JP6808585B2 - Construction method of concrete floor slab - Google Patents

Description

The present invention relates to a method for constructing a concrete floor slab.

Techniques for replacing concrete slabs have been proposed for repairing concrete slabs. For example, Patent Document 1 discloses a technique in which a concrete slab to be replaced is divided into a primary construction section and a secondary construction section, the existing concrete slab is removed, and a new concrete slab is installed. ing. In the technique of Patent Document 1, the existing concrete slab of the primary construction part is removed, and a new concrete slab is installed in the primary construction part from which the existing concrete slab has been removed, and the primary construction lane is used as a traveling lane for the vehicle. While the new concrete slab of the construction part is being used, the existing concrete slab of the secondary construction part adjacent to the primary construction part is removed, and the existing concrete slab is removed. A floor slab is installed. In the technique of Patent Document 1, the concrete slab installed in the primary construction part and the concrete slab installed in the secondary construction part, and the concrete slab of the primary construction part and the concrete slab of the secondary construction part are used. A post-tension material extending over the entire area is inserted, and the inserted post-tension material applies prestress to the concrete slab of the primary construction part and the concrete slab of the secondary construction part.

JP-A-2015-151768

By the way, for convenience of construction, the concrete slab may be divided into three or more, the existing concrete slab may be removed, and a new concrete slab may be installed. However, it is not possible to apply prestress by the post-tension method until after all the new concrete slabs divided into three or more have been installed. Before the application of prestress, for example, the installed concrete slab cannot be used as the traveling lane on which the vehicle travels, and there is a drawback that the degree of freedom in using the concrete slab during construction is low.

After the two concrete slabs are installed, a post-tension material is inserted into the two concrete slabs, and the inserted post-tension material applies prestress to the two concrete slabs to apply prestress to the two concrete slabs. The post inserted into the third concrete slab after installing the third concrete slab and inserting a separate post tension material into the third concrete slab while using It is also conceivable to connect the tension material and the post tension material inserted into the two existing concrete slabs to apply prestress to the three concrete slabs. However, there is a drawback that the connecting portion for connecting the post tension materials becomes large in size and expensive. Further, since a large-sized connecting portion is formed on the concrete slab, the defective cross section of the concrete slab becomes large, and there is a drawback that the strength of the concrete slab is structurally disadvantageous.

Therefore, an object of the present invention is to provide a method for constructing a concrete slab that can apply prestress without connecting post-tension materials while improving the degree of freedom in using the concrete slab during construction. To do.

The present invention comprises a removal step of removing the first post-tension material from the first concrete slab to which prestress is applied by the first post-tension material inserted into the first concrete slab, and a first post-tension by the removal step. A second post tension extending over the first concrete slab and the second concrete slab on the first concrete slab from which the material has been removed and the second concrete slab adjacent to the first concrete slab. A concrete floor slab including an insertion step of inserting a material and a prestress applying step of applying prestress to the first concrete floor slab and the second concrete floor slab by the second post tension material inserted by the insertion step. It is a construction method of.

According to this configuration, the first concrete slab before the removal step is prestressed by the first post tension material inserted into the first concrete slab, so that, for example, a vehicle is driven. The first concrete slab can be used as the traveling lane, and the degree of freedom in using the concrete slab during construction can be improved. Further, in the removal step, the first post tension material is removed from the first concrete slab, and in the insertion step, the first concrete slab from which the first post tension material has been removed by the removal step and the first concrete slab are used. A second post-tension material extending over the first concrete slab and the second concrete slab is inserted into the adjacent second concrete slab, and in the prestress applying step, the second post-tension material is inserted by the insertion step. Since the two post-tension materials apply prestress to the first concrete slab and the second concrete slab, the pre-stress can be applied without connecting the post-tension materials. Therefore, it is possible to apply prestress without connecting the post-tension materials while improving the degree of freedom in using the concrete floor slab during construction.

In this case, the first concrete slab from which the first post-tension material is removed by the removal step covers all of the first concrete slab divided into two or more, and all of the divided first concrete slab. It is preferable that the extending first post-tension material is inserted and prestressed by the first post-tension material.

According to this configuration, the first concrete slab from which the first post-tension material is removed by the removal step is the entire first concrete slab divided into two or more, and the first concrete slab divided into two or more. Since the first post-tension material extending all over is inserted and prestressed by the first post-tension material, even if the first concrete slab is divided into two or more, After being prestressed by the first post-tension material, it can be used, for example, as a traveling lane in which a vehicle travels, and the degree of freedom in using a concrete slab during construction can be improved. Further, since the concrete slab can be divided into three or more as a whole of the first concrete slab and the second concrete slab, the degree of freedom of construction can be improved.

Further, in the insertion step, the first concrete slab and the second concrete slab are formed by inserting the second post tension material into the portion of the first concrete slab into which the first post tension material removed in the removal step has been inserted. It is preferable to insert the second post-tension material extending over the first concrete slab and the second concrete slab into the concrete slab.

