A reinforcement device for prefabricated concrete square columns

Abstract

The present invention discloses a reinforcement device for a prefabricated concrete square column. Tensile bases are fixedly provided at both the top and bottom sides of the concrete square column. More than two fixed bases are arranged between the two tensile bases. The tensile bases and the fixed bases are longitudinally provided with first steel bar holes for prestressed steel bars to pass through. Prestressed nuts are threadedly connected to both ends of the prestressed steel bars. The tensile bases and the fixed bases are also transversely provided with second steel bar holes for threaded steel bars to pass through. Fastening nuts are threadedly connected to both ends of the threaded steel bars. A square pipe is sleeved outside the concrete square column. L-shaped steel plates are arranged at the four corners inside the square pipe, and both the L-shaped steel plates and the square pipe are fixedly connected to the threaded steel bars. The present invention adopts a splicing structure, without the need to equip large-scale machinery on site, is convenient for construction, can shorten the construction period. At the same time, the prestressed steel bars fixed around the concrete square column can comprehensively improve the horizontal stiffness, flexural bearing capacity and crack resistance of the concrete column.

Description

Technical Field

[0001] The present invention relates to the technical field of reinforced concrete structure strengthening, and more specifically, to a strengthening device for precast concrete square columns. Background Art

[0002] Since 1978 in China, the construction of infrastructure has experienced rapid development for decades. With the continuous increase in the number of infrastructure projects, the demand for maintenance, strengthening, and repair of the huge infrastructure scale has also been increasing.

[0003] The existing strengthening methods for concrete flexural members (columns) mainly include cast-in-place concrete to increase the column cross-section, external steel plate or fiber-reinforced polymer (FRP) confinement, etc. The more advanced strengthening method is to reserve a cutting groove on the surface of the concrete column, and then fix the precast concrete formwork on the surface of the concrete column through structural adhesives. However, these methods all have certain disadvantages. For example, the method of cast-in-place concrete to increase the column cross-section requires complex formwork engineering and large casting equipment, and the construction period is long, and the quality of casting is difficult to control; the external steel plate faces the problem of steel plate corrosion; the external FRP confinement has a very limited improvement in the flexural capacity of the concrete column; while the fixing methods such as external precast concrete slabs are simple in construction, but the improvement in the horizontal stiffness, flexural bearing capacity, crack resistance performance, etc. of the concrete column during an earthquake is not obvious. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that it is inconvenient to cast concrete on-site for strengthening concrete columns, and the seismic performance of the concrete columns after strengthening is improved limitedly. In order to overcome the defects of the prior art, the present invention proposes a strengthening device for precast concrete square columns, which adopts a splicing structure, does not require large-scale machinery on-site, is convenient for construction, can shorten the construction period, and at the same time, the prestressed steel bars fixed around the concrete square column can comprehensively improve the horizontal stiffness, flexural bearing capacity, and crack resistance performance of the concrete column.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a reinforcement device for an assembled concrete square column, which includes a tensile base, a fixed base, prestressed steel bars, prestressed nuts, threaded steel bars, fastening nuts, L-shaped steel plates and square tubes. Tensile bases are fixedly provided at the top and bottom sides of the concrete square column. More than two fixed bases are arranged between the two tensile bases, and the fixed bases are fixedly connected to the concrete square column. The tensile base and the fixed base are longitudinally provided with first steel holes for the prestressed steel bars to pass through. Prestressed nuts are threadedly connected to both ends of the prestressed steel bars. The tensile base and the fixed base are also horizontally provided with second steel holes for the threaded steel bars to pass through. Fastening nuts are threadedly connected to both ends of the threaded steel bars. The square tube is sleeved outside the concrete square column. L-shaped steel plates are arranged at the four corners inside the square tube, and the L-shaped steel plates and the square tube are fixedly connected to the threaded steel bars.

[0007] In a preferred technical solution of the present invention, the L-shaped steel plates and the square tubes are both provided with installation holes for the threaded steel bars to pass through.

[0008] In a preferred technical solution of the present invention, the square tube is composed of more than two reinforcement plates spliced end to end.

[0009] In a preferred technical solution of the present invention, tensile stress seats are detachably installed at both ends of the tensile base.

