Deck joint structure

Abstract

To propose a floor slab joint structure that enables labor saving during construction and shortens a construction period.SOLUTION: A floor slab joint structure 1 in which reinforcing bars 3 protruding from each of end surfaces 23 of adjacent reinforced concrete precast floor slabs 2 are joined by an empty lap joint is provided. The reinforcing bar 3 is a floor slab vertical reinforcement 21 arranged on the precast floor slab 2, and includes a fiber reinforcement mortar 5 filled in a gap 11 formed between the facing end surfaces 23, and a fixing body 4 made of steel plate fixed to a tip of the reinforcing bar 3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a deck joint structure for a concrete precast deck. [Background technology]

[0002] Precast deck slabs that are laid consecutively are connected via filler concrete, filler mortar, etc. (hereinafter simply referred to as "filler") poured into the joints. For example, Patent Document 1 discloses a deck joint structure in which end faces of precast decks with protruding loop reinforcements are butted together with a specified gap between them, distribution bars that cross the loop reinforcements are arranged, and filler concrete is poured into the gap between the end faces. In the joint structure of Patent Document 1, a jaw portion that covers the underside of the gap is formed on the lower part of the precast deck. However, in the conventional deck joint structure, after laying the precast decks, it is time-consuming to place the distribution bars on the inside of the loop bars. In addition, the precast decks need to be laid with their jaws butted together, but since there is a risk of damage if the precast decks come into contact with each other during laying, the work must be done carefully and requires skilled techniques. In addition, since there is a limit to the processing dimensions of the loop bars, the reduction in the thickness of the precast deck members is also limited when considering the overlap of the loop bars. Furthermore, since the gaps between the precast decks become large due to the dimensions of the loop bars, more concrete is required, which takes time for pouring work and hinders the shortening of the construction period. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-236258 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to propose a deck joint structure that enables labor saving during construction and shortens the construction period. [Means for solving the problem]

[0005] In order to solve such problems, the present invention provides a deck slab in which reinforcing bars protruding from the end faces of the deck slabs installed at a predetermined interval are joined together by open lap joints. In addition, the reinforcement between the opposing end faces is omitted. The deck joint structure comprises fiber-reinforced mortar filled between the opposing end faces and an anchor fixed to the tip of the reinforcing bar. The reinforcing bars are SD390 or less, and the joint length of the open lap joint, which is the distance between the end faces of the reinforcing bars on the reinforcing bar side of the anchorage of the two reinforcing bars joined by the open lap joint, is within the range of 5 to 15 times the diameter of the reinforcing bars, and the net spacing between adjacent reinforcing bars placed on the same deck slab is within the range of 6 to 8 times the diameter of the reinforcing bars and within the range of 2.5 to 3 times the outer diameter or width of the anchorage. The fiber reinforced mortar has a design strength of 50N / mm 2 The above means that more than 0.5% by volume of fibers are mixed in. In addition, the anchor is formed by fixing a circular or rectangular steel plate having an outer diameter or width that is at least twice the diameter of the reinforcing bar and a thickness of at least 12 mm to the tip of the reinforcing bar. Furthermore, it is desirable that the distance between the tip of the reinforcing bar protruding from the end face of one deck and the end face of the other deck be within a range of 15 mm to 45 mm. According to this deck joint structure, since the reinforcing bars with anchors formed at their ends are arranged, it is possible to shorten the anchoring length of the reinforcing bars, and as a result, it is possible to reduce the gap between the end faces. Therefore, the amount of fiber-reinforced mortar filled in the gap is reduced, the time required for pouring is reduced, and the construction period can be shortened. By using fiber-reinforced mortar as a filler, the filler exhibits high tensile resistance, so that the distribution reinforcement can be omitted. As a result, the work of arranging the distribution reinforcement can be omitted, and the work during construction can be reduced. In addition, since there is no need to consider bending of the reinforcing bars, the freedom of setting the thickness of the deck plate is improved. Effect of the Invention

