JPH05287901A - Construction of stairs - Google Patents

Abstract

PURPOSE:To raise the efficiency of construction work by a method in which a steel formwork is fixed to the downside of truss like fabricated reinforcing bars set between the upper and lower landings, a stepped steel formwork is fixed to the upside of the fabricated reinforcing bars, and concrete is placed through the hole of the step face of the upside formwork to form stairs. CONSTITUTION:A truss like fabricated reinforcing bars 1 consisting of an upper chord member 1a, a lower chord member 1b, and a lattice bar 1c is set between upper and lower landings. A steel formwork 2 is fixed by welding to the downside of the bars 1, a stepped steel formwork 3 is likewise fixed to the upside of the bars 1 by cast-in or split method. A concrete-placing hole 6 is formed in the step face of the formwork 3, sheathing boards are welded to both sides of the formwork 3, and concrete C is placed through the hole 6. The construction work of stairs can thus be attained with high efficiency with saved power without the needs for timbering for the formwork.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing stairs by casting concrete in situ.

[0002]

2. Description of the Related Art Conventionally, in RC (reinforced concrete) and SRC (reinforced concrete) buildings,
When constructing stairs by casting concrete on site, as a support work, a large number of pipe supports are erected in the staircase, and these pie supports are used to support steel pipe large hauls and joists, and for landing on joists. Since the formwork and the formwork for the raised floor were installed, and the construction was carried out by the method of arranging the raised bar and placing concrete on them, there were the following drawbacks.

In a narrow space, complex formwork, bar arrangement work, and support work must be carried out according to the inclination of the raised floor, which has been a bottleneck in the progress of the process. Since the pipe supports for supporting work are forested on the step floor, it is difficult for workers to pass through, and the staircase can be used as a work passage until the concrete hardens and the formwork and supporting work are removed. There wasn't.

[0004]

SUMMARY OF THE INVENTION The present invention has been made with the above points in mind, and its purpose is to construct a staircase by cast-in-place concrete, because of the stepped floor portion. Complicated formwork construction, bar arrangement work,
By eliminating the support work, the stairs will not become a bottleneck in the process progress of RC and SRC buildings, and the staircase can be used for work passages (transportation of materials etc.) from before the concrete is placed. It is intended to be used as a passage having a large width).

[0005]

In order to achieve the above object, in the present invention, a truss-shaped assembly rebar, an iron plate lower surface form fixed to a lower portion of the truss-shaped assembly rebar, and the truss-shaped assembly. While placing the stepped-bed driving form having a stepped steel plate top form fixed to the upper part of the reinforcing bar between the upper and lower landings, concrete is poured into the stepped-bed driving form. We are constructing stairs.

As a concrete procedure for erection of the stepped-bed driving form between the upper and lower landings, for example, an iron plate lower surface formwork having a truss-shaped rebar in front is installed between the upper and lower landings, After that, when assembling a stepped floor driving form by fixing a stair-shaped steel plate upper formwork to the upper part of the truss-shaped assembly rebar, and on the upper part of the truss-shaped assembly rebar preliminarily attached to the iron plate lower formwork It is conceivable that an iron plate upper surface formwork is fixed and a stepped floor driving formwork is assembled in advance, and this is suspended on the site by a lifting machine or the like and installed between the upper and lower landings. The present invention may employ any of these procedures.

In either case, it is desirable to form a concrete pouring hole at a position corresponding to the tread surface of the iron plate upper surface form for the reason described later. As the steel plate upper surface form, a striped steel plate, punching metal, expanded metal or the like can be used in addition to a steel plate having a smooth surface.

As for the upper and lower landings, since it is easy to work horizontally, the plywood floor formwork is supported by pipe supports through joists and large tows, as in the conventional construction method. After hardening of concrete, it may be demolded and constructed, and a landing driving form consisting of truss-shaped rebar and an iron plate bottom form fixed to the lower part of it is used for steel columns around the staircase. It is also possible to construct the landing by erection and placing concrete on the formwork.