According to this configuration, in the insertion step, the first concrete is inserted by inserting the second post tension material into the portion of the first concrete floor slab into which the first post tension material removed by the removal step has been inserted. Since the second post tension material extending over the first concrete floor slab and the second concrete floor slab is inserted into the floor slab and the second concrete floor slab, the first post tension material was inserted. Prestress can be applied by the second post tension material inserted by diverting the insertion holes, insertion grooves, sheath pipes, etc. of the first concrete slab, and new insertion holes, insertion grooves, etc. can be applied to the first concrete slab. There is an advantage that it is not necessary to provide a sheath tube or the like.

Further, in the removal step, a part of the first post tension materials among the plurality of first post tension materials inserted in the first concrete floor slab is removed, and in the insertion step, a plurality of first post tensions are removed by the removal step. The first concrete slab from which a part of the material has been removed and the second concrete slab adjacent to the first concrete slab extend over the first concrete slab and the second concrete slab. In the prestress applying step, it is preferable to apply prestress to the first concrete slab and the second concrete slab by the second post tension material inserted in the insertion step. Is.

According to this configuration, in the extraction step, a part of the first post tension material among the plurality of first post tension materials inserted in the first concrete floor slab is removed, and in the insertion step, a plurality of first post tension materials are removed by the removal step. The first concrete slab from which a part of the first post tension material was removed, the second concrete slab adjacent to the first concrete slab, and the first concrete slab and the second concrete slab. A second post-tension material extending over the entire area is inserted, and in the prestress applying step, prestress is applied to the first concrete slab and the second concrete slab by the second post-tension material inserted in the insertion step. Therefore, even during the removal step, the insertion step, and the prestress applying step, the prestress is maintained on the first concrete slab by the remaining first post tension material that was not removed in the removing step. .. Therefore, for example, the first concrete slab can be used as the traveling lane in which the vehicle travels while the removal step, the insertion step, and the prestress applying step are performed, and the degree of freedom in using the concrete slab during construction. Can be further improved.

Further, as a traveling lane for traveling the vehicle, it is preferable to use a first concrete slab before the first post tension material is removed by the removing step.

According to this configuration, as the traveling lane for traveling the vehicle, the first concrete floor slab before the first post tension material is removed by the removing process is used, so that the time for closing the road can be shortened. ..

Further, in the removal step, when a part of the first post-tension material among the plurality of first post-tension materials inserted in the first concrete slab is removed, it is used as a traveling lane for traveling the vehicle. It is preferable to use the first concrete slab from before the first post-tension material is removed by the removing step to after the prestress is applied by the prestress applying step.

According to this configuration, as a traveling lane for traveling the vehicle, the first concrete floor slab from before the first post-tension material is removed by the removing process to after being prestressed by the prestress applying process. Is used, so the time of road closure can be further shortened.

Further, one end face of the first concrete slab and the second concrete slab that come into contact with each other has a convex portion, and the other end face of the first concrete slab and the second concrete slab that come into contact with each other has a concave portion. The convex portion and the concave portion are formed of fiber reinforced concrete, and it is preferable to further include a fitting step of fitting the convex portion and the concave portion to each other before the insertion step.

According to this configuration, one end face of the first concrete slab and the second concrete slab that abut each other has a convex portion, and the other end face of the first concrete slab and the second concrete slab that abut each other has a convex portion. The first concrete slab and the second concrete into which the second post tension material is inserted in the insertion step in order to further include a fitting step of having the recesses and fitting the protrusions and the recesses to each other before the insertion step. It becomes easy to align the insertion holes, insertion grooves, sheath pipes, etc. with the floor slab. Further, since the convex portion and the concave portion are formed of fiber reinforced concrete, the strength before and after joining can be improved.

According to the construction method of the concrete slab of the present invention, it is possible to apply prestress without connecting the post-tension materials while improving the degree of freedom in using the concrete slab at the time of construction.