[0006] According to the deck slab joint structure of the present invention, it is possible to reduce labor during construction and also to shorten the construction period. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a plan view showing the deck joint structure of the present embodiment. [Diagram 2] FIG. 2 is a side view showing the deck joint structure of the present embodiment. [Diagram 3] FIG. 1 is a plan view showing an overview of a test model for a demonstration experiment. [Figure 4] 1 is a graph showing the relationship between rebar strain and pull-out load in a demonstration experiment. [Diagram 5] FIG. 2 shows an overview of a test specimen used in a demonstration experiment, where (a) is a plan view and (b) is a side view. [Figure 6] 1A and 1B are diagrams showing an overview of a test specimen of a comparative example in a demonstration experiment, in which (a) is a plan view and (b) is a side view. [Figure 7] 1 is a graph showing the relationship between load and deflection in a demonstration experiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In this embodiment, a slab joint structure 1 is described which joins together a number of precast slabs 2 laid continuously in the bridge axis direction during bridge construction. The slab joint structure 1 includes a pair of precast slabs 2, 2 arranged with a gap 11 therebetween, and fiber-reinforced mortar 5 filled between the end faces 23 of the precast slabs 2 (the gap 11).

[0009] The precast slab 2 is made of reinforced concrete. As shown in Figs. 1 and 2, inside the precast slab 2, two tiers of vertical floor slab reinforcements 21 are arranged along the bridge axis direction (left and right direction in the drawings), and horizontal floor slab reinforcements 22 intersecting the vertical floor slab reinforcements 21 are arranged. In addition, reinforcing bars 3 are protruding from an end face 23 of the precast slab 2. As shown in Fig. 2, the reinforcing bars 3 in this embodiment are the parts of the vertical floor slab reinforcements 21 that protrude from the end face 23 and are arranged in the gaps 11. The reinforcing bars 3 in this embodiment are SD345. The reinforcing bars 3 may be planted in the end face 23 of the precast slab 2 separately from the vertical floor slab reinforcements 21. In this embodiment, a shear key 24 is formed on the end surface 23 of the precast floor slab 2 to improve the transferability of force between the fiber-reinforced mortar 5 and the precast floor slab 2. The end surface 23 is roughened to improve the bond with the fiber-reinforced mortar 5. The shear key 24 is a trapezoidal recess in cross section formed near the middle between the reinforcing bars 3 arranged vertically. In this embodiment, the shear key 24 is continuous in the width direction of the precast floor slab 2 (vertical direction in FIG. 1), but the shear key 24 may be formed intermittently. The cross-sectional shape of the shear key 24 is not limited, and may be, for example, rectangular or circular. The shear key 24 may be a protrusion formed on the end surface 23.

[0010] As shown in Fig. 1, in the deck joint structure 1, reinforcing bars 3 protruding from an end face 23 of one precast deck 2 and reinforcing bars 3 protruding from an end face 23 of the other precast deck 2 are arranged alternately in a plan view. In this embodiment, the reinforcing bars 3 are arranged such that the reinforcing bars 3 protruding from the end face 23 of the other precast deck 2 are arranged near the midpoint between the reinforcing bars 3 protruding from the end face 23 of one precast deck 2. In other words, the intervals between the reinforcing bars 3 arranged alternately are equal. An anchor 4 is formed at the tip of the reinforcing bar 3. The anchor 4 in this embodiment is formed by fixing a rectangular steel plate having a size of 40×70 mm (width is at least twice the reinforcing bar diameter of the reinforcing bar 3) and a thickness of at least 12 mm to the tip of the reinforcing bar 3. The method of fixing the anchor 4 to the reinforcing bar 3 is not limited, and for example, it may be fixed by welding, friction welding or gas pressure welding. In addition, when the reinforcing bar 3 is threaded, a nut may be used for the reinforcing bar 3 as the anchor 4, or a steel plate with a bolt hole may be used. In addition, the anchor 4 is not limited to one formed by fixing a separate member (steel plate) to the reinforcing bar 3, and may be, for example, an enlarged diameter portion (so-called a bump) formed by compressing the end in the axial direction.

