Ingot milling type steel fiber self-supporting truss composite slab and construction method thereof

Abstract

The steel ingot milling type steel fiber self-supporting truss composite slab and construction method thereof relate to the field of building. The steel ingot milling type steel fiber self-supporting truss composite slab comprises a prefabricated concrete layer, a cast-in-situ concrete layer and a truss steel bar, the bottom steel bar of the truss steel bar is embedded in the prefabricated concrete layer, and the top steel bar of the truss steel bar is embedded in the cast-in-situ concrete layer; at least one of the prefabricated concrete layer and the cast-in-situ concrete layer is embedded with a steel ingot milling type steel fiber; and each end of the steel ingot milling type steel fiber is provided with an anchoring end. The steel ingot milling type steel fiber added in the composite slab can effectively improve the crack resistance, tensile resistance and shear resistance of the concrete, so that the bottom steel bar of the truss steel bar does not extend out of the prefabricated concrete layer, thereby avoiding the problem of collision between the extended steel bar and the beam steel bar during installation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building, in particular to a laminated slab. BACKGROUND

[0002] With the continuous development of the construction industry, prefabricated buildings have been more and more widely used in China, and prefabricated laminated slab is the most widely used prefabricated component in prefabricated buildings.

[0003] The bottom steel bars of the existing prefabricated laminated slab are often extended outside the prefabricated concrete layer, thereby increasing the structural strength of the connection and reducing the cracking of the prefabricated concrete layer or the cast-in-place concrete layer. However, during installation, the extended steel bars are prone to collision with beam steel bars. SUMMARY

[0004] The present application aims to provide a steel ingot milling type steel fiber self-supporting truss laminated slab to solve the above technical problems.

[0005] The present application also aims to provide a construction method of the steel ingot milling type steel fiber self-supporting truss laminated slab.

[0006] The technical problems solved by the present application can be realized by the following technical solutions:

[0007] The steel ingot milling type steel fiber self-supporting truss laminated slab comprises a prefabricated concrete layer at the bottom and a cast-in-place concrete layer at the top.

[0008] It also comprises a truss steel bar, the bottom steel bar of which is embedded in the prefabricated concrete layer, and the top steel bar of which is embedded in the cast-in-place concrete layer.

[0009] At least one of the prefabricated concrete layer and the cast-in-place concrete layer is embedded with a steel ingot milling type steel fiber.

[0010] Both ends of the steel ingot milling type steel fiber are provided with an anchoring end.

[0011] The laminated slab of the present application is additionally provided with a steel ingot milling type steel fiber, which can effectively improve the crack resistance, tensile resistance and shear resistance of the concrete, thereby allowing the bottom steel bar of the truss steel bar of the present application not to extend from the prefabricated concrete layer, and further avoiding the problem of collision between the extended steel bar and the beam steel bar during installation.

[0012] Preferably, the steel ingot milling type steel fiber is embedded in the prefabricated concrete layer; the thickness of the prefabricated concrete layer is less than one fourth of the total thickness of the prefabricated concrete layer and the cast-in-place concrete layer. The steel ingot milling type steel fiber is embedded in the prefabricated concrete layer, so that the crack resistance, tensile resistance and shear resistance of the prefabricated concrete layer are improved, thereby allowing the thickness of the prefabricated concrete layer to be reduced and the thickness of the cast-in-place concrete layer to be increased, and further allowing the pipeline to be conveniently embedded in the cast-in-place concrete layer.

[0013] The construction method of the steel ingot milling type steel fiber self-supporting truss composite slab is characterized in that the prefabricated concrete layer and the truss steel bar are prefabricated and formed into a prefabricated composite slab in a prefabrication factory, then the prefabricated composite slab is transported to a construction site, and cast-in-place concrete is cast on the prefabricated concrete layer to form a cast-in-place concrete layer, and the part of the truss steel bar exposed above the prefabricated concrete layer is embedded into the cast-in-place concrete layer when the cast-in-place concrete is cast. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Part of the structure of the present application is shown in the accompanying drawings. DETAILED DESCRIPTION

[0015] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application will be further described in conjunction with specific drawings.