(A) is a vertical cross-sectional view of a cross section perpendicular to the bridge axis showing a state in which a concrete slab is installed in the floor slab primary construction process of the embodiment, and (B) is a cross-sectional view of (A) by α line. is there. (A) is a vertical cross-sectional view with a cross section perpendicular to the bridge axis showing a state in which the concrete slab is installed adjacent to the concrete slab of FIG. 1 (A) in the secondary construction process of the floor slab of the embodiment. (B) is a cross-sectional view taken along line β of (A). In (A), in the secondary construction process of the floor slab of the embodiment, the first post-tension material extending over the entire divided first concrete floor slab of FIG. 2 (A) is inserted, and the first post-tension material is inserted. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis showing the state of being prestressed by the above, and FIG. (A) shows a state in which one of the plurality of first post tension materials inserted into the first concrete floor slab of FIG. 3 (A) is removed in the removal step in the third construction step of the floor slab of the embodiment. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis shown, and (B) is a cross-sectional view with δ line of (A). (A) is a cross section perpendicular to the bridge axis showing a state in which the convex portion of the first concrete floor slab and the concave portion of the second concrete floor slab are fitted to each other in the fitting step in the tertiary construction step of the floor slab of the embodiment. It is a vertical sectional view, (B) is a front view which shows the convex part of the 1st concrete slab. (A) is a vertical cross-sectional view showing a state in which fiber reinforced concrete of the first buried form of the first concrete slab is placed, and (B) is a second buried form of the second concrete slab. It is a vertical sectional view which shows the state which the fiber reinforced concrete is cast. By placing concrete using the first buried formwork and the second buried formwork as the buried formwork, a concrete slab having a convex portion on one end face and a concave portion on the other end face is manufactured. It is a vertical cross-sectional view which shows the state which is present. With the convex portion of the first buried formwork and the concave portion of the second buried formwork fitted to each other, concrete is cast using the first buried formwork and the second buried formwork as the buried formwork. It is a vertical cross-sectional view which shows the state which the 1st concrete slab which includes a convex part in an end face is manufactured, and the 2nd concrete slab which includes a concave part in an end face is manufactured. (A) shows a state in which one of the plurality of first post tension materials inserted into the first concrete floor slab of FIG. 4 (A) was removed in the removal step in the third construction step of the floor slab of the embodiment. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis, and (B) is a cross-sectional view with ε line of (A). In (A), the second post tension material is inserted into the portion of the first concrete floor slab into which one first post tension material removed by the removal step was inserted in the insertion step in the third construction step of the floor slab of the embodiment. 9 (A) is a vertical cross-sectional view showing a state in which the second post tension material is inserted into the first concrete slab and the second concrete slab in FIG. 9 (A) with a cross section perpendicular to the bridge axis. Is a cross-sectional view taken along the line ζ of (A). (A) is a bridge shaft showing a state in which prestress is applied to the first concrete slab and the second concrete slab in FIG. 10 (A) by one second post tension material in the prestress applying step. It is a vertical cross-sectional view with a vertical cross section, and (B) is a cross-sectional view with η line of (A). (A) shows a state in which one of the plurality of first post tension materials inserted into the first concrete floor slab of FIG. 11 (A) is removed in the removal step in the third construction step of the floor slab of the embodiment. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis shown, and (B) is a cross-sectional view with a θ line of (A). In (A), a central separation zone and a wall railing are provided on the first concrete slab and the second concrete slab in which the removal step, the insertion step and the prestress applying step in the tertiary construction step of the floor slab shown in FIG. It is a vertical cross-sectional view which shows the installation state by the cross section perpendicular to the bridge axis, and (B) is the cross-sectional view by ι line of (A). (A) shows a state in which all of the plurality of first post tension materials inserted into the first concrete floor slab of FIG. 3 (A) are removed in the removal step in the floor slab tertiary construction step of the embodiment. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis, and (B) is a cross-sectional view with a κ line of (A). In (A), the second post-tension material is inserted into all parts of the first concrete floor slab into which a plurality of first post-tension materials removed by the removal step are inserted in the insertion step in the third construction step of the floor slab of the embodiment. 9 (A) is a vertical cross-sectional view showing a state in which the second post tension material is inserted into the first concrete slab and the second concrete slab in FIG. 9 (A) with a cross section perpendicular to the bridge axis. Is a cross-sectional view taken along the line λ of (A). (A) is perpendicular to the bridge axis showing a state in which the first concrete slab and the second concrete slab of FIG. 15 (A) are prestressed by a plurality of second post tension materials in the prestress applying step. It is a vertical sectional view with a simple cross section, and (B) is a horizontal sectional view taken along line μ of (A). In (A), a part of the first post tension material among the plurality of first post tension materials inserted into the first concrete floor slab of FIG. 3 (A) in the removal step in the floor slab tertiary construction step of the embodiment. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis showing a state in which every other bridge is removed, and (B) is a cross-sectional view taken along line ν of (A). In (A), the second post-tension material is placed in the portion of the first concrete floor slab into which the first post-tension material removed every other one in the removal step is inserted in the insertion step in the third construction step of the floor slab of the embodiment. It is a vertical cross-sectional view of the cross section perpendicular to the bridge axis showing the state in which the second post tension material is inserted into the first concrete slab and the second concrete slab by inserting, and (B) is (A). It is a cross-sectional view by ξ line. In (A), prestress is applied to the first concrete floor slab and the second concrete floor slab of FIG. 18 (A) by the second post tension material in the prestress applying step in the floor slab tertiary construction step of the embodiment. It is a vertical cross-sectional view with a cross section perpendicular to the bridge axis showing the state, and (B) is a cross-sectional view with ο line of (A).

Hereinafter, the construction method of the concrete floor slab according to the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 (A) and 1 (B), the method of constructing the concrete slab of the present embodiment is, for example, to repair the concrete slab of the bridge 100 by changing the concrete slab to a new precast slab. It is applied when replacing with. In the present embodiment, the floor slab primary construction process, floor board secondary construction process, and floor board tertiary construction process are sequentially performed, and the concrete floor slab is divided into three parts to remove the existing concrete floor slab and to remove the new concrete floor slab. Installation is done.

