KR101765334B1 - Construction methods of precast concrete slab having its connection part being concealed by coupled ribs and, precast concrete slab used therefor - Google Patents

Abstract

Since the joint portion between the PC slabs is hidden and located in the setback space between the pair of adjacent ribs, there is no need for a separate lower surface caulking work or finishing work on the joint portion, and crack control, If the PC slabs are arranged continuously, the same pair of rib patterns are repeated at regular intervals, so that the building finishing effect is excellent. In addition, PC-slabs and RC slabs are placed on the joints of PC slabs It is possible to reduce the cracks by concentrating and placing the reinforcing bars efficiently. By incorporating the lightweight bodies inside the slabs, it is possible to reduce the self weight of the slabs and to improve the heat insulating performance, and the lightweight bodies form the spot- So that the height of the ribs can be increased, and the slab end portion Continuous design of moments and PC ribs (ribs formed in PC slabs) and on-site casting ribs are integrated with each other to be integrated with each other, so that the load bearing capacity and the sectional strength can be increased by resistance to stress, The same PC slab product can be used in the roof layer of underground structures (for example, an underground parking lot) and the underground layer beneath it, so that the mold specifications can be unified and the production method can be simplified, It has an advantage that economical efficiency can be secured by controlling the ratio of concrete (RC).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a coupled-rib-type precast concrete slab having a joint part hidden therein, and a precast concrete slab having a con- cave-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a precast concrete slab, and more particularly, to a method of constructing a precast concrete slab, in which a joint portion between PC slabs is hidden in a setback space between a pair of adjacent ribs, It is easy to maintain crack control, stain due to leakage and the like, and when the PC slabs are arranged continuously, the same pair of rib patterns are repeated at regular intervals, To a method of constructing a cast concrete slab. The present invention also relates to a precast concrete slab used in such a construction method.

Generally, as a method of constructing a slab, there are a method of constructing a slab by installing a formwork on a site and pouring concrete, a method of constructing a slab by placing concrete in a factory and then transporting the slab to a site (precast concrete slab, PC Slab).

In the meantime, there is a method of completing the slab by placing topping concrete on the PC slab in the field, such as a double tee PC slab, a PC slab having a plurality of ribs, a reverse rib PC slab, a hollow core PC slab, half PC slabs, etc. Generally 50 ~ 200mm of topping concrete is laid on PC slabs to make slabs.

When such PC slabs are continuously disposed, there is a problem that the joint part between the PC slabs is directly exposed to the outside. Such a problem will be described as an example of the double T-PC slab of FIG. 1 and FIG. 2 as follows.

Fig. 1 shows the double-tee PC slab, and Fig. 2 shows the placement of the locally-laid concrete on a double tee PC slab.

As shown in the figure, since the joints (joints) 3 between the PC slabs 1 are exposed to the outside, extra caulking work or finishing work is required on the lower surface in order to shield the joints, There is a problem that the upper crack easily occurs in the joint portion 3 due to the thickness, and thus the construction cost such as maintenance and maintenance increases. If caulking and finishing of the joint part (3) is required in the whole area, the cost is considerably high because it can occupy 5% or more of the slab cost portion during the framing work.

Further, if leakage occurs due to cracks in the joint part (3), there is a problem that the appearance is poor and the maintenance is inconvenient because the unevenness easily occurs.

Furthermore, even in the case of the same PC slab, there may be a gap and a step difference in the joint part due to the difference in the amount of protrusion caused by the prestress, and irregular spacing (gap) may occur because the PC slab is not arranged at a constant interval have.

3 shows a PC slab 5 and an on-site concrete 6 used in an underground structure, for example, a roof layer (uppermost layer) of an underground parking lot. FIG. 4 shows a PC Slab (7) and cast-in-place concrete (8) are shown.

The height p1 of the rib 5a is larger than the height q1 of the underground layer rib 7a and the height p2 of the cast concrete 6 is also lower than that of the underground layer Is greater than the height (q2) of the concrete (8). As described above, since the PC slabs 5 of the roof layer and the PC slabs 7 of the basement layer are different from each other in size, the molds for manufacturing the PC slabs 5 must be different from each other. This leads to an increase in the manufacturing cost of the PC slabs.

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above problems, and a separate lower surface caulking work or finishing work is required in the joint portion because the joint portion between the PC slabs is hidden in the setback space between the adjacent pair of ribs PC slabs and PC slabs are concentrated and laid on the joints of PC slabs and PC slabs, cracks can be reduced by efficiently placing reinforcing bars, and PC slabs And an object of the present invention is to provide a construction method.

It is still another object of the present invention to provide a method for constructing a PC slab, wherein the same pair of rib patterns are repeated at regular intervals when the PC slabs are continuously arranged, and thus the construction finish effect is excellent.

Another object of the present invention is to reduce the weight of the slab and improve the heat insulation performance by including the lightweight body in the inside of the slab so that the lightweight body also acts as a mold for forming the spotted ribs The present invention also provides a method of constructing a PC slab.

It is a further object of the present invention to provide a method and apparatus for continuously controlling the moment of a slab end, a PC (rib formed on a PC slab) and a spotting rib integrally integrated with each other, And to provide a method of constructing a slab.

