KR20130105091A - Light-weight ribbed truss deck consist of ribbed deck and steel bar truss - Google Patents

Abstract

PURPOSE: A lightweight rib truss deck combining a rib deck and a steel wire truss is provided to reduce the amount of electricity consumed to manufacture a deck by mechanically integrating the rib deck and the steel wire truss. CONSTITUTION: A lower permanent mold steel plate is attached to a lattice feet (180) formed on the lower part of a steel wire truss (100) comprising an upper chord (120), a lower chord (140), and a lattice (160) in a lightweight rib truss deck combining a rib deck and the steel wire truss. The lattice feet of the steel wire truss is pushed into a ⊂-shaped groove (370) of a shallow curved rib deck or a deep curved rib deck which is cold-formed into a steel plate (200) of 0.5 mm thicknesses so that the weight of concrete and construction loads are supported without welding. [Reference numerals] (a) Steel wire truss; (AA) Deep curved rib truss deck-a cross sectional view; (b) Rib deck; (c) Combination of a steel wire truss and a rib deck

Description

Light-weight Ribbed Truss Deck Consist of Ribbed Deck and Steel Bar Truss}

The present invention reduces the weight of the deck itself, as well as the pillars and foundations by reducing the weight of the deck through the new cross-sectional shape while utilizing the production facilities for the existing steel truss and rib deck, lightweight rib truss to improve the seismic performance of the building It's about the deck.

As shown in FIG. 1 (a), a truss deck that welds a 0.5 mm thick flat steel plate 20 to the bottom of a steel truss 10 and uses it as a permanent formwork first appeared in the mid-1990s and is currently widely used in domestic construction sites. It is becoming. This is an alternative method to improve the problem of low economic feasibility because the material of the rib deck (23 of FIG. 7), which was traditionally applied to the steel structure, is 1.2-3.2mm thick steel plate and is not recognized as a structural material due to fire resistance and is used only for formwork. . Unlike conventional reinforced concrete slabs, truss decks are applied to the steel plate trusses to omit temporary supports until concrete is cured, and thin steel plates welded to the bottom of the steel trusses (Fig. 1 (a) and 1 (c) 20) is a permanent formwork has the advantage of eliminating the task of assembling and disassembling separate formwork.

The cross-sectional shape of the existing truss deck is a flat plate, similar to the general slab, and increases the slab thickness and the thickness of the steel wire (12, 14, 16 in Fig. 1 (a)) with respect to the slab span and the increase in the working load. However, if you increase the thickness of the steel wire with the slab thickness intact, the sag increases, and the usability is hindered.Increasing the slab thickness to prevent sag increases not only the height of the slab but also the self-weight, which greatly increases the overall structure of the substructure such as beams, columns, and foundations. There is a problem that acts as a big burden.

On the other hand, in the case of increasing the thickness of the truss deck in general buildings, the lack of shear strength is rarely the cause. In other words, the standard thickness alone is sufficient to secure shear strength in most cases. The reason for actually increasing the thickness of the truss deck is to secure the distance between the tension side steel wire lower chord (14 in Fig. 1 (a)) or the top chord (12 in Fig. 1 (a)) of the steel truss and the opposite compression side concrete. As a result, the vicious cycle of increasing the weight of the steel truss by increasing the weight of the added concrete and increasing the burden on the lower structures such as beams and column foundations continues. Therefore, in order to reduce the thickness of concrete while reducing the thickness of the slab, various methods are used. Among them, hollow slab (Figure 6), joist slab (Figure 8), two-way waffle slab, etc. to be. However, all of these lightweight structures except formwork (Fig. 9) require formwork at the factory or the site, and the problem is that the cost is larger than the cost reduction obtained by reducing the concrete.

Hollow slab (Fig. 6) is to add a cylindrical buried pipe in the slab cross section at the construction site, the cylindrical buried pipe is an increase factor of the cost and when the concrete buried buried in the buried buoyancy buoyancy buoyancy or do not move from side to side There are also extra materials and field work costs that can be restrained. In addition, since the specific gravity of the hollow section cross-section removed compared to the entire cross-sectional area is not large, the weight reduction effect can not be greatly expected.