As shown in FIGS. 1 (A) and 1 (B), the floor slab primary construction step is performed. In the floor slab primary construction process, a temporary median strip 31 is installed. The temporary median strip 31 and the wall balustrades 36 and 37 divide the traveling lane 41 on which the vehicle runs on the existing concrete floor slab 60 during construction and the floor slab primary construction section 51 on which the floor slab primary construction process is performed. Will be done. A concrete floor slab 1 which is a precast floor slab is installed in the floor slab primary construction section 51. The concrete floor slab 1 has a sheath pipe 3 into which a post tension material described later is inserted and a pretension material 4. The panel filling construction section 71 between each of the concrete floor slabs 1 is filled with a filler such as mortar.

As shown in FIGS. 2 (A) and 2 (B), the floor slab secondary construction step is performed. In the floor slab secondary construction process, the temporary median strip 31 is moved. The temporary median strip 31 and the wall balustrade 37 perform a traveling lane 41 for running a vehicle during construction on a concrete floor slab 1 newly installed in the floor slab primary construction process, and a floor slab secondary construction process. The floor slab secondary construction section 52 is partitioned. A concrete floor slab 2, which is a precast floor slab, is installed in the floor slab secondary construction section 52 so as to be adjacent to the concrete floor slab 1. Like the concrete floor slab 1, the concrete floor slab 2 also has a sheath pipe 3 into which a post-tension material is inserted and a pre-tension material 4.

As shown in FIGS. 2 (A) and 2 (B), a first post tension material 81 formed of a steel wire such as a steel stranded wire is inserted into the sheath pipe 3 of the concrete floor slabs 1 and 2. The first post tension material 81 extends over the concrete floor slab 1 and the concrete floor slab 2. As shown in FIGS. 3 (A) and 3 (B), the end of the first post tension material 81 is fixed by fixing tools 5 and 15 such as nut type grips while being tensioned by a jack. The panel filling construction section 72 between each of the concrete floor slabs 2 is filled with a filler such as mortar.

As a result, the concrete slabs 1 and 2 form the first concrete slab 10. The first concrete slab 10 from which the first post tension material 81 is removed by the removal step described later is divided into all of the first concrete slabs 10 divided into two concrete slabs 1 and 2. The first post tension material 81 extending over the entire concrete floor slab 10 is inserted, and prestress is applied by the first post tension material 81.

For the removal step described later, the end of the first post tension material 81 fixed by the fixing tool 15 at the end of the concrete floor slab 1 is outside the fixing tool 5 by the length of the release extra length 6. It has been issued. Further, the fixing tool 15 on the side of the release extra length 6 includes a release grip different from the normal fixing tool 5. Further, for the removal step described later, the inside of the sheath pipe 3 of the first concrete floor slab 10 into which the first post tension material 81 is inserted is not filled with a filler such as grout. In the examples of FIGS. 3A and 3B, the first concrete slab 10 is divided into two concrete slabs 1 and 2, and the entire divided first concrete slab 10 is covered. Although prestressed by the extending first post tension material 81, the first concrete slab 10 is divided into three or more concrete slabs, and the entire divided first concrete slab 10 is covered. Prestress may be applied by the extending first post tension material 81.

As shown in FIGS. 4 (A) and 4 (B), the floor slab tertiary construction step is performed. In the floor slab tertiary construction process, the temporary median strip 31 is further moved. The wall rail 36 is removed. The temporary separation zone 31 and the wall column 37 allow the vehicle to run on the first concrete floor slab 10 newly installed in the floor slab primary construction process and the floor slab secondary construction process. The passenger lane 42 and the floor slab tertiary construction section 53 on which the floor slab tertiary construction process is performed are partitioned.

A second concrete floor slab 20, which is a precast floor slab, is installed in the floor slab tertiary construction section 53 so as to be adjacent to the first concrete floor slab 10. The second concrete floor slab 20 also has a sheath pipe 3 into which a post-tension material is inserted and a pre-tension material 4 like the concrete floor slabs 1 and 2. Further, the second concrete floor slab 20 further has a box removal portion 25 for exposing each of the fixing tools 5 on the side of the second concrete floor slab 20 of the first post tension material 81 for the removal step.

As shown in FIGS. 5 (A) and 5 (B), one end surface 11 of the first concrete slab 10 and the second concrete slab 20 that are in contact with each other has a convex portion 12, and the first one that is in contact with each other has a convex portion 12. The other end surface 21 of the concrete slab 10 and the second concrete slab 20 has a concave portion 22, and the convex portion 12 and the concave portion 22 are formed of fiber reinforced concrete. In the present embodiment, when the second concrete floor slab 20 before the insertion step described later is installed in the floor slab tertiary construction section 53, a fitting step of fitting the convex portion 12 and the concave portion 22 to each other is performed. ..

The convex portion 12 has a quadrangular pyramid trapezoidal shape, and the concave portion 22 has a shape corresponding to the quadrangular pyramid trapezoidal convex portion 12. A sheath pipe 3 into which a post tension material is inserted is provided between each of the convex portions 12 of the first concrete floor slab 10. Similarly, a sheath pipe 3 into which a post tension material is inserted is provided between each of the recesses 22 of the second concrete floor slab 20.

