Joint structure of concrete members

Abstract

To provide a joint structure of a concrete member, which enables a top slab part to be joined to a side wall part even if an overhanging part is not provided at an upper end of the side wall part, and which can be constructed in a short period of time.SOLUTION: The concrete side wall part 8 is joined to a precast concrete top plate member 11 at a joint part 12. The concrete portion 12a of the joining portion 12 is formed of fiber-reinforced concrete having a compression strength of 50N / mm2 to 200N / mm2. Thus, the joining part 12 functions as a fixing body of the side wall main reinforcement 15 and the top slab main reinforcement 17, and sectional force is transmitted between these reinforcements via the fiber reinforced concrete, and the width of the joining part 12 can be narrowed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a joint structure between a concrete wall and a top slab. [Background technology]

[0002] Conventionally, reinforced concrete structures or prestressed concrete structures having wall sections and top plates have often been constructed entirely from cast-in-place concrete. Patent Document 1 discloses a joint structure between a precast concrete side wall member and a precast concrete top plate member, and a construction method for the same. In the joint structure and construction method described in Patent Document 1, an overhang portion is formed at the upper end of the side wall member toward the top plate member, and the end of the top plate member is placed on the overhang portion. The overhang portion ensures the joint length between the reinforcing bars of the side wall member and the top plate member, and also eliminates the need to install a lower formwork or shoring to support it when pouring cast-in-place concrete to form a joint for joining the side wall member and the top plate member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-127363 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, rapid construction is required to maximize the power generation period when constructing floating structures for floating offshore wind power generation facilities. Constructing such concrete structures entirely using cast-in-place concrete results in a long construction period. Providing overhangs in precast concrete side walls, as in the structure described in Patent Document 1, results in a larger volume than plate-shaped components, reducing the number of side wall components that can be loaded per transport vehicle. Furthermore, forming side walls with such overhangs using cast-in-place concrete requires lower formwork and shoring to form the overhangs, resulting in a long construction period.

[0005] Furthermore, if a precast concrete top plate is to be joined to the side walls without providing an overhang, the joint formed with cast-in-place concrete must be long to ensure the joint length between the main reinforcement of the top plate and the main reinforcement of the side walls. This requires the installation of lower formwork and shoring, which lengthens the construction period.

[0006] In view of the above background, the present invention aims to provide a joint structure for reinforced concrete members that can be constructed in a short period of time and that allows the top plate to be joined to the side wall without providing a protrusion at the upper end of the side wall. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one aspect of the present invention is a joint structure for concrete members including reinforcing bars, comprising: side wall sections (6, 8) made of reinforced concrete, each including a side wall concrete section (14, 19) and side wall main reinforcements (15, 20) including protruding portions (15a, 20a, 20b) protruding from the upper end surfaces of the side wall concrete sections; a top slab member (11) made of precast concrete, joined to the upper end portions of the side wall sections so as to form a predetermined angle with respect to the side wall sections, and including a top slab concrete section (16) and top slab main reinforcements (17) including protruding portions (17c, 17d) protruding from the side end surfaces of the top slab concrete section on the side wall section side; and a top slab member (11) made of precast concrete, wherein the protruding portions of the side wall main reinforcements and the protruding portions of the top slab main reinforcements are embedded, and the compressive strength is 50 N / mm 2 ~200N / mm 2(Regarding a numerical range, "X or more and Y or less" will be expressed as "X to Y", the same applies below.) and a joint (12, 13) including a concrete portion (12a, 13a) formed of fiber-reinforced concrete.

[0008] According to this aspect, the concrete portion of the joint is made of fiber-reinforced concrete with a predetermined strength or higher, so the joint functions as an anchor for the rebars protruding into the joint. Therefore, even if the rebars protrude into the joint only a short distance, the cross-sectional forces are sufficiently transmitted between the rebars protruding into the joint via the fiber-reinforced concrete. This allows the width of the joint to be approximately the thickness of the side wall, eliminating the need for overhanging portions on the side wall and eliminating the need for lower formwork or shoring, thereby shortening the construction period.

[0009] In the above aspect, it is preferable that the edge of the upper end surface of the side wall concrete portion (14, 19) on the side of the top concrete portion abuts against the lower edge of the side end surface of the top concrete portion.

[0010] In this case, the upper end surface of the concrete side wall functions as a lower formwork when pouring concrete into the joint, eliminating the need for a separate lower formwork. Furthermore, compared to when the top plate member is placed on the upper end surface of the side wall, the wall thickness of the top plate member is effectively utilized to ensure sufficient width for the joint.

[0011] In the above aspect, the side wall portions (6, 8) are part of the side wall (3) of the floating structure (1) of the floating offshore wind power generation facility, and the top plate member (11) is part of the top plate (4) of the floating structure.

[0012] According to this aspect, the floating structure can be constructed in a short period of time without providing a protruding portion at the upper end of the side wall.

[0013] In the above embodiment, a pair of the top plate members (11) may be joined to the joint portion (12) so that the side end surfaces of the top plate members (11) face each other with the joint portion (12) therebetween.

