JP2020133260A - Concrete slab joint structure and concrete slab joining method - Google Patents

Abstract

To provide a concrete slab joint structure and concrete slab joining method that can eliminate a range where the pre-stress is introduced redundantly while the pre-stress is introduced into the joint.SOLUTION: A first concrete slab 10A is pre-stressed by a pre-tensioning method with a pre-tensioning tendon 13A. A second concrete slab 20 is pre-stressed by a post-tensioning method with a post-tensioning tendon 23, so that the first concrete slab 10A and the second concrete slab 20 are independently and separately pre-stressed. The joining of the pre-tensioning tendon 13A and the post-tensioning tendon 23 allows pre-stresses to be introduced at the joint between the first concrete slab 10A and the second concrete slab 20 while eliminating the range of redundant pre-stresses being introduced.SELECTED DRAWING: Figure 1

Description

The present invention relates to a concrete slab joining structure and a concrete slab joining method.

For repairing concrete slabs, a technique has been proposed in which an existing concrete slab is replaced with a new slab. For example, Patent Document 1 describes a technique in which the width direction of a road is divided into a primary construction section and a secondary construction section, and an existing concrete slab is replaced with a new slab in the order of the primary construction section and the secondary construction section. It is disclosed. In the technique of Patent Document 1, the existing floor slab of the secondary construction section is used as a road, and the existing floor slab of the primary construction section is replaced with a new floor slab. After the new slab of the primary construction section is put into service as a road, the existing slab of the secondary construction section will be replaced with a new slab. The new floor slab of the primary construction part and the new floor slab of the secondary construction part are joined, and the entire primary construction part and the secondary construction part are used as a road.

In the technique of Patent Document 1, a new concrete slab in which prestress by the pretension method is introduced is installed in the primary construction section. After a new concrete slab is installed in the secondary construction section, the post spans the entire range of the floor slab in the secondary construction section in the width direction and a part of the width direction of the floor slab in the primary construction section. Tension tension material is inserted. The post-tension tension material introduces prestress by the post-tension method in the entire range of the floor slab in the secondary construction section in the width direction and a part of the floor slab in the primary construction section in the width direction. The floor slab and the floor slab of the primary construction section are joined.

Japanese Patent No. 6323776

By the way, in the above technique, it is necessary to introduce prestress in the new floor slab used for the passage of vehicles in the primary construction section. In addition, prestress must be introduced at the joint between the new floor slab of the primary construction section and the new floor slab of the secondary construction section.

However, when prestress by the post-tension method is introduced into the new floor slab in the secondary construction section, the post-tension tension material covers the entire range of the floor slab in the secondary construction section in the width direction and the floor of the primary construction section. Since it is inserted over a part of the width direction of the plate, the prestress by the pretension method and the prestress by the post tension method are introduced in the floor slab of the primary construction part in duplicate. Is generated, and the amount of steel required for the tension material becomes large, which is uneconomical.

Therefore, an object of the present invention is to provide a concrete slab joining structure and a concrete slab joining method that can eliminate the range in which prestress is introduced in duplicate while prestress is introduced into the joint. And.

The present invention is a joint structure of a concrete slab in which a first concrete slab and a second concrete slab are joined, and the first concrete slab is prestressed by a pretension method by a pretension tensioning material. The second concrete slab has been introduced, and prestress by the post tension method is introduced by the post tension tension material, and the joint structure of the concrete slab in which the pretension tension material and the post tension tension material are connected. Is.

According to this configuration, in the joint structure of the concrete slab in which the first concrete slab and the second concrete slab are joined, the first concrete slab introduces prestress by the pretension method by the pretension tension material. Since the second concrete slab is prestressed by the post-tension method by the post-tension tensioning material, the first concrete slab and the second concrete slab are independently prestressed. It has been introduced. Furthermore, by connecting the pretension tension material and the post tension tension material, prestress is introduced at the joint between the first concrete slab and the second concrete slab, and prestress is introduced in duplicate. It is possible to eliminate the range that has been set.