[0009]

According to the above construction, the required strength of the formwork can be obtained by the truss-shaped assembly rebar, so that when the formwork for the raised floor is installed between the upper and lower landings, the formwork for the raised floor is used. Since no support work is required, pipe supports do not stand upright on the terraced floor, and the terraced formwork is equipped with a stair-shaped steel plate upper surface formwork. The steel plate top formwork of the formwork can be used as a temporary staircase, and the staircase can be used as a working passage. In addition, since it is possible to attach the truss-shaped assembled rebar to the iron plate lower surface formwork in advance, and to bend the iron plate upper surface formwork in advance in a staircase shape, it is possible to perform bar arrangement work and formwork on site. Labor can be saved and stairs can be constructed efficiently.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. A shown in FIG. 4 is an RC staircase, and as shown in FIGS. 1 to 3, a plurality of truss-shaped assembled reinforcing bars 1 arranged in parallel with each other and fixed to the lower part of the truss-shaped assembled reinforcing bars 1. A stepped floor driving form B having an iron plate lower surface form 2 and a stepped iron plate upper surface form 3 fixed to the upper part of the truss-shaped assembly rebar 1, and a beam steel frame 5 of the upper and lower landings 4
In the state of being installed between, the concrete C is poured into the inside of the stepped floor casting form B from the concrete placing hole 6 formed at a position corresponding to the tread surface of the iron plate upper face form 3. It was built.

The truss-shaped assembled rebar 1 serves to secure formwork strength before placing concrete, and as a rebar to reinforce the concrete C of stairs. The upper chord member 1a and the lower chord member 1a. 1b and a lattice reinforcement 1c welded thereto, and a substantially inverted V-shaped rebar 7 welded to the upper chord member 1a is welded to the upper surface of the lower steel form 2 made of an iron plate. It is attached in advance to the frame 2 and is integrated with the lower plate mold 2 made of an iron plate. The upper plate form 3 made of iron plate may be formed by bending a single plate of steel plate for all stages, but in the illustrated embodiment, as shown in FIG. 1 and FIG. The upper plate form 3 made of an iron plate is formed by connecting a required number of split forms 3a bent in a stepwise manner with
Is configured.

In order to construct the stepped floor driving form B between the beam steel frames 5 of the upper and lower landings 4, the stepped floor driving form B having the above-described structure is assembled in advance at another place. May be carried to the site and installed between the beam steel frames 5 of the upper and lower landings 4, but in this embodiment, the following procedure is adopted.

That is, the beam steel frame 5 of the upper and lower landings 4 is formed by connecting both ends of the bottom plate form 2 made of iron plate to which the truss-shaped assembly rebar 1 is attached in advance.
At the same time, the both ends of the truss-shaped assembly rebar 1 are welded to the steel rod 8 welded to the beam steel frame 5. Thereafter, as shown in FIG. 1, the divided formwork 3a is sequentially fixed to the upper part of the truss-shaped assembly rebar 1 from the lower stage to form the upper plate formwork 3 made of iron plate. Is being assembled. Figure 1,
Reference numeral 9 shown in FIG. 2 is an iron plate dam for fixing concrete on the side surface, and the lower end portion thereof is fixed to an angle member 10 installed between the beam steel frames 5 of the upper and lower landings 4.

The split mold 3a is fixed to the upper portion of the truss-shaped assembled rebar 1 as follows. That is, in advance
In each split form 3a, a cut is made in a part of the rising portion of the upper edge, the plate portion between the cuts is bent downward, or another plate material is provided at an appropriate position on the back surface (for example, the back surface of the tread). The attachment piece 11 is provided by welding or the like. on the other hand,
A plurality of horizontal bars 12 are welded over the upper chord members 1a of a plurality of truss-shaped assembled reinforcing bars 1 arranged in parallel, and a plurality of vertical bars 13 (three in the illustrated embodiment) are welded over the horizontal bars 12. The horizontal bar 12 and the vertical bar 13 serve as a reinforcing bar spacer for securing the concrete covering thickness of the upper chord member 1a when forming the mounting portion of the mounting piece 11. The welding of the horizontal bars 12 and the vertical bars 13 may be carried out after the iron plate lower surface formwork 2 is erected, but in this embodiment, in order to minimize the welding work on site,
This is done prior to the installation of the iron plate lower surface formwork 2 in advance.
Then, as shown in FIG. 1, the split mold 3a is placed on the vertical bar 13 from the lower one, and the contact portion between the attachment piece 11 and the vertical bar 13 is fixed by means such as spot welding.

According to the above-mentioned embodiment, since the required formwork strength is obtained by the truss-shaped assembly rebar 1, the supporting work for the stepped-bed driving form B is unnecessary, and the pipe support is provided on the stepped-bed portion. Since it is not forested and the stepped-bed driving form B is provided with the stepped iron plate upper surface form 3, the stepped-up iron plate upper surface type of the stepped-bed driving form B before the concrete C is placed. The frame 3 can be used as a temporary staircase, and the staircase can be used as a work passage.

