Truss-type shear reinforcement material having double anchorage functions at both top and bottom thereof

Abstract

The present invention relates to a shear reinforcement material of a reinforced concrete structure, which is installed in a reinforced concrete structure to increase resistance against shear failure. The truss-type shear reinforcement material having double anchorage functions at both top and bottom thereof is configured by installing double anchor heads on the top and the bottom of a truss (20), which is formed by connecting an upper member (24) with a lower member (26) through connection members (21) such as vertical members (22) or inclined members (23). Therefore, the shear reinforcement material according to the present invention can improve shear resistance, shear reinforcement and ductility, because upper anchor heads (34) and the upper member (24) carry out a double anchorage function on the top while lower anchor heads (44) and the lower member (26) carry out a double anchorage function on the bottom, and furthermore, improves construction quality as building a concrete structure becomes more convenient.

Description

TECHNICAL FIELD[0001]The present invention relates to a truss-type shear reinforcement device having double anchorage functions at upper and lower sides thereof, and more particularly, to such a truss-type shear reinforcement device of a reinforced concrete structure, which is installed in a reinforced concrete structure to increase resistance against shear failure. The truss-type shear reinforcement device having double anchorage functions at upper and lower sides thereof is configured by installing double anchorage at the upper and lower sides of a truss, which is formed by connecting an upper chord member with a lower chord member through connection members such as vertical members or diagonal members, thereby improving shear resistance, shear reinforcement and ductility and improving construction quality while making construction of a concrete structure more convenient.BACKGROUND ART[0002]In a reinforced concrete structure constructed through application of reinforcing bars and ...

AI Technical Summary

Benefits of technology

[0023]The truss-type shear reinforcement device having double anchorage functions at upper and lower sides thereof according to the present invention has a structure in which upper and lower anchor heads 34 and 44 are mounted at the upper and lower sides of a truss 20 including an upper chord member 24 and a lower chord member 26 which are connected with each other by the connection members 21. Thus, the upper anchor head 34 and the upper chord member 24 perform a double anchorage function at the upper side of the shear reinforcement device, and the lower anchor head 44 and the lower chord member 26 perform a double anchorage function at the lower side of the shear reinforcement device, so that shear resistance and ductility of the inventive shear reinforcement device is further improved as compared to the conventional prior art. Particularly, the conventional shear reinforcement device has a limitation in that a shear reinforcement range must be reduced by the coating thickness of the shear reinforcement device and the thickness of the members, thereby deteriorating the reinforcement performance. On the other hand, the inventive truss-type shear reinforcement device having double anchorage functions at upper and lower sides thereof has an advantage in that since a vertical shear reinforcement range is covered up to the entire range except the concrete coating thickness, the shear reinforcement performance can be maximized. In addition, the inventive truss-type shear reinforcement device having double anchorage functions at upper and lower sides thereof can further achieve a confining effect in the longitudinal direction, i.e., in the direction of an X axis through the truss, and is excellent in its own bending resistance. Moreover, the upper side of the shear reinforcement device in which the upper anchor heads 34 are mounted and the lower side of the shear reinforcement device in which lower anchor heads 44 are mounted are in a symmetrical relationship, so that the shear reinforcement device has a very stable reinforcement performance against the stress reversal of the shear reinforcement portion due to an earthquake load, and the like. Besides, the inventive shear reinforcement device does not produce any interference with the reinforcing bars placed in concrete, thereby further improving constructionability. In addition, the function of the spacers 32 and 42 for adjusting the placement position and distance of the reinforcing bars is performed automatically, and thus the reinforcing bars can be placed at more accurate positions through the height adjustment of the truss 20, thereby shortening the construction period while effectively improving construction quality.

Problems solved by technology

Thus, if the joint does not have a sufficient shear resistance, there is a great risk of occurrence of shear failure.

Referring to FIGS. 1 and 2, a conventional shear reinforcement method entails a problem in that since the shear reinforcement device (i.e., stirrup 100, shear stud 200 and shear band 300) is deformed at the time of stress reversal, the shear performance is remarkably lowered upon the repeated exertion of the shear stress.

Further, the concrete coating thickness during construction must be necessarily taken into consideration, but is difficult to precisely control actually, thus resulting in a problem in that construction defects occur or the performance of the structure is deteriorated.

Moreover, since the conventional shear reinforcement devices are difficult for field workers with repetitive motion tasks to install, careful attention must be paid to installation of the shear reinforcement devices and satisfaction of the required design conditions is difficult.

Thus, this makes it difficult to work as well as much working time is spent.

Since such a method of using the stirrup 100 requires that the thickness of the stirrup 100 should be taken into consideration, it is difficult to actually satisfy the specified concrete coating thicknesses L1 and L2 due to an error of work.

The method for using the shear stud 200 as the shear reinforcement device, however, still encounters a problem.

The method for using the shear band 300 as the shear reinforcement device, however, still encounters a problem in that in case of applying the sheet, there occurs an interference between the sheet and the placement of the upper and lower reinforcing bars, making the construction difficult, and in that in case of the sheet, the shear band 300 blocks concrete at the time of pouring of concrete for the slab, thus resulting in defective filling of concrete.

In particular, in case of the shear band 300 to which the sheet is applied, there is caused a problem in that the shear band 300 isolates concrete being poured, and thus the strength of the joints between slabs and columns is rather weakened due to isolation of concrete.

In addition, the method for using the shear band 300 as the shear reinforcement device still involves a drawback in that it has the same problems as those occurring in the above-mentioned stirrup 100 and shear stud 200, as well as the shear band 300 is widened transversely at the upper and lower sides thereof and upon the expansion of the stress as shown in FIG. 2(c).

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