KR20100055759A - Manufacturing method of floor slab made of reversed triangular wire truss with thin steel plate rib deck concrete form - Google Patents

Abstract

PURPOSE: A method for manufacturing a floor slab of a reversed triangular wire truss and a thin steel plate deck is provided to prevent lateral buckling, and to improve the bearing strength of a structure. CONSTITUTION: A method for manufacturing a floor slab of a reversed triangular wire truss and a thin steel plate deck is as follows. Two upper chord member(3) and a lower chord member form a v-shape. A reversed triangular wire truss is manufactured by welding two diagonal members(5) with the upper and lower chord members in left and right inclined surfaces. Wire tie bars(6) are welded with the upper chord members at a right angle.

Description

Manufacturing Method of Floor Slab Made of Reversed Triangular Wire Truss with Thin Steel Plate Rib Deck Concrete Form}

The main purpose of the construction is to obtain floor plates for various purposes, and beams, columns, and foundations supporting the floor plates are successively transferred to the designated foundations. In terms of the entire building, 40% of floor boards, 30% of beams, 20% of columns and 10% of foundations occupy about 10% of construction costs. As above, the specific gravity of the bottom plate is the largest, so if the bottom plate is excessive, the construction cost goes up by itself, but it also adversely affects the substructure in turn.

Reinforced concrete deck plate composition method uses permanent formwork or temporary formwork. In general, hypothetical formwork is labor-intensive and tends to turn into permanent formwork, but the development of new methods is expected due to the recent surge in raw materials.

The base plate is mainly concrete, except for the conventional reinforced concrete slab that uses the formwork and formwork. The thickness of the corrugated steel deck (Fig. 1), flat or triangular steel truss is increased by forming 1.2 ~ 3.2mm steel plate into the bone shape. Welding to a 0.5mm flat steel sheet at regular intervals can be divided into a truss deck (Fig. 2) to serve as a permanent formwork of concrete.

The gold deck is also divided into formwork and structural, which formally reinforces the reinforcing bars within the concrete section including the bones, so it is safe to damage or remove the gold deck after curing the concrete, and to reinforce the wire mesh only on the upper flat section except the bone. Silver must also serve as formwork and rebar, so it must be permanently maintained. However, the formwork gold deck is only a temporary name, and in fact there is no way to recover it has never been reused. Formwork gold decks, which are economically declining due to rising raw material prices, have disappeared, and structural gold decks have almost left their positions on truss decks.

On the other hand, if the focus is solely on the economics of the base plate itself, the above wins and loses, but if the precise calculation of the base, beams, pillars, and foundation costs, there is no difference between the heavy truss deck and the lightweight structural gold deck. However, users prefer truss decks because truss decks embedded in concrete are no different from reinforced concrete slabs that have been used for a long time. As a result, 10 domestic producers have almost given up on the production of gold decks and are producing and supplying only truss decks in bulk.

In the truss deck, the triangular steel truss has one upper chord (3), two lower chords (4), and two left and right, and the two left and right pairs of S-shaped repetitive yarns (5) are bent to the outside and welded with a 0.5 mm steel sheet (Fig. 2b). ) Is unreasonable in structure. The floor is designed to target the most uniform load and the second is doubled compared to the stress of the upper end (ωℓ ^2/12) stress in the lower center (ωℓ ^2/24). Therefore, to design the truss as a triangle, it is reasonable to have two upper chords and one lower chord. Therefore, the existing triangular steel truss uses a thick upper chord and the lower chord uses two thin steel chords. The truss deck should be safe under the weight and construction load of the steel truss not only after the completion of construction but also during the curing of concrete. The temporary column should be installed at the bottom due to excessive floor deflection.

On the other hand, since the truss deck is permanently attached to the bottom 0.5mm steel sheet for the formwork, there is a disadvantage that it is difficult to remove when melted by moisture in the basement. To this end, a plywood integrated deck (FIG. 3) has been developed to temporarily attach a plywood to the bottom of the steel wire truss and use it as a formwork and to remove and recycle the concrete after curing, but has not received much attention due to excessive labor costs.