Further, since the truss-shaped assembled rebar 1 is preliminarily attached to the bottom plate form 2 made of iron plate and the top form frame 3 made of iron plate is also bent in a stepwise manner in advance, there is no need for rebar work on site. Therefore, the formwork construction is easy. Moreover, the iron plate upper surface form 3
Since the concrete pouring holes 6 are formed at the positions corresponding to the tread surface, it is possible to easily fill all the inside of the stepped floor driving form B with concrete.

In this embodiment, after the concrete C has been cast, as the surface finish of the stairs, paint such as paint is applied to the lower surface of the iron plate lower surface mold 2 and, as shown in FIG. Although the plastic tile 14 is directly adhered to the tread surface portion of, the mortar may be applied once and the plastic tile 14 may be adhered. Reference numeral 15 is a slip stopper attached to the corner between the front edge of the tread and the upper edge of the riser. Although not shown, the upper surface mold 3 made of iron plate may be painted like the lower surface mold 2 made of iron plate, or a striped steel plate may be used as the upper mold 3 made of iron plate and the surface finish may be omitted.

When the concrete C is placed on the upper side of the stepped-bed driving form B, the previously placed concrete C is still fluid and flows out from the concrete placing hole 6 on the lower side. If there is a risk, the concrete pouring hole 6 should be covered with an appropriate plate material until the concrete C is hardened to some extent. Although not shown, a mounting piece 11 is provided on the lower edge of each split mold 3a,
The split mold 3a may be fixed to the vertical streaks 13 sequentially from the upper one.

FIG. 5 shows another embodiment of the present invention. In this embodiment, punching metal or expanded metal is used as the iron plate upper surface form 3, and the corners of the trailing edge of the tread and the lower edge of the riser are tied to the vertical stripes 13 with the number lines 16 to form the upper surface of the iron plate. It is characterized in that the form 3 is fixed to the upper part of the truss-shaped rebar 1. The other structure is the same as that of the above-mentioned embodiment, and the description thereof will be omitted.

[0020]

As described above, according to the present invention, the truss-shaped assembled rebar can provide the required formwork strength, so that no support work is required for the driving formwork for the raised floor, and the pipe is attached to the raised floor portion. Since the support does not stand upright, and the stepped floor driving formwork has a staircase-shaped top plate formwork, the steel plate topside formwork can be used as a temporary staircase before concrete placement,
It is possible to use the staircase as a passage for work. In addition, since it is possible to attach the truss-shaped assembled rebar to the iron plate lower surface formwork in advance, and to bend the iron plate upper surface formwork in advance in a staircase shape, it is possible to perform bar arrangement work and formwork on site. Labor can be saved and stairs can be constructed efficiently. Particularly, according to the second aspect, since the concrete placing holes are formed at the positions corresponding to the tread surface of the steel plate upper surface formwork, concrete can be easily applied to every corner inside the step floor driving formwork. Can be filled.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a stepped floor driving form for explaining a method of constructing stairs according to the present invention.

FIG. 2 is a vertical sectional front view of a main part before concrete is poured.

FIG. 3 is a vertical cross-sectional side view of a main part in the middle of pouring concrete.

FIG. 4 is a vertical sectional side view of an RC staircase constructed by the above method.

FIG. 5 is an exploded perspective view of a flooring driving form according to another embodiment of the present invention.

[Explanation of symbols]

 B ... Driving form for terraced floor C ... Concrete 1 ... Truss-shaped rebar 2 ... Iron plate bottom form 3 ... Iron plate top form 6 ... Concrete placement hole

Claims (2)

[Claims] 1. A truss-shaped assembled reinforcing bar, an iron plate lower surface formwork fixed to a lower portion of the truss-shaped assembled reinforcing bar, and a step-like iron plate upper surface formwork fixed to an upper portion of the truss-shaped assembled reinforcing bar. A method for constructing a staircase, comprising constructing a staircase by placing concrete provided inside the stepped-bed driving formwork between the upper and lower landings, and placing concrete inside the stepped-bed driving formwork. 2. The method for constructing stairs according to claim 1, wherein a concrete pouring hole is formed at a position corresponding to the tread surface of the iron plate upper surface formwork.