JP5512712B2 - Joint structure of concrete floor slab edge in bridge - Google Patents

Description

  The present invention relates to a joint structure of a concrete slab end in a bridge such as a river bridge, an overpass, a viaduct or the like.

  In general, as shown in FIG. 1, the gap 3 formed between the ends of the concrete slabs 1 and 2, or the upper part of the gap 3 formed between the ends of the concrete slab 1 and the abutment 2 ′ is referred to as a finger joint. A structure in which a non-joint joint 4 for meshing the corrugated plate 4a is provided and the expansion and contraction in the gap 3 is freely made within the range of the meshing interval of the corrugated plate 4a is mainly used.

  However, the above-mentioned finger joint has a problem in that the surrounding concrete is significantly worn, and the finger joint protrudes on the road surface, thereby inducing noise and vibration caused by the traveling vehicle.

  In recent years, as means for coping with this problem, Patent Documents 1 and 2 below describe a stepped portion at the upper part of the gap formed between the ends of the concrete slab or between the edge of the concrete slab and the abutment. A structure in which an elastic joint is formed by forming and placing a highly stretchable filler in the stepped portion is proposed.

  The following Patent Document 1 fills the stepped portion with a highly stretchable pavement material to form an elastic joint portion. Similarly, Patent Document 2 below fills the stepped portion with a highly elastic cement mortar and forms an elastic joint portion. The joint structure is formed and absorbs bending stress at the elastic joint part. However, in reality, there is a problem that the high elastic pavement material or the high elastic cement mortar is crushed due to repeated load caused by running the vehicle. ing.

  The former is a structure that reinforces a highly elastic pavement material with a reinforcing bar and integrates it with the concrete floor slab, but because it is a pavement material, it cannot obtain the same strength as the existing floor slab concrete, and is due to the above repeated running load Crushing cannot be effectively prevented.

  Similarly, the latter has an anti-cracking sheet embedded in the high-elastic cement mortar, but because it is a high-elastic cement mortar, it cannot provide the same strength as existing floor slab concrete, and effectively prevents the above crushing. I can't.

  In order to solve the problems of Patent Documents 1 and 2, the following Patent Document 3 places concrete that is not stretchable or elastic on the stepped portion, and embeds a connecting rebar straddling the gap in the concrete. Presents a proposal for an interlocking structure that can be displaced integrally between concrete slabs or between concrete slabs and abutments.

  However, in the structure that is rigidly connected with the reinforced concrete, bending stress concentrates on the connecting rebar, and cracks of the concrete cannot be forbidden, and the result is a reversal of the ability to absorb expansion and contraction due to play.

  In addition, the following Patent Document 1 does not generate cracks by configuring an elastic joint portion with a highly stretchable pavement material, and the following Patent Document 2 configures an elastic joint portion with a high elastic cement mortar and prevents cracks in the elastic joint portion. In order to suppress cracking by embedding a sheet, Patent Document 3 below aims to disperse cracks and improve toughness with a short fiber reinforcing material. Here, cracks are cracks generated in the joint itself, that is, crack width. It means a crack that reaches the deep part of the joint.

  On the other hand, the present invention to be described later does not generate these cracks, generates innumerable fine cracks limited to the surface layer portion of the joint joint, and connects the inside of the infinite number of fine cracks with reinforcing fibers to cause bending stress. This is a joint structure that absorbs odor and has a completely different technical idea from each patent document that is concerned about the occurrence of cracks.

Japanese Patent No. 2923586 JP 2011-162981 A JP 2012-1979

  As described above, the joint structures of Patent Documents 1 and 2 cannot obtain the same strength as the existing floor slab concrete and cannot effectively prevent the collapse.

  The joint structure of Patent Document 3 is structured to be rigidly connected with the reinforced concrete in order to solve the problems of Patent Documents 1 and 2, but the bending stress is concentrated on the connecting reinforcing bars and the cracking of the concrete is prohibited. In other words, the result is a reversal of the expansion and contraction absorption capacity due to play.