When the bottom plate is lengthened when the same uniformly distributed overburden load (上載荷重) the length of the bending moment has a length proportional to the square and the deflection is proportional to the length of the fourth power (for ^{example: M = ωl 2/8,} δ = 5ωl 4/384 EI ). For example, the length of the bottom plate (l) 4m is only 1.33 times of 3m, but the bending moment ( M ) is 1.78 times, the deflection amount (δ) is 3.16 times. Therefore, in order to be satisfied with such a large value, the thickness of the bottom plate is usually increased, and consequently, a vicious cycle in which the bending moment and the deflection amount becomes larger by the increased weight. Therefore, in general, when the length of the bottom plate is more than 4m, the temporary column is installed at the bottom of the bottom plate during construction.

Reducing the weight of the bottom plate is the main task, but the gold deck is a representative example of the weight reduction, but the existing gold deck has a thickness of 1.2mm to 3.2mm, so it is not economical to use it alone for formwork or structural use. Meanwhile, the 0.5mm thick flat steel plate used for the truss deck lower plate serves only as a temporary temporary material to receive the weight and work load of concrete that is poured on the flat or triangular steel truss made of steel wire and put on it during construction. Phenomenon occurs and rust occurs because it is permanently exposed to the surface. In addition, since the domestic truss deck all three steel wire truss (Fig. 2) is placed on a 600mm wide flat steel sheet, there is a steel wire truss every 20cm. This is because the steel wire truss spacing cannot be spaced due to the strength of the hypothetical flat sheet steel that cannot be attached to and removed from the bottom of the steel truss.

The bending moment of the bottom plate is doubled at the center of the end value when subjected to equally distributed load. Nevertheless, the current triangular steel truss has one upper chord and two lower chords (FIG. 2), so it is unreasonable to adjust the thickness of the steel wire. Therefore, if you try to reverse the triangular steel truss of Figure 2 in order to improve this, since the lower chord is one, when the flat plate is attached to the lower portion of the flat plate to increase the thickness of the distance between the distance of the rise Cause. Therefore, applying the reverse triangular steel truss (1) does not increase the thickness of the steel sheet to form the form by reducing the self-weight of the concrete, it should also look for ways to remove it after curing the concrete.

Existing steel truss is to weld a three-sided yarn on each of the left and right slopes between one upper chord and two lower chords. Becomes Since this is not an authentic truss, the load resistance capability is greatly reduced. The reason for taking the trapezoid is the measure for facilitating the welding joint with the flat steel sheet by extending the yarn downward. In the present invention, the steel wire truss is arranged upside down, so that the upper chords are two and the lower chords are one, so that all the materials and the top and bottom chords meet.

Existing steel truss (Fig. 2b) has one upper chord but two sets of yarns rising from the two lower chords at oblique angles are held at an angle, so transverse buckling is prevented and the two lower chords are horizontally buckled. Serves to prevent. However, in the present invention, since the reverse triangular steel truss (1) is used, two phase chords are separated in parallel like a rail in the air, and thus, additional measures are required to prevent horizontal buckling under compression.

Molding the gold deck with a 0.5mm steel sheet as shown in Figure 6 has its limits in maximizing economics by itself. Therefore, it is necessary to develop a simple method of hanging the steel truss at suitable intervals and then dismantling it later. In addition, if a certain part of 0.5mm steel sheet hangs on the steel truss, local stress may be applied and damage may be required. The thin steel plate golden deck (2) needs a special device that can be easily removed after curing the concrete, and it is convenient to provide a baseboard for attaching the ceiling to the bottom of the bottom plate at the time of construction of the bottom plate.