In this case, it is preferable that the first concrete slab and the second concrete slab are joined via a filling portion, and the filling portion is filled with the filling concrete.

According to this configuration, the first concrete slab and the second concrete slab are joined to each other via a filling portion, and the stuffing portion is filled with the stuffed concrete, so that the first concrete slab and the second concrete slab are joined. It is possible to improve the water resistance of the portion where the second concrete slab is joined.

In this case, the interstitial concrete is preferably an expandable concrete that expands when it hardens after casting.

According to this configuration, since the interstitial concrete is an expandable concrete that expands during hardening after casting, it is possible to reduce cracks due to shrinkage after hardening.

Further, in the present invention, the first installation step of installing the first concrete slab in which the prestress by the pretension method is introduced by the pretension tension material and the first concrete slab installed in the first installation step are For the second installation process of installing the second concrete slab after being used for the passage of vehicles, the joining process of joining the first concrete slab and the second concrete slab, and the second concrete slab. It includes a post-tension process that introduces pre-stress by a post-tension method using a post-tension tension material, and the joining process is a method of joining a concrete floor slab that connects the pre-tension tension material and the post-tension tension material.

In this case, in the joining step, it is preferable that the first concrete slab and the second concrete slab are joined via the filling portion, and the filling portion is filled with the filling concrete.

According to this configuration, in the joining process, the first concrete slab and the second concrete slab are joined via the filling portion, and the filling portion is filled with the filling concrete, so that the dimensions are flexible. It is possible to absorb dimensional variations of the first concrete slab and the second concrete slab, construction errors, and the like by the filling portion having the above. Therefore, the robustness against dimensional variations and construction errors of the first concrete slab and the second concrete slab is improved.

Further, before placing the concrete forming the first concrete slab to be installed in the first installation step, a pretension tensioning material having a tubular member and a closing portion that closes one end of the tubular member is placed in the concrete. A tensile force is applied to the tubular member by an insertion member that is placed at a site, is inserted inside the tubular member, and presses the closing portion while being pressed from the other end of the tubular member, and concrete is cast at the casting site. It is preferable to introduce prestress into the first concrete slab by removing the tensile force applied to the tubular member by the inserting member after the cast concrete is hardened.

According to this configuration, the pretension tensioning material having a tubular member and a closing portion that closes one end of the tubular member is concrete before placing the concrete forming the first concrete slab to be installed in the first installation step. A tensile force is applied to the tubular member by an insertion member that is inserted inside the tubular member and presses the closing portion while being pressed from the other end of the tubular member. Concrete is cast at the casting site. Prestress is introduced into the first concrete slab by removing the tensile force applied to the tubular member by the inserting member after the cast concrete is hardened. Therefore, prestress by the pretension method can be introduced into the first concrete floor slab without the need for a large-scale device.

According to the concrete slab joining structure and the concrete slab joining method of the present invention, it is possible to eliminate the range in which prestress is introduced in duplicate while the prestress is introduced in the joint portion.