The end face 11 is a first buried formwork 13 which is used for placing concrete of the first concrete floor slab 10 and includes a convex portion 12 and is formed of fiber reinforced concrete. Further, the end face 21 is a second buried formwork 23 which is used for placing concrete of the second concrete floor slab 20 and includes a recess 22 and is formed of fiber reinforced concrete. In fiber reinforced concrete, reinforcing fibers such as synthetic fibers and steel fibers cut into several [mm] to several [cm] are mixed in the concrete. The fiber reinforced concrete of the present embodiment has a compressive strength of 100 to 400 [N / mm ² ] on the 28th day of the material age.

Hereinafter, a method for manufacturing such concrete slabs 1 and 2 and a second concrete slab 20 will be described. First, a method of manufacturing the first buried form 13 and the second buried form 23 will be described. As shown in FIGS. 6 (A) and 6 (B), either one of the first buried form 13 and the second buried form 23 is either the first buried form 13 or the second buried form 23. It is manufactured by placing fiber reinforced concrete using one or the other as a formwork. In the example of FIG. 6A, the first buried formwork 13 is manufactured by casting fiber reinforced concrete 93 using the second buried formwork 23 and the formwork 91 as formwork. Further, in the example of FIG. 6B, the second buried formwork 23 is manufactured by placing the fiber reinforced concrete 93 using the first buried formwork 13 and the formwork 92 as the formwork. As described above, in the fiber reinforced concrete 93, reinforcing fibers such as steel fibers cut into several [mm] to several [cm] are mixed in the concrete, and the compressive strength on the 28th day of the material age is 100 to 400. It is [N / mm ² ].

As shown in FIG. 7, in the present embodiment, the first buried formwork 13 formed of the fiber reinforced concrete 93 is embedded, including the convex portion 12 on the outer surface opposite to the side on which the concrete 94 is placed. By placing concrete 94 as a frame, concrete slabs 1 and 2 and a second concrete slab 20 including a convex portion 12 on the end face 11 are manufactured. Further, in the present embodiment, the concrete 94 includes a recess 22 on the outer surface opposite to the side on which the concrete 94 is cast, and uses the second buried form 23 formed of the fiber reinforced concrete 93 as the buried form. The concrete slabs 1 and 2 and the second concrete slab 20 including the recess 22 in the end face 21 are manufactured by casting.

As shown in FIG. 7, in the present embodiment, the first buried formwork 13 and the second buried formwork 23 are arranged so as to face each other while the convex portion 12 and the concave portion 22 are directed in the directions opposite to each other. By placing concrete 94 using the 1 buried formwork 13 and the 2nd buried formwork 23 as the buried formwork, a concrete floor containing a convex portion 12 on one end face 11 and a concave portion 22 on the other end face 21. The concrete floor slabs 1 and 2 and the second concrete floor slab 20 which are plates are manufactured.

As shown in FIG. 8, the first buried form 13 and the second buried mold are in a state where the convex portion 12 of the first buried form 13 and the concave portion 22 of the second buried form 23 are fitted to each other. By placing concrete 94 using the frame 23 as an embedded formwork, concrete slabs 1 and 2, which are concrete slabs including a convex portion 12 on the end face 11, and a second concrete slab 20 are manufactured, and the end faces are manufactured. Concrete floor slabs 1 and 2 and a second concrete floor slab 20 which are concrete floor slabs including recesses 22 in 21 may be manufactured. That is, in the manufacturing method shown in FIG. 8, concrete slabs 1 and 2 and a second concrete slab 20 having the same shape and having the convex portion 12 and the concave portion 22 easily fitted to each other with higher accuracy are manufactured. Will be done.

Returning to FIGS. 4 (A) and 4 (B), the first concrete slab 10 to the first post tension material 81 prestressed by the first post tension material 81 inserted into the first concrete slab 10. The removal process is performed. In the removal step, one of the first post-tensioning materials 81 among the plurality of first post-tensioning materials 81 inserted into the first concrete slab 10 is, for example, 1 in order from the end of the first concrete slab 10. Books are removed one by one.

In the removal step, the jack 7 applies tension to the release extra length 6 at the end of the first post tension material 81 opposite to the second concrete floor slab 20, and the fixing tool 15 is removed. Further, the fixing tool 5 at the end of the first post tension material 81 on the side of the second concrete floor slab 20 is also removed by using the box removal portion 25. After the fixing tools 5 and 15 are removed, the first post tension material 81 is removed from the sheath tube 3 as shown in FIGS. 9A and 9B. For the sake of clarification of the illustration, in FIG. 9A and the like below, the illustration of the release extra length 6 and the like of the first post tension material 81 that has not yet been removed in the removal step is omitted.

Further, in the examples of FIGS. 4 (A) and 4 (B), the second concrete floor slab 20 is installed in the floor slab tertiary construction section 53 before the removal process, and the fitting process is performed. Later, the second concrete floor slab 20 may be installed in the floor slab tertiary construction section 53, and the fitting step may be performed.