  As described above, each of the preceding examples effectively achieves the purpose of eliminating unconnected joints that absorb expansion and contraction without physically connecting between concrete slabs or between concrete slabs and abutments, such as finger joints. Is difficult.

  The present invention provides a connection joint structure that absorbs bending stress appropriately while effectively preventing crushing by eliminating cemented mortar represented by the above finger joint and applying cement mortar rich in reinforcing fibers. Is.

When Yojutsu, Joint Gap formed between concrete slab edge, or wider stepped portion is formed along the Joint Gap on top of Joint Gap formed between concrete slab edge and abutment, the reinforcing fibers in the stepped portion Cast cement mortar to form a rigid joint, and when bending stress is applied to the rigid joint , innumerable microcracks are induced in the surface layer of the cement mortar containing reinforcing fibers And a joint structure of a concrete floor slab end having a structure for absorbing the bending stress by bridging and connecting the inside of the fine crack with a reinforcing fiber, and inserting an interstitial material into the gap, and an upper end of the interstitial material Projecting into the stepped-down portion, forming a projecting portion, and embedding the projecting portion in a lower layer portion of a rigid coupling joint made of cement mortar containing the reinforcing fiber, and projecting the rigid coupling joint to the upper end of the interposing material In the part where the part is buried Thinning Te, a structure to actively induce fine cracks due to the bending stress in the surface layer corresponding to the site where the thin Nikuka, appropriately absorb bending stresses yet high strength concrete slab end in the bridge The coupling joint structure is provided.

  The cement mortar includes both a cement mortar containing a polymer resin or a cement mortar not containing a polymer resin, and a cement mortar containing reinforcing fibers is a cement mortar rich in reinforcing fibers in both cement mortars.

  Preferably, the reinforcing fiber is a short fiber having a length of 15 mm or less, and the above-mentioned cross-linking structure is constituted by a rich blend of 1.0 to 3.0 vol% in the cement mortar, and the bending stress is surely To absorb.

  Also, an anchor bar rising from the bottom surface of the stepped portion is provided, the anchor bar is embedded in a rigid joint made of cement mortar containing the reinforcing fiber, and the fine crack is induced in the surface layer above the anchor bar. A fine crack-inducing layer is formed, and fine cracks can be effectively induced while the rigid joint is firmly anchored to a concrete slab or an abutment.

In addition, the raised surface of the concrete floor slab end or the abutment surface of the abutment forming the clearance is cut to form a shaved portion, and the shaved portion is repaired with cement mortar containing reinforcing fibers to form a repaired portion. the rigid connection joints by integrating the cement mortar reinforcing fiber-containing to form, it is possible to anchor the rigid fittings to more firmly concrete slab or abutments on.

  In addition, although the said patent document 2 is disclosing mixing | blending a fiber with a highly elastic cement mortar (paragraph 0037,0038 of patent document 2), the cement mortar of this patent document is alpha-sol (brand name) as an elasticity imparting material. Is a high-elasticity cement mortar in which cement and fibers are poorly blended in this elasticity-imparting material, and the fibers hardly contribute to the prevention of crushing and are inventions that absorb bending stress by high elasticity. As in the invention, the function of inducing a myriad of shallow microcracks in the surface layer of a rigid joint made of cement mortar containing reinforcing fibers (polymer cement mortar containing reinforcing fibers) and bridging the inside of the microcracks with reinforcing fibers is completely We do not have and do not assume.

  The present invention has a structure in which a concrete floor slab or a concrete floor slab and an abutment are rigidly connected and integrated with a rigid joint made of cement mortar containing reinforcing fibers, and a number of fine cracks are formed on the surface layer of the rigid joint. A joint structure with high strength and high toughness can be realized with a simple structure by cooperating with the structure that induces and bridges the inside of the fine crack with a reinforcing fiber to absorb the bending stress.