(A) is a plan view showing the joint structure of the concrete floor slab of the first embodiment after the joining step and the post-tensioning step, and (B) is a vertical sectional view taken along line α of (A). (A) is a plan view which shows the 1st installation process of the concrete floor slab joint structure of 1st Embodiment, and (B) is a vertical sectional view by β line of (A). (A) is a vertical sectional view showing a state in which concrete is cast while the pretension tension material is applied with a tensile force by the dummy tension material during the production of the first concrete slab of FIG. 2 (B). ) Is a vertical cross-sectional view showing a state in which the dummy tension material is removed after the concrete of (A) is hardened, and (C) is a vertical cross-sectional view showing a first concrete slab from which the formwork of (B) has been removed. Is. (A) is a plan view which shows the 2nd installation process of the concrete floor slab joint structure of 1st Embodiment, and (B) is a vertical sectional view by γ-ray of (A). (A) is a plan view showing the state before filling the interstitial part of the interstitial part of the joint structure of the concrete floor slab of the first embodiment with the interstitial concrete, and (B) is the δ line of (A). It is a vertical sectional view. (A) is a plan view showing a post-tension process of the joint structure of the concrete floor slab of the first embodiment, and (B) is a vertical cross-sectional view taken along line δ of (A). (A) is a vertical cross-sectional view showing a state before the tensile force of the pretension tension material of the joint structure of the concrete floor slab of the second embodiment is applied, and (B) is the pretension tension material of (A). It is a vertical cross-sectional view which shows the state which the tensile force was applied before the concrete was placed. (A) is a vertical cross-sectional view showing a state in which the pretension tensioning material of FIG. 7 (B) is arranged at the concrete placing site forming the first concrete slab, and (B) is the concrete of (A). It is a vertical cross-sectional view which shows the state which the prestress was introduced into the 1st concrete slab by the pretension tensioning material after hardening, and (C) is the 1st concrete which the formwork, sleeve and stopper of (B) were removed. It is a vertical sectional view which shows the floor slab. It is a vertical cross-sectional view which shows the joining structure of the concrete slab of the 2nd Embodiment after a joining step and a post-tension step.

Hereinafter, the concrete slab joining structure and the concrete slab joining method according to the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1A and 1B, in the concrete slab joint structure 1A according to the first embodiment of the present invention, the first concrete slab 10A and the second concrete slab 20 are joined. Has been done.

In the joint structure 1A of the concrete slab of the present embodiment, for example, the width direction of the road is divided into the primary construction section 81 and the secondary construction section 82, and the existing concrete slab of the primary construction section 81 is a new first concrete. It is applied when the existing concrete slab of the secondary construction section 82 is replaced with a new second concrete slab 20 after being replaced with the floor slab 10A. In this case, the existing slab of the secondary construction section 82 is used as a road, and the existing slab of the primary construction section 81 is replaced with a new first concrete slab 10A. After the new first concrete slab 10A of the primary construction section 81 is put into service as a road, the existing slab of the secondary construction section 82 is replaced with a new second concrete slab 20. The new first concrete slab 10A of the primary construction section 81 and the new second concrete slab 20 of the secondary construction section 82 are joined, and the first concrete slab 10A of the primary construction section 81 and the secondary construction section are joined. The entire 82 and the second concrete slab 20 are used as a road.

The first end surface 11 of the first concrete slab 10A and the second end surface 21 of the second concrete slab 20 face each other via the filling portion 30. The first concrete slab 10A and the second concrete slab 20 are joined to each other via a filling portion 30, and the filling portion 30 is filled with the filling concrete 31. The filling portion 30 is a concrete and a second concrete floor forming the first concrete slab 10A between the first end surface 11 of the first concrete slab 10A and the second end surface 21 of the second concrete slab 20. It means that it is a portion formed by the interstitial concrete 31 filled separately from the concrete forming the plate 20. The interstitial concrete 31 is an expandable concrete that expands when it hardens after being placed. The expandable concrete includes, for example, a concrete admixture specified in JIS A 6202.

The joint structure 1A of the concrete floor slab of the present embodiment includes a first joint reinforcing bar 12 projecting from the first end surface 11 to the filling portion 30, and a second joint reinforcing bar 22 protruding from the second end surface 21 to the filling portion 30. To be equipped. In the present embodiment, the first joint reinforcing bar 12 and the second joint reinforcing bar 22 that are alternately adjacent to each other at equal intervals in the extending direction of the filling portion 30 (the extending direction of the road) are separated by two steps in the vertical direction. Are arranged. A ceramic anchor is attached to the end of the first joint reinforcing bar 12 and the second joint reinforcing bar 22 on the side of the filling portion 30.

