribs.

  As described above, the ribbed floor slab 1 has a plurality of molds 3,... Arranged in the main direction, and prestress is simultaneously introduced into all the ribbed floor slabs 1.

  At this time, the tension members 2A between the ribbed floor slabs 1 and 1 are elastically deformed corresponding to the tension force, and these tension members 2A elastically contract simultaneously with the introduction of prestress. As a result, a moving amount of several tens of centimeters occurs.

  Thus, if the movement generated with the contraction of the tendon 2A is restricted, it becomes impossible to introduce a prestress of a desired size into each ribbed floor slab 1. Therefore, before introducing the prestress, Replacement to the sliding support portion 13 that supports the ribbed floor slab 1 without restraining the movement in the direction is performed.

  The sliding support portion 13 can support the weight of the ribbed floor slab 1 and the weight of the mold 3 including the support frame 4.

  The position and number of the sliding support portions 13 to be installed depend on the expression strength by the primary curing, but, for example, as shown in FIG. The generation of stress that causes cracks in the plate 1 can be controlled.

  As shown in FIG. 11A, the portion of the bottom mold 31 supported by the sliding support portion 13 is arranged as a rectangular partial support plate 31a with an edge cut off from other portions. That is, the bottom formwork 31 above each of the sliding support portions 13,... Is opened in a rectangular shape larger than the plane of the sliding support portion 13, and the partial support plates 31a,. Are arranged respectively.

  When the ribbed floor slab 1 moves in the main direction due to the introduction of prestress, the partial support plate 31a also moves following the ribbed floor slab 1 and is supported by the support jack 10 as shown in FIG. The other bottom mold 31 and the support frame 4 are left in place without moving.

  FIG. 12 shows the periphery of the sliding support portion 13 in a state where the floor slab 1 with ribs is molded and the bottom formwork 31 other than the partial support plate 13 is removed and the ribbed floor slab 1 can be moved. A cross-sectional view is shown.

  A sliding layer 13a formed of a lubricant such as grease is provided between the sliding support portion 13 and the partial support plate 31a, and the partial support plate 31a is smooth without receiving any resistance on the sliding support portion 13. It is configured so that it can move horizontally.

  Next, the manufacturing method of the floor slab 1 of the present embodiment will be described.

  First, the support frame 4 and the bottom mold 31 are installed on the support jack 10, and a plurality of rib molds 34,... Are fixed on the bottom mold 31, and the main end face mold is formed on the outer edge thereof. 32 and 32 and the side molds 33 and 33 are arranged to assemble the mold 3.

  Such assembly of the mold 3 is repeated between the fixed abutments 71 and 72 as shown in FIGS.

  Then, the tension members 2A,... Arranged in the main direction are inserted and arranged from above into the slits 32a,. Fix both ends of the fixed abutment 71 and the movable abutment 73 to each other.

  The placement work of the tension members 2A,... Can be performed simply by inserting them into the slits 32a,... Positioned from above, so that many tension members 2A,. Can be arranged.

  Further, the tension members 2B,... In the sub-direction are also arranged by being inserted from above into the slits 33a,... Of the side molds 33, 33, fixed to the fixed abuts 81, 82, and the tension jack 83, respectively. Set.

  The tension members 2A and 2B arranged in this way are initially subjected to initial tension for loosening, and the tension members 2A and 2B are installed at the exact positions of the slits 32a and 33a by attaching the shielding member 6A. .

  Thereafter, the tension jacks 74,... Are extended to give a predetermined tension force to the tension materials 2A,... In the main direction, and the tension jacks 83,.・ Give predetermined tension by extending each

  After applying a predetermined tension to the tension members 2A and 2B in this manner, the fiber reinforced cementitious mixed material is filled as a cementitious mixed material inside each of the molds 3,.

  After filling with the fiber-reinforced cement-based mixed material, surface treatment such as leveling is performed, and primary curing is performed until a predetermined strength is developed.

  After the primary curing is finished, the main direction end face formwork 32,... And the side face formwork 33,.

  Further, the support jack 10 is lowered, and the weight of the ribbed floor slab 1, the bottom mold 31, and the like is received by the sliding support 13 installed below each mold 3.

  Here, the load supported by the support jack 10 is supported by the sliding support portion 13, and a gap is left between the support frame 4 and the support jack 10.

  When the demolding jack 11 is operated and the small piece 11a is pushed upward in the state where the ribbed floor slab 1 is supported by the sliding support portion 13 as described above, the bottom surface mold 31 and the rib mold are caused by the reaction force. The frame 34 (excluding the rib mold 34 on the partial support plate 31) is lowered and separated from the lower end surface of the floor slab 1 with ribs, and air can enter between them to suppress the occurrence of a vacuum state.

  In addition to the place where the small piece 11a is installed, the air flows in the same way at the place where the plug bodies 12A and 12B are installed, and the occurrence of a vacuum state can be suppressed.

  Then, when the bottom formwork 31 and the rib formwork 34 other than the partial support plate 31 a are removed from the ribbed floor slab 1, the lower end of the support frame 4 comes into contact with the support jack 10 and is removed from the bottom. The mold 31, the rib mold 34, and the support frame 4 are supported by the support jack 10 (see FIG. 12).