It is still another object of the present invention to provide a method of constructing a PC slab capable of reducing the amount of rebar using pre-assembled shear reinforcement.

It is another object of the present invention to provide a method of manufacturing a PC slab which can use the same PC slab product in a roof layer of an underground structure (for example, an underground parking lot) And a method of constructing a PC slab.

It is still another object of the present invention to provide a method of constructing a PC slab, which can secure economical efficiency by adjusting the ratio of PC and spotted concrete in each construction step.

It is still another object of the present invention to provide a PC slab used in such a construction method.

In order to solve the above problems, a method of constructing a precast concrete slab according to the present invention is characterized in that a PC rib 46 formed at both side ends of a horizontal plate 10 is spaced apart from a PC rib 46 of a neighboring PC slab by a predetermined distance d .

The interval d is an interval at which the joint portion 50 can be concealed by the PC rib 46 when the joint portion 50 of the PC slab and the PC slab is viewed in the lower side direction of the PC slab.

A pair of PC ribs 40 and 43 or two pairs of PC ribs 40 and 43 or three pairs of PC ribs 40 and 43 are inserted between the PC ribs 46 on both sides of the PC slab And may be formed on the horizontal plate along the longitudinal direction.

At this time, the PC ribs 40 and the PC ribs 43 are spaced apart from each other by the distance d. Therefore, when the PC slabs are arranged continuously, the same rib pattern is repeated when viewed from below, thereby improving the architectural aesthetics.

It is preferable that the interval d is 20 mm to 300 mm.

In order to construct a roof layer of an underground structure (for example, an underground parking lot) using the present invention, it is necessary to (a) place a PC slab and a lightweight body 30 on a PC slab provided with a lightweight body 30, And inserting the second terminal.

At the position corresponding to the PC ribs 46 and the PC ribs 40 and 43 in the step (a), the lightweight bodies 30 are installed to be spaced apart from each other, the spotted concrete is placed in the spaced spaces, A rib 62 is formed.

At this time, the center axis C1-C1 of the two adjacent PC ribs 46 and the PC ribs 40, 43 coincides with the center axis C2-C2 of the spot placement ribs 62, It is preferable that the portion between the inner side surfaces 45 of the PC ribs 46 and the portion between the outer side surfaces 41 and 44 of the PC ribs 40 and 43 correspond to the site striking ribs 62 So that the two PC ribs 46 and the spotting ribs 62 are integrated with each other in a perfect combination and the PC ribs 40 and 43 and the spotting ribs 62 are integrally combined to resist the stresses together .

In order to construct a basement layer (a lower layer of a roof layer) of an underground structure (for example, an underground parking lot) using the present invention, (b) casting the cast concrete in a state where the lightweight body 30 is not placed on the PC slab ; ≪ / RTI >

According to the present invention, the PC slabs of steps (a) and (b) have the same size, and the difference in load size can be accommodated by adjusting the amount of the cast concrete placed and the arrangement of reinforcing bars.

The protrusion 48 may be formed on the outer side surface 47 of the PC rib 46. The projection 48 cooperates with the projection 48 of the adjacent PC slab to maintain the spacing d. By putting on-cast concrete in the upper space of the protrusion 48, the thickness of the spotted concrete of the joint portion 50 becomes thick, thereby increasing the crack rigidity of the joint portion 50.

According to the present invention, the thickness t of the horizontal plate 10 and the thickness u of the projection 48 between the PC ribs 40 and 43 can be adjusted according to the magnitude of the compressive force.

Another aspect of the present invention is a PC slab comprising: a horizontal plate (10); A PC rib 46 formed at both side ends of the horizontal plate 10 and extending downward from a lower surface of the horizontal plate; And a projection 48 formed to protrude from the outer side surface 47 of the PC rib 46.

The protrusions 48 are spaced a predetermined distance d between the outer side surfaces 47 in cooperation with the protrusions 48 of the adjacent PC slabs and are spaced apart from each other by the space formed by the protrusions 48 and the outer side surfaces 47. [ Can be poured on site.

The interval d is an interval at which the joint portion 50 can be concealed by the PC rib 46 when the joint portion 50 of the PC slab and the PC slab is viewed in the lower side direction of the PC slab.

The present invention has the following effects.

First, since the joint between the PC slabs is hidden and located in the setback space between the adjacent pair of ribs, there is no need for a separate lower surface caulking work or finishing work on the joint part, and the joint between the PC slab and the PC slab It is possible to reduce the cracks by concentrating and installing the spotted concrete (RC) and arranging the rebar efficiently, and it is easy to maintain the stain due to leakage.

Second, when the PC slabs are arranged continuously, the same pair of rib patterns are repeated at regular intervals, so that the construction finishing effect is excellent.

Third, the weight of the slab is included in the inside of the slab to reduce the weight of the slab, to improve the heat insulation performance, and to increase the height of the rib by allowing the lightweight body to act as a mold for forming the spotted ribs (ribs formed by the cast concrete).

Fourth, the continuing design of the moments of the slab ends and the PC ribs (ribs formed on the PC slab) and the spotted ribs are integrated with each other to form a perfect composite, which can increase the load bearing capacity and the sectional strength by resisting stress.