A is a pair of concrete floor slabs adjacent to each other through a gap in an existing bridge, or a perspective view schematically showing a part of a concrete floor slab and an abutment that are adjacent via a gap, and B is stepped down above the gap. Sectional drawing which shows the state which formed the part. Sectional drawing and the expanded sectional view of a fine crack which show the state which formed the cement mortar containing a reinforcement fiber in the said step-down part, and formed the rigid coupling joint. A cut-out part is formed at the end of the concrete floor slab or the abutment, and the cut-out part is repaired with a cement mortar containing reinforcing fibers to form a repaired part , and the repaired part contains reinforcing fibers that form the rigid joint Sectional drawing which shows the state integrated with the cement mortar, and an expanded sectional view of a fine crack. A to E show examples of the structure of an anchor bar provided with a locking part, A is a side view showing an example in which a nut is screwed onto the upper end of the anchor bar to form a locking part, and B shows the upper end of the anchor bar. The side view which shows the example which shape | molded in the shape and formed the latching | locking part, C is a side view which shows the example which bent the anchor muscle in the reverse U shape, and formed the latching | locking part, D is the upper end of the anchor muscle The perspective view which shows the example which provided the latching | locking part which consists of a board | plate material extended to a horizontal direction in E, and E is a perspective view which shows the example which provided the latching | locking part which extends in the horizontal direction at the upper end of the anchor muscle.

  The best mode of a joint structure of a concrete floor slab end in a bridge according to the present invention will be described below with reference to FIGS.

  FIG. 1A shows a finger joint which is an unconnected joint at an upper part of a gap 3 formed between the ends of the concrete floor slabs 1 and 2 or a concrete floor slab 1 and an abutment 2 ′ in an existing bridge. FIG. 4 is a perspective view schematically showing a state in which 4 is arranged with a part cut away. In the figure, reference numeral 15 denotes a pavement formed by a pavement material such as asphalt on the concrete floor slabs 1 and 2 or the abutment 2 '.

  When the joint structure according to the present invention is applied to the existing bridge, the finger joint 4 is first removed together with the surrounding mounting concrete, and a step is formed above the gap 3 as shown in FIG. 1B. The drop part 5 is formed.

  When the joint structure according to the present invention is applied to a new bridge, as shown in FIG. 1B, each of the concrete floor slabs 1, 2 upper ends, or the floor slab end of the concrete floor slab 1 and the abutment 2 ', respectively. A stepped portion 5 is formed in the upper portion in advance, or the stepped portion 5 is formed by scraping the upper ends of the concrete slabs 1 and 2 or the upper ends of the concrete slab 1 and the abutment 2 'on the spot. To do.

  In FIG. 1, 6 is a reinforcing reinforcing bar embedded in the concrete floor slabs 1 and 2 or the abutment 2 ′, and the reinforcing bar 6 is exposed in the stepped portion 5 in a state of rising from the bottom surface 5 a of the stepped portion 5. Yes. By embedding the reinforcing bar 6 in a rigid coupling 9 described later, the rigid coupling 9 is firmly anchored to the concrete floor slabs 1 and 2 or the abutment 2 ′.

  In the present application, the concrete floor slabs 1 and 2 are concrete floor slabs formed with cast-in-place concrete, PC concrete floor slabs formed at a factory, or steel girders (H-shaped steel girders, etc.) and cast concrete floor slabs. Or all the concrete slabs in the composite bridge etc. which were formed with PC concrete slabs are included.

  Next, as shown in FIG. 2, an interstitial material 7 having compression elasticity made of foamed polystyrene or urethane resin or the like is press-fitted into the gap 3, and cement mortar 8 containing reinforcing fibers is inserted into the stepped-down portion 5 from above. It casts and forms the rigid coupling joint 9 which consists of the cement mortar 8 containing this reinforcing fiber, and rigidly couples both concrete floor slabs 1 and 2 end upper part, or concrete floor slab 1 end upper part, and abutment 2 'upper part.

The inter-write member 7 is lower-side with closing without gaps an upper opening of the inserted said free between 3 within the Joint Gap 3, the upper end 7a to form the protrusions are protruded from the Joint Gap 3, the upper end projecting portion 7a The rigid joint 9 is embedded in the lower layer portion of the cemented mortar 8 containing the reinforcing fiber, and the rigid joint 9 is thinned at the portion where the upper end protruding portion 7a of the interposing material 7 is embedded.