The joint structure 1A of the concrete floor slab of the present embodiment includes reinforcing reinforcing bars 40 that intersect each other so as to be orthogonal to the first joint reinforcing bars 12 and the second joint reinforcing bars 22. In the present embodiment, two reinforcing reinforcing bars 40 are connected at each step in the vertical direction of the first joint reinforcing bar 12 and the second joint reinforcing bar 22 that are alternately adjacent to each other at equal intervals in the extending direction of the filling portion 30. ing. Therefore, the joint structure 1A of the concrete floor slab of the present embodiment includes a total of four reinforcing reinforcing bars 40. Epoxy resin coating is applied to the first joint reinforcing bar 12, the second joint reinforcing bar 22, and the reinforcing reinforcing bar 40. The reinforcing reinforcing bar 40 is connected to the first joint reinforcing bar 12 and the second joint reinforcing bar 22 by a binding wire or the like.

The first concrete slab 10A is formed of precast concrete cast at a factory or the like other than the construction site to which the joint structure 1A of the concrete slab of the present embodiment is applied. In the first concrete floor slab 10A, prestress by the pretension method is introduced by the pretension tension material 13A. Either a steel rod or a steel pipe can be applied to the pretension tension material 13A. In the present embodiment, the deformed PC steel rod is applied to the pretension tension material 13A. The first concrete slab 10A may be formed of cast-in-place concrete cast at a construction site to which the joint structure 1A of the concrete slab of the present embodiment is applied.

The second concrete slab 20 is formed of precast concrete. Prestress by the post-tension method is introduced into the second concrete floor slab 20 and the filling portion 30 by the post-tension tension material 23. The second concrete slab 20 has a sheath pipe 24 for accommodating the post-tension tensioning material 23. The sheath tube 24 is made of, for example, polyethylene. Grout is filled between the gap between the sheath tube 24 and the post tension tensioning member 23. The second concrete floor slab 20 may be formed of cast-in-place concrete.

The post tension tension material 23 is a pregrout PC steel material. The pre-grout PC steel material is a steel stranded wire coated with a room temperature curable resin as a grout material on the surface thereof and coated with a sheath such as polyethylene. In the pre-grout PC steel material, the room temperature curable resin is cured after the introduction of prestress, and the pre-grout PC steel material and concrete are integrated. The post-tension tensioning material 23 may have a cylindrical shape such as a steel rod or a steel pipe.

In the present embodiment, the pre-tension tension material 13A and the post-tension tension material 23 are connected by a coupler 50 having a substantially circular pipe shape embedded in the first concrete floor slab 10A. In the present embodiment, since the ends of the pretension tension material 13A and the post tension tension material 23 that are connected to each other have a cylindrical shape and have a screw groove on the outer peripheral surface, the coupler 50 having a screw groove on the inner peripheral surface Therefore, they can be easily connected to each other. The distance between the pretension tension material 13A and the post tension tension material 23 in the extending direction of the packing portion 30 is 600 mm to 750 mm. For example, 3 to 4 pre-tension tensioning members 13A and post-tensioning tensioning members 23 are arranged for each of the first concrete slab 10A and the second concrete slab 20.

Hereinafter, a method of joining the concrete floor slab of the present embodiment will be described. As shown in FIGS. 2A and 2B, the first installation step of installing the first concrete slab 10A in which the prestress by the pretension method is introduced by the pretension tension material 13A is performed. In the present embodiment, the first concrete slab 10A formed of precast concrete is installed in the first installation step.

In the first installation process, for example, when the width direction of the road is divided into the primary construction section 81 and the secondary construction section 82, the existing floor slab of the secondary construction section 82 is used as a road and the primary construction section 81 is used. This is done to replace the existing slab of the first concrete slab 10A with a new first concrete slab 10A. The installed first concrete slab 10A is in service for the passage of vehicles. A load F due to the passage of a vehicle is applied to the first concrete floor slab 10A. In the present embodiment, the first concrete slab 10A and the second concrete slab 20 are joined via the filling portion 30, and the filling portion 30 is filled with the filling concrete 31. Therefore, the first concrete The width of the slab 10A in the width direction of the road is smaller than the width of the existing slab of the primary construction section 81 in the width direction of the road.