[0011] In the deck joint structure 1 of the present embodiment, as shown in FIG. 1, the reinforcing bars 3 protruding from the end faces 23 of a pair of precast decks 2, 2 installed opposite each other are joined by an open lap joint. The open lap joint is formed by overlapping the ends of the reinforcing bars 3 in the axial direction with a gap between the reinforcing bars 3, thereby forming a state in which the reinforcing bars 3 are joined by the adhesive force between the fiber reinforced mortar 5 (concrete, etc.) and the reinforcing bars 3. The joint length of the open lap joint is 2.4 times or more, preferably 5 times or more, and more preferably within a range of 5 to 15 times the reinforcing bar diameter. In addition, the reinforcing bar interval (reinforcing bar pitch) is 8 times or less than the reinforcing bar diameter, and preferably within a range of 6 to 8 times the reinforcing bar diameter. In addition, the distance between the tip of the reinforcing bar 3 protruding from the end face 23 of one precast deck 2 and the end face 23 of the other precast deck 2 is within a range of 15 mm or more and less than 45 mm, and preferably within a range of 15 mm or more and less than 30 mm.

[0012] Fiber-reinforced mortar 5 is filled between the end faces 23 of adjacent precast floor slabs 2 (gaps 11). The design standard strength of the fiber-reinforced mortar 5 is 50 N / mm 2 In the present embodiment, the fiber reinforced mortar 5 has a strength of 24 / mm3 at 3 hours. 2 , 7-day strength is 60N / mm 2The type of fiber-reinforced mortar 5 is not limited to the rapid hardening type. For example, a material having a strength of 100 N / mm 2 An ultra-high strength type may be used.

[0013] Next, the construction procedure of the deck joint structure 1 will be described. First, the precast deck 2 is laid. The precast deck 2 is laid by placing one precast deck 2 at a predetermined position and then suspending the other precast deck 2 from above. At this time, a gap 11 of a predetermined size is formed between the end faces 23 of adjacent precast decks 2. In addition, the reinforcing bars 3 protruding from the end face 23 of one precast deck 2 are arranged between the reinforcing bars 3 protruding from the end face 23 of the other precast deck 2. An anchor 4 is formed in advance at the tip of the reinforcing bar 3. Once the precast deck 2 has been laid, the sides and bottom of the gap 11 are covered with formwork (not shown) as necessary. Note that in cases where there is no risk of the fiber-reinforced mortar 5 flowing out from below the gap 11, such as when a main girder is disposed below the gap 11, the formwork on the bottom of the gap 11 may be omitted. After the periphery of the gap 11 is covered with formwork, the gap 11 is filled with fiber reinforced mortar 5. It is preferable to manufacture the fiber reinforced mortar 5 on-site. The fiber reinforced mortar 5 is cured, and when it has attained a predetermined strength, the formwork is removed.

[0014] According to the deck joint structure 1 of this embodiment, the reinforcing bars 3 with the anchors 4 formed at their ends are arranged, so that it is possible to shorten the anchorage length of the reinforcing bars 3, and as a result, it is possible to reduce the gaps 11 between the precast decks 2 (end faces 23). Therefore, the amount of fiber reinforced mortar 5 to be filled in the gaps 11 is reduced, and the time required for pouring the fiber reinforced mortar 5 is shortened, which in turn makes it possible to shorten the construction period. The reinforcing bars 3 protruding from the end surface 23 are straight and do not require bending. This eliminates the cost required for bending the reinforcing bars 3. In addition, since there is no need to consider bending the reinforcing bars 3, the thickness of the precast floor slab 2 can be set to 240 mm or less, allowing for greater freedom in setting the thickness. By making the precast floor slab 2 thinner, the precast floor slab 2 becomes easier to handle and the amount of fiber reinforced mortar 5 filled in the gaps 11 can be reduced, shortening the construction period. In addition, by reducing the amount of fiber reinforced mortar 5, it is possible to downsize the manufacturing equipment for the fiber reinforced mortar 5 and reduce the labor required to manufacture the fiber reinforced mortar 5. In addition, since no jaws are formed at the ends of the precast deck 2, the precast decks 2 are less likely to come into contact with each other when they are laid. Furthermore, the precast deck 2 that is laid later can be placed in a predetermined position by hanging it vertically from above, making positioning easy. Therefore, the work of laying the precast deck 2 can be easily performed without requiring skilled techniques.