In PC structure, spancrete (Fig. 9) is the only economical because it is manufactured by injection (pushing method) without formwork, but due to the characteristics of PC structure, wire mesh is laid on top to fill gaps between unit members, so-called topping. (Topping) Since concrete (24 of FIG. 9) must be added, the effect of reducing the floor thickness is halved, and rather, the cost of construction is added. PC structures other than span concrete are also less economical due to the need for topping concrete.

The DT slab (Fig. 8) is used for some long spans such as overpasses and factories, and also needs topping concrete (24 in Fig. 8), and is inefficient in many ways for use in a medium span of about 6 m, which is the target of the present invention. . Finally, the waffle slab (not shown) is placed on the general formwork side by side with FRP formwork shaped like a square basin, placed in the + -shaped valleys created between them, and then poured into concrete, and then poured concrete. Falls.

Applicant, unlike the existing truss deck (Fig. 1 (a)) is a new method for attaching the rib deck formed by forming a thin steel sheet between the steel wire truss (10) upside down 180 ° and arranged parallel to them (ultra thin plate rib deck) Patent application for composite plate manufacturing method (not shown) and application number 10-2008-0103102 using a combination of steel wire truss and steel truss has been delayed due to the recent economic downturn. For the transitional period until new investments in production facilities are possible, we have developed a truss deck (Fig. 1 (c)) to reduce the weight by adding a fin formwork (30) to the existing truss deck as shown in Fig. 2. Considering the reduction in the volume of the lower structure due to the weight reduction of the floor slab, the overall economic efficiency is obvious, but the additional volume of the existing rib deck and the form steel sheet overlaps with the addition of a separate form steel sheet to form a hollow. Because of this inefficiency, it is difficult to convince consumers who are only familiar with the fragmentary unit price comparison because they are often more expensive than the existing truss deck (Fig. 1 (a)).

In the architectural design process and construction site, it is desired to connect only the girders between the columns and the columns and to omit the small beams installed between the beams, or to increase the spacing of the beams. It is limited. The slab's economic span is generally 3 to 4m, although it depends on the size of the load. The reason is that when the span of the slab becomes longer, the value of the bending moment is increased by the square of the span and the amount of deflection increases by four squares. For example, when the load is the same, the bending moment and deflection of the slab with span 6m are 4 times and 16 times of span 3m slab, respectively. In addition, as the span increases, the thickness of the slab needs to be increased. However, since the increase in thickness is directly related to the weight of the slab, it is difficult to make the "snowy". For this reason, truss deck manufacturing plants have facilities to produce truss decks for slab thickness 20cm, 25cm and 30cm, but the flagship product is only 15cm.

Other existing methods to improve the above problems include a slim floor / deep deck, TU beam / TU deck formed of a U-shaped groove deeper than the rib deck of Figure 7 to a thick steel sheet of 1.2- 3.2 mm. However, since they are not recognized for their fireproof structure, they use only steel sheets as formwork, so they are expected to be useful only in reducing floor height and shortening construction period.

Therefore, the present invention utilizes the existing truss deck (Fig. 1 (a)) steel wire truss (10) production equipment and the existing equipment for producing rib deck with a steel plate of 0.5mm thickness as it is without the steel wire truss and rib deck without welding or welding Find ways to combine easily. An object of the present invention is to reduce the amount of concrete used to reduce the weight of the bottom plate to reduce the overall infrastructure structure and mechanically integrated without welding the steel truss and rib deck to reduce the amount of power required to manufacture the deck. Reductions in concrete, steel and power are linked to reduced carbon emissions.

Improves seismic resistance by removing as much of the slab section as possible to reduce its own weight. In addition, for some consumers who do not prefer to reduce the thickness of the slab, the shallow rib rib truss deck method should be proposed instead of the deep bone rib truss deck.