As shown in FIGS. 10A and 10B, the first concrete slab 10 from which one first post tension material 81 was removed by the removal step and the first concrete slab 10 adjacent to the first concrete slab 10 The insertion step of inserting the second post tension material 82 extending over the first concrete slab 10 and the second concrete slab 20 into the two concrete slabs 20 is performed.

In the insertion step, a steel wire such as a steel stranded wire was formed in the sheath pipe 3 which is a part of the first concrete plate bridge 10 into which one first post tension material 81 removed by the removal step was inserted. By inserting the second post tension material 82, one extending over the first concrete slab 10 and the second concrete slab 20 and the first concrete slab 10 and the second concrete slab 20. The second post tension material 82 of the above is inserted.

As shown in FIGS. 11A and 11B, one second post tension material 82 inserted in the insertion step prestresses the first concrete slab 10 and the second concrete slab 20. The prestress applying step is performed. In the prestress applying step, the first concrete slab 10 is formed by one second post tension material 82 inserted into one sheath pipe 3 of the first concrete slab 10 and the second concrete slab 20 by the insertion step. And the second concrete floor slab 20 are prestressed. Both ends of the second post-tension material 82 are fixed by the fixing tool 5 while being tensioned by a jack.

As shown in FIGS. 12A and 12B, in the floor slab tertiary construction step, the removal step as described above is performed again. In the removal step, for example, one first post adjacent to the first post tension material 81 removed in the previous removal step among the plurality of first post tension materials 81 inserted into the first concrete floor slab 10. The tension material 81 is removed one by one from the end of the first concrete floor slab 10. The insertion step and the prestress applying step as described above are performed again.

In the removal step, insertion step, and prestress applying step as described above, the first post tension material 81 is completely removed, and the second post tension is applied to all of the sheath pipe 3 from which all the first post tension material 81 is removed. The material 82 is inserted, and the process is performed until the first concrete slab 10 and the second concrete slab 20 are prestressed by all of the second post tension materials 82 inserted into all of the sheath pipes 3. In the present embodiment, in the removal step, a part of the first post tension material among the plurality of first post tension materials 81 inserted into the first concrete floor slab 10 is removed, and the traveling lane for traveling the vehicle is removed. As the 41 and the overtaking lane 42, the first concrete slab 10 is used from before the first post tension material 81 is removed by the removing step to after the prestress is applied by the prestress applying step.

As shown in FIGS. 13 (A) and 13 (B), a removal step, an insertion step, and a prestress applying step are performed on all of the first post tension material 81, and all of the second post tension material 82 After both ends are fixed by the fixing tool 5, the sheath pipe 3 into which the second post tension material 82 is inserted is grouted over the entire length of the sheath pipe 3 extending over the first concrete slab 10 and the second concrete slab 20. Etc. are filled. The boxed portion 25 at the portion where the second post tension material 82 is inserted is also filled with the filler 26 such as grout. The panel filling construction section 73 between each of the second concrete floor slabs 20 is filled with a filler such as mortar.

As shown in FIGS. 13 (A) and 13 (B), the temporary median strip 31 is removed. A new median strip 38 and a wall rail 39 will be installed. The new median strip 38 and the wall balustrade 39 separate the traveling lane 41 and the overtaking lane 42. In addition, although the wall height column 39 is shown in FIG. 13 (A), at this stage, the bridge surface of the entire width and the wall height columns 37 and the wall height columns 39 on both sides are completed, so that the median strip 38 is formed. It is not always necessary and does not have to be installed.

According to the present embodiment, the first concrete slab 10 before the removal step is prestressed by the first post tension material 81 inserted into the first concrete slab 10, for example. The first concrete slab 10 can be used as the traveling lane 41 on which the vehicle travels, and the degree of freedom in using the concrete slab during construction can be improved. Further, in the removal step, the first post tension material 81 is removed from the first concrete floor slab 10, and in the insertion step, the first concrete floor slab 10 from which the first post tension material 81 has been removed by the removal step and the first one. A second post tension material 82 extending over the first concrete slab 10 and the second concrete slab 20 is inserted into the second concrete slab 20 adjacent to the concrete slab 10, and a prestressing process is performed. Then, since the second post tension material 82 inserted in the insertion step applies prestress to the first concrete floor slab 10 and the second concrete floor slab 20, the prestress is applied without connecting the post tension materials to each other. Can be granted. Therefore, it is possible to apply prestress without connecting the post-tension materials while improving the degree of freedom in using the concrete floor slab during construction.

Further, in the present embodiment, the first concrete slab 10 from which the first post tension material 81 is removed by the removal step is divided into all of the first concrete slab 10 divided into two or more. Since the first post tension material 81 extending over the entire concrete floor slab 10 is inserted and prestressed by the first post tension material 81, the first concrete floor slab 10 is divided into two or more. After being prestressed by the first post-tension material 81, it can be used, for example, as a traveling lane 41 for traveling a vehicle, and the concrete slab can be freely used during construction. The degree can be improved. Further, since the concrete slab can be divided into three or more as a whole of the first concrete slab 10 and the second concrete slab 20, the degree of freedom of construction can be improved.