Existing truss decks have a large floor weight, so the distance between steel wire trusses is unified to 200mm.However, if two steel wire trusses are arranged at 600mm width, the truss quantity is 2/3, or 67%, so the convenience and economic efficiency Will be excellent. In the existing steel truss was a problem that can not find the source of corrosion and leakage of flat steel sheet, but this problem can be solved.

In forming 0.5mm thin steel plate into the gold deck, embossing protrusions 10 are formed on the upper flange of the main stress and the left and right webs 9 of which the main stress is the main stress, thereby preventing local buckling and belly phenomenon, and preventing reverse triangulation. The troughs of the steel truss (1) and the thin steel plate deck (2) is differentiated from the conventional three by arranging two in a 600mm width. Inverted triangular steel truss is a combination of two compression top chords and one tension bottom chord, and is made of a combination where each top and bottom chord and yarn meet in a triangle to increase efficiency in structural strength, and the top chords are horizontal tie bars. Simplification by connecting to (6) prevents lateral buckling.

Hanging the thin steel plate golden deck (2) attached to the reverse triangular steel truss to reduce the load of the reverse triangular steel truss when the thin steel plate golden deck serves as a formwork during construction. On the left and right ends of the lower plate of the steel plate bone deck, the outer upward protrusion 11 is formed to be used as a jaw to hang the demolding mechanism, which becomes a means for increasing the cross-section of the lower flange. Local damage of the steel plate lower deck plate 8 is prevented by a large washer 12, and the lower plate and the large washer are fastened using bolts and nuts. The 8mm nut is used for attaching the ceiling mount after demolding the thin steel plate deck.

The thin plate corrugated deck (2) that matches the shape of the inverted triangular steel truss is a bone shape, thereby reducing the amount of concrete in the slab. The numerical values recorded at the left end of FIG. 5B are the thickness of the entire bottom plate and the height of the plate portion (75 mm) and the ribs below it, respectively. The lower part of 75mm thick flat concrete is empty except for ribs, so the concrete volume and self weight is 65% (average thickness 9.75cm) compared to the 15cm truss deck. Compared with truss decks of 18cm and 20cm thickness, 59.2% (corresponding to 10.66cm) and 56.3% (corresponding to 11.26cm) respectively, greatly reducing the weight, and greatly improving the economics of its own design as well as substructures such as beams and column foundations. Savings.

By increasing the arrangement of the reverse triangular steel truss (1) to 300mm intervals instead of the conventional triangular steel truss arranged every 200mm intervals, the basic quantity and workload of each member is reduced. The attachment of the reverse triangular steel truss and the thin steel plate deck is bolt nut type and demolded after curing of concrete so that it is free from the problem of zinc plating damage and rust caused by welding heat. In addition, it is economical as well as the leak source can be easily found by removing the thin steel plate deck deck formwork attached to the reverse triangular steel truss.

Whale truss is a very reasonable structure, and the basic requirement of the truss is that the triangular steel wire truss of the present invention is made in accordance with the above principle because the end of the three constituent members in each part forms a triangle meets at one point. When the thin steel sheet is molded as shown in Fig. 6, when the downward load is applied, the following stresses are generated in each component. The upper plate 7 is compressive + warp, the left and right webs are shear + warp + tension, and the lower plate 8 is tension + warp. What is written in front and above is main stress and what is written in back is negative stress. The lower plate having the main stress is a tension force, there is no fear of causing local buckling, but as the present invention uses a large washer 12 as it can cause local destruction or deformation when a concentrated load acts such as suspending locally on a steel truss, After curing the concrete to provide a traumatic projection (11) on both ends of the lower plate (8) of the bone to utilize the work to remove the thin steel plate deck (2).

Meanwhile, the upper plate and the left and right webs 9 form embossing reinforcement protrusions 10 to prevent local buckling and improve load resistance capability. By controlling the local buckling, which is the most vulnerable to the above measures, thin steel plate gold is given the ability to support some of the concrete weight and work load. The method is differentiated from the existing truss deck method in which 100% of the strength is designed to rely on the steel truss, so that there is a lot of room for structural strength and allowable sag control, and thus, the temporary holding can be omitted.