Fifth, pre-assembled shear reinforcement can be used to reduce the rebar amount.

Sixth, since the same PC slab products can be used for the roof layer of underground structures (for example, underground parking lots) and the underground layer beneath it, it is possible to unify the mold specifications and simplify the production method.

Seventh, it is possible to secure economical efficiency by adjusting the ratio of PC to RC (concrete pavement) by construction stage.

1 is a perspective view showing a double tee PC slab according to the prior art;
Fig. 2 is a cross-sectional view showing that the double-tee PC slabs of Fig. 1 are continuously installed and the cast-in-place concrete is laid on a continuously installed double tee PC slab.
3 is a cross-sectional view showing a roof layer of an underground parking lot constructed according to the prior art;
4 is a sectional view showing a basement of an underground parking lot constructed according to the prior art.
5 is a perspective view showing a PC slab used in a roof layer of an underground parking lot in a construction method according to the present invention;
6 is a sectional view taken along the line AA 'of FIG. 5;
7 is a cross-sectional view taken along line BB 'of FIG. 5;
8 is a sectional view taken along the line CC 'in Fig. 5;
Figure 9a is a perspective view showing pre-assembled shear reinforcement that can be used in lieu of lattice reinforcing bars in the PC slab of Figure 5;
FIG. 9B is a front view of FIG. 9A. FIG.
Fig. 10 is a bottom view of Fig. 5; Fig.
Fig. 11A is a cross-sectional view showing that the PC slab of Fig. 5 is continuously installed, and the cast concrete is placed on a continuously installed PC slab. Fig.
11B is an enlarged view of a portion X1 in Fig.
11C is an enlarged view of a portion X2 in Fig.
12 is an enlarged view showing a modification of the joint portion of the PC slab;
13 is a cross-sectional view showing a modification of the PC slab used in the roof layer of the underground parking lot in the construction method according to the present invention.
14 is a perspective view showing a PC slab used in a basement of an underground parking lot in a construction method according to the present invention;
Fig. 15 is a cross-sectional view showing that the PC slab of Fig. 14 is continuously installed, and the cast concrete is placed on a continuously installed PC slab. Fig.
16 is a bottom view showing a modification of the PC slab used in the construction method according to the present invention.
FIG. 17 is a cross-sectional view taken along the line DD 'of FIG. 16;
Figs. 18A-18G are cross-sectional views showing that PC-slabs are installed continuously and that cast-in-place concrete is laid on a continuously installed PC slab. Fig.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely examples of the present invention and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

In this specification, a precast concrete slab will be briefly referred to as a " PC slab ". As it is known, the PC slab is manufactured at the factory and then transported to the construction site, where the cast concrete is laid on top of the PC slab.

The ribs formed in the PC slabs will be referred to as 'PC ribs' and the ribs formed in the cast-in-place concrete will be referred to as 'spotting ribs'. The composite rib is a rib formed by combining a PC rib and a spotting rib.

FIG. 5 is a perspective view showing a PC slab used in a roof layer of an underground parking lot in the construction method according to the present invention, and FIG. 6 is a sectional view taken on line A-A 'of FIG.

Referring to the drawings, the PC slab 100 includes a horizontal plate 10, PC ribs 40, 43, and 46 formed downwardly from the horizontal plate 10, and a lightweight (30).

The horizontal plate 10 and the PC ribs 40, 43 and 46 are integrally formed of precast concrete. The PC slab 100 may be filled with a reinforcing bar, a wire, a steel material, or the like, and a prestress may be applied thereto. In the present specification, the horizontal board 10 is not limited to the mathematical or geometric mean horizontal board only, but the upper and / or lower surface of the board or the horizontal board having a stepped step formed on the horizontal board, Includes a plate formed to be inclined, and is used to include a structure employed in a plate connected to a rib of a PC slab in the art.

6 to 8, the horizontal plate 10 and the PC ribs 40, 43 and 46 are provided with the lattice reinforcing bars 20 and the longitudinal reinforcing bars 22 and 24 along the longitudinal direction of the PC slab, And an end reinforcing bar 26 may be installed.

The lattice reinforcing bar 20 is a zigzag bent reinforcing bar, and is periodically protruded above the horizontal plate 10. [ The protruding portion integrates the PC slab 100 with the spotted concrete. Although the lattice bar 20 is arranged at a uniform density at the end and the center of the PC slab 100, the lattice bar 20 may be arranged more densely at the end of the PC slab 100 than at the center.

Instead of the lattice reinforcing bar 20, a stirrup reinforcing bar, a vertical reinforcing bar, an inclined reinforcing bar (warp wire), a shear connection member, a pre-assembling shear reinforcing bar, and a shear key may be used. The above configurations not only improve the shear performance but also make the PC ribs 40, 43, 46 and the spotting ribs 62 to be in perfect combination so as to behave as one.

As shown in FIGS. 9A and 9B, the pre-assembled shear reinforcing bar has a structure in which a plurality of oblique reinforcing bars arranged at predetermined intervals are coupled to each other by two horizontal reinforcing bars, . The upper portion of the oblique direction reinforcing bar is protruded above the horizontal plate 10 so that the PC slab 100 and the cast concrete are integrally formed.