Further, in the present embodiment, in the insertion step, the second post tension material 82 is inserted into the portion of the first concrete floor slab 10 into which the first post tension material 81 removed by the removal step has been inserted. , The second post tension material 82 extending over the first concrete slab 10 and the second concrete slab 20 is inserted into the first concrete slab 10 and the second concrete slab 20. Prestress can be applied by the second post tension material 82 inserted by diverting the insertion hole, insertion groove, sheath pipe 3 and the like of the first concrete floor slab 10 into which the 1 post tension material 81 has been inserted. There is an advantage that it is not necessary to provide a new insertion hole, insertion groove, sheath pipe or the like in the first concrete floor slab 10.

Further, in the present embodiment, as the traveling lane 41 for traveling the vehicle, the first concrete floor slab 10 before the first post tension material 81 is removed by the removing step is used, so that the traffic closure time is shortened. can do.

Further, in the present embodiment, a part of the first post tension material 81 among the plurality of first post tension materials 81 inserted into the first concrete floor slab 10 is removed, and the traveling lane 41 for traveling the vehicle is removed. As a result, since the first concrete slab 10 is used from before a part of the first post-tension material 81 is removed by the removing step to after being prestressed by the prestress applying step, the traffic is closed. Can be further shortened.

Further, in the present embodiment, one end surface 11 of the first concrete slab 10 and the second concrete slab 20 which are in contact with each other has a convex portion 12, and the first concrete slab 10 and the second concrete floor which are in contact with each other have a convex portion 12. The other end surface 21 of the plate 20 has a concave portion 22, and a second post tension material 82 is provided in the inserting step in order to further include a fitting step of fitting the convex portion 12 and the concave portion 22 to each other before the inserting step. It becomes easy to align the positions of the insertion hole, the insertion groove, the sheath pipe 3, and the like in the first concrete slab 10 and the second concrete slab 20 to be inserted. Further, since the convex portion 12 and the concave portion 22 are formed of the fiber reinforced concrete 93, the strength before and after the joining can be improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and is implemented in various forms. For example, as shown in FIGS. 14 (A) and 14 (B), in the extraction step, all the first post tension materials among the plurality of first post tension materials 81 inserted into the first concrete floor slab 10 are used. 81 was removed, and as shown in FIGS. 15 (A) and 15 (B), in the insertion step, the first concrete slab 10 in which all of the plurality of first post tension materials 81 were removed by the removal step. A second post tension material 82 extending over the first concrete slab 10 and the second concrete slab 20 is inserted into the second concrete slab 20 adjacent to the first concrete slab 10. As shown in FIGS. 16A and 16B, in the prestressing step, the first concrete slab 10 and the second concrete slab 20 are formed by the second post tension material 82 inserted in the insertion step. May be prestressed.

Further, as shown in FIGS. 17A and 17B, in the removal step, a part of the first posttension material 81 among the plurality of first post tension material 81 inserted into the first concrete floor slab 10 is used. The material 81 was removed, and as shown in FIGS. 18A and 18B, in the insertion step, a part of the plurality of first post-tension materials 81 was removed by the removal step, and the first concrete floor was removed. A second post tension material 82 extending over the first concrete floor slab 10 and the second concrete floor slab 20 is inserted into the plate 10 and the second concrete floor slab 20 adjacent to the first concrete floor slab 10. Then, as shown in FIGS. 19 (A) and 19 (B), in the prestress applying step, the first concrete slab 10 and the second concrete slab 10 are formed by the second post tension material 82 inserted in the insertion step. Prestress may be applied to 20 and the like.

In the examples of FIGS. 17 (A), 17 (B), 18 (A), 18 (B), 19 (A) and 19 (B), the first post-tension material 81 is removed every other one. Although the step, the insertion step and the prestress applying step are performed, the removing step, the inserting step and the prestress applying step may be performed at intervals of two or more of the first post tension material 81. Further, the extraction step, the insertion step, and the prestress applying step may be performed in the order of the odd numbers of the plurality of first post tension materials 81 numbered 1 to n, or in the order of the even numbers. It may be performed in the order of random numbers. Further, finally, a part of the first post tension material 81 in the first post tension material 81 may be left as it is without being replaced by the second post tension material 82.

In this way, in the extraction step, a part of the first post tension material 81 among the plurality of first post tension materials 81 inserted in the first concrete floor slab 10 is removed, and in the insertion step, a plurality of first post tension materials 81 are removed by the removal step. The first concrete slab 10 and the first concrete slab 10 adjacent to the first concrete slab 10 were added to the first concrete slab 10 from which a part of the first post tension material 81 was removed. The second post tension material 82 extending over the two concrete floor slabs 20 is inserted, and in the prestress applying step, the first concrete floor slab 10 and the second post tension material 82 are inserted by the second post tension material 82 inserted in the insertion step. 2 In the embodiment in which the concrete floor slab 20 is prestressed, the first post-tension material 81, which is not removed in the removal step, is used during the removal step, the insertion step, and the prestress application step. The application of prestress to the concrete floor slab 10 is maintained. Therefore, for example, the first concrete slab 10 can be used as the traveling lane 41 for traveling the vehicle while the removal step, the insertion step, and the prestress applying step are performed, and the concrete slab 10 can be used at the time of construction. The degree of freedom can be further improved.