The first concrete floor slab 10A is manufactured as follows. As shown in FIG. 3A, inside the formwork 201, together with reinforcing bars such as the first joint reinforcing bar 12, the pretension tension material 13A and the pretension tension material 13A near the formwork surface 201p of the formwork 201. A coupler 50 connected to one end of the is arranged. A dummy tension material 180 is connected to the coupler 50 from the outside of the formwork surface 201p of the formwork 201. The pretension tension material 13A connected to the dummy tension material 180 via the coupler 50 is given a tensile force P by the dummy tension material 180. Concrete C is placed in the formwork 201.

As shown in FIG. 3B, the prestress S is introduced into the concrete C by removing the dummy tension material 180 from the coupler 50 after the concrete C has hardened. As shown in FIG. 3C, the first concrete slab 10A is manufactured by removing the formwork 201.

As shown in FIGS. 4 (A) and 4 (B), the second concrete slab 20 is installed after the first concrete slab 10A installed in the first installation process is used for the passage of vehicles. The second installation process is performed. The first joint reinforcing bar 12 protruding from the first end surface 11 to the filling portion 30 and the second joint reinforcing bar 22 protruding from the second end surface 21 to the filling portion 30 are adjacent to each other. A load F due to the passage of a vehicle is applied to the first concrete floor slab 10A. In the present embodiment, the first concrete slab 10A and the second concrete slab 20 are joined via the filling portion 30, and the filling portion 30 is filled with the filling concrete 31. Therefore, the second concrete The width of the slab 20 in the width direction of the road is smaller than the width of the existing slab 82 of the secondary construction section 82 in the width direction of the road.

As shown in FIGS. 5A and 5B, a joining step of joining the first concrete slab 10A and the second concrete slab 20 is performed. In the joining step, the pretension tension material 13A such as a deformed PC steel rod and the post tension tension material 23 such as the pregrout PC steel material inserted into the sheath pipe 24 of the second concrete plate bridge 20 are connected by the coupler 50.

In the joining step, the reinforcing reinforcing bar 40 is arranged in the filling portion 30. Epoxy resin coating is applied to the first joint reinforcing bar 12, the second joint reinforcing bar 22, and the reinforcing reinforcing bar 40. The reinforcing reinforcing bar 40 is connected to the first joint reinforcing bar 12 and the second joint reinforcing bar 22 by a binding wire or the like. As shown in FIGS. 1 (A) and 1 (B), in the joining step, the first concrete slab 10A and the second concrete slab 20 are joined via the filling portion 30 to the filling portion 30. The interstitial concrete 31 is filled. As described above, the interstitial concrete 31 is an expandable concrete that expands when it hardens after being placed.

As shown in FIGS. 6A and 6B, after the filling concrete 31 of the filling portion 30 is hardened, the second concrete floor slab 20 is prestressed by the post-tension method by the post-tension tensioning material 23. The post-tension process to be introduced is performed. When the tensile force P is applied to the post-tension tensioning material 23 such as the pregrout PC steel material, the prestress S is introduced into the second concrete floor slab 20 and the filling portion 30. After the introduction of the prestress S, grout is filled between the gap between the sheath tube 24 and the post-tension tensioning material 23.

In the present embodiment, in the joint structure 1A of the concrete slab in which the first concrete slab 10A and the second concrete slab 20 are joined, the first concrete slab 10A is pretensioned by the pretension tension material 13A. Since prestress is introduced and prestress by the post tension method is introduced in the second concrete slab 20 by the post tension tension material 23, the first concrete slab 10A and the second concrete slab 20 are respectively. Prestress is introduced independently and separately. Further, by connecting the pretension tension material 13A and the post tension tension material 23, prestress is introduced into the joint portion between the first concrete slab 10A and the second concrete slab 20, and the prestress overlaps. It is possible to eliminate the range in which prestress is introduced. That is, the amount of steel required for the tension material is minimal.