[0015] In addition, by using fiber reinforced mortar 5 as the filler to fill the gaps 11, the filler exhibits high tensile resistance, making it possible to omit reinforcement bars. As a result, since there is no need to place reinforcement bars in narrow gaps, the amount of work required during construction can be reduced compared to conventional joint structures. Furthermore, even if cracks occur in the hardened fiber reinforced mortar 5, the cross-linking effect of the fibers in the fiber reinforced mortar 5 prevents the cracks from widening, so that the durability is high. By using a material that hardens quickly as the fiber-reinforced mortar 5, it becomes possible to carry out construction early, and therefore to open the road to traffic early. In addition, fiber reinforced mortar 5 generally contains a large amount of cement, and the hardened body has a dense structure, making it difficult for substances to penetrate and providing high durability. Also, by mixing an expansive material to compensate for shrinkage, gaps 11 are less likely to open, reducing the intrusion of water, oxygen, etc., and improving durability.

[0016] Hereinafter, the results of an experiment carried out on the deck joint structure 1 of this embodiment will be described. First, as shown in Fig. 3, when a tensile force P is applied to a reinforcing bar 3 joined by an open lap joint in a fiber-reinforced mortar 5, the occurrence of cracks in the hardened body of the fiber-reinforced mortar 5 was confirmed. The reference numeral 6 in Fig. 3 denotes a strain gauge. (1) Verification of the open lap joint length First, the effect of the open lap joint length L1 was confirmed. In the experiment, a pull-out test was performed for Case 1, where the open lap joint length L1 was 95 mm (equivalent to 5D), Case 2, where the open lap joint length L1 was 190 mm (equivalent to 10D), and Case 3, where the open lap joint length L1 was 285 mm (equivalent to 15D). For each case, the experiment was performed on two test specimens. The reinforcing bars 3 used were SD345 and D19 mm. A circular steel plate with a diameter of 50 mm and a thickness of 12 mm was fixed to the end of the reinforcing bars 3 as an anchor 4. The fiber reinforced mortar 5 (filling material) had a strength of 24 / mm at 3 hours. 2 , and the strength at 7 days was 59.3N / mm 2 The fast-hardening fiber reinforced mortar 5 was used. The width L2 of the gap 11 in cases 1 to 3 was 149 mm, 244 mm, and 339 mm, respectively. The rebar spacing (reinforcement pitch) I of the rebars 3 was 150 mm. The test results are shown in Table 1. The relationship between the strain (rebar strain) generated in the rebars and the pull-out load in case 1 (gap width 149 mm), case 2 (gap width 244 mm), and case 3 (gap width 339 mm) is shown in Figure 4. The pull-out test ended with the breakage of the threaded part of the rebar 3 in all test specimens (cases 1 to 3).