Further, in the above embodiment, the first post tension material 81 and the second post tension material 82 are formed of steel wire such as a stranded steel wire, but the first post tension material 81 and the second post tension material 82 are made of steel. It may be formed from rods. Further, in the above embodiment, all of the concrete floor slabs 1 and 2 and the second concrete floor slab 20 installed in the floor slab primary construction section 51, the floor slab secondary construction section 52, and the floor slab tertiary construction section 53 are pretensioned. Although it was a pretension floor slab containing the material 4, for the floor slab secondary construction part 52 and later other than the floor slab primary construction part 51, for example, when the main girder support of the bridge 100 is short, the pretension material 4 is used. An inexpensive RC plate slab that does not include it may be installed.

1,2 ... Concrete floor slab, 3 ... Sheath pipe, 4 ... Pretension material, 5 ... Fixing tool, 6 ... Extra length for release, 7 ... Jack, 10 ... First concrete floor slab, 11 ... End face, 12 ... Convex Part, 13 ... 1st buried formwork, 15 ... Fixing tool, 20 ... 2nd concrete floor slab, 21 ... End face, 22 ... Recessed, 23 ... 2nd buried formwork, 25 ... Boxing part, 26 ... Filling material, 31 ... Temporary separation zone, 36, 37 ... Wall formwork, 38 ... Central separation zone, 39 ... Wall formwork, 41 ... Running lane, 42 ... Overtaking lane, 51 ... Floor slab primary construction department, 52 ... Floor slab secondary construction Part, 53 ... Floor slab tertiary construction part, 60 ... Existing concrete floor slab, 71, 72, 73 ... Panel packing construction part, 81 ... 1st post tension material, 82 ... 2nd post tension material, 91, 92 ... Type Formwork, 93 ... Fiber reinforced concrete, 94 ... Concrete, 100 ... Bridge.

Claims (6)

It is a concrete slab construction method in which the existing concrete slab is removed and a new concrete slab is installed.
After removing the existing concrete slab, the first concrete slab installation process for newly installing the first concrete slab divided into two or more, and
After the first concrete slab installation step, the first post-tension material that extends over the entire first concrete slab divided into two or more. And the first prestress applying step of applying the prestress to the first concrete floor slab by the first post tension material.
After the first prestressing step, after removing the existing concrete slab, the second concrete slab is installed so as to be adjacent to the first concrete slab, and the second concrete slab installation step.
A removal step of removing the first post tensioning member from said first concrete deck prestressing is applied by the first post-tensioning member which is inserted into the first concrete slab by the first prestressing step ,
The first concrete slab and the second concrete are added to the first concrete slab from which the first post tension material has been removed by the removal step and the second concrete slab adjacent to the first concrete slab. The insertion process of inserting the second post-tension material that extends over the floor slab, and
A concrete slab comprising a second prestress applying step of applying prestress to the first concrete slab and the second concrete slab by the second post tension material inserted by the insertion step. Construction method. In the insertion step, the first concrete floor is inserted by inserting the second post tension material into the portion of the first concrete floor slab into which the first post tension material removed by the removal step has been inserted. The concrete slab according to claim 1 , wherein the second post-tension material extending over the first concrete slab and the second concrete slab is inserted into the slab and the second concrete slab. Construction method. In the removal step, a part of the first post tension material among the plurality of first post tension materials inserted into the first concrete slab is removed.
In the insertion step, the first concrete slab from which a part of the plurality of first post tension materials has been removed by the removal step and the second concrete slab adjacent to the first concrete slab are formed. , Insert the second post-tension material extending over the first concrete slab and the second concrete slab.
In the second prestress applying step, claim 1 or 2 which applies prestress to the first concrete slab and the second concrete slab by the second post tension material inserted by the insertion step. Construction method of concrete floor slab described in. The method for constructing a concrete slab according to claim 1 or 2 , wherein the first concrete slab before the first post tension material is removed by the removal step is used as a traveling lane for traveling the vehicle. .. As a traveling lane for traveling a vehicle, the first concrete slab from before the first post-tension material is removed by the removing step to after being prestressed by the second prestress applying step. 3. The method for constructing a concrete slab according to claim 3 . One end face of the first concrete slab and the second concrete slab that abut each other has a convex portion, and the other end face of the first concrete slab and the second concrete slab that abut each other has a concave portion. The convex portion and the concave portion are formed of fiber reinforced concrete.
The method for constructing a concrete slab according to any one of claims 1 to 5 , further comprising a fitting step of fitting the convex portion and the concave portion to each other before the insertion step.

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