  In other words, in the portion where the upper end protruding portion 7a of the interposing material 7 is embedded in the lower layer portion of the rigid joint 9 having the thickness indicated by T in the drawing, the upper end protruding portion 7a is embedded at T ′ in the drawing. As shown in the drawing, a fine crack 10 due to bending stress is positively induced in the surface layer 8a of the cement mortar 8 containing the reinforcing fiber corresponding to the thinned portion.

  Therefore, whether the fine cracks 10 are densely generated in the surface layer 8a at the thinned portion (the fine crack inducing layer 9a described later) and are generated in the surface layer 8a at other portions (the portion having the thickness T). Or hardly occurs.

  Further, in addition to the reinforcing bars 6, a plurality of anchor bars 6 'are set up at equal intervals along the bridge width direction on the bottom surface 5a of the stepped portion 5 shown in FIG. 1 as shown in FIG. The reinforcing bar 6 and the anchor bar 6 'are embedded in the rigid coupling joint 9, and the rigid coupling joint 9 is firmly locked to the concrete slabs 1 and 2 or the abutment 2'. The anchor bar 6 'is erected firmly by an adhesive 18 filled in a hole 17 drilled in the bottom surface 5a of the stepped portion 5.

  As a result, both the concrete floor slabs 1 and 2 or the concrete floor slab 1 and the abutment 2 'are securely joined and integrated, and the surface layer of the cement mortar 8 containing the reinforcing fibers above the anchor bars 6'. 8a, that is, the surface layer 9a of the rigid joint 9 is used as a microcrack inducing layer 9a. A microcrack 10 is intentionally induced in the microcrack inducing layer 9a, and the inside of the microcrack 10 is cross-linked with reinforcing fibers 11 to The bending stress applied to the rigid joint 9 is absorbed.

  More specifically, the anchoring portion 16 of the anchor bar 6 'is erected in the lower layer of the rigid joint 9 having the thickness indicated by T in the figure, limited to the height indicated by T1 in the figure. The surface layer 9a of the rigid joint 9 having a thickness indicated by T2 in the drawing, that is, T2 in the drawing is used as a microcrack inducing layer 9a, and microcracks 10 are positively induced in the microcrack inducing layer 9a. In addition, the inner surface 10a of the fine crack 10 is cross-linked with the reinforcing fiber 11 to absorb the bending stress. In addition, the said locking part 16 of each anchor reinforcement 6 'is arrange | positioned by arrange | equalizing height, respectively, and forms the said fine crack induction layer 9a.

  In the joint structure according to the present invention, the microcrack 10 is generated in the microcrack-inducing layer 9a against the tensile force generated by the shrinkage of the concrete slabs 1 and 2 or the abutment 2 '. Can withstand cross-linking.

  Preferably, as shown in FIG. 4A, a male screw portion 6'a is formed at the upper end of the anchor bar 6 ', and a nut 14 is screwed into the male screw portion 6'a. 16, anchor bars 6 ′ having the locking portions 16 are embedded in the rigid coupling joint 9 to prevent the rigid coupling joint 9 from floating.

  In addition, the said latching | locking part 16 (nut 14) can be freely adjusted within the range in which the said external thread part 6'a is formed.

  In addition, as shown in FIG. 4D, one or more locking portions 16 made of a plate material extending in the lateral direction are formed on the nut 14, or a bar material extending in the lateral direction on the nut 14 as shown in FIG. 4E. One or a plurality of locking portions 16 are formed to reliably prevent the rigid coupling joint 9 from floating.

  As another example of the anchor bar 6 ', as shown in FIG. 4B, the upper end of the anchor bar 6' is formed into a hook shape to form a locking portion 16, or as shown in FIG. It is optional depending on the implementation to bend the 6 'in an inverted U shape to form the locking portion 16 and prevent the rigid coupling joint 9 from floating. In the anchor bar 6 'of the structural example shown in FIGS. 4B and 4C, the standing height can be adjusted, and the height of the locking portion 16 can be adjusted.