[0017] [Table 1]

[0018] As shown in Table 1, in case 1 where the open lap joint length L1 was 5D, cracks occurred, but the size of the cracks was small, less than 0.04 mm. In addition, the load at which the cracks occurred was 70 kN or more for both the first and second bodies, which was less than the load at the time of service (rebar stress at the time of service = 120 N / mm 2→ This is much higher than the pull-out load of 34kN in this test, so there will be no practical problems. Also, in cases 2 and 3 where the open lap joint length L1 was 10D and 15D, no cracks occurred. From the above tests, the strength at 7 days was 59.3N / mm 2 It was confirmed that when the above fiber reinforced mortar 5 was used, it was sufficient to ensure that the open lap joint length L1 was 5D or more. In addition, as shown in Fig. 4, in all cases of Case 1 (gap width 149 mm), Case 2 (gap width 244 mm), and Case 3 (gap width 339 mm), the maximum strain of the rebar was 2000 × 10 -6 Therefore, the yield point of the reinforcing bar is approximately 400 N / mm 2 (≒(2.05×10 5 N / mm 2 )×(2000×10 -6 )) and it was confirmed that SD390 rebar could be used.

[0019] (2) Verification of rebar spacing Next, the effect of rebar spacing I was confirmed. In the experiment, the rebar spacing I in cases 1, 4, and 5 was set to 150 mm, 125 mm, and 175 mm, respectively, and the occurrence of cracks was confirmed. Other conditions in cases 4 and 5 (open lap splice length L1, materials used, etc.) were the same as in case 1. The test results are shown in Table 2.

[0020] [Table 2]

[0021] As shown in Table 2, in Case 5, where the rebar spacing I was 175 mm, cone-shaped fracture occurred in the first body, and cracks of about 0.2 mm occurred in the second body. On the other hand, in Case 1, where the rebar spacing I was 150 mm, and Case 4, where it was 125 mm, only fine cracks of 0.04 mm or less occurred. In Case 5, the crack initiation load was 58 kN or more for both the first and second bodies, and was greater than the load at the time of service (rebar stress at the time of service = 120 N / mm 2→ This is significantly higher than the pull-out load of 34kN in this test, so no practical problems will arise. Therefore, when using rebars 3 (SD345, rebar diameter 19mm) with circular steel plates of 50mm diameter and 12mm thickness fixed as anchors 4, and rapid-hardening fiber reinforced mortar 5, the rebar spacing I may be 175mm or less, and 150mm or less is more preferable.

[0022] (3) Verification of the type of fiber-reinforced mortar Next, the effect of changing the type of fiber-reinforced mortar 5 was confirmed. In the experiment, in case 1, the strength at 3 hours was 24 / mm 2 , and the strength at 7 days was 59.3N / mm 2 In case 6, the strength of the early-hardening fiber-reinforced mortar was 101 N / mm 2 The ultra-high strength fiber reinforced mortar 5 was used. The other conditions of Case 6 (open lap joint length, gap interval, reinforcing bar, anchor, etc.) were the same as those of Case 1. The test results are shown in Table 3. As shown in Table 3, it was confirmed that when ultra-high strength fiber reinforced mortar 5 was used, no cracks occurred even when the open lap joint length L1 was set to 95 mm.

[0023] [Table 3]

[0024] (4) Verification of the distance between the anchor and the end face of the precast deck Next, the results of investigating the effect of changing the distance between the anchor 4 and the end face 23 of the precast deck 2 are shown. In this experiment, the distance between the anchor 4 and the end face 23 of the precast deck 2 was set to 15 mm in case 1 and 30 mm in case 7. Other conditions for case 7 (open lap joint length L1, materials used, etc.) were the same as those for case 1. The test results are shown in Table 4. As shown in Table 4, when the distance between the anchor 4 and the end face 23 of the precast deck 2 was widened to 30 mm, cone-shaped fracture occurred. However, the crack initiation load was 50 kN or more for both the first and second bodies, and was below the load at the time of service (rebar stress at the time of service = 120 N / mm 2 (equivalent to the pull-out load of 34 kN in this test), so no practical problems will arise. On the other hand, if the distance between the anchor 4 and the end face 23 of the precast floor slab 2 is set to 15 mm or less, it becomes difficult to fill with the fiber reinforced mortar 5. Therefore, the distance between the anchor 4 and the end face 23 of the precast floor slab 2 should be set within the range of 15 mm to 45 mm, more preferably within the range of 15 mm to 30 mm, and even more preferably around 15 mm.