All domestic truss decks are arranged with three sets of steel trusses on 600mm wide steel sheets. However, in the present invention, by arranging two sets of inverted triangular steel trusses in the same width, it is basically required to reduce the steel wire usage of the upper and lower chords and sand. The method of manufacturing the reverse triangular steel truss and thin steel plate deck deck plate as shown in Figure 5a is as follows.

a. The inverted triangular steel truss (1) meets at the same point that the two left and right two-sided yarns (5), each of which is made of repetitions of four letters on the left and right slopes of which two upper and lower chords and one lower chord, are each folded at the same point, respectively Manufactured to be a truss. The steel wire thickness of the truss up and down chords and yarns is determined by the structural calculation in consideration of the reduction of the weight of the bottom plate due to the use of the thin steel plate golden deck (2). The height of the top and bottom chords is to be subtracted from the total height of the bottom plate, and the horizontal width between the materials divided into the top and bottom chords is 200mm.

b. A steel wire tie bar 6 having a diameter of about 5 mm is welded every 200 mm in a direction perpendicular to the phase chords 3 of the inverted triangular steel truss (2 × 2 = 4 phase chords arranged in parallel with unit widths of 600 mm apart). .

c. As shown in FIG. 6, a thin steel plate deck 2 is formed of a steel plate of about 0.5 mm. One bone is arranged on the left and right sides at 600mm width and 300mm intervals, and the bottom width of each bone is about 60mm and the left and right webs 9 are inclined outward toward the top so that the gap between the upper and left webs is about 120mm. (7). The height of the web is molded with the difference of basic type such as 75mm, 105mm, 125mm.

On the left and right web surface to form a triangular embossing projection 10 so as to be buried in concrete, the upper plate forms an embossing projection in a direction perpendicular to the left and right web at intervals of 200 mm. Embossing projections provide a reinforcement effect that controls the local buckling of webs and upper flanges whose main stresses are subjected to shear and compression, respectively. In addition, both ends of the thin steel plate deck as shown in Figure 5a to form a male and female c-type compressive exposed joint projections 14 to be easily separated from the adjacent thin steel plate deck when demolding.

On the left and right ends of the bone lower plate, as shown in Fig. 5d, an outward upward protrusion (11) is formed to be used as a jaw to pull out a tool (Fig. 7) for demoulding after concrete curing. It increases the cross-sectional area.

d, in the center of the lower plate of the thin steel plate deck, bolt holes 13 having a diameter of about 16 mm at intervals of 600 mm. As shown in Figure 5c, 5d 8mm nut is attached to the lower chord of the steel wire truss and the bottom of the left and right yarns, so it is difficult to be installed in the correct position to drill a large 16mm hole with a margin.

e. The lower chords of the two sets of reverse triangular steel truss (1) assembled by the tie bar (6) in the b is arranged the reverse triangular steel truss so as to enter every goal of the thin steel plate bone deck, and put a large washer 12 at 600mm intervals The 8mm bolt 16 is driven into the nut 15 through the bolt hole provided in d) to fix the thin steel plate deck to the steel wire truss.

f. The thin steel plate deck formwork manufactured by the a to e process is transported to the site to be installed, and it is cured by placing the reinforcing bar after placing it in the beam to pour concrete.

g. Through the above procedure, the composite structure consisting of reverse triangular steel truss and thin steel plate deck can secure the stiffness to control the deflection of the floor due to the self-weight of the concrete and the working load even when the span is longer than 4m. Will be.

h. Pour the bottom plate concrete (concrete volume is only 65.0 to 56.3% of the regular bottom plate with uniform thickness) (if the bottom plate is placed on the upper part of the beam, the empty space between the upper plate of the steel plate rib deck and the upper plate of the beam) The description of measures to prevent the concrete from leaking out is omitted).

i. Loosen the bolt (16mm) from the nut (15) and demold the sheet steel deck (2). The demoulding method is such that both wings of the dedicated tool are caught by the jaws of the outward facing protrusions 11 on the left and right sides of the lower plate and endure the pulling force downward.

j. Exposed bone has an 8mm nut every 600mm, so it is used to fix the ceiling or the brace that hangs the duct.