The longitudinal reinforcing bars 22 and 24 are installed on the lower end of the PC ribs 40, 43 and 46 along the longitudinal direction of the PC slab and the horizontal plate 10, respectively.

The end reinforcement 26 is installed at the end of the PC slab 100, one end of which is exposed to the outside.

6 to 8 and 10, the PC ribs 40, 43 and 46 are formed downward from the lower surface of the horizontal plate 10 and extend along the longitudinal direction of the PC slab 100 Respectively.

A pair of PC ribs 40 and 43 are formed adjacent to each other at a central portion of the horizontal plate 10 and one PC rib 46 is formed at both sides of the horizontal plate 10.

The width w of the PC ribs 40, 43 and 46 becomes larger toward both end portions in the longitudinal direction than the longitudinal center portion of the PC slab 100. [ For example, the width w of the PC ribs 40, 43, and 46 may be widened to one side or both sides from the both ends (fulcrum portions) of the slab, preferably, at intervals of L / 6 to L / (L: length of the slab). This configuration makes it possible to effectively resist the compressive force of the lower portion of the neutral shaft during the design of the continuous moment.

However, the width w of the PC ribs 40, 43, 46 may be uniform (constant) along the longitudinal direction.

A pair of PC ribs 40 and 43 are formed to be spaced apart from each other by a predetermined distance d. The distance d is the distance between the facing surfaces of the PC ribs 40 and 43, and the interval d is described below.

The thickness t of the horizontal plate 10 between the PC ribs 40 and 43 can be increased or decreased as necessary in order to resist the compressive force. That is, since the portion between the PC ribs 40 and 43 is not visible from the outside, if the compressive force acting on the horizontal plate 10 is large, the thickness of the portion can be increased accordingly. The thickness of the projection 48 (u in Fig. 6) can also be increased or decreased depending on the magnitude of the compressive force. The projection 48 will be described below.

The PC ribs 46 at the both end sides are spaced apart from the PC ribs 46 of the adjacent PC slabs 100 by the distance d as shown in Figs. 11A to 11C. It is preferred that the PC ribs 46 have the same external shape (i.e., the same rib height and width w) as the PC ribs 40 and 43. This is the same when PC slabs 100 are installed continuously So that the rib pattern is repeated so as to enhance the aesthetics.

The interval d is preferably 20 mm to 300 mm as an interval for hiding the joint portion 50 of the PC slab 100 by the pair of adjacent PC ribs 46. If the interval d is less than 20 mm, the arrangement of the PC slabs 100 will be noticeable even if they are slightly twisted. If the distance d is larger than 300 mm, it is not preferable because the joint portion 50 can be easily seen from the outside.

On the other hand, the width (w) of the PC rib is preferably 50 mm to 300 mm.

The distance d may be maintained by the protrusions 48. The protrusions 48 are formed along the longitudinal direction of the PC slab 100 on the outer side surface 47 of the PC rib 46 and are provided so as to be brought into contact with the protrusions 48 of the adjacent PC slab 100 Thereby maintaining the interval d. As described above, the thickness u of the projection 48 can be increased or decreased according to the magnitude of the compressive force acting on the slab.

It is preferable that the projection 48 is located at a height equal to or greater than the width w of the PC rib 46 from the lower end of the PC rib 46 or at a height equal to or longer than the distance d from the lower end of the PC rib 46. [ If the projection 48 is located lower than the height, it is not preferable because the joint portion 50 is easily exposed.

On the other hand, the horizontal board 10 further extends outwardly from the outer side surface 47, and the length of the extended portion 12 is shorter than the projecting length of the projection 48. A groove 49 is formed between the projection 48 and the extended portion 12 and the groove 49 forms a space together with the groove 49 of the adjacent PC slab 100. [ The space is filled with the cast concrete 60.

The concrete filled in the space prevents the PC slabs 100 from moving up and down differently due to the normal force when different vertical forces act on the adjacent PC slabs 100 to prevent cracking of the joints 50. That is, the concrete filled in the space acts as a wedge.

Also, since the concrete filled in the space increases the thickness of the spotted concrete 60, the crack stiffness of the joint portion 50 also increases.

As described above, when the conventional PC slab (1 in Fig. 1) is continuously installed, there is a problem that the joining portion (3 in Fig. 2) of the PC slab 1 is directly exposed to the outside. Or a finishing work was required.

In contrast, in the installation structure according to the present invention, the joining portion 50 of the PC slab 100 is formed of a pair (not shown) for a large area such as a parking lot, And the joint portion 50 is obscured by the PC rib 46 and is not visible from the outside because it is dark, so that the caulking work or the finishing work is not required, Accordingly, it is possible to eliminate the cost and construction period required for the construction.

In addition, when the PC slabs 100 are continuously installed, the PC ribs 46 are paired with the PC ribs 46 of the neighboring PC slabs 100 to form the same pattern as the PC ribs 40 and 43 . Therefore, in the installation structure according to the present invention, since the same rib pattern is repeated, excellent external beauty can be produced.