  As described above, the joint structure according to the present invention repeatedly anchors the rigid joint 9 to the concrete floor slabs 1, 2 or the abutment 2 ′ by the retention effect of the locking portion 16 of the anchor bar 6 ′. The crushing of the rigid coupling joint 9 due to traveling load is effectively prevented.

  In addition, the reinforcing fiber 11 in the cement mortar 8 constituting the rigid coupling joint 9 is entangled with the locking portion 16, and the effect of mooring the rigid coupling joint 9 to the concrete floor slabs 1, 2 or the abutment 2 'is increased. To do.

Further, as shown in FIG. 3, in the present invention, the shaving portion 12 is provided on the rising surfaces 1a, 2a of the ends of the concrete floor slabs 1 and 2 or the rising surface 2'a of the abutment 2 'forming the clearance 3 shown in FIG. formed, to repair該削Ri portion 12 in the reinforcing fiber filled cement mortar 8 to form a repair part 13, by integrating cement mortar 8 of reinforcing fiber-containing constituting the rigid connection fitting 9 to the restoration unit 13 The concrete floor slabs 1 and 2 or the concrete floor slab 1 and the abutment 2 'are rigidly connected, and the surface layer 8a of the cement mortar 8 containing the reinforcing fibers, that is, the surface layer 9a of the rigid joint 9 is infinitely fine. It can be set as the structure which produces the crack 10 and absorbs the said bending stress.

  That is, first, the cut portion 12 is filled with a cement mortar 8 containing reinforcing fibers through a mold and repaired to form a repair portion 13, and the interstitial material 7 is press-fitted between the inner end surfaces of the repair portion 13. Then, cement mortar 8 containing reinforcing fibers is placed in the stepped portion 5 and integrated with the repaired portion 13 to form the rigid joint 9. The rigid coupling joint 9 is securely locked to both the concrete floor slabs 1 and 2 or the concrete floor slab 1 and the abutment 2 'by the repairing part 13.

  Also in this case, in addition to the reinforcing bar 6, the anchor bar 6 ′ is raised and provided on the bottom surface 5 a of the stepped portion 5, and the reinforcing bar 6 and the anchor bar 6 ′ are embedded in the rigid joint 9. The rigid joint 9 is firmly locked to both the concrete floor slabs 1 and 2 or the concrete floor slab 1 and the abutment 2 ', and the upper part of the anchor bar 6' is used as the fine crack inducing layer 9a.

  In the present invention, the scraped portion 12 is formed on one rising surface forming the clearance 3, the scraped portion 12 is repaired with cement mortar 8 containing reinforcing fibers, and the repaired portion 13 is formed. The case where the cement mortar 8 including the reinforcing fiber constituting the reinforcing fiber 13 is integrated with the cement mortar 8 including the reinforcing fiber constituting the rigid joint 9 is not excluded.

As described above, the connecting joint structure according to the present invention has a wide step along the gap 3 at the upper part of the gap 3 formed between the ends of the concrete decks 1 and 2 or between the concrete deck 1 and the abutment 2 '. A rigid portion comprising a cement mortar 8 with reinforcing fibers formed in the stepped portion 5 between the pair of concrete floor slabs 1 and 2 or between the upper ends of the concrete floor slab 1 and the abutment 2 '. The joint 9 is rigidly coupled, and the surface layer of the rigid joint 9 is used as a microcrack inducing layer 9a. The microcrack 10 is positively induced in the microcrack inducing layer 9a and the inside of the microcrack 10 is reinforced fiber 11 It is set as the structure which bridge | crosslinks and absorbs bending stress.