[0014] According to this aspect, it is possible to construct a joint structure that is T-shaped when viewed from the extending direction of the joint portion.

[0015] In the above embodiment, the protruding portions (17d) of the top plate main reinforcement (17) in a pair of the top plate members (11) may be embedded in the concrete portion (12a) of the joint portion (12) so as to form a gap lap joint with each other.

[0016] According to this aspect, the cross-sectional force transmission performance of the joint between the top plate main reinforcements is improved.

[0017] In the above embodiment, the top plate main reinforcements (17) may be arranged in two tiers, upper and lower, and in the direction of extension of the top plate main reinforcements, the portion of the joints (12, 13) that receives the top plate main reinforcements arranged in the upper tier may be wider than the portion of the joints that receives the top plate main reinforcements arranged in the lower tier.

[0018] According to this aspect, the bond length of the top plate main reinforcement arranged in the upper stage to the concrete can be secured.

[0019] In the above-mentioned aspect, when viewed from the extension direction of the joint (13), the top plate member is joined to only one horizontal side of the side wall portion, the horizontal width of the concrete portion (13a) of the joint changes so as to widen upward, the joint surfaces between the concrete portion of the joint and the side wall concrete portion (19) are inclined at an angle of 40° to 50° with respect to the horizontal direction, and the joint surfaces between the concrete portion of the joint and the top plate concrete portion (16) may be inclined at an angle of 40° to 50° with respect to the horizontal direction.

[0020] According to this aspect, the joint formed of fiber-reinforced concrete extends along a surface inclined at 40° to 50° from the horizontal, extending into the top concrete portion and the side wall concrete portion, thereby suppressing cracks that propagate from the area where the extension lines of the top concrete portion and the side wall concrete portion overlap, thereby improving the strength around the joint.

[0021] When viewed from the extension direction of the joint, the top plate member (11) is joined to only one horizontal side of the side wall portion (6), the horizontal width of the concrete portion (13a) of the joint (13) changes in stages so that it widens upward, the line connecting the upper end of the side surface of the side wall concrete portion (19) distal to the top plate concrete portion (16) and the upper end of the side surface of the side wall concrete portion (19) proximal to the top plate concrete portion is inclined at an angle of 40° to 50° with respect to the horizontal direction, and the line connecting the edge of the lower surface of the top plate concrete portion facing the side wall concrete portion and the edge of the upper surface of the top plate concrete portion facing the side wall concrete portion may be inclined at an angle of 40° to 50° with respect to the horizontal direction.

[0022] According to this aspect, the joint formed of fiber-reinforced concrete gradually expands along a line inclined at 40° to 50° from the horizontal, extending into the top concrete portion and the side wall concrete portion. This suppresses cracks that propagate from the area where the extension line of the top concrete portion and the extension line of the side wall concrete portion overlap, thereby improving the strength around the joint.

[0023] In the above embodiment, the protruding portions (15a, 20a) of the side wall main reinforcements (15, 20) may form loop reinforcements or extend linearly, and the protruding portions (17c, 17d) of the top plate main reinforcements (17) may form loop reinforcements or extend linearly.

[0024] According to this aspect, if the reinforcement is loop reinforcement, the attachment length of the protruding part to the concrete is increased, and the transmission performance of cross-sectional forces such as axial force and moment between each main reinforcement is improved at the joint; if the reinforcement is straight, it becomes easier to form the side wall parts and top plate members.

[0025] In the above embodiment, when viewed from the extending direction of the joint (13), one top plate member (11) is joined to the joint, the top plate main reinforcements (17) are arranged in two tiers, upper and lower, and the side wall main reinforcements (20) are arranged in two tiers in the thickness direction of the side wall portion (6), and the protruding portion (17e) of the top plate main reinforcement arranged in the upper tier and the protruding portion (20c) of the side wall main reinforcement arranged in the tier located distal to the top plate member may be curved to form a lap joint.

[0026] According to this embodiment, the connection between the top plate main reinforcement and the side wall main reinforcement is strengthened by the gap lap joint. [Effects of the Invention]

[0027] According to the above aspect, the top plate portion can be joined to the wall portion without providing a protrusion portion at the upper end of the wall portion, and a joining structure for reinforced concrete members can be provided that can be constructed in a short period of time. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a plan view showing the arrangement of the top plate member in a floating structure according to an embodiment; [Figure 2] Cross-sectional view taken along line II-II in Figure 1. [Figure 3] An explanatory diagram showing the construction method for the joint between the bulkhead and the top plate (A: conventional technology, B: embodiment) [Figure 4] Reinforcement plan view of the joint between the partition wall and the top plate according to the embodiment [Figure 5] An explanatory diagram showing the construction method for the joint between the exterior wall and the top plate (A: conventional technology, B: embodiment) [Figure 6] Reinforcement plan view of the joint between the exterior wall and the top plate according to the embodiment [Figure 7] Reinforcement diagram of the joint between the bulkhead and the top plate according to the modified example (A: front view, B: plan view) [Figure 8] Reinforcement diagram of the joint between the exterior wall and the top plate according to the modified example (A: front view, B: plan view) [Figure 9]Reinforcement diagram of the joint between the exterior wall and the top plate according to the modified example (A: front view, B: plan view) [Figure 10] FIG. 10 is a front view showing the shape of a joint according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a floating structure 1 of a floating offshore wind power generation facility according to an embodiment, and FIG. 2 shows a cross section taken along line II-II in FIG. 1. The floating structure 1 includes a base 2 that defines the underside of the floating structure 1, side walls 3 erected on the base 2, and a top slab 4 that is joined to the upper ends of the side walls 3 and defines the upper side of the floating structure 1. The floating structure 1 is a reinforced concrete structure or a prestressed concrete structure, and is floated on the ocean or lake to support a tower (not shown) of the floating offshore wind power generation facility. The floating structure 1 is a barge-type structure, and the base slab 2 and the top slab 4 are generally flat plates, with their outer contours roughly matching each other in a plan view. The floating structure 1 is constructed on land near the planned location of the floating offshore wind power generation facility and then towed to the planned installation site.