[0016] REFERENCE Figure 1 The steel ingot milling type steel fiber self-supporting truss composite slab comprises a prefabricated concrete layer 1, a cast-in-place concrete layer 2, a truss steel bar 3, a steel ingot milling type steel fiber, etc.

[0017] The construction method of the steel ingot milling type steel fiber self-supporting truss composite slab is that the prefabricated concrete layer 1 and the truss steel bar 3 are prefabricated and formed into a prefabricated composite slab in a prefabrication factory, then the prefabricated composite slab is transported to a construction site, and cast-in-place concrete is cast on the prefabricated concrete layer 1 to form a cast-in-place concrete layer 2, and the part of the truss steel bar 3 exposed above the prefabricated concrete layer 1 is embedded into the cast-in-place concrete layer 2 when the cast-in-place concrete is cast.

[0018] The truss steel bars 3 include bottom steel bars at the bottom, top steel bars at the top, and side wall steel bars connecting the top steel bars and the bottom steel bars. The side wall steel bars are preferably corrugated, with the peaks of the corrugations connected to the top steel bars and the valleys of the corrugations connected to the bottom steel bars. There are preferably two side wall steel bars connected to the same top steel bar, with the two side wall steel bars forming an angle of preferably 30 to 70 degrees. The number of bottom steel bars is preferably equal to the number of side wall steel bars. The ends of the bottom steel bars are not exposed outside the prefabricated concrete layer 1. This avoids collision between the exposed bottom steel bars and the beam steel bars during installation.

[0019] The prefabricated concrete layer 1 can also be embedded with a first steel bar mesh formed by the first steel bars 5 and the second steel bars 4. The first steel bars are below the bottom steel bars and are perpendicular to the bottom steel bars. The bottom steel bars and the first steel bars are connected at the interface. The connection can be welding, steel bar binding, etc. The second steel bars 4 are above the first steel bars 5 and are parallel to the bottom steel bars. There are preferably at least one second steel bar between two adjacent truss steel bars 3, and preferably only one second steel bar. The first steel bars and the second steel bars are preferably deformed steel bars. This increases the contact area between the first steel bar mesh and the concrete.

[0020] The cast-in-place concrete layer 2 can also be embedded with a second steel bar mesh formed by the third steel bars 6 and the fourth steel bars 7. The third steel bars 6 are above the top steel bars and are perpendicular to the top steel bars. The top steel bars and the third steel bars 6 are connected at the interface. The connection can be welding, steel bar binding, etc. The fourth steel bars 7 are above the third steel bars and are parallel to the top steel bars. There are preferably at least one fourth steel bar between two adjacent truss steel bars 3, and preferably two fourth steel bars. The third steel bars and the first steel bars are preferably not directly opposite, and the fourth steel bars and the third steel bars are preferably not directly opposite. This improves the bonding strength between the cast-in-place concrete layer 2 and the prefabricated concrete layer 1, and improves the overall crack resistance, tensile resistance and shear resistance. The third steel bars and the fourth steel bars are preferably deformed steel bars. This increases the contact area between the second steel bar mesh and the concrete.