Further, according to the present embodiment, in the joining step, the first concrete floor slab 10A and the second concrete floor slab 20 are joined via the filling portion 30, and the filling portion 30 is filled with the filling concrete 31. Therefore, the width of the first concrete slab 10A and the second concrete slab 20 in the width direction can be made smaller than the existing floor slabs of the primary construction section 81 and the secondary construction section 82. The filling portion 30 having flexibility in the width direction of the first concrete slab 10A and the second concrete slab 20 can absorb dimensional variations and construction errors. Therefore, the robustness against dimensional variation and construction error of the first concrete slab 10A and the second concrete slab 20 is improved. Further, after the interstitial concrete 31 is hardened, the water resistance of the portion where the first concrete slab 10A and the second concrete slab 20 are joined can be improved. Further, according to the present embodiment, since the interstitial concrete 31 is an expandable concrete that expands at the time of hardening after casting, cracks can be reduced.

Further, according to the present embodiment, the first concrete floor slab 10A can be formed of precast concrete depending on the situation. Further, according to the present embodiment, since the second concrete floor slab 20 has a sheath pipe 24 for accommodating the post-tension tension material 23, prestress due to the post-tension tension material 23 is more easily introduced. Further, according to the present embodiment, since either end of the pre-tension tensioning material 13A and the post-tensioning tensioning material 23 which are connected to each other has a cylindrical shape, the connection is easy and the connection strength is improved. Can be done. Further, according to the present embodiment, since the post-tension tensioning material 23 is a pre-grout PC steel material, the grout work at the construction site can be reduced, and the workability is further improved.

Hereinafter, a second embodiment of the present invention will be described. As shown in FIG. 9, in the joint structure 1B of the concrete slab of the present embodiment, the prestress by the pretension method is introduced into the first concrete slab 10B by the pretension tension material 13B, and the first installation step. Then, the first concrete floor slab 10B in which the prestress by the pretension method is introduced by the pretension tension material 13B is installed.

First, the pretension tension material 13B of the present embodiment will be described. FIG. 7A is a vertical cross-sectional view showing a state before the tensile force P of the pretension tension material 13B is applied, and FIG. 7B is a state in which the tensile force P of the pretension tension material 13B is applied. It is a vertical sectional view which shows. As shown in FIGS. 7 (A) and 7 (B), the pretension tensioning material 13B of the present embodiment is used before placing the concrete forming the first concrete slab 10B installed in the first installation step. It has a tubular member 131 arranged at a concrete casting site and a closing portion 132 that closes one end 131a of the tubular member 131. As shown in FIG. 7B, the insertion member 133 is inserted into the tubular member 131 and presses the closing portion 132 while being pressed from the other end 131b of the tubular member 131 before the concrete is placed. A tensile force P is applied to the member 131.

In the examples of FIGS. 7 (A) and 7 (B), the tubular member 131 and the closed portion 132 are separate members, but the tubular member 131 and the closed portion 132 are integrated members by casting or the like. There may be. Further, in the examples of FIGS. 7 (A) and 7 (B), the insertion member 133 is a cylindrical member, but the insertion member 133 may be a tubular member.

As shown in FIGS. 7A and 7B, the tubular member 131 is pressed from the other end 131b of the tubular member 131 via the sleeve 134, the stopper 137, the pushing member 136, and the rod 135. The sleeve 134 is fixed to the other end 131b of the tubular member 131 by engaging the thread groove on the outer peripheral surface near the other end 131b of the tubular member 131 with the thread groove on the inner peripheral surface of the sleeve 134.