1 is a perspective view of a gold deck (a is a formwork, b is a structural deck plate),

2 is a perspective view of the truss deck (a is a flat steel truss, b is a triangular steel truss),

3 is a perspective view of the integral plywood deck,

Figure 4 is a welded joint of the trapezoidal sand and flat sheet of the existing truss deck,

5A is a perspective view of an inverted triangular steel truss,

5b is a front view of an inverted triangular steel truss,

5c is an assembled view of the reverse triangle steel truss,

5d is a detailed view of the bolted joint of the reverse triangle steel truss,

6 is a shape diagram of the steel plate gold deck,

7 is a conceptual view of the thin steel plate deck demolding tool.

<Code Description of Drawings>

One ; Reverse triangular steel truss 2; Steel Plate Plate Deck

3; Phase current 4; Present

5; Material 6; Tie bar

7; Upper plate 8; Bottom plate

9; Web 10; Embossing projection

11; Traumatic projections 12; Large washer

13; Bolt hole 14; Compression Extrusion

15; Nut 16; volt

Claims (3)

In the reverse triangular steel truss and thin steel plate deck deck manufacturing method, (a) The reverse triangular steel truss (1) has two upper chords and one lower chord consisting of V-shapes, and two sets of yarns (5) on the left and right inclined planes, each of which repeats the upper and lower chords, and the upper and lower chords. Manufacturing by welding to meet the same point and become a truss; (b) the height between the upper chord and the lower chord is obtained by subtracting the top and bottom covering thickness from the entire height of the bottom plate, and welding the steel wire tie bar 6 to the top chord 3 in a direction perpendicular to the top chord; (c) the lower steel sheet is molded into a thin steel plate deck of about 0.5 mm, and the thin steel plate deck is made of two ribs in a width of 600 mm; (d) The lower end of the goal becomes the lower plate 8 and the left and right inclined material becomes the web 9, and the web is inclined outward toward the upper end so that the upper part is wider than the lower part, and the end of the upper part of the web is connected to the adjacent web. Manufacturing to the upper plate (7); (e) Both ends of the thin steel plate deck have male and female c-type compressive exposed joint projections 14, the left and right web surfaces are made of triangular embossing projections 10, and the upper plate is embossed projections in a direction perpendicular to the left and right webs. Manufacturing to form; (f) manufacturing a bolt hole 13 at an appropriate interval in the center of the lower plate of the thin steel plate deck to insert the bolts, and forming outer upward protrusions 11 at both ends of the lower plate; Reverse triangular steel truss and thin steel plate formwork deck plate manufacturing method comprising a The method of claim 1; The web 9 of the thin steel plate deck 2 is manufactured by dividing the height into 75 mm, 105 mm, 125 mm, and the like; And A nut is welded at the lower end where the lower chord (4) and the yarn (5) of the inverted triangular steel truss meet, and a large washer (12) is installed at the outer end of the thin steel plate golden deck and the thin steel plate truss is connected to the steel plate truss with the bolt (16). Reverse triangular steel truss and thin steel plate deck deck formwork manufacturing method characterized in that fixed to the nut 15 of The method of claim 1; The formwork consisting of reverse triangular steel truss and thin steel plate gold deck is used to pour the floor concrete, loosen the bolts after curing, and draw them to the lower side by using the outward facing protrusions 11 at both ends of the lower plate (8) to demold the steel plate golden deck. Reverse triangular steel truss and thin steel plate deck deck plate manufacturing method characterized in that

Images