JPS61216954A - Construction of hollow slab - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method of constructing a hollow slab made of reinforced concrete (Re construction).

Problems to be Solved by the Invention Conventionally, when constructing an RO floor slab, two types of formwork and shoring were generally required to ensure the required strength of the concrete.
~3 layers were prepared and dismantled in 14 to 21 days. If the formwork and shoring can be prepared for only one layer and dismantled quickly, there will be great benefits in terms of increasing the operational efficiency of the formwork and shoring and reducing costs by shortening the construction period. However, in order to demold the concrete quickly, it is necessary to develop the concrete's demolding strength quickly, which necessitates the use of early-strengthening cement and thermal curing. In cold weather,
Even if such a method is adopted, there may be cases where the required compressive strength cannot be confirmed at an early stage. Furthermore, recently, large floor slabs have been adopted, and when pouring concrete for the upper floors, the slab concrete strength needs to be 300 Kl/am2 or more.

This invention has been made in view of the above-mentioned problems. The purpose was to develop a hollow slab construction method that would quickly develop the strength of poured concrete slabs, increase the operating efficiency of temporary construction materials such as formwork and shoring, and at the same time shorten the construction period and reduce costs. There are suggestions.

Means for Solving the Problems The method of constructing a floor slab according to the present invention is to place a bag body into which air is blown into a formwork in which concrete is poured to form a floor slab, and to create a hollow space within the floor slab. A heating element is housed in the bag of 75, and the concrete is kept warm and cured by the heat generated by the heating element, allowing for early dismantling of formwork and shoring.

Function: According to this construction method, heat is generated from inside the poured concrete, and the concrete can be kept at a temperature of about 60 to 70 degrees Celsius and cured, so the strength of the concrete is developed early, and formwork, shoring, etc. can be quickly dismantled and temporary construction can be carried out. Material utilization efficiency and construction period reduction can be achieved.

In addition, the floor slab can be troweled quickly, there is no need to install a heat insulating layer around the formwork, and a hollow floor slab with a hollow section inside can be produced extremely efficiently and in a short period of time.

Compared to conventional thermal air curing, this method requires less equipment and has the advantage of facilitating early quality control of concrete.

Example This construction method will be explained below with reference to drawings and examples.

As shown in Fig. 1, a large formwork 1 (e.g. Flying Shore) or a thin precast board (e.g. Omnya board) is placed at the lower surface position where the floor slab is to be constructed, and upper end reinforcements 2, lower end reinforcements 3, etc. are placed on top of it. At the same time, the unbonded C steel wire 4 is wired in a suspended manner on the thickness surface. An airbag formwork 5 is disposed at a predetermined position between the upper end reinforcing bars 2 and the lower end reinforcing bars 3 arranged in this way. The airbag formwork 5 usually has a rectangular or circular cross section and a length that corresponds to the dimensions of a section of concrete being poured.Multiple airbag formworks 5 are arranged in parallel at predetermined intervals and are used to supply pressurized air from a compressor. Press it into the desired shape and size, and temporarily fix it with supporting hardware.

A surface heating element 6 (approximately 2 tta thick) whose heat source is an electric heater is housed inside the air bag formwork 5.
When one block of concrete 7 has been placed on the formwork 1, the surface heating element 6 is turned on and kept warm at a temperature of 60 to 70°C. After the concrete 7 reaches the strength necessary for dismantling the formwork and shoring, it is demolded.

In this embodiment, unbonded PC steel wires 4 are wired inside the slab in order to give high strength to the concrete slab at the time of demolding, so that the strength of the concrete 7 is, for example, 180.
4/cm2, the steel wire 4 was tensed to introduce stress to compensate for the lack of strength required for demolding.

The air bag formwork 4 in the concrete 7 is evacuated and recovered through a damaged hole 8 provided in the floor slab as shown in FIG.

At the same time, the surface heating element 6 is also collected, and then an airbag 9 for repairing the damaged hole is applied to the lower side of the damaged hole 8, and non-shrinkable mortar 10 is stuffed into the hole from above to close it. Airbag formwork 4
A hollow part 11 was formed after the was collected, and this hollow part was used for air conditioning ducts, electrical wiring, etc.

The recovered airbag formwork 4 and surface heating element 6 are used repeatedly to pour concrete 7 and construct a hollow slab.

The airbag formwork can be manufactured by combining circular and rectangular airbags depending on the shape of the hollow portion, as shown in FIG. That is, as shown in (a) lb), the air bag form 5 having a rectangular cross section may be used alone, or the air bag forms 5, 5 may be stacked and stored in a sheet bag 12 to form a predetermined shape. Or (0), (+1), (+3)
As shown in the figure, the airbag formwork 5I having a circular cross section may be used alone, or may be arranged in parallel, or may be stored in a stacked sheet bag 12 and formed into a predetermined shape.

Effects This invention is as described above, and this construction method has high operating efficiency of temporary materials such as formwork and shoring, and can significantly shorten the construction period and reduce construction costs.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the construction state of this hollow slab construction method, Fig. 2 is a longitudinal cross-sectional view of the damaged hole portion where the air bag formwork is recovered, Fig. 3 (alt (t)), (C ), (d)(
θ) is a vertical cross-sectional view showing another example of the airbag formwork. 1.Φ formwork, 2.O top reinforcement, 3..bottom reinforcement, 400 unbonded PC steel wire, 5.51.air pack formwork, 6..
Surface heating element, 7... Concrete, 8... Damaged hole, 9...
Air bag for repairing damaged holes 10...Non-shrinking mortar, 11
・Hollow part, 1.・Sheet bag. Figure 1 IEZ Flash

Claims (1)

[Claims] (1) Place a bag into which air is blown into the formwork in which concrete is to be cast to form a floor slab, provide a hollow part within the floor slab, and store a heating element inside the bag. , a hollow slab construction method that uses the heat generated by this heating element to insulate and cure the concrete, allowing for early dismantling of formwork and shoring.