The stopper 137 is screwed into the sleeve 134 by engaging the thread groove on the inner peripheral surface of the sleeve 134 with the thread groove on the outer peripheral surface of the stopper 137. The stopper 137 presses the insertion member 133 via the pushing member 136 and the rod 135. Further, the stopper 137 includes a rod insertion hole portion 137h for inserting the rod 139. The anchor nut 138 is fixed in the vicinity of the other end 131b of the tubular member 131 by engaging the thread groove on the outer peripheral surface near the other end 131b of the tubular member 131 and the thread groove on the inner peripheral surface of the anchor nut 138. Has been done.

As shown in FIG. 7B, the rod 139 is inserted into the rod insertion hole 137h of the stopper 137. The rod 139 pushed by the hydraulic jack applies a compressive force p to the closing portion 132 via the pushing member 136, the rod 135, and the inserting member 133, so that the tubular member 131 is given a tensile force P. The stopper 137 is screwed into the sleeve 134 to limit the movement of the pushing member 136, the rod 135 and the inserting member 133. As described above, the tensile force P of the pretension tension material 13B is applied.

Next, a method of manufacturing the first concrete floor slab 10B using the pretension tensioning material 13B will be described. The first concrete slab 10B may be formed of precast concrete cast at a factory or the like other than the construction site to which the joint structure 1B of the concrete slab of the present embodiment is applied. It may be formed of cast-in-place concrete placed at the construction site to which the joint structure 1B of the concrete floor slab is applied. Further, in the following description, description and illustration of the first joint reinforcing bar 12 and other reinforcing bars will be omitted.

As shown in FIG. 8A, in the first installation step, the tubular member 131 and the tubular member 131 are placed before the concrete C forming the first concrete slab 10B to be installed in the first installation step is placed. A pretension tensioning material 13B having a closing portion 132 that closes one end portion 131a is arranged at a casting portion of concrete C. As described above, a tensile force P is applied to the tubular member 131 by the insertion member 133 which is inserted into the tubular member 131 and presses the closing portion 132 while being pressed from the other end portion 131b of the tubular member 131. The formwork 202 is arranged so as to surround the casting site.

The concrete C is cast by injecting the concrete C into the formwork 202 surrounding the casting site. As shown in FIG. 8B, the prestress S is introduced into the concrete C by removing the tensile force P applied to the tubular member 131 by the inserting member 133 after the cast concrete C is hardened. .. The pulling force P is removed by removing the stopper 137 from the sleeve 134. As shown in FIG. 8C, the sleeve 134, the rod 135, and the pushing member 136 are removed from the tubular member 131, and the formwork 202 is removed, so that the pretension tension material 13B causes prestress by the pretension method. The introduced first concrete slab 10B is manufactured.

As shown in FIG. 9, in the first installation step, the first concrete slab 10B in which the prestress by the pretension method is introduced by the pretension tension material 13B is installed. In the second installation step, the second concrete slab 20 is installed substantially in the same manner as in the first embodiment, but the coupler 50 located outside the first end surface 11 of the first concrete slab 10B is interspersed with concrete 31. The sheath pipe 24 is extended to the side end of the second concrete plate bridge 20 of the coupler 50 installed in the coupler 50 in the joining process in order to insulate from.

In the joining step, the other end 131b of the tubular member 131 of the pretension tensioning material 13B and the post tension tensioning material 23 are connected by the coupler 50 in substantially the same manner as in the first embodiment, but the first concrete floor slab 10B In order to insulate the coupler 50 located on the outside of the first end surface 11 from the interstitial concrete 31, the coupler 50 is covered with a coupler sheath 25 connected to a sheath pipe 24. In the post-tension step, pre-stress by the post-tension method is introduced into the second concrete floor slab 20 and the filling portion 30 by the post-tension tension material 23 as in the first embodiment.