3, 4 and 5 as shown in the c-shaped groove 370 of deep bone rib deck or shallow rib rib deck formed by cold forming the lattice foot 180 of the steel wire truss 100 with a steel plate 200 having a thickness of 0.5 mm. It is possible to support the work load and the weight of the concrete itself when pouring the concrete 410 without any additional action such as welding by pushing.

The production equipment is less burdensome since only the equipment for cold forming the steel sheet 200 while changing the steel truss (100) of the existing truss deck (Fig. . In addition, since the lattice foot 180 and the rib deck can be integrally inserted in the longitudinal direction without welding, it is easy to manufacture and helps the energy saving and carbon emission reduction policy. The weight reduction of the slab helps to improve the seismic performance of the structure, and the deep valley shape space may be utilized as a lamp, an electric wire, or a piping space (FIG. 10).

On the other hand, instead of forming a wall by bending from the top of the c-shaped groove of the rib deck to form a wall, the shallow rib rib truss deck (Fig. 5) which allows the sole plate thickness to be thinned only by the thickness of the steel wire of the lattice foot, due to the cover 310 directly bent into the L shape. Compared with other existing truss decks, the concrete saving effect is minimal, but there is an advantage that the lattice foot 180 and the rib deck can be assembled by inserting without welding.

Compared with other truss deck products, the volume reduction effect of the present invention is 45% lower than conventional truss decks and 16% concrete savings compared to the applicant's previous invention omega truss decks (Fig. 1 (c)). It was confirmed that there is an effect, that is, the weight saving effect (Fig. 11).

1 is a cross-sectional view of a light weight 트 truss deck by combining the Ω formwork with the existing truss deck,
Figure 2 is a perspective view of the lightweight Ω truss deck lightweight by combining the Ω formwork with the existing truss deck,
3 is a cross-sectional view of deep bone rib truss deck,
4 is a perspective view of a deep bone rib truss deck,
5 is a cross-sectional view of the shallow rib rib truss deck
6 is a cross-sectional view of the hollow slab to which the cylindrical buried tube is applied to the truss deck;
7 is a sectional view of the rib deck;
8 is a sectional view of the DT slab,
9 is a cross-sectional view of the spancrete,
10 is a cross-sectional view illustrating a method of inserting a light or wire pipe into a deep valley,
FIG. 11 is a table comparing steel plates and concrete quantities of the conventional truss deck and the improved omega truss deck thereof with the lightweight truss deck of the present invention.

One phase current 120 which is the upper root of the existing steel wire truss (100 in Figure 3 (a)) utilized in the present invention; Two lower chords 140 which are lower roots; The two left and right pairs of lattice 160 for integrating the upper and lower muscles by welding are bent steel wires in the form of trusses, and a lattice foot 180 is formed at the lower portion thereof.

The lightweight rib truss deck according to the present invention is formed by forming a lattice foot 180 formed on an existing steel wire truss 100 on a c-shaped wave rib rib deck formed by cold forming a steel plate 200 having a thickness of 0.5 mm as shown in FIG. By pushing in the c-shaped groove 370, it is possible to support the work load of the concrete placing process and the weight of the concrete 410 itself without additional measures, such as welding, welding. For the shape of the rib deck, refer to the cross-sectional view (Fig. 3 (c)) of the deep bone rib truss deck in which the steel wire truss and the rib deck are integrated. The steel sheet is laid under the steel truss as shown in Figure 3 (b) to form a c-shaped groove 370 from the left and right end of the lattice toe. And bends upward from the top of the c-shaped groove 370 to form a wall 320, the height of the wall 320 is bent horizontally again at a point at least 50mm lower than the upper surface of the slab that is finally formed after concrete placement The open rectangular cover 310 is formed. Due to the cover 310, when the concrete is poured, the concrete is not filled with the hollow is formed. The cross-sectional shape of the hollow is an internal cross-section except the protrusion of the c-shaped groove 370 at a height of at least 50 mm from the entire thickness of the slab. The rectangle has a maximum width of 150mm. The spacing between each hollow depends on the arrangement spacing of the steel truss 100 and the minimum thickness of the concrete coating on the steel truss 100. The minimum spacing between the hollows is 100 mm when the above constraints are reflected. The maximum height of the hollow is limited to ensure a minimum thickness of 50 mm of slab thinning.