[0010] In a preferred technical solution of the present invention, the fixed base includes an inner fixed block, an outer fixed block, prestressed bolts and a mounting plate. The inner fixed block and the outer fixed block are fixedly connected by prestressed bolts. Semi-circular grooves are vertically provided on the sides of the inner fixed block and the outer fixed block close to each other, and two adjacent semi-circular grooves can be spliced to form the first steel hole. A mounting plate is vertically fixedly provided on one side of the outer fixed block, and the second steel hole is located on the mounting plate.

[0011] In a preferred technical solution of the present invention, the concrete square column is provided with rebar planting holes, and one end of the prestressed bolt is fixedly arranged in the rebar planting holes through planting glue.

[0012] The beneficial effects of the present invention are as follows:

[0013] The reinforcement device for an assembled concrete square column proposed by the present invention adopts a spliced structure, without the need to equip large-scale machinery on site, is convenient for construction, can shorten the construction period, and at the same time, the prestressed steel bars fixed around the concrete square column can comprehensively improve the horizontal stiffness, flexural bearing capacity and crack resistance of the concrete column. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a reinforcement device for an assembled concrete square column provided by a specific embodiment of the present invention;

[0015] Figure 2 is Figure 1 the top view of;

[0016] Figure 3 is Figure 1 the structural schematic diagram of the fixed base in;

[0017] Figure 4 the structural schematic diagram of the installation of prestressed steel bars.

[0018] In the figure:

[0019] 1. Concrete square column; 2. Tensile base; 3. Fixed base; 31. Inner fixed block; 32. Outer fixed block; 33. Prestressed bolt; 34. Semi-circular groove; 35. Installation plate; 4. First steel bar hole; 5. Prestressed steel bar; 6. Prestressed nut; 7. Second steel bar hole; 8. Threaded steel bar; 9. Fastening nut; 10. L-shaped steel plate; 11. Square pipe; 111. Reinforcement plate; 12. Installation hole; 13. Tensile stress seat; 14. Drilled hole for planting steel bars. Specific implementation manners

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation manners.

[0021] Such as Figures 1-4As shown in the figure, in the embodiment, a reinforcement device for an assembled concrete square column is provided, including a tensile base 2, a fixed base 3, a prestressed steel bar 5, a prestressed nut 6, a threaded steel bar 8, a fastening nut 9, an L-shaped steel plate 10 and a square tube 11. Tensile bases 2 are fixedly arranged at the top and bottom sides of the concrete square column 1. More than two fixed bases 3 are arranged between the two tensile bases 2, and the fixed bases 3 are fixedly connected with the concrete square column 1. Both the tensile base 2 and the fixed base 3 are longitudinally provided with first steel holes 4 for the prestressed steel bar 5 to pass through. Prestressed nuts 6 are threadedly connected to both ends of the prestressed steel bar 5. Second steel holes 7 for the threaded steel bar 8 to pass through are also horizontally provided on the tensile base 2 and the fixed base 3. Fastening nuts 9 are threadedly connected to both ends of the threaded steel bar 8. The square tube 11 is sleeved outside the concrete square column 1. L-shaped steel plates 10 are arranged at the four corners inside the square tube 11, and both the L-shaped steel plates 10 and the square tube 11 are fixedly connected with the threaded steel bar 8. In this embodiment, more than two tensile bases 2 and fixed bases 3 are evenly and fixedly arranged on the side wall of the concrete square column 1 from top to bottom, and both the tensile base 2 and the fixed base 3 are horizontally arranged to support the square tube 11. The tensile base 2 and the fixed base 3 can be made of low-alloy structural steel or ordinary carbon structural steel. Among them, during installation, an adhesive is pre-coated on the sides of the tensile base 2 and the fixed base 3 and the side of the concrete square column 1, and then they can be attached to the side wall of the concrete square column 1 for fixation. The adhesive is one of an organic adhesive or an inorganic adhesive. The organic adhesive is preferably resin, and the inorganic adhesive is preferably an inorganic adhesive mainly composed of borax and magnesium sulfate. The prestressed steel bar 5 is preferably a precision rolled threaded steel bar, and the prestressed nut 6 is preferably a precision rolled threaded steel nut. And the two prestressed nuts 6 can respectively abut against the end faces of the two tensile bases 2, so as to fix the prestressed steel bar 5 on the concrete square column 1. The fastening nut 9 is preferably made of stainless steel 201, and the threaded steel bar 8 is preferably a hot-rolled ribbed steel bar. Two fastening nuts 9 are threadedly connected to both ends of each threaded steel bar 8, and the two fastening nuts 9 are respectively located inside and outside the square tube 11. Since the L-shaped steel plate 10 is located between one of the fastening nuts 9 and the inner wall of the square tube 11, the two fastening nuts 9 can fix the L-shaped steel plate 10 and the square tube 11 to the threaded steel bar 8. During installation, the construction personnel use an electric fixed-torque nut gun to tighten the prestressed nut 6 and the fastening nut 9, and the prestressed steel bar 5 and the threaded steel bar 8 can generate prestress. The material of the L-shaped steel plate 10 is hot-rolled thick steel plate. The square tube 11 is sleeved on the concrete square column 1 to protect the concrete square column 1 and help improve the horizontal stiffness, flexural bearing capacity, crack resistance, etc. of the concrete column during an earthquake, and extend the service life.