[0030] The base slab 2 is a reinforced concrete structure or a prestressed concrete structure. The base slab 2 according to the embodiment is formed of cast-in-place concrete, but may be formed in part or entirely by joining multiple precast concrete members.

[0031] The side walls 3 include outer walls 6 that define the outer peripheral surface of the floating structure 1, and bulkheads 8 arranged between the outer walls 6. The outer walls 6 are connected at their lower ends to the outer peripheral edge of the base slab 2 and at their upper ends to the outer peripheral edge of the top slab 4. The bulkheads 8 are erected on the base slab 2 and connect the side walls 3 to each other, the side walls 3 to other bulkheads 8, or other bulkheads 8 to each other. The bulkheads 8 are joined at their upper ends to the top slab 4. The base slab 2, the outer walls 6, the bulkheads 8, and the top slab 4 define multiple hollow spaces 9 within the floating structure 1 for generating buoyancy. The outer walls 6 and the bulkheads 8 are made of reinforced concrete or prestressed concrete and have a plate shape that is approximately perpendicular to the base slab 2 and the top slab 4. The side walls 3 according to this embodiment are entirely formed of cast-in-place concrete, but may be partially or entirely formed by joining multiple precast concrete members. A cylindrical tower connecting portion 10 to which a tower (not shown) is connected is provided in the center of the floating structure 1 in a plan view.

[0032] The top slab 4 is disposed approximately parallel to the bottom slab 2. The top slab 4 is formed by joining a plurality of precast concrete top slab members 11 to the side walls 3. The top slab members 11 are made of reinforced concrete or prestressed concrete, have a flat plate shape, and are joined to the side walls 3 and / or partition walls 8 at their edges in plan view.

[0033] The partition wall 8 and the top plate member 11 are joined to each other by a joint 12. At the joint 12, a pair of top plate members 11 are joined to the partition wall 8 and a pair of top plate members 11 are joined to each other so as to form a T-shape when viewed in a direction parallel to the main surfaces of the joined partition wall 8 and top plate member 11, i.e., in the extending direction of the joint 12. The outer wall 6 and the top plate member 11 are joined to each other by a joint 13. At the joint 13, the top plate member 11 is joined to the outer wall 6 so as to form an L-shape when viewed in a direction parallel to the main surfaces of the joined outer wall 6 and top plate member 11, i.e., in the extending direction of the joint 13.

[0034] The joints 12 and 13 have a compressive strength of 50 N / mm 2 ~200N / mm 2The joints 12 and 13 include concrete sections 12a and 13a formed by pouring the fiber-reinforced concrete at the construction site of the floating structure 1. The fibers of the fiber-reinforced concrete used in the joints 12 and 13 include, for example, steel fibers, carbon fibers, aramid fibers, polyolefin fibers such as polypropylene and polyethylene, and vinylon fibers.

[0035] Fig. 3(A) shows the joint structure between a bulkhead 108 erected on a bottom slab 102 and a top slab 104 in a conventional floating structure 101 constructed entirely of cast-in-place concrete, Fig. 3(B) shows the joint structure between a bulkhead 8 and a pair of top slab members 11 in a floating structure 1 according to an embodiment, and Fig. 4 is a plan view showing the arrangement of reinforcement near a joint 12 according to an embodiment. The arrangement of reinforcement and the construction method for the T-shaped joint 12 will be described with reference to Figs. 3 and 4.

[0036] The partition wall 8 joined to the top plate member 11 includes a partition wall concrete section 14 formed of concrete, partition wall main reinforcements 15 extending in the vertical direction and partially embedded in the partition wall concrete section 14, and partition wall reinforcing bars 23 (see Figure 7(A)) perpendicular to the partition wall main reinforcements 15 and embedded in the partition wall concrete section 14. The partition wall main reinforcements 15 are arranged in two stages in the thickness direction of the partition wall 8, and have protruding portions 15a protruding from the upper end surface of the partition wall concrete section 14. The protruding portions 15a of the partition wall main reinforcements 15 extend linearly in the vertical direction. The partition wall main reinforcements 15 have a strength of 345 N / mm 2 ~490N / mm 2 and is, for example, a high strength reinforcing bar of SD345, SD390 or SD490 as specified in JIS G 3112.