  The fine crack 10 is a fine crack having a width of 0.05 mm to 0.1 mm and a depth of 10 mm to 20 mm, and a tensile force due to contraction or bending stress of the concrete floor slabs 1 and 2 and the abutment 2 'is applied to the rigid joint 9. Is applied to the surface layer 9a of the rigid joint 9, that is, the fine crack induction layer 9a, absorbs the tensile force and effectively prevents the rigid joint 9 from being broken.

  As shown in FIGS. 2 and 3, the reinforcing fibers 11 blended in the cement mortar 8 in the fine cracks 10 bridge and connect the opposing inner surfaces 10 a of the fine cracks 10, and the concrete shrinkage and bending stress. Absorbs effectively.

  The reinforcing fibers 11 appear at random on the inner surface 10a of the microcrack 10 and effectively prevent rainwater from entering the microcrack 10 together with the reinforcing fibers 11 to be bridged and connected.

  In other words, the fine crack 10 is generated only in the fine crack inducing layer 9a which is the surface layer of the rigid joint 9. Accordingly, as shown in FIGS. 2 and 3, the anchor bar 6 'is provided with its locking portion 16 limited to the height indicated by T1, and a fine crack inducing layer 9a having a thickness of T2 is formed. The generation of the fine crack 10 is ensured, and the rigid joint 9 is firmly anchored to the concrete floor slabs 1 and 2 or the abutment 2 'as described above.

  Further, by embedding the upper end protruding portion 7a of the interposing material 7 in the lower layer portion of the rigid coupling joint 9, the rigid coupling joint 9 is thinned, and the thinned portion (the portion having a thickness T 'in the figure). The microcrack 10 is positively induced in the microcrack induction layer 9a.

<Formulation example 1>
The cement mortar 8 containing the reinforcing fiber according to the present invention is preferably exemplified as follows:
Water 250-450kg / m ³
Polymer resin 10-100 kg / m ³
Cement (Portland cement) 800-1600kg / m ³
Silica fume 20-350kg / m ³
Fine aggregate (maximum particle size is 1 mm or less) 100-700 kg / m ³
High performance AE water reducing agent or high performance water reducing agent 5% or less of cement weight Reinforcing fiber 11 (short fiber) 10-40 kg / m ³
Antifoaming agent (as powder) 0.2-15 kg / m ³
Consists of.

<Formulation example 2>
The cement mortar 8 with reinforcing fibers in the case of forming the joint structure according to the present invention in a short period of time is preferably blended as follows.
Water 250-450kg / m ³
Cement (ultrafast cement) 700-1500 kg / m ³
Silica fume 10 to 150 kg / m ³
Fine aggregate (maximum particle size is 1mm or less) 350-750kg / m ³
High performance AE water reducing agent or high performance water reducing agent 5% or less of cement weight Reinforcing fiber 11 (short fiber) 10-40 kg / m ³
Antifoaming agent (as powder) 0.2-15 kg / m ³

  As said polymer resin, polymer resins, such as a styrene butadiene resin type | system | group, a polyacrylic acid ester resin type | system | group (acrylic resin type | system | group), an ethylene vinyl acetate resin type | system | group, a vinyl acetate / veova resin type, are used, for example.

  As the reinforcing fiber 11, a high-strength polyethylene fiber, a polyvinyl alcohol fiber, or a mixed fiber of high-strength polyethylene fiber and polyvinyl alcohol fiber is used, and preferably 1.0 to 3.0 vol% is blended in the cement mortar. The inside of the fine crack 10 is cross-linked.

  The length of the reinforcing fiber 11 is 15 mm or less, preferably 6 to 12 mm, and the same diameter is selected in the range of 0.006 to 0.05 mm. Alternatively, the bulky reinforcing fibers 11 are converged in the range of 200 to 5000, and blended as convergent fibers having a length of 6 to 25 mm and a diameter of 0.5 to 3 mm. Alternatively, it is optional depending on the practice to mix and mix the above-mentioned loose reinforcing fibers 11 and the converged reinforcing fibers 11.