[0022] Specifically, mounting holes 12 through which the threaded steel bars 8 can pass are provided on both the L-shaped steel plate 10 and the square pipe 11. In this embodiment, two mounting holes 12 with perpendicular and offset central axes are provided on the L-shaped steel plate 10, so that the threaded steel bars 8 on two adjacent side surfaces of the concrete square column 1 do not interfere with each other.

[0023] Specifically, the square pipe 11 is composed of more than two reinforcing plates 111 spliced end to end. In this embodiment, the adjacent reinforcing plates 111 are fixedly connected by an adhesive. The reinforcing plate 111 is an FRP strip, and the material of the FRP strip is made of one or a combination of carbon fiber, glass fiber, aramid fiber, basalt fiber, polyethylene terephthalate synthetic fiber, and polyethylene naphthalate synthetic fiber.

[0024] Specifically, tension force seats 13 are detachably installed at both ends of the tension base 2. In this embodiment, the tension force seats 13 are detachably installed on the tension base 2, so that it is not necessary to cut the tension base 2, reducing the construction difficulty. The jack is preferably a screw jack. The tension force seats 13 are equipped with tensile steel bars, and the gripper of the jack can clamp the tensile steel bars and pull them downward, so as to be able to pull the tension base 2 to move, and then drive the prestressed steel bars 5 to stretch and deform synchronously and generate prestress, so as to improve the flexural strength of the concrete square column 1.

[0025] Specifically, the fixed base 3 includes an inner fixed block 31, an outer fixed block 32, a prestressed bolt 33, and a mounting plate 35. The inner fixed block 31 and the outer fixed block 32 are fixedly connected by the prestressed bolt 33. Semi-circular grooves 34 are vertically provided on the sides of the inner fixed block 31 and the outer fixed block 32 close to each other, and two adjacent semi-circular grooves 34 can be spliced to form the first steel bar hole 4. A mounting plate 35 is vertically fixed on one side of the outer fixed block 32, and the second steel bar hole 7 is located on the mounting plate 35. In this embodiment, the diameter of the prestressed steel bar 5 should be slightly larger than the diameter of the first steel bar hole 4, so that the inner fixed block 31 and the outer fixed block 32 can clamp and fix the prestressed steel bar 5 and generate compressive stress on it to prevent the prestressed steel bar 5 from returning to its original length. A fixing nut is threadedly connected to the prestressed bolt 33, and by screwing the fixing nut, the inner fixed block 31 and the outer fixed block 32 can be closely fitted. The outer fixed block 32 and the mounting plate 35 are integrally formed, and the mechanical properties are better. In addition, fixing holes are provided on both the tension base 2 and the fixed base 3, and the prestressed bolt 33 can pass through the fixing holes and fix the tension base 2 and the fixed base 3 on the side wall of the concrete square column 1.

[0026] Specifically, planting holes 14 are provided on the concrete square column 1, and one end of the prestressed bolt 33 is fixedly arranged in the planting hole 14 through planting glue. In this embodiment, multiple rows of planting holes 14 are provided on the side wall of the concrete square column 1. The component of the planting glue is epoxy resin.