[0037] Each of the pair of top plate members 11 includes a top plate concrete portion 16 made of concrete, top plate main reinforcements 17 partially embedded in the top plate concrete portion 16, and stirrups (not shown) arranged to surround the top plate main reinforcements 17. The top plate main reinforcements 17 include axial reinforcements 17a and straight axial reinforcements 17b arranged perpendicular to the axial reinforcements 17a. The axial reinforcements 17a and straight axial reinforcements 17b are arranged in two rows, one above the other. The top plate main reinforcements 17 have protruding portions 17c protruding from the side of the top plate concrete portion 16. The protruding portions 17c of the axial reinforcements 17a form loop reinforcements that connect the axial reinforcements 17a arranged in two rows, one above the other. When viewed from the extension direction of the joint 12, the protruding portions 17c of the axial reinforcements 17a are arranged so as to partially overlap the protruding portions 15a of the partition wall main reinforcements 15, but the two do not necessarily have to abut each other. The vertical length of the protruding portions 15a of the bulkhead main reinforcement 15 is the anchorage length of the bulkhead main reinforcement 15 in the joint 12, and is generally 15 times or more the diameter of the reinforcement, although this depends on the diameter of the reinforcement. The protruding portions 17c of the axial reinforcement 17a protruding from the opposing side surfaces of a pair of top plate members 11 are arranged to form a lap joint with a gap. That is, the protruding portion 17c of the axial reinforcement 17a of one top plate member 11 is arranged offset in the extension direction of the joint 12 relative to the protruding portion 17c of the axial reinforcement 17a of the other top plate member 11, and both are arranged so as to partially overlap when viewed from the extension direction of the joint 12. The joint length of the alternatingly arranged protruding portions 17c of a pair of top plate members 11 is preferably approximately 7.5 to 15 times the diameter of the reinforcement. The top plate main reinforcement 17 has a strength of 345 N / mm 2 ~490N / mm 2 and is, for example, a high strength reinforcing bar of SD345, SD390 or SD490 as specified in JIS G 3112.

[0038] The side of the top concrete section 16 has planes that are approximately parallel to the vertical direction at the top where the axial reinforcement 17a arranged in the upper row protrudes and at the bottom where the axial reinforcement 17a arranged in the lower row protrudes, and an inclined surface is provided between the two so that the bottom protrudes more than the top.

[0039] When installing the top plate member 11, brackets 18 are removably fixed to both main surfaces of the partition wall 8. The brackets 18 are fixed to the partition wall 8 so that the upper surfaces of the brackets 18 are flush with the upper end surfaces of the partition wall concrete sections 14. A pair of top plate members 11 are placed on the corresponding brackets 18 so that the lower edges of the opposing side surfaces of each top plate member 11 abut the corresponding side edges of the upper surface of the partition wall 8. At the location that will become the joint 12, the top plate reinforcing bars 12b are arranged along the extension direction of the joint 12 so that they intersect with the upper and lower protrusions 17c. Fiber-reinforced concrete is poured to approximately the same height as the upper surface of the top plate member 11 in the area surrounded by the upper surface of the partition wall concrete section 14 and the side surface of the top plate concrete section 16, so as to embed the protrusions 15a of the partition wall main reinforcement bars 15, the protrusions 17c of the axial reinforcement bars 17a, and the top plate reinforcing bars 12b, thereby forming the joint 12. The brackets 18 are removed after the fiber-reinforced concrete has hardened. If the extension direction of the top plate main reinforcement 17 embedded in the joint 12 is the width direction of the joint 12, the lower part of the opposing side surfaces of the pair of top plate members 11 protrudes more than the upper part, so the width of the part that receives the axial reinforcement 17a arranged in the upper row of the joint 12 is wider than the width of the part that receives the axial reinforcement 17a arranged in the lower row of the joint 12.

[0040] As shown in Figure 3(A), if the top slab 104 is formed using cast-in-place concrete, a lower formwork 131 and shoring 132 are required to support it. Simply replacing the top slab 104 shown in Figure 3(A) with a precast concrete member requires the joints to be longer to ensure the joint lengths between the bulkhead main reinforcement 115 and the axial reinforcement 117a and between the axial reinforcement 117a themselves. This requires the installation of a lower formwork and shoring to support the concrete poured at the joints. In this embodiment, as shown in Figure 3(B), the width of the joint 12 at the bottom corresponds to the thickness of the bulkhead 8, and the upper part is only slightly wider than the bottom. Therefore, the extension lengths of the bulkhead main reinforcement 15 into the joint 12 and the joint lengths of the axial reinforcement 17a of the pair of top slab members 11 and the joint lengths into the joint 12 are shorter than those of conventional structures. However, by forming the joints 12 from fiber-reinforced concrete of a predetermined strength or more, the joints 12 function as anchors for the reinforcing bars embedded in the joints 12. Therefore, even if the penetration length (anchor length) and joint length are short, the cross-sectional forces of the joints 12, such as moments and axial forces, are sufficiently transmitted via the fiber-reinforced concrete between the partition main reinforcement 15 and the axial reinforcement 17a, and between the axial reinforcement 17a of the pair of top plate members 11.