[0021] At least one of the prefabricated concrete layer 1 and the cast-in-place concrete layer 2 is embedded with steel ingot milling steel fibers. The two ends of the steel ingot milling steel fiber are respectively provided with an anchoring end. In scheme 1, the length of the steel ingot milling steel fiber in the prefabricated concrete layer 1 is greater than the distance between the second steel bar and the bottom steel bar. The length of the steel ingot milling steel fiber in the cast-in-place concrete layer 2 is greater than the greater one of the distance between the fourth steel bar and the top steel bar and the distance between the adjacent two fourth steel bars. The size of the steel ingot milling steel fiber is limited in the present application, so that the steel ingot milling steel fiber can be more stably present in the cast-in-place concrete layer 2 or the prefabricated concrete layer 1, thereby improving the crack resistance, tensile resistance and shear resistance of the concrete layer in which the steel ingot milling steel fiber is located. The steel ingot milling steel fiber is preferably radially twisted by more than 20 degrees. Thus, the contact surface with the concrete is changed, and the connection firmness with the concrete is improved. The two side edges of the steel ingot milling steel fiber are respectively provided with side wings, and the extension directions of the side wings are preferably different. The width of the anchoring end is preferably greater than the width of other parts of the steel ingot milling steel fiber. Alternatively, the anchoring end is connected to the steel ingot milling steel fiber through a neck portion with a smaller width. Alternatively, the end of the steel ingot milling steel fiber is outwardly protruded to form the anchoring end. Alternatively, the end of the steel ingot milling steel fiber is inwardly turned to form the anchoring end. Thus, the area of the anchoring end is increased. A recess is preferably provided on the anchoring end, which is beneficial to improve the contact effect of the steel ingot milling steel fiber with the concrete and improve the connection firmness with the concrete. In scheme 2, the length of the steel ingot milling steel fiber is 32 mm, and the width is 2.6 mm. The steel ingot milling steel fiber is preferably in a strip shape, one surface of the steel ingot milling steel fiber is a smooth surface, and the other surface is a rough surface, thereby improving the connection firmness with the concrete. A through hole can also be provided on the steel ingot milling steel fiber. Thus, the through hole is used to increase the connection firmness with the concrete.

[0022] Preferably, the prefabricated concrete layer 1 is embedded with the steel ingot milling steel fiber; the thickness of the prefabricated concrete layer 1 is less than one fourth of the total thickness of the prefabricated concrete layer 1 and the cast-in-place concrete layer 2. The steel ingot milling steel fiber is embedded in the prefabricated concrete layer 1 in the present application, so that the crack resistance, tensile resistance and shear resistance of the prefabricated concrete layer 1 are improved, thereby allowing the thickness of the prefabricated concrete layer 1 to be reduced and the thickness of the cast-in-place concrete layer 2 to be increased, and further allowing the pipeline to be conveniently embedded in the cast-in-place concrete layer 2.

[0023] Preferably, a magnet ring in a ring shape is sleeved on the second steel bar or the fourth steel bar. The ingot-milled steel fiber is preferably made of alloy steel. The magnet ring has a magnetic attraction to the ingot-milled steel fiber, which can effectively improve the arrangement of the ingot-milled steel fiber in the prefabricated concrete layer 1. There are multiple magnet rings, and the magnet rings are preferably arranged at equal intervals. The magnet ring is preferably a magnet ring with a notch. Thus, the notch is clamped on the second steel bar or the fourth steel bar. Further preferably, the second steel bar or the fourth steel bar is provided with a concave portion at equal intervals. The width of the concave portion is smaller than the width of the notch of the magnet ring. Thus, during use, the magnet ring is first clamped on the second steel bar or the fourth steel bar by the concave portion, and then the magnet ring is screwed to the portion without the concave portion along the steel bar, so as to fix the magnet ring.

[0024] The prefabricated concrete layer 1 is free of steel wire mesh due to the addition of the ingot-milled steel fiber. The bottom steel bar, the first steel bar, and the second steel bar do not protrude from the prefabricated concrete layer 1 due to good crack resistance, tensile resistance, and shear resistance. The top steel bar, the third steel bar, and the fourth steel bar do not protrude from the cast-in-place concrete layer 2.

[0025] The concrete used to form the prefabricated concrete layer 1 and the cast-in-place concrete layer 2 is preferably steel fiber concrete. The steel fiber concrete is preferably concrete added with ingot-milled steel fiber. The method of adding ingot-milled steel fiber to the concrete is as follows: Method 1: The ingot-milled steel fiber is added during dry mixing, for example, poured into an aggregate conveying belt and conveyed to a mixer together with stones, or directly poured into the mixer. Method 2: The ingot-milled steel fiber is added during wet mixing and directly poured into the mixer. The dosage of the ingot-milled steel fiber is preferably 30 kg / m 3 .

[0026] The steel fiber concrete can be stirred by a forced mixer or rapidly rotated and stirred on site by a concrete mixing and transporting vehicle. The stirring time of the forced mixer is preferably 10 s to 30 s longer than that of ordinary concrete, and should be determined through on-site stirring tests.