As a result of the performance test, the cement mortar 8 containing the reinforcing fibers according to the blending examples 1 and 2 has a modulus of elasticity of 20 to 40 GPA, a tensile strength of 6 to 15 N / mm ² , and a compressive strength of 30 N / mm ² or more. Met. In particular, the cement mortar 8 containing the reinforcing fibers according to the blending example 2 had a compressive strength of 24 N / mm ² or more in 3 hours after placing.

  As described above, the joint structure according to the present invention can achieve both high strength and high toughness with a simple structure. In addition, it is possible to effectively reduce costs and time without complicated work in arrangement work and repair work.

  Further, if the upper surface of the rigid joint 9 is flush with the upper surface of the pavement 15 on the two concrete floor slabs 1 or 2 or the abutment 2 ', it is possible to effectively prevent the generation of noise due to vehicle running.

  The present invention does not exclude the formation of the pavement 15 on the upper surface of the rigid coupling 9.

  In the present application, the numerical range indicated by “˜” between the lower limit value and the upper limit value represents all the numerical values (integer value and decimal value) between the lower limit value and the upper limit value.

  DESCRIPTION OF SYMBOLS 1, 2 ... Concrete floor slab, 2 '... Abutment, 1a, 2a, 2'a ... Rising surface, 3 ... Free space, 4 ... Non-coupling joint (finger joint), 5 ... Stepped part, 5a ... Bottom surface, 6 ... Reinforcing bar, 6 '... Anchor bar, 6'a ... Male thread part, 7 ... Interstitial material, 7a ... Upper end (upper end protruding part), 8 ... Cement mortar with reinforcing fiber, 8a ... Surface layer, 9 ... Rigid coupling joint , 9a ... fine crack inducing layer (surface layer), 10 ... fine crack, 10a ... inner surface, 11 ... reinforcing fiber, 12 ... shaving part, 13 ... restoration part, 14 ... nut, 15 ... pavement part, 16 ... locking part , 17 ... hole, 18 ... adhesive, T ... thickness of rigid joint, T1 ... height of anchoring portion of anchor muscle, T2 ... thickness of fine crack-inducing layer, T '... thickness of thinned portion.

Claims (4)

Joint Gap formed between concrete slab edge, or the top of the Joint Gap formed between concrete slab edge and the abutment to form a stepped portion, and Da設cement mortar reinforcing fiber-containing to the stepped portion When a rigid coupling joint is formed and bending stress is applied to the rigid coupling joint , innumerable fine cracks are induced in the surface layer of the cement mortar containing the reinforcing fibers constituting the rigid coupling joint and the inside of the fine cracks is reinforced fiber. A joint structure of a concrete floor slab end having a structure that absorbs the bending stress by bridging and connecting, and inserting an interstitial material into the gap and projecting the upper end of the interstitial material into the stepped-down portion Forming a protruding portion, burying the protruding portion in a lower layer portion of a rigid coupling joint made of cement mortar containing the reinforcing fiber, and thinning the rigid coupling joint at a portion where the upper end protruding portion of the interposing material is embedded; Thinned part Joint structure of the concrete slab end in the bridge, characterized in that it has a structure to actively induce fine cracks due to the bending stress in the surface layer corresponding to.   2. The reinforcing fiber according to claim 1, wherein the reinforcing fiber is a short fiber having a length of 15 mm or less, and the cross-linked structure is constituted by a rich blend of 1.0 to 3.0 vol% in the cement mortar. Joint structure of concrete floor slab edge in bridge.   An anchor bar that rises from the bottom surface of the stepped portion is provided, the anchor bar is embedded in a rigid joint made of cement mortar containing the reinforcing fiber, and a fine crack is induced in the surface layer above the anchor bar. The joint structure at the end of a concrete floor slab in a bridge according to claim 1, wherein a crack-inducing layer is formed. The raised surface of the concrete slab edge forming the gap or the rising surface of the abutment is shaved to form a shaved part, and the shaved part is repaired with cement mortar containing reinforcing fibers to form a repaired part . joint structure of the concrete slab end in the bridge according to any one of claims 1-3, characterized in that integrated cement mortar reinforcing fiber-containing forming the rigid connection joints.

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