The stepped jaw formed on the outside of the rib deck by the c-shaped groove is used as a jaw that hangs the support 360 when the wire 380 or the pipe 390 is inserted into the lower inner space of the lightweight rib truss deck. Use as a fixed jaw of 400.

As described above, the lightweight rib truss deck of the present invention basically does not need to reduce the deep bone shape or concrete as shown in FIG. 3 by forming a c-shaped groove 370, and then folding the hollow by 180 degrees immediately. Only the step corresponding to the outer height of the c-shaped groove 370 on the lower surface of the slab is also possible shallow rib lightweight rib truss deck (Fig. 5) formed at regular intervals at least 100 mm apart.

It is a rib truss deck consisting of three sets of triangular steel wire truss 100 in a unit width of 600-750mm as shown in Figure 4 and the two ends are placed on the upper part of the beam to repeat the operation in the transverse direction to form a bottom of the beam Connecting the phase currents 120 cut off at the end (not shown) and adding a back muscle 110 (see Fig. 3 (c)) after the concrete is finished to the bottom plate is the same as the existing method.

In order to secure the rigidity of the cover 310 and the wall 320, forming the embossing 330 in the process of forming the rib deck is the same as the existing molding method.

100 liner truss 320 wall
110 Power Muscle 330 Embossing
120 phase current 360 wiring / piping support
140 lower current 370 t
160 Lattice 380 Wiring
180 Lattice Foot 390 Piping
200 steel plate 400 fixture
310 cover 410 concrete

Claims (2)

The lower portion of the steel truss 100 consisting of a lattice 160 of one upper chord 120, two lower chords 140, and steel wires bent in a truss form to weld two pairs of left and right welds to the upper chords and the lower chords. In the truss deck attaching the lower permanent formwork steel sheet to the lattice foot 180 formed in the;
A steel plate of 0.4 to 0.6mm thickness having a c-shaped cross-section, which can support the working load when the concrete is poured and the weight of the concrete itself without any additional fixing measures. The c-shaped groove 370 protruding toward the lower outer side is formed at the lower side to be assembled in the longitudinal direction without welding and pressure welding, and the steel plate is bent upward from the top of the c-shaped groove 370 to form the wall 320. However, the cross section height is lowered in the lower part of the slab due to the cover 310 formed in a rectangular shape with the lower side bent horizontally at a point at least 50 mm lower than the upper surface of the slab which is finally formed after concrete pouring. After pouring concrete, at least 50mm is subtracted from the total thickness of the finished slab and based on the internal cross-section except the protrusion of the c-shaped groove 370. Deep rib lightweight rib truss deck with a combination of rib deck and steel wire truss, characterized in that the rectangular hollow having a width of up to 150 mm is formed at regular intervals of at least 100 mm and the thickness of the thinnest part of the slab is secured to 50 mm or more (Fig. 3). ). The lower portion of the steel truss 100 consisting of a lattice 160 of one upper chord 120, two lower chords 140, and steel wires bent in a truss form to weld two pairs of left and right welds to the upper chords and the lower chords. In the truss deck attaching the lower permanent formwork steel sheet to the lattice foot 180 formed in the;
A steel plate of 0.4 to 0.6mm thickness having a c-shaped cross-section, which can support the working load when the concrete is poured and the weight of the concrete itself without any additional fixing measures. The c-shaped groove 370 protruding toward the lower outer side is formed at the lower side so that the insertable assembly can be performed without welding and pressure welding, and by folding the straight c-shaped groove 370 with a steel plate and then folding it straight 180 degrees without facing upward. Steps corresponding to the outer height of the c-shaped groove 370 on the bottom of the slab is a shallow rib lightweight rib truss deck combining rib deck and steel wire truss, characterized in that formed at regular intervals at least 100mm interval (Fig. 5).

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