In the present embodiment, a pre having a tubular member 131 and a closing portion 132 that closes one end portion 131a of the tubular member 131 before placing the concrete C forming the first concrete floor slab 10B installed in the first installation step. The tension tension member 13B is arranged at the casting site of the concrete C, and is inserted into the tubular member 131 and pressed from the other end 131b of the tubular member 131 while pressing the closing portion 132 to the tubular member 131 by the insertion member 133. A tensile force P is applied. Concrete C is placed at the casting site. After the cast concrete C is hardened, the tensile force P applied to the tubular member 131 is removed by the insertion member 133, so that the prestress S is introduced into the first concrete slab 10B. Therefore, the prestress S by the pretension method can be introduced into the first concrete floor slab 10B without the need for a large-scale device.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and is implemented in various forms. For example, the configurations, shapes, and arrangements of the pretension tension members 13A and 13B, the post tension tension members 23, and the coupler 50 in the above embodiment can be appropriately changed.

1A, 1B ... Joint structure, 10A, 10B ... 1st concrete slab, 11 ... 1st end face, 12 ... 1st joint reinforcing bar, 13A, 13B ... Pretension tension material, 20 ... 2nd concrete slab, 21 ... 2 end face, 22 ... 2nd joint reinforcing bar, 23 ... post tension tension material, 24 ... sheath pipe, 25 ... coupler sheath, 30 ... interstitial part, 31 ... interstitial concrete, 40 ... reinforcing reinforcing bar, 50 ... coupler, 81 ... Primary construction part, 82 ... Secondary construction part, 131 ... Tubular member, 131a ... One end, 131b ... Other end, 132 ... Closing part, 133 ... Inserting member, 134 ... Sleeve, 135 ... Rod, 136 ... Pushing member, 137 ... Stopper, 137h ... Rod insertion hole, 138 ... Anchor nut, 139 ... Rod, 180 ... Dummy tension material, 201, 202 ... Formwork, 201p ... Formwork surface, F ... Load, P ... Tensile force, p ... Compressive force, S ... prestress, C ... concrete.

Claims (6)

It is a joint structure of a concrete slab in which the first concrete slab and the second concrete slab are joined.
In the first concrete slab, prestress by the pretension method is introduced by the pretension tension material.
In the second concrete slab, prestress by the post-tension method is introduced by the post-tension tension material.
A joint structure of a concrete floor slab in which the pretension tension material and the post tension tension material are connected. The concrete slab according to claim 1, wherein the first concrete slab and the second concrete slab are joined via a filling portion, and the filling portion is filled with the filling concrete. Joined structure. The joint structure of a concrete floor slab according to claim 2, wherein the interstitial concrete is an expandable concrete that expands when it hardens after casting. The first installation process of installing the first concrete slab in which prestress by the pretension method is introduced by the pretension tension material, and
The second installation step of installing the second concrete slab after the first concrete slab installed in the first installation step is used for the passage of vehicles, and
A joining step of joining the first concrete slab and the second concrete slab,
A post-tension process that introduces pre-stress by the post-tension method using a post-tension tensioning material on the second concrete floor slab, and
With
In the joining step, a method of joining a concrete floor slab that connects the pretension tension material and the post tension tension material. The concrete slab according to claim 4, wherein in the joining step, the first concrete slab and the second concrete slab are joined via a filling portion, and the filling portion is filled with the filling concrete. Joining method. Prior to placing the concrete forming the first concrete slab installed in the first installation step, the concrete is subjected to the pretension tension material having a tubular member and a closing portion that closes one end of the tubular member. Placed at the casting site of
A tensile force is applied to the tubular member by an insertion member that is inserted into the tubular member and presses the closed portion while being pressed from the other end of the tubular member.
The concrete is poured into the casting site,
The fourth or fifth aspect of the present invention, wherein prestress is introduced into the first concrete slab by removing the tensile force applied to the tubular member by the insertion member after the cast concrete is hardened. How to join concrete floor slabs.

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