Further, a hanger (not shown) for hanging equipment such as electric wires and an illumination lamp can be easily installed in a narrow space between the PC ribs 40 and 43 and / or a narrow space between the PC ribs 46 have. Conventionally, in order to install the hanger, the horizontal plate 10 has to be punched. In the present invention, the support and the hanger can be provided by utilizing the rib side of the narrow space.

12 shows a structure in which a connecting reinforcing bar 64 is installed at the joint portion 50 of the PC slab 100. [ The connecting reinforcing bars 64 may be installed at predetermined intervals along the longitudinal direction of the PC slab 100. The connecting reinforcing bars 64 are installed to cross the jointing portions 50 to reinforce the jointing portions 50 to prevent cracks.

The PC ribs 40 and 43 are formed between the opposite ends of the horizontal plate 10 as shown in FIG. It may not exist.

More than one pair of PC ribs 40 and 43 may be formed. For example, two pairs of PC ribs 40 and 43 may be formed to divide the width of the horizontal plate 10 into three And three pairs of PC ribs 40 and 43 can be formed so as to divide the width of the horizontal plate 10 into four, which will be easily understood by those skilled in the art with reference to the present specification.

The lightweight body 30 is installed on the horizontal plate 10 along the longitudinal direction of the PC slab and the spotted concrete 60 is placed on the lightweight body 30 and the horizontal plate 10. The main reinforcing bars 65 and the reinforcing rods 66 may be embedded in the cast concrete 60 at the upper portion of the lightweight body 30.

The lightweight body 30 is made of a material having a specific gravity smaller than that of concrete. Preferably, the lightweight body 30 is made of a material selected from the group consisting of foamed EPS, polystyrene resin, plastic, recycled lightweight material (recycled lightweight material), recycled papers, concrete, and the like.

The inside of the lightweight body 30 may be filled solidly (i.e., tightly), but a groove may be formed in a portion where the interior of the lightweight body 30 is empty or facing the horizontal plate 10. [ In addition, a grid may be provided in the interior of the lightweight body 30 or appropriate vertical members may be installed so as not to be damaged when there is an impact from the outside at the construction site or when the worker is stepping on the lightweight body 30. The lattice and the vertical members may be made of the same material as that of the lightweight body 30.

The lightweight body 30 may be installed on the PC slab 10 at the construction site but it is preferable that the lightweight body 30 is placed on the concrete before the concrete is cured when the PC slab 10 is manufactured in the factory, (Bonded) to the PC slab 10, as shown in Fig. This is because the light weight body 30 has a small specific gravity, so it may float up when the cast concrete is laid.

(Not shown) may be formed on the upper surface of the lightweight body 30 in a direction perpendicular to the longitudinal direction of the slab. The concrete poured into the above-mentioned gravel serves as a sort of beam having a rib as a point. One or more of the bones may be formed per lightweight body 30. In the construction site, heavy equipment such as ready-mixed concrete vehicles, freight vehicles, etc. can be moved on the slab immediately after curing of the cast-in-place concrete is completed. In this case, the concrete of the bone plays a role of preventing cracking and increasing the resistance to the vehicle load.

The lightweight bodies (30) are installed at predetermined intervals in the width direction of the PC slab (10). The lightweight body 30 is not provided at the positions corresponding to the PC ribs 46 and the PC ribs 40 and 43 (i.e., at positions corresponding to the PC ribs 46 and the PC ribs 40 and 43) The light weight bodies 30 are installed so as to be spaced apart from each other). In the spaced-apart space, concrete is laid in the field to form the spotting ribs 62, so that the spotting ribs 62 have the same width as the spacing.

Concretely, the center axis C1-C1 of the PC ribs 40 and 43 coincides with the center axis C2-C2 of the spotting rib 62 and the center axis C1- The light weight members 30 are spaced apart from each other so that the center axis C2 of the spotting ribs 62 coincides with the central axis C2-C2 of the spotting ribs 62. The central axis C1-C1 of the PC ribs 40 and 43 does not mean the central axis of the PC rib 40 and the PC rib 43, 43) is acting as a rib. The center axes C1-C1 of the two PC ribs 46 are arranged in such a manner that when the PC slabs 100 are continuously installed, assuming that two neighboring PC ribs 46 behave as one rib, it means.

The center axes C1-C1 and the center axes C2-C2 coincide with each other when the center axes C1-C1 and C2-C2 coincide with each other or the PC ribs and the on- (C1-C1) (C2-C2) are structurally substantially coincident with each other so as to behave like a rib. The fact that the central axes C1-C1 and C2-C2 are structurally substantially identical means that both sides of the ribs are asymmetric and the center axes C1-C1 and C2-C2 are slightly inclined, . ≪ / RTI >

As an alternative to the configuration in which the central axis C-C1 and the central axis C2-C2 coincide with each other or with the above-described configuration, a portion between the inner side surfaces 45 of the two PC ribs 46 and a portion between the PC ribs 40 The light weight body 30 is provided so that the portion between the outer side surfaces 41 and 44 of the upper and lower portions 43 and 43 corresponds to the spotting ribs 62. This is because the width s2 of the portion and the spotting ribs 62 are the same or substantially equal to each other or at least the upper end width s1 of the portion and the lower end width s2 of the spotting ribs 62 are the same or substantially the same So that excessive stress concentration does not occur at the connecting portion of the ribs, and the ribs are integrated to act as one rib.