[0041] In the example shown in the figure, the axial reinforcement 17a is embedded in the concrete portion 12a of the joint 12, but the axial reinforcement 17b also has a protrusion 17c similar to the axial reinforcement 17a and is embedded in the concrete portions 12a, 13a formed by fiber-reinforced concrete at the other joints 12, 13.

[0042] Fig. 5(A) shows the joint structure between an outer wall 106 and one top slab 104 in a conventional floating structure 101 constructed entirely of cast-in-place concrete, Fig. 5(B) shows the joint structure between an outer wall 6 and one top slab member 11 in a floating structure 1 according to an embodiment, and Fig. 6 is a plan view showing the arrangement of reinforcement near a joint 13 according to an embodiment. The arrangement of reinforcement and the construction method for the L-shaped joint 13 will be described with reference to Figs. 5 and 6.

[0043] The exterior wall 6 includes an exterior wall concrete section 19 made of concrete, exterior wall main reinforcements 20 extending in the vertical direction and partially embedded in the exterior wall concrete section 19, and exterior wall reinforcing bars 24 (see Figure 8(A)) perpendicular to the exterior wall main reinforcements 20 and embedded in the exterior wall concrete section 19. The exterior wall main reinforcements 20 are arranged in two stages in the thickness direction of the exterior wall 6, and have protruding parts 20a that protrude from the upper end surface of the exterior wall concrete section 19. The protruding parts 20a of the exterior wall main reinforcements 20 form loop reinforcements so that the reinforcing bars arranged in two stages are connected. The exterior wall main reinforcements 20 have a strength of 345 N / mm 2 ~490N / mm 2 and is, for example, a high strength reinforcing bar of SD345, SD390 or SD490 as specified in JIS G 3112.

[0044] The top plate member 11 has the same characteristics as that of the member joined to the T-shaped joint 12 (see Figures 3(B) and 4), except for the side surface of the top plate concrete portion 16 on the joint 13 side. The side surface of the top plate concrete portion 16 on the joint 13 side is a plane parallel to the main surface of the exterior wall 6. When viewed from the extension direction of the joint 13, the protruding portion 17c of the top plate main reinforcement 17 is arranged so as to partially overlap the protruding portion 20a of the exterior wall main reinforcement 20. The two do not need to abut each other, forming a gap lap joint. The protruding length of the protruding portion 17c of the top plate main reinforcement 17 is the anchorage length of the top plate main reinforcement 17 in the joint 13, and is approximately 7.5 to 15 times the diameter of the rebar. The vertical length of the protruding portion 20a of the exterior wall main reinforcement 20 is the anchorage length of the exterior wall main reinforcement 20 in the joint 13, and is approximately 15 times or more the diameter of the rebar, although this depends on the diameter of the rebar.

[0045] When installing the top plate member 11, a bracket 18 is removably fixed to the main surface of the exterior wall 6 on the side facing the top plate member 11. The bracket 18 is fixed to the exterior wall 6 so that its upper surface is flush with the upper end surface of the exterior wall concrete portion 19. The top plate member 11 is placed on the bracket 18 so that the lower edge of the side surface of the top plate member 11 on the joint 13 side abuts the side edge of the upper surface of the exterior wall 6 on the side facing the top plate member 11. At the location that will become the joint 13, distribution reinforcement 13b extending in the extension direction of the joint 13 is arranged so as to intersect with the protruding portion 20a of the exterior wall main reinforcement 20 and the protruding portion 17c of the top plate main reinforcement 17. To form the side surface on the opposite side of the top plate member 11 at the joint 13, a formwork 26 (see Figure 8) is installed along the outer main surface or extended surface of the exterior wall 6. Fiber-reinforced concrete is poured into the area surrounded by the upper surface of the exterior wall concrete portion 19, the side surface of the top slab concrete portion 16, and the formwork 26, to a height approximately flush with the upper surface of the top slab member 11, so as to embed the protruding portions 20a of the exterior wall main reinforcements 20, the protruding portions 17c of the top slab main reinforcements 17, and the distribution reinforcements 13b, thereby forming the joint 13. After the fiber-reinforced concrete has hardened, the brackets 18 are removed. If the extension direction of the top slab main reinforcements 17 embedded in the joint 13 is taken as the width direction of the joint 13, then the lower portion of the side surface of the top slab member 11 facing the joint 13 protrudes more than the upper portion, and therefore the width of the portion of the joint 13 that receives the axial reinforcements 17a arranged in the upper row is wider than the width of the portion of the joint 13 that receives the axial reinforcements 17a arranged in the lower row.