[0025] [Table 4]

[0026] (5) Verification of the effects of gap width and type of filling material Next, as shown in Figures 5(a) and (b), the effects of gap width and type of filler were verified using a test specimen with a total length of 3,000 mm and a width of 825 mm formed by joining a pair of precast decks 2. Specifically, the effects of gap width and type of filler were confirmed based on the relationship between vertical load Pv and deflection when a vertical load Pv was applied (bending test). The vertical load Pv was applied to each of the specimens at two positions 400 mm from the center in the longitudinal direction. The specimens were supported at two positions 1200 mm from the center in the longitudinal direction. A pair of precast decks 2 are joined by lap joints within fiber reinforced mortar 5 filled in the gaps 11 between the precast decks 2.

[0027] In case a, the gap width was set to 100 mm (corresponding to a lap joint length of 2.4D), and in case b, the gap width was set to 150 mm (corresponding to a lap joint length of 5D). Bending tests were conducted for each of cases a and b. In cases a and b, the strength of the filler after 7 days was 101N / mm 2Ultra-high strength fiber reinforced mortar 5 was used. Also, as the reinforcing bars 3, SD345, D19mm different diameter reinforcing bars were used. To the ends of the reinforcing bars 3, circular steel plates with a diameter of 50mm and a thickness of 12mm were fixed as anchors 4. Furthermore, the reinforcing bar spacing (reinforcing bar pitch) of the reinforcing bars 3 was 150mm. In case c, the gap width was set to 100 mm (equivalent to a gap lap joint length of 2.4 D), in case d, the gap width was set to 150 mm (equivalent to a gap lap joint length of 5 D), and in case e, the gap width was set to 250 mm (equivalent to a gap lap joint length of 10 D). Bending tests were carried out for each of cases c to e. The filler in cases c to e had a strength of 24 N / mm 2 , and the strength at 7 days was 59.3N / mm 2 A fast-hardening fiber-reinforced mortar of SD345 and D19 was used for the reinforcing bars 3. A circular steel plate of 50 mm in diameter and 12 mm in thickness was fixed to the end of the reinforcing bars 3 as an anchor 4. The spacing (reinforcing bar pitch) of the reinforcing bars 3 was 150 mm. Furthermore, as a comparative example, as shown in Fig. 6(a) and (b), the end faces of the precast deck 2, from which the loop reinforcements protrude, were butted together with a gap width of 340 mm, distribution bars were arranged to cross the loop reinforcements, and filling concrete was poured into the gap 11 between the end faces. A bending test was conducted on a specimen. The filling concrete in case f had a strength of 65.9 N / mm 2 The concrete used was SD345, D19 deformed bar for reinforcing bar 3. The location of application of the vertical load Pv and the support points of the specimen for case f were the same as those for cases a to e. The length of the lap splice of the loop bar was 279 mm (equivalent to 14.7 D).

[0028] Experiments were conducted on one specimen for each case. The test results are shown in Table 5. Figure 6 shows the load-deflection relationship for case a (gap width 100mm), case b (gap width 150mm), case c (gap width 100mm), case d (gap width 150mm), case e (gap width 250mm), and case f (gap width 340mm).

[0029] [Table 5]

[0030] As shown in Table 5, in cases a, b, and f, the PCa section (precast deck 2) failed, not the gap, so the test was terminated. The maximum load in case a was 266.9 kN, and the maximum load in case b was 280.4 kN, both of which exceeded the maximum load of 237.7 kN in case f. In addition, as shown in Figure 6, it was confirmed that the load-deflection relationships in cases a and b exceeded that of case f. As shown in Table 5, in case c, a large crack occurred in the gap, causing the load to decrease, and the test was terminated. The maximum load was 187.3 kN, which was lower than the maximum load of 237.7 kN in case f. Furthermore, as shown in Table 5, in cases d, e, and f, the PCa section (precast deck 2) was destroyed, and the test was terminated. It was confirmed that the maximum load in case d was 268.8 kN, and the maximum load in case e was 280.4 kN, both of which exceeded those in case f. Furthermore, as shown in Figure 6, the load-deflection relationships in cases d and e exceeded that of case f, but the load-deflection relationship in case c was lower than that of case f.