In the present invention, the light weight body 30 also serves as a mold for forming the spotting ribs 62, and accordingly, it is not necessary to provide a separate die for forming the spotting ribs 62 in the construction method according to the present invention .

With the above arrangement, the field-placing ribs 62 are formed at positions corresponding to the PC ribs 46, 40, The width of the spotting ribs 62 may increase or decrease toward the upper end from the lower end thereof. In addition, the width s2 of the spotting ribs 62 is equal to or substantially equal to the width s1.

The spotting ribs 62 are integrated with the PC ribs 46, 40 and 43 to increase the total height of the ribs. 11b, the height h1 of the PC ribs 46, 40, 43 and the height h2 of the spotting ribs 62 are combined to form a composite rib having a total height h (= h1 + h2) do.

In the present invention, since the lightweight body 30 is provided on the upper surface of the PC slab 10, the amount of concrete can be greatly reduced compared with the conventional method. The continuous slab can be constructed by placing reinforcing bars in the cast concrete 60 or applying post tension thereto.

In addition, even if the load to be borne by the slab is different, the PC slab 10 of the same size can be used because it can be changed by changing the thickness of the casting of the spotted concrete 60 or by changing the amount and arrangement of the reinforcing bars.

For example, in underground parking lots, a large load acts on the roof layer and a relatively small load acts on the underground floor below the roof layer. In order to achieve this, the height of the ribs of the roof layer is set to be larger than the height of the ribs of the basement layer, as described in the Background of the Invention of the Background Art. For this purpose, the PC slab of the roof layer has a size ). Therefore, in the past, equipment for manufacturing a PC slab of a roof layer (a mold and the like) and a facility for manufacturing a PC slab of a basement layer were different, which resulted in an increase in production cost, production time, and complicated processes.

In contrast, in the present invention, the same PC slabs 100 are used for the roof layer and the basement layer, and the thickness and thickness of the cast concrete 60 are changed or the amount and arrangement of the reinforcing bars are changed. Accordingly, the present invention can greatly simplify the manufacturing cost and production cost of the PC slab. At the same time, in the present invention, in order to reduce the amount of the spotted concrete 60, the lightweight body 30 is used and the spotting ribs 62 are formed by the lightweight body 30 so that the PC ribs 46, (43) so that the load supporting force and the sectional force are increased.

In addition, in the present invention, economical efficiency can be secured by controlling (optimizing) the ratio of PC (precast concrete) and RC (spotted concrete) to each construction step in the composite construction method.

In other words, PC slabs are manufactured with the installation cost of 500,000 ~ 700,000 won / m ^3, and 60,000 ~ 90,000 won / m ³ (excluding the frame ratio and reinforcing bars) ) Is 10 ~ 15% of the PC. In the case of underground parking lot construction in the present invention, the amount of PC is reduced by 10 ~ 40% and the amount of concrete placed in the building is increased by 10 ~ 40% It is possible to minimize the field work and to secure economical efficiency, shorten the air and secure the quality.

Further, according to the present invention, when the thickness of the horizontal plate 10 and the cast-in-place concrete 60 are combined, it is approximately 250 mm, which is thicker than the conventional 150 mm. Further, it can be seen that the heat insulating property is further increased considering that the light weight body 30 is mostly a heat insulating material.

FIG. 14 is a perspective view showing a PC slab used in a basement layer (lower layer of a roof layer) of an underground parking lot, and FIG. 15 is a sectional view showing that the PC slab is continuously installed and a cast concrete is placed on a continuously installed PC slab to be. In Figs. 14 and 15, the same reference numerals as those in Figs. 1 to 13 denote the same elements.

As shown in the figure, the PC slab 100 in the basement layer has the same dimensions as the PC slab 100 in the roof layer, and instead, the thickness and the arrangement of the reinforcing bars, etc., ).

FIG. 16 is a bottom view showing a modification of the PC slab used in the construction method according to the present invention, and FIG. 17 is a cross-sectional view taken along the line D-D 'in FIG. 16 and 17, the same reference numerals as those in Figs. 1 to 15 denote the same elements.

Compared with the PC slab 100, the PC slab 200 is different from the PC slab 200 in that the length of the ribs 40, 43, 46 is short and the thickness of both ends 14 of the horizontal plate 10 is thick, The width w of each of the first, second, third, fourth, fifth, and sixth embodiments 40, 43, 46 is constant along the longitudinal direction of the PC slab 200. Except for the differences, the PC slabs 200 are identical in construction to the PC slabs 100.

The PC slabs 200 can effectively resist the shear force and the warpage since both end portions 14 of the horizontal plate 10 are thick.

Further, the height R of both end portions 14 can be increased or decreased as needed. The lower surface of both end portions 14 is positioned above the lower ends of ribs 40, 43 and 46 (height R is less than rib height) or below position (height R is less than rib height) Lt; / RTI >

The PC slab 200 may be provided with the lightweight body 30 on the horizontal board 10 when used in a roof layer, like the PC slab 100.

18A to 18D are sectional views showing that the PC slabs 300, 400, 500, and 600 are continuously installed, and on-site concrete 60 is installed thereon. 18A to 18D, the same reference numerals as those in Figs. 1 to 17 denote the same elements.