[0046] As shown in FIG. 5(A), if the top slab 104 is formed using cast-in-place concrete, a lower formwork 131 and shoring 132 are required to support it. Simply replacing the top slab 104 shown in FIG. 5(A) with a precast concrete member requires a longer joint to ensure the joint length between the exterior wall main reinforcement 120 and the top slab main reinforcement 117, which necessitates the installation of a lower formwork and shoring to support the concrete poured at the joint. In this embodiment, as shown in FIG. 5(B), the penetration length of the top slab main reinforcement 17 and the exterior wall main reinforcement 20 into the joint 13 is shorter than the joint length in conventional structures. However, because the joint 13 is formed using fiber-reinforced concrete of a predetermined strength or higher, the joint 13 functions as an anchor for the reinforcing steel bars embedded in the joint 13. Therefore, even if the penetration length (anchorage length) is short, cross-sectional forces at the joint 13, such as moment and axial force, are sufficiently transmitted between the exterior wall main reinforcement 20 and the top slab main reinforcement 17 via the fiber-reinforced concrete.

[0047] The effects of the embodiment will be described with reference to Figures 1 to 6. Because the concrete portions 12a, 13a of the joints 12, 13 are formed from fiber-reinforced concrete of a predetermined strength or greater, the joints 12, 13 function as anchors for the reinforcing bars that protrude into them. Therefore, even if the length of each reinforcing bar that protrudes into the joints 12, 13 is short, the cross-sectional forces of the joints 12, 13, such as axial force and moment, are sufficiently transmitted between the reinforcing bars that protrude into the joints 12, 13 via the fiber-reinforced concrete.

[0048] Construction time is shortened because there is no need to install the lower formwork 131 or shoring 132 for installing the top slab 4. Because the exterior wall 6 and partition wall 8 do not have overhanging portions, if they are formed with cast-in-place concrete, there is no need to install the lower formwork 131 or shoring 132 for forming the overhanging portions, shortening the construction time, and if they are formed with precast concrete members, transportation efficiency is improved. It is desirable that the workers who install the lower formwork 131 and shoring 132 be skilled workers, but because this work is not required, the joining work can be performed by workers who are not skilled workers.

[0049] By aligning the lower edge of the side of the top plate member 11 with the side edge of the upper end face of the exterior wall 6 or partition wall 8, lower formwork and shoring are unnecessary. Also, compared to when the top plate member 11 is placed on the upper end face of the exterior wall 6 or partition wall 8, the wall thickness of the exterior wall 6 or partition wall 8 is effectively utilized to ensure the width of the joints 12, 13.

[0050] By making the protruding portion 17c of the top plate main reinforcement 17 at the joint 12 a loop reinforcement, the connection between the pair of top plate members 11 is strengthened. By making the protruding portion 17c of the top plate main reinforcement 17 and the protruding portion 20a of the exterior wall main reinforcement 20 at the joint 13 a loop reinforcement, the connection between them is strengthened.

[0051] The width of the joints 12, 13 at the bottom is equal to the thickness of the partition wall 8 or outer wall 6 to be joined, and is wider at the top than at the bottom, ensuring the bond length of the top plate main reinforcement 17 arranged at the upper level to the concrete.

[0052] As shown in Figures 3(B) and 5(B), in the above embodiment, the protruding portion 17c of the top plate main reinforcement 17 and the protruding portion 20a of the exterior wall main reinforcement 20 are loop reinforcements, and the protruding portion 17c of the top plate main reinforcement 17 and the protruding portion 15a of the partition wall main reinforcement 15 or the protruding portion 20a of the exterior wall main reinforcement 20 form a lap joint. In a modification of the above embodiment shown in Figures 7 and 8, the protruding portion 17d of the top plate main reinforcement 17 and the protruding portion 20b of the exterior wall main reinforcement 20 extend linearly in the extension direction of each main reinforcement. Furthermore, the joint 13 shown in Figure 8 has a rectangular cross section perpendicular to the extension direction. Other than these, the modification has the same configuration as the above embodiment, and the same reference numerals are used.

[0053] As shown in Figure 7, at the joint 13 between the bulkhead 8 and a pair of top plate members 11, the protruding portions 17d of the top plate main reinforcements 17 of the pair of top plate members 11 form gap lap joints at the upper and lower stages, respectively. This improves the transmission performance of cross-sectional forces at the joint 13, such as axial force and moment, between the top plate main reinforcements 17.

[0054] The linear shape of the protrusions 17d, 20b facilitates the manufacture of the top plate member 11 and the formation of the joints 13. Even if the protrusions 17d, 20b are linear, the cross-sectional forces of the joints 12, 13, such as axial force and moment, are sufficiently transmitted between the reinforcing bars protruding into the joints 12, 13 via the fiber-reinforced concrete, as in the above embodiment. The elimination of the need for the installation of the lower formwork 131 and shoring 132, as well as the associated effects, effects related to the positional relationship between the top plate member 11 and the exterior wall 6 or partition wall 8, and effects resulting from the shape of the joints 13 are the same as in the above embodiment.

[0055] Figure 9 shows another modified example of the joint 13 between the exterior wall 6 and the top plate member 11. The joint 13 of the modified example shown in Figure 9 differs from the joint 13 shown in Figures 5(B) and 6 in the shapes of the protruding portions 17d, 17e of the top plate main reinforcement 17 and the protruding portions 20b, 20c of the exterior wall main reinforcement 20, but has a common configuration in other respects. Common symbols are used for common configurations.