[0031] From the above results, the strength at 7 days was 101N / mm 2 When ultra-high strength fiber reinforced mortar 5 is used as a filler (cases a and b), it was confirmed that if the free lap joint length L1 is ensured to be 2.4D or more, a joint structure with higher strength than a deck joint structure using loop joints can be constructed. In addition, the strength at 7 days was 59.3N / mm 2 When the above fiber-reinforced mortar 5 is used (cases c to e), it was confirmed that if the free lap joint length is ensured to be 5D or more (cases d and e), a joint structure with higher strength can be constructed than a deck joint structure using a loop joint. Although case c is slightly inferior in terms of strength, it is possible to reduce labor during construction and shorten the construction period.

[0032] Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each component can be appropriately modified without departing from the spirit of the present invention. In the above embodiment, SD345 is used as the reinforcing bar 3, but the standard (yield point) of the reinforcing bar 3 is not limited as long as it is SD390 or less, and may be, for example, SD295. If necessary, the reinforcing bar 3 may be coated with a synthetic resin such as an epoxy resin. By coating the reinforcing bar 3 with a resin, the same effect as when no resin coating is performed can be obtained, and the reinforcing bar 3 can be prevented from corroding. The shape of the anchor 4 is not limited as long as its outer diameter or width is at least twice the diameter of the reinforcing bar 3 and its thickness is at least 12 mm. In the above embodiment, the intervals between the reinforcing bars 3 protruding from the opposing end faces 23 and arranged alternately are equal, but the intervals between the reinforcing bars 3 protruding from the opposing end faces 23 do not necessarily have to be equal. The fiber reinforced mortar 5 may be manufactured on-site, or may be manufactured in a plant outside the site and transported thereto. Furthermore, the fiber reinforced filler is not limited to fiber reinforced mortar, and fiber reinforced concrete may be used as long as workability and filling properties are ensured. [Explanation of symbols]

[0033] 1 Deck joint structure 11. Gap 2 Precast deck 21 Deck vertical reinforcement 22 Deck slab horizontal reinforcement 23 End face 24 Shear Key 3. Steel Bars 4 Fixing body 5 Fiber-reinforced mortar (fiber-reinforced filler)

Claims

1. A deck joint structure in which reinforcing bars protruding from the end faces of decks installed at a predetermined interval are joined by open lap joints, and the reinforcing bars between the opposing end faces are omitted. Fiber-reinforced mortar filled between the opposing end faces; and an anchor fixed to the tip of the reinforcing bar, The fiber reinforced mortar has a design standard strength of 50 N / mm ２ The above contains 0.5% or more of fibers by volume, The anchor is a circular or rectangular steel plate having an outer diameter or width that is at least twice the diameter of the reinforcing bar and a thickness of at least 12 mm; A deck joint structure characterized in that the reinforcing bars have SD390 or less, the joint length of the open lap joint, which is the distance between the end faces of the reinforcing bars on the reinforcing bar side of the anchorage of both reinforcing bars joined by the open lap joint, is within the range of 5 to 15 times the diameter of the reinforcing bars, and the net spacing between adjacent reinforcing bars arranged on the same deck slab is within the range of 6 to 8 times the diameter of the reinforcing bars and within the range of 2.5 to 3 times the outer diameter or width of the anchorage.

2. A deck joint structure as described in claim 1, characterized in that the distance between the anchoring body of the reinforcing bar protruding from the end face of one deck and the end face of the other deck is within the range of 15 mm to 45 mm.

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