[0027] The preparation method of the prefabricated composite slab comprises the following steps: step 1, the bottom steel bars of the truss steel bars 3 are fixedly connected to the first steel mesh, and then the truss steel bars 3 and the first steel mesh are placed in a mold; step 2, steel fiber concrete is poured into the mold; step 3, a flat plate is placed above the steel fiber concrete, and the steel fiber concrete is tamped by using a flat plate vibrator; step 4, after the steel fiber concrete is semi-dry, the flat plate is removed, and the steel fiber concrete is maintained until the steel fiber concrete is dry; and step 5, the mold is removed. The flat plate is used for vibration, compared with manual insertion and tamping, damage to the dispersion uniformity of the steel ingot milling type steel fiber in the steel fiber concrete can be effectively avoided. After the steel fiber concrete is semi-dry, the flat plate is removed, the flat plate and the mold can be used to slow down the loss rate of water in the steel fiber concrete, and cracking of the prefabricated composite slab can be avoided.

[0028] In step 1, a magnet ring in a ring shape can be sleeved on the second steel bar. The magnet ring plays a role of adsorbing the steel ingot milling type steel fiber. Under the adsorption of the magnet ring, the steel ingot milling type steel fiber near the magnet ring rotates in the direction of the magnet ring, so that the steel ingot milling type steel fiber is arranged in order, and the combination degree of the steel ingot milling type steel fiber and the concrete is improved.

[0029] The fourth steel bar is located at a higher position, and when the steel fiber concrete is cast on the upper side of the prefabricated concrete layer 1, the magnet ring on the fourth steel bar will affect the arrangement of the steel ingot milling type steel fiber during the pouring of the steel fiber concrete, and the steel ingot milling type steel fiber at the junction of the prefabricated concrete layer 1 and the cast-in-place steel fiber concrete layer is likely to be too few, which causes the junction to be prone to cracking. However, the situation can be changed by the following method:

[0030] The preparation method of the cast-in-place concrete layer 2 comprises the following steps: step 1, fixing and connecting the top steel bars of the truss steel bars 3 to the second steel mesh; step 2, pouring the steel fiber concrete on the prefabricated concrete layer 1 to form a first layer of steel fiber concrete layer; step 3, sleeving the magnet ring on the fourth steel bar; step 4, pouring the steel fiber concrete on the first layer of steel fiber concrete layer to form a second layer of steel fiber concrete layer; and step 5, placing a flat plate above the second layer of steel fiber concrete layer and tamping the steel fiber concrete by using the flat plate vibrator. The first layer of steel fiber concrete layer is not vibrated, so that the overall weight of the formed concrete composite slab is reduced. After the filling of the first layer of steel fiber concrete layer is completed, the magnet ring is placed, the magnet ring attracts the steel ingot milling type steel fiber on the surface of the first layer of steel fiber concrete layer, so that the steel ingot milling type steel fiber partially enters into the second layer of steel fiber concrete, and the direction of the steel ingot milling type steel fiber in the second layer of steel fiber concrete is guided. The method can effectively avoid the problem that the steel ingot milling type steel fiber is too few at the joint of the prefabricated concrete layer 1 and the cast-in-place steel fiber concrete layer, so that the joint is easy to crack. The magnet rings on the second steel bar and the fourth steel bar can attract each other, so that the bonding strength of the prefabricated concrete layer 1 and the cast-in-place steel fiber concrete layer is enhanced.

[0031] The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A construction method of a steel ingot milled profile steel fiber self-supporting truss composite slab, characterized by, The prefabricated concrete layer and the truss steel bar are prefabricated into a prefabricated composite slab in a prefabricating factory, and a first steel bar mesh is also embedded in the prefabricated concrete layer, wherein the first steel bar mesh is formed by interlaced connection of first steel bars and second steel bars, and a magnet ring in a ring shape is sleeved on the second steel bars; Then, the prefabricated composite slab is transported to a construction site, and cast-in-place concrete is cast on the prefabricated concrete layer to form a cast-in-place concrete layer, wherein a second steel bar mesh is embedded in the cast-in-place concrete layer, and the second steel bar mesh is formed by interlaced connection of third steel bars and fourth steel bars; The preparation method of the cast-in-place concrete layer comprises the following steps: step 1, the top steel bar of the truss steel bar is fixedly connected to the second steel bar mesh; step 2, steel fiber concrete is cast on the prefabricated concrete layer to form a first layer of steel fiber concrete layer; step 3, the magnet ring is sleeved on the fourth steel bar; step 4, steel fiber concrete is cast on the first layer of steel fiber concrete layer to form a second layer of steel fiber concrete layer; and step 5, a flat plate is placed above the second layer of steel fiber concrete layer, and the steel fiber concrete is tamped by using a flat plate vibrator. The concrete used for forming the prefabricated concrete layer and the concrete used for forming the cast-in-place concrete layer are both concrete added with steel ingot milling steel fibers, and the steel ingot milling steel fibers are made of alloy steel.