[0056] The lower protruding portion 17d of the top plate main reinforcement 17, which is arranged in two upper and lower rows, and the inner protruding portion 20b of the exterior wall main reinforcement 20, which is arranged in two rows in the thickness direction, extend linearly in the extension direction of each main reinforcement. The upper protruding portion 17e of the top plate main reinforcement 17 and the outer protruding portion 20c of the exterior wall main reinforcement 20 are curved so as to overlap each other when viewed from the extension direction of the joint 13, forming a gap lap joint. The curved portions of the protruding portions 17e and 20c are arc-shaped with a length of approximately 1 / 4 of the circumference. The protruding portions 17e and 20c form a gap lap joint, which strengthens the connection between them. Configurations common to the above embodiment have the same functions and effects as the above embodiment.

[0057] FIG. 10 shows modified examples of the shape of the joint 13. In the modified joint 13 shown in FIG. 10(A), the horizontal width of the concrete portion 13a of the joint 13 changes continuously when viewed in the direction of extension of the joint 13. That is, the joint surface of the concrete portion 13a of the joint 13 with the top slab concrete portion 16 and the exterior wall concrete portion 19 is inclined. The joint surface between the concrete portion 13a of the joint 13 and the exterior wall concrete portion 19 is inclined at an angle of 40° to 50°, preferably 45°, from the horizontal. Similarly, the joint surface between the concrete portion 13a of the joint 13 and the top slab concrete portion 16 is inclined at an angle of 40° to 50°, preferably 45°, from the horizontal. The angles of the joint surfaces of the exterior wall concrete portion 19 and the top slab concrete portion 16 with respect to the horizontal plane of the joint 13 may be equal to or different from each other.

[0058] In the joint 13 according to the modified example shown in Figure 10(B), the horizontal width of the concrete portion 13a of the joint 13 changes in stages when viewed in the direction of extension of the joint 13. A line connecting the upper end of the side surface of the exterior wall concrete portion 19 distal to the top slab concrete portion 16 and the upper end of the side surface proximal to the top slab concrete portion 16 is inclined at an angle of 40 to 50 degrees, preferably 45 degrees, relative to the horizontal. Similarly, a line connecting the edge of the lower surface of the top slab concrete portion 16 facing the exterior wall concrete portion 19 and the edge of the upper surface of the top slab concrete portion 16 facing the exterior wall concrete portion 19 is inclined at an angle of 40 to 50 degrees, preferably 45 degrees, relative to the horizontal. The angles of the joint surfaces of the exterior wall concrete portion 19 and the top slab concrete portion 16 relative to the concrete portion 13a of the joint 13 relative to the horizontal may be equal to or different from each other.

[0059] In the modified example shown in Figures 10(A) and 10(B), the joint 13 formed from fiber-reinforced concrete extends along a line inclined at 40° to 50° from the horizontal, extending into the top concrete portion 16 and the exterior wall concrete portion 19, thereby suppressing cracks propagating from the corner (the portion where the extension line of the top concrete portion 16 and the extension line of the exterior wall concrete portion 19 overlap when viewed from the extension direction of the joint 13), thereby improving the strength around the joint 13.

[0060] Although the specific embodiments have been described above, the present invention is not limited to the above embodiments and modifications and can be implemented in a wide variety of ways. The protruding portions of the bulkhead main reinforcement may be loop reinforcement. The present invention may also be applied to rigid-frame reinforced concrete structures other than floating structures, such as box culverts, which have side walls and a top plate. The brackets do not need to be removed after the joint hardens. The bulkhead or exterior wall and the top plate member may be joined at an angle other than 90°. Distribution reinforcement does not need to be provided at the joint. At the joint between the bulkhead and the top plate member, the width of the joint may be the same as the width of the bulkhead throughout the entire vertical direction. In the embodiment shown in Figures 5(B) and 9, the width of the joint between the exterior wall and the top plate member may be the same as the width of the exterior wall throughout the entire vertical direction, as in the joint shown in Figure 8. In the embodiment shown in Figure 8, the width of the joint between the exterior wall and the top plate member may be wider at the top than at the bottom, as in the joint shown in Figures 5(B) and 9. In the modification shown in FIG. 10, the shapes of the protruding portions of the exterior wall main reinforcements and the top plate main reinforcements may be straight or curved as shown in FIG. 8 or FIG. 9, instead of loop reinforcements. [Explanation of symbols]

[0061] 1: Floating structure 3: Side wall 4:Top version 6: External wall (side wall) 8: Partition wall (side wall part) 11: Top plate member 12,13:Joint part 14: Partition concrete section (side wall concrete section) 15: Bulkhead main reinforcement (side wall main reinforcement) 15a:Protrusion 16: Top concrete section 17:Top version main line 17c, 17d, 17e: Protrusion 19: Exterior wall concrete section (side wall concrete section) 20: Exterior wall main reinforcement (side wall main reinforcement) 20a, 20b, 20c: Protrusion

Claims

1. A concrete side wall portion including a side wall concrete portion and a side wall main reinforcement including a protrusion protruding from an upper end surface of the side wall concrete portion; a top plate member made of precast concrete, joined to the upper end of the side wall portion so as to form a predetermined angle with respect to the side wall portion, the top plate member including a concrete top portion and a top plate main reinforcement including a protruding portion protruding from a side end surface of the concrete top portion on the side wall portion side; The protruding portions of the side wall main reinforcement and the protruding portions of the top plate main reinforcement are buried, and the compressive strength is 50 N / mm ２ ~200N / mm ２ a joint including a concrete portion formed by the fiber-reinforced concrete; A joint structure for concrete members comprising:

2. 2. A joining structure for concrete members according to claim 1, wherein the edge of the upper end surface of the side wall concrete portion on the side facing the top concrete portion abuts against the lower edge of the side end surface of the top concrete portion.