  The pre-stress is first introduced by releasing the tension between the fixed abutments 81 and 82 by cutting the tension members 2B,.

  Then, the tension material 2A in the main direction is cut and released, and prestress is introduced in the main direction of the floor slabs with ribs 1,.

  At this time, the ribbed floor slab 1 supported by the sliding support portion 13 through the partial support plate 31a moves on the sliding support portion 13 due to elastic contraction of the tension material 2A. Since the frame 31 and the rib mold 34 are removed as shown in FIG. 12, they do not follow the movement.

  Note that end surfaces such as anticorrosion treatment are applied to the cut surfaces of the tendons 2A and 2B.

  And the produced floor slab 1 with a rib is moved, and the heat curing as a secondary curing is started.

  On the other hand, in the production yard, in order to produce the next floor slab 1 with ribs, the mold 3 is cleaned and the plane position and height are adjusted. Here, since the bottom formwork 31 and the rib formwork 34 are not moved in the horizontal direction when the prestress is introduced, it is not necessary to correct the planar position and the labor for preparation can be saved. .

  Next, operation of the ribbed floor slab 1 and the manufacturing apparatus thereof will be described.

  The ribbed floor slab 1 of the present invention configured as described above includes a floor slab portion 1a and a plurality of rib portions 1b, which are integrally formed of a cement-based mixed material such as concrete, and the rib portion 1b. Prestress is introduced in the stretching direction and the stretching orthogonal direction.

  For this reason, the floored slab 1 without a joint part can be manufactured easily. Moreover, since this production can be performed in a controlled place such as a factory or a field production yard, it can be produced with high quality.

  Furthermore, since prestress is introduced in two directions, the member cross section can be reduced and the weight can be reduced.

  In particular, by using the fiber-reinforced cement-based mixed material as the cement-based mixed material, if the same structural strength is used, the weight can be reduced to 30% to 45% when using conventional concrete. At the same time, durability can be improved.

  If the superstructure such as the bridge girder of the bridge is constructed with the lightweight ribbed slab 1 in this way, the seismic load can be greatly reduced, so the cross section of the substructure can be reduced and the total construction cost can be greatly reduced. it can.

  In addition, the mold surface of the rib mold 34 is formed of rubber, styrene foam or the like so that it can be more easily deformed than the mold surface of the bottom mold 31 formed of a steel plate or the like. Even if self-shrinkage occurs, the rib formwork 34 follows and deforms, so that self-shrinkage is not constrained, so that a tensile force is not generated in the cement-based mixed material and cracks are not generated.

  Furthermore, after the cementitious mixed material is hardened, when the small piece 11a that forms a part of the bottom surface mold 31 is pushed by the demolding jack 11, a gap is formed around the small piece 11a and air flows.

  Therefore, the mold can be easily removed without generating a vacuum state between the lower end surface of the ribbed floor slab 1 and the bottom mold 31. That is, if a vacuum state or a depressurized state is generated at the time of demolding, the initial demolding load is increased, causing excessive force to be applied to the rib portion 1b or the like, or causing cracks. However, such a damage or the like can be prevented by providing the demolding jack 11.

  Moreover, if the bottom body form 31 or a part of the upper end surface of the rib form part 34 is used as the plug bodies 12A and 12B, and the plug bodies 12A and 12B are shaped so as to expand upward, the bottom form frame 31 or When the rib mold 34 is lowered, a gap is formed around the plug bodies 12A and 12B attached to the lower end surface of the floor slab 1 with ribs, and the occurrence of a vacuum state can be prevented.

  Furthermore, by providing slits 32a for accommodating the tension material 2A disposed in the extending direction of the rib portion 1b in the main-direction end face mold 32 for forming the end surface in the extending direction of the rib portion 1b, a number of tension materials 2A, Can be easily installed at an accurate position.

  Further, the slit 32a is configured such that the shielding member 6A, which is a separate member from the main-direction end face formwork 32, is disposed, so that the shielding member 6A is removed first when demolding and competes with the tension material 2A. The main-direction end face formwork 32 can be easily removed without matching.

  Here, when the tension members 2B,... Are arranged in the direction perpendicular to the extending direction of the rib portion 1b, the side mold 33 is also provided with the slits 33a, so that the plurality of tension members 2B,. Can be installed, and the side mold 33 can be easily removed.

  Further, a part of the bottom mold 31 is formed by a partial support plate 31a that can be separated from the other by vertical movement, and is supported from below by the sliding support unit 13 so that the partial support plate 31a can slide. Let

  In this state, when prestress is introduced in the extending direction of the rib portion 1b by a pretension method, the ribbed floor slab 1 moves on the sliding support portion 13 without receiving a large movement resistance, and the other bottom formwork 31 is left in the original plane position without moving.

  For this reason, the preparation work for producing another ribbed floor slab 1 using this bottom formwork 31 is reduced again, and the ribbed floor slab 1 that efficiently introduces prestress in two directions is produced. Can be repeated.