[0027] The present invention also provides a reinforcement method for a reinforcement device of a prefabricated concrete square column, comprising the following steps:

[0028] S1. Grind and clean the surface of the concrete 1 to be reinforced;

[0029] S2. Drill rebar planting holes 14 on the side wall of the concrete square column 1, then use an adhesive to fixedly bond four tension bases 2 to the upper end of the side wall of the concrete square column 1, bond two or more fixing bases 3 to the middle part of the side wall of the concrete square column 1, insert a prestressed bolt 33 into the fixing holes on the tension base 2 and the fixing base 3, and then use a rebar planting adhesive to fix the prestressed bolt 33 on the tension base 2 in the rebar planting hole 14, thereby realizing the fixation of the tension base 2 to the upper end of the side wall of the concrete square column 1;

[0030] S3. Arrange the four tension bases 2 on the lower end of the side wall of the concrete square column 1 in an attached but non-bonded manner, then insert the prestressed steel bars 5 into the first rebar holes 4 on the tension base 2 and the fixing base 3, and use an electric fixed-torque nut gun to tighten the prestressed steel bars 5 and the prestressed nuts 6, wherein the position of the fixing holes on the lower tension base 2 should be slightly higher than the lowermost rebar planting hole 14;

[0031] S4. Sleeve the two ends of the lower tension base 2 with tension stress-bearing seats 13, then clamp the tensile steel bars on the tension stress-bearing seats 13 with a screw jack biter, thereby driving the prestressed steel bars 5 to stretch downward, causing the prestressed steel bars 5 to generate tensile stress, and when the fixing holes on the lower tension base 2 are aligned with the rebar planting holes 14, insert and fix all the remaining prestressed bolts 33 in the rebar planting holes 14, thereby fixing the fixing base 3 and the lower tension base 2 on the side wall of the concrete square column 1, and finally remove the tension stress-bearing seats 13;

[0032] S5. Pass the threaded steel bars 8 through the second rebar holes 7 and the mounting holes 12, and each set a fastening nut 9 on the side of the L-shaped steel plate 10 and the reinforcement plate 111 away from each other, then use an electric fixed-torque nut gun to tighten the fastening nut 9 and the threaded steel bar 8, thereby fixing the L-shaped steel plate 10 and the reinforcement plate 111 around the concrete square column 1, and causing the threaded steel bars 8 to generate compressive stress, thereby applying prestress to the concrete square column 1.

[0033] The present invention is described by way of preferred embodiments. Those skilled in the art will know that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. The present invention is not limited by the specific embodiments disclosed herein, and other embodiments falling within the scope of the claims of this application belong to the scope of protection of the present invention.

Claims

1. A reinforcement device for an assembled concrete square column, characterized in that: It includes a stretching base (2), a fixed base (3), prestressed steel bars (5), prestressed nuts (6), threaded steel bars (8), fastening nuts (9), L-shaped steel plates (10) and square tubes (11). The stretching bases (2) are fixedly arranged at the top and bottom sides of the concrete square column (1). More than two fixed bases (3) are arranged between the two stretching bases (2), and the fixed bases (3) are fixedly connected to the concrete square column (1). Both the stretching base (2) and the fixed base (3) are longitudinally provided with first steel holes (4) for the prestressed steel bars (5) to pass through. Prestressed nuts (6) are threadedly connected to both ends of the prestressed steel bars (5). The stretching base (2) and the fixed base (3) are also horizontally provided with second steel holes (7) for the threaded steel bars (8) to pass through. Fastening nuts (9) are threadedly connected to both ends of the threaded steel bars (8). The square tube (11) is sleeved outside the concrete square column (1). L-shaped steel plates (10) are arranged at the four corners inside the square tube (11), and both the L-shaped steel plates (10) and the square tube (11) are fixedly connected to the threaded steel bars (8); the fixed base (3) includes an inner fixed block (31), an outer fixed block (32), prestressed bolts (33) and a mounting plate (35). The inner fixed block (31) and the outer fixed block (32) are fixedly connected by the prestressed bolts (33). Semi-circular grooves (34) are vertically opened on the sides of the inner fixed block (31) and the outer fixed block (32) close to each other, and two adjacent semi-circular grooves (34) can be spliced to form the first steel hole (4). A mounting plate (35) is perpendicularly fixedly arranged on one side of the outer fixed block (32), and the second steel hole (7) is located on the mounting plate (35); a rebar planting hole (14) is opened on the concrete square column (1), and one end of the prestressed bolt (33) is fixedly arranged in the rebar planting hole (14) through planting glue.

2. The reinforcement device for an assembled concrete square column according to claim 1, characterized in that: Mounting holes (12) for the threaded steel bars (8) to pass through are opened on both the L-shaped steel plates (10) and the square tubes (11).

3. The reinforcement device for an assembled concrete square column according to claim 2, characterized in that: The square tube (11) is composed of more than two reinforcing plates (111) spliced end to end.

4. The reinforcement device for an assembled concrete square column according to claim 1, characterized in that: Stretching force seats (13) are detachably installed at both ends of the stretching base (2).

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