3. the side wall portion is a part of a side wall of a floating structure of a floating offshore wind power generation facility, The joint structure for concrete members according to claim 2 , wherein the top plate member is a part of the top plate of the floating structure.

4. 4. The joint structure for concrete members according to claim 2, wherein a pair of the top plate members are joined to the joint portion so that the side end faces of the top plate members face each other across the joint portion.

5. 5. The joint structure of concrete members according to claim 4, wherein the protruding portions of the top plate main reinforcement of the pair of top plate members are embedded in the concrete portion of the joint so as to form a gap lap joint with each other.

6. The top plate main reinforcement is arranged in two layers, upper and lower, 4. The joint structure of concrete members according to claim 2, wherein a portion of the joint that receives the top plate main reinforcement arranged at an upper level is wider than a portion of the joint that receives the top plate main reinforcement arranged at a lower level in the extending direction of the top plate main reinforcement.

7. A joint structure for concrete members described in any one of claims 1 to 3, wherein, when viewed from the extension direction of the joint, the top plate member is joined to only one horizontal side of the side wall portion, when viewed from the extension direction of the joint, the horizontal width of the concrete portion of the joint changes so that it widens toward the top, the joint surfaces between the concrete portion of the joint and the side wall concrete portion are inclined at an angle of 40° to 50° with respect to the horizontal direction, and the joint surfaces between the concrete portion of the joint and the top plate concrete portion are inclined at an angle of 40° to 50° with respect to the horizontal direction.

8. 4. A concrete member joint structure as described in any one of claims 1 to 3, wherein, when viewed from the extension direction of the joint, the top plate member is joined to only one horizontal side of the side wall portion, the horizontal width of the concrete portion of the joint changes gradually so as to widen toward the top, a line connecting the upper end of the side surface of the side wall concrete portion distal to the top plate concrete portion and the upper end of the side surface of the side wall concrete portion proximal to the top plate concrete portion is inclined at an angle of 40° to 50° with respect to the horizontal direction, and a line connecting the edge of the lower surface of the top plate concrete portion facing the side wall concrete portion and the edge of the upper surface of the top plate concrete portion facing the side wall concrete portion is inclined at an angle of 40° to 50° with respect to the horizontal direction.

9. The protruding portion of the side wall main reinforcement forms a loop reinforcement or extends linearly, The joint structure of concrete members according to any one of claims 1 to 3, wherein the protruding portion of the top plate main reinforcement forms a loop reinforcement or extends linearly.

10. The protruding portion of the side wall main reinforcement forms a loop reinforcement or extends linearly, 8. The joint structure of concrete members according to claim 7, wherein the protruding portion of the top slab main reinforcement forms a loop reinforcement or extends linearly.

11. The protruding portion of the side wall main reinforcement forms a loop reinforcement or extends linearly, 9. The joint structure of concrete members according to claim 8, wherein the protruding portion of the top slab main reinforcement forms a loop reinforcement or extends linearly.

12. When viewed from the extending direction of the joint portion, one of the top plate members is joined to the joint portion, The top plate main reinforcement is arranged in two layers, upper and lower, The side wall main reinforcement is arranged in two stages in the thickness direction of the side wall portion, 4. The joint structure of concrete members according to claim 1, wherein the protruding portion of the top plate main reinforcement arranged in the upper stage and the protruding portion of the side wall main reinforcement arranged in the stage located distal to the top plate member are curved to form a lap joint with each other.

13. When viewed from the extending direction of the joint portion, one of the top plate members is joined to the joint portion, The top plate main reinforcement is arranged in two layers, upper and lower, The side wall main reinforcement is arranged in two stages in the thickness direction of the side wall portion, 8. The joint structure of concrete members according to claim 7, wherein the protruding portion of the top plate main reinforcement arranged in the upper stage and the protruding portion of the side wall main reinforcement arranged in the stage located distal to the top plate member are curved to form a lap joint with each other.

14. When viewed from the extending direction of the joint portion, one of the top plate members is joined to the joint portion, The top plate main reinforcement is arranged in two layers, upper and lower, The side wall main reinforcement is arranged in two stages in the thickness direction of the side wall portion, 9. The joint structure of concrete members according to claim 8, wherein the protruding portion of the top plate main reinforcement arranged in the upper stage and the protruding portion of the side wall main reinforcement arranged in the stage located distal to the top plate member are curved to form a lap joint with each other.

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