The PC slabs 300, 400, 500 and 600 are connected to the PC slabs 300, 400, 500 and 600 by the protrusions 312 formed on the outer side of the PC rib 310, Spaced apart. The PC slabs 300, 400, 500, and 600 may be formed of the same material as the PC slabs 300, 400, 500, and 600, The cracking stiffness at the joint portion of the crack can be increased.

The PC ribs 310 and 330 are formed on the horizontal plate 10 so that at least a part of the side surfaces of the PC ribs 310 and 330 are made by molding the lightweight body 30 as a mold. The PC slabs 300 and 400 are formed such that the upper ends of the PC ribs 310 and 330 extend laterally to prevent the lightweight body 30 from being separated from the PC slabs 300 and 400 and the PC slabs 500 and 600 Is formed such that the lightweight body 30 is embedded in the PC slabs 500 and 600. [

18E shows a PC slab 700 having only two PC ribs 310. The PC ribs 310 are formed only on both sides of the horizontal plate 10 and are not formed in the middle part of the horizontal plate 10. [

18F and 18G are sectional views showing that the PC slabs 800 and 900 are continuously installed and the cast concrete 60 is laid thereon. 18F and 18G, the same reference numerals as those in Figs. 1 to 18E denote the same components.

The PC slabs 800 and 900 show a structure in which the horizontal plate 10 is further extended laterally than the outer side surface of the PC rib 310. [ The extended portion 12 cooperates with the extended portion 12 of the adjacent PC slabs 800 and 900 to form a space thereon, in which the cast concrete 60 is laid.

The thickness of the spotted concrete is increased due to the concrete placed in the space, and thus the crack rigidity at the joint portion of the PC slabs 800 and 900 can be increased.

10: horizontal plate 12: extended portion of horizontal plate
14: end of PC slab 20: lattice bar
22, 24: longitudinal reinforcement 26: end reinforcement
30: Lightweight body 40, 43, 46, 310, 330: PC rib
41: Outer side 44 of PC rib 40: Outer side of PC rib 43
45: inner side 47 of PC rib 46: outer side of PC rib 46
48: projection 49: groove
50: joint part of PC slab 60: field cast concrete
62: field striking rib 64:
65: main direction reinforcement 66:
100, 200, 300, 400, 500, 600, 700, 800, 900: PC slab
C1-C1: Center axis of the PC rib C2-C2: Center axis of the spot placement rib
d: Width between PC ribs W: Width of PC ribs
h: height of composite ribs h1: height of PC ribs
h2: Height of spotting ribs u: Thickness of projections

Claims (13)