2. The construction method of steel ingot milled fiber self-supporting truss composite slab according to claim 1, characterized in that: The preparation method of the prefabricated composite slab comprises the following steps: step 1, the bottom steel bar of the truss steel bar is fixedly connected to the first steel bar mesh, and then the truss steel bar and the first steel bar mesh are placed in a mold; step 2, steel fiber concrete is cast into the mold; step 3, a flat plate is placed above the steel fiber concrete, and the steel fiber concrete is tamped by using a flat plate vibrator; step 4, after the steel fiber concrete is semi-dried, the flat plate is removed, and the steel fiber concrete is maintained until the steel fiber concrete is completely dried; and step 5, the mold is removed.

3. The steel ingot milled steel fiber self-supporting truss composite slab obtained by the construction method of claim 1 or 2, characterized by, The prefabricated composite slab comprises a prefabricated concrete layer located below and a cast-in-place concrete layer located above; The prefabricated composite slab further comprises a truss steel bar, wherein the bottom steel bar of the truss steel bar is embedded in the prefabricated concrete layer, and the top steel bar of the truss steel bar is embedded in the cast-in-place concrete layer; Each end of the steel ingot milling steel fiber is provided with an anchoring end. The prefabricated concrete layer further comprises a first steel bar mesh, wherein the first steel bar mesh is formed by interlaced connection of first steel bars and second steel bars, the first steel bars are located below the bottom steel bars and are perpendicular to the bottom steel bars, and the bottom steel bars and the first steel bars are connected together at the junctions; the second steel bars are located above the first steel bars and are parallel to the bottom steel bars, and the ends of the bottom steel bars, the first steel bars and the second steel bars do not protrude from the prefabricated concrete layer; The cast-in-place concrete layer further comprises a second steel bar mesh, wherein the second steel bar mesh is formed by interlaced connection of third steel bars and fourth steel bars, the third steel bars are located above the top steel bars and are perpendicular to the top steel bars, and the top steel bars and the third steel bars are connected together at the junctions; the fourth steel bars are located above the third steel bars and are parallel to the top steel bars, and the ends of the top steel bars, the third steel bars and the fourth steel bars do not protrude from the cast-in-place concrete layer; The second steel bar and the fourth steel bar are sleeved with annular magnet rings, and the ingot-milled steel fiber is made of alloy steel.

4. The steel ingot milled profile steel fiber self- supporting truss composite slab according to claim 3, characterized in that, The thickness of the prefabricated concrete layer is less than one fourth of the total thickness of the prefabricated concrete layer and the cast-in-situ concrete layer.

5. The steel ingot milled profile steel fiber self- supporting truss composite slab as claimed in claim 3, wherein, The truss steel bar further comprises a side wall steel bar connecting the bottom steel bar and the top steel bar, the side wall steel bar is corrugated, the crest of the side wall steel bar is connected to the top steel bar, and the trough of the side wall steel bar is connected to the bottom steel bar. The side wall steel bars connected to the same top steel bar are two, and the two side wall steel bars form an included angle, and the included angle is 30 to 70 degrees. The end of the bottom steel bar is not exposed outside the prefabricated concrete layer.

6. The steel ingot milled profile steel fiber self- supporting truss composite slab as claimed in claim 3, wherein, The ingot-milled steel fiber is radially twisted by more than 20 degrees, and the ingot-milled steel fiber is provided with a side wing at each side edge.

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