  Although the best embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are possible. Are included in the present invention.

  For example, in the above-described embodiment, prestress is introduced into the ribbed floor slab 1 by the pretension method, but the present invention is not limited to this, and a ribbed floor slab in which prestress is introduced by the post tension method is used. You can also.

  Furthermore, in the said embodiment, although the ribbed floor slab 1 was shape | molded with the said fiber reinforced cementitious mixed material, it is not limited to this, It is ribbed with cementitious mixed materials, such as normal concrete and high-strength concrete. A floor slab can also be formed. In this case, reinforcing bars are arranged inside the floor slab with ribs as necessary.

It is the perspective view which showed the floor slab with the rib of the best embodiment of this invention. It is the perspective view which showed the formwork of the floor slab of a rib of the best embodiment of this invention. It is sectional drawing which showed the structure of three types of rib formwork. (A) is the side view which looked at the formwork from the main direction end surface formwork side, (b) is a top view near the main direction end face formwork. It is a perspective view explaining the arrangement configuration of the shielding member and tension material divided into the upper and lower sides. It is a perspective view explaining the installation state of the shielding member divided | segmented into right and left. It is a top view of the production yard of a ribbed floor slab. It is a side view of the production yard of a ribbed floor slab. It is a figure explaining the structure of the periphery where the demolding apparatus was attached, Comprising: (a) is sectional drawing of the AA line direction of (b), (b) is a top view. (A) is sectional drawing explaining the structure which provided the stopper in the mold for ribs, (b) is sectional drawing explaining the structure which provided the stopper in the bottom mold. (A) is a top view explaining the structure which has arrange | positioned the sliding support part under the mold, (b) is sectional drawing of the BB line direction of (a). It is sectional drawing explaining the structure of a slide support part periphery.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Floor slab with rib 1a Floor slab part 1b Rib part 1c Side wall part (rib part)
2A, 2B Tensile material 3 Mold 31 Bottom mold 31a Partial support plate 32 Main direction end mold 32a Slit 33 Side mold 33a Slits 34-36 Rib mold 6A, 6B Shielding member 11 Demolding jack )
11a Small piece 12A, 12B Plug body 13 Sliding support part

Claims (9)

A floor slab part and a plurality of rib parts that are juxtaposed and juxtaposed from the floor slab part are integrally formed of a cementitious mixed material, and tension disposed in the rib part toward the extending direction of the rib part A ribbed floor slab in which prestress is introduced by a material and prestress is introduced by a tension material disposed in the floor slab portion in a direction orthogonal to the extending direction . 2. The ribbed floor slab according to claim 1 , wherein the prestress is introduced by a pretension method in which a cementitious mixed material is attached to a tension material in both the stretching direction and the direction perpendicular to the stretching direction . A floor slab part and a ribbed floor slab production apparatus in which a plurality of rib parts projecting from the floor slab part are integrally formed of a cement-based mixed material,
The mold surface of the rib mold that forms the side surface of the rib portion and the bottom surface of the floor slab portion is formed of a material that is easier to deform than the mold surface of the bottom surface mold frame that forms the lower end surface of the rib portion. An apparatus for producing a floor slab with ribs. A part of the bottom formwork is formed by a small piece that can be separated from other parts of the bottom formwork by moving in the vertical direction, and by pressing the small piece, the bottom face of the bottom formwork and the ribbed floor slab 4. The apparatus for producing a floor slab with ribs according to claim 3, further comprising a demolding device for separating the slab. A part of the upper end surface of the bottom mold or rib mold is formed by a plug that can be separated from other parts of the bottom mold or rib by moving in the vertical direction. 5. The apparatus for producing a floor slab with ribs according to claim 3 or 4, wherein the apparatus has a shape spreading upward. The main-direction end face mold for molding the end face in the extending direction of the rib portion of the floor slab with ribs is provided with a slit that accommodates the tension material disposed in the extending direction of the rib portion, and the surroundings of the tension material ribbed deck of the manufacturing apparatus according to any one of claims 3 to 5, characterized in that for providing the shielding member in the gap of the slit.   The side mold for molding the side surface in the direction perpendicular to the extending direction of the rib portion of the floor slab with ribs is provided with a slit for accommodating a tension material disposed in the direction perpendicular to the extending direction of the rib portion, and the circumference around the tension material The apparatus for producing a floor slab with ribs according to claim 6, wherein a shielding member is disposed in the gap of the slit. A part of the bottom mold is formed by a partial support plate that can be separated from other parts of the bottom mold by moving in the vertical direction, and a sliding support portion on which the partial support plate is slidable is provided below. ribbed deck of the manufacturing apparatus according to any one of claims 3 to 7, characterized in that provided. Assembling the manufacturing apparatus ribbed slab according to any one of claims 3 to 8, by disposing the tendon was strained toward the stretching direction and the stretching direction orthogonal to the rib portion, of the mold A method for producing a ribbed floor slab, comprising filling a cement-based mixed material therein and removing the rib form and the bottom form after the cement-based mixed material reaches a predetermined strength.

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