delete A method of constructing a PC slab having a horizontal plate and a PC rib extending downward from a lower surface of the horizontal plate,
PC ribs 46 are formed at both side ends of the horizontal plate 10 along the longitudinal direction of the PC slab,
The PC slabs are installed such that the PC ribs 46 at the opposite ends thereof are spaced apart from the PC ribs 46 formed on both sides of the adjacent PC slabs by a predetermined distance d,
The interval d is an interval at which the joint portion 50 can be concealed by the PC rib 46 when the joint portion 50 of the PC slab and the PC slab is viewed in the lower side direction of the PC slab,
A pair of PC ribs 40 and 43 or two pairs of PC ribs 40 and 43 or three pairs of PC ribs 40 and 43 are inserted between the PC ribs 46 on both sides of the PC slab Is formed on the horizontal plate along the longitudinal direction,
The PC ribs 40 and the PC ribs 43 are spaced apart from each other by the distance d,
When the PC slabs are continuously arranged, the same rib pattern is repeated when viewed from below. A method of constructing a PC slab having a horizontal plate and a PC rib extending downward from a lower surface of the horizontal plate,
PC ribs 46 are formed at both side ends of the horizontal plate 10 along the longitudinal direction of the PC slab,
The PC slabs are installed such that the PC ribs 46 at the opposite ends thereof are spaced apart from the PC ribs 46 formed on both sides of the adjacent PC slabs by a predetermined distance d,
The interval d is an interval at which the joint portion 50 can be concealed by the PC rib 46 when the joint portion 50 of the PC slab and the PC slab is viewed in the lower side direction of the PC slab, d is from 20 mm to 300 mm,
PC ribs 40 and 43 are formed on the horizontal plate along the longitudinal direction of the PC slab between the PC ribs 46 on both side ends,
(a) installing a lightweight body (30) on a PC slab, and then placing a cast concrete to cover the PC slab and the lightweight body (30)
At the position corresponding to the PC ribs 46 and the PC ribs 40 and 43 in the step (a), the lightweight bodies 30 are installed to be spaced apart from each other, the spotted concrete is placed in the spaced spaces, A rib 62 is formed,
The center axes C1-C1 of the two adjacent PC ribs 46 and PC ribs 40 and 43 coincide with the center axis C2-C2 of the field erecting ribs 62, The portion between the inner side surfaces 45 of the ribs 40 and 43 and the outer side surfaces 41 and 44 of the PC ribs 40 and 43 corresponds to the spotting ribs 62,
Wherein the two PC ribs 46 and the spotting ribs 62 are integrated and the PC ribs 40 and 43 and the spotting ribs 62 are integrated to resist the stress together. 3. The method of claim 2,
(a) installing a lightweight body (30) on a PC slab, and then placing a cast concrete to cover the PC slab and the lightweight body (30)
At the position corresponding to the PC ribs 46 and the PC ribs 40 and 43 in the step (a), the lightweight bodies 30 are installed to be spaced apart from each other, the spotted concrete is placed in the spaced spaces, A rib 62 is formed,
The center axes C1-C1 of the two adjacent PC ribs 46 and PC ribs 40 and 43 coincide with the center axis C2-C2 of the field erecting ribs 62, The portion between the inner side surfaces 45 of the ribs 40 and 43 and the outer side surfaces 41 and 44 of the PC ribs 40 and 43 corresponds to the spotting ribs 62,
Wherein the two PC ribs 46 and the spotting ribs 62 are integrated and the PC ribs 40 and 43 and the spotting ribs 62 are integrated to resist the stress together. The method according to claim 3 or 4,
(b) casting the spotted concrete without installing the lightweight body (30) on the PC slab,
The construction method is used for constructing an underground structure,
The step (a) is used for constructing a roof layer of an underground structure, the step (b) is used for constructing a basement layer below a roof layer,
Wherein the PC slabs of steps (a) and (b) have the same size. 5. The method according to any one of claims 2 to 4,
Projections 48 are formed on the outer side surfaces 47 of the PC ribs 46 at both side ends,
Wherein said projection (48) cooperates with a projection (48) of a neighboring PC slab to maintain said spacing (d). The method according to claim 6,
The protrusion 48 is located at a height equal to or greater than the width w of the PC rib 46 from the lower end of the PC rib 46 or at a height equal to or longer than the distance d from the lower end of the PC rib 46. [ Construction method of slab. The method according to claim 6,
A groove 49 is formed in the upper portion of the projection 48,
Wherein the grooves (49) are filled with the locally poured concrete placed on the PC slab at the construction site. The method according to claim 2 or 3,
Wherein the thickness t of the horizontal plate 10 between the PC ribs 40 and 43 is adjusted according to the magnitude of the compressive force. Horizontal plate;
A PC rib 46 formed at both side ends of the horizontal plate 10 and extending downward from a lower surface of the horizontal plate; And
And a projection (48) formed to protrude from the outer side surface (47) of the PC rib (46)
The protrusions 48 are spaced a predetermined distance d between the outer side surfaces 47 in cooperation with the protrusions 48 of the adjacent PC slabs and are spaced apart from each other by the space formed by the protrusions 48 and the outer side surfaces 47. [ , There is a cast concrete pouring place,
The interval d is an interval at which the joint portion 50 can be concealed by the PC rib 46 when the joint portion 50 of the PC slab and the PC slab is viewed in the lower side direction of the PC slab,
The protrusion 48 is located at a height equal to or greater than the width w of the PC rib 46 from the lower end of the PC rib 46 or at a height equal to or longer than the distance d from the lower end of the PC rib 46. [ Slabs. Horizontal plate;
A PC rib 46 formed at both side ends of the horizontal plate 10 and extending downward from a lower surface of the horizontal plate; And
And a projection (48) formed to protrude from the outer side surface (47) of the PC rib (46)
The protrusions 48 are spaced a predetermined distance d between the outer side surfaces 47 in cooperation with the protrusions 48 of the adjacent PC slabs and are spaced apart from each other by the space formed by the protrusions 48 and the outer side surfaces 47. [ , There is a cast concrete pouring place,
The interval d is an interval at which the joint portion 50 can be concealed by the PC rib 46 when the joint portion 50 of the PC slab and the PC slab is viewed in the lower side direction of the PC slab,
A pair of PC ribs 40 and 43 or two pairs of PC ribs 40 and 43 or three pairs of PC ribs 40 and 43 are inserted between the PC ribs 46 on both sides of the PC slab Is formed on the horizontal plate along the longitudinal direction,
The PC ribs 40 and the PC ribs 43 are spaced apart from each other by the distance d,
When the PC slabs are arranged in succession, the same rib pattern is repeated when viewed from below,
And the interval (d) is 20 mm to 300 mm. 12. The method of claim 11,
And a light weight body (30) provided on the horizontal plate,
At the positions corresponding to the PC ribs 46 and the PC ribs 40 and 43, the light weight bodies 30 are installed so as to be spaced apart from each other, the spotted concrete is placed in the spaced spaces,
The spaced intervals are such that the center axes C1-C1 of the two adjacent PC ribs 46 and the PC ribs 40 and 43 coincide with the center axes C2-C2 of the spotting ribs, The portion between the inner side surfaces 45 of the PC ribs 46 and the portion between the outer side surfaces 41 and 44 of the PC ribs 40 and 43 corresponds to the width s2 of the field- Wherein the slab is a slab. 13. The method according to claim 11 or 12,
The protrusion 48 is located at a height equal to or greater than the width w of the PC rib 46 from the lower end of the PC rib 46 or at a height equal to or longer than the distance d from the lower end of the PC rib 46. [ Slabs.

Images