JPH0358026B2 - - Google Patents

Description

[Detailed description of the invention] Recently, the deterioration of the quality of concrete in RC concrete buildings has become a major social problem, and it has been pointed out that the biggest factor is high water content. Patent application No. 124149 was filed in 1982 as a construction method invented for the purpose of solving problems.
No. 1543003 (name of the invention, dewatering and strengthening method for horizontal slabs in concrete buildings, hereinafter referred to as the original invention) was filed.
-25863), but the gist of the original invention is to support the bottom surface from below along the outer periphery of a wood fiber cement board reinforced with a reinforcing material, and to support the bottom surface of the wood fiber cement board reinforced with a reinforcing material from below. This is a method for dewatering and strengthening horizontal slabs in concrete buildings, which is characterized by laying concrete. Therefore, the original invention solves the various drawbacks caused by the excessive water content of the ready-mixed concrete currently used in RC concrete construction, and also shortens and simplifies the construction period, or improves the use of work vehicles that are problematic during urban redevelopment. Although the effects are immeasurable, such as making it possible for people to be stationed for long periods of time inside a building under construction, further study revealed that the following three problems remained. (a) When there is a large temperature difference between the inside and outside of the building due to heating in winter, the tip of the vertical part of the supporting steel beam (angle steel) may come into direct contact with the cold concrete that has been cooled by the outside air. As a result, the entire supporting steel frame becomes cold, and there is a risk of condensation forming on the parts that come into contact with the hot and humid side of the room.

(b) During the period when the concrete is not dry (3 to 5 years), rust is likely to occur on the supporting steel beams due to moisture dissipation.

(c) If an unexpected large impact is applied to the wood fiber cement board during construction work, there is a risk that the wood fiber cement board may break and fall, making it difficult to ensure work safety.

The present invention was researched to solve and improve the above three problems, and the results of Experiment 1 will be explained based on Figure 1. Figure 1 shows an experimental structure with the same configuration as the original invention. In the figure, 1 is a concrete layer with a thickness of 100 m/m, 2 is a wood fiber cement board with a thickness of 50 m/m, and 3 is an angle steel layer with a thickness of 6 m/m.
50m/m x 50m/m, the measurement position A in the figure was set at a position 100m/m away from the surface of concrete layer 1, and the temperature was set at 10°C at this position. The measurement position B in the figure was set at a position 100 m/m away from the angle steel 3, and the temperature was set at 27°C at this position.

As a result of the experiment under the condition of 17° temperature difference between inside and outside, B
When the humidity on the measurement position side was set to 75%, condensation occurred on the surface C of the angle steel. Also, for this occasion, I measured the base D of angle steel 3 and found it to be 20℃. In the above experiment, conditions were set that were substantially the same as the inside and outside temperatures and environment when heating a room in winter, and it was confirmed that dew condensation occurs under normal conditions in the original invention in winter.

Next, Figure 2 is a diagram showing the same configuration in which a part of the configuration of the present invention was tested. In the figure, 4 is a concrete layer with a thickness of 100 m/m, and 5 is a wood fiber cement board with a thickness of 50 m/m.
m/m, 6 is angle steel 6m/m×50m/m×50
m/m, 7 is a foamed synthetic resin insulation material (trademark Styroform, thermal conductivity 0.03) covered on the upper end side of the angle steel 6 in a direction parallel to the angle steel 6, and the cross section is 15 m/m x 15 m/m It has a prismatic shape. In this case, the measurement position E in the figure was set at a position 100 m/m away from the surface of the concrete layer 4, and the temperature was set at 2°C at this position. The measuring position F in the figure was set at a position 100 m/m away from the angle steel 6, and the temperature was set at 29°C at this position. In this case, the temperature difference between inside and outside is 27
When the humidity on the F side exceeded 80% at ℃, dew condensation was observed to occur on the surface of the angle steel 6 at point G.
That is, the above experiment was carried out by protecting the angle steel 6 from concrete by covering the upper end of the angle steel 6 with a square column of foamed synthetic resin insulation material 7 with a width of 15 m/m and a thickness of 15 m/m. 1 and experiment 2
Research has revealed that there is a 10° difference in condensation temperature and a 10% difference in humidity. Based on these results, the present invention provides petrochemical insulation (for example, foamed synthetic resin insulation) on the upper end side (concrete pouring surface side) of the supporting steel beam that supports the wood fiber cement board of the original invention from below. It was invented to have a configuration in which a prismatic or plate-shaped piece of steel is covered in parallel with the supporting steel beam as an essential component. If one side of the angle steel 9 is shorter than the thickness of the wood fiber cement board 8 as shown in FIG. Almost the same effect can be expected even if the petrochemical heat insulating material 10 is covered, and in this case, an even greater effect can be expected because the space H exists at the upper end of the angle steel 9. Even better results can be expected if appropriate insulation and soundproofing materials are used.

Next, I would like to discuss the results of research on the anti-corrosion effect of angle steel, which is the problem (b) of the original invention, as there is no petrochemical insulation material in the structure of the original invention.
In this case, as shown in Figure 4, the concrete layer 11
The moisture 12 inside falls straight downward, and a large amount of moisture stays at position J on one side of the angle steel 13 in the horizontal direction, causing rust and corrosion. In contrast, in the case of the configuration of the present invention, as shown in FIG. 5, the moisture 15 in the concrete layer 14 avoids the petrochemical insulation material 17 covered on the angle steel 16 and falls to the bottom. The orthogonal inner part K of the angle steel 16 can always be maintained in a dry state, thereby preventing the angle steel from rusting and corrosion. Therefore, it is desirable that the width of the petrochemical heat insulating material used in the present invention be equal to or larger than the sum of the two horizontal sides of the angle steel. When constructing slabs in warm regions where the temperature difference is small, or when constructing the lowest floor slab, rust prevention is the main objective, so tape with high moisture permeability may be used instead of heat insulating material. Furthermore, in order to solve the problem of the original invention with respect to the unexpected large impact, the present invention uses wood fiber cement boards 1 arranged in parallel as shown in FIG.
In the experiment, when the support steel beam 20 is driven into the rear parallel ends of the holding steel beams 19 and 18 in the direction perpendicular to the holding steel beams 19, the width of the holding steel beams 19 and 18 is 910 m/m x 910 m/ m wood fiber cement board 18 to 2
Even if a load L of 200 kg is applied to the broken part after the wood fiber cement board 18 is broken as shown in FIG. 7 by driving the spool 20 and applying impact, the hook hanging action of the spool 20 and the breakage prevention effect of the reinforcing material 21 are still maintained. together with 200
It was confirmed that it could withstand a load of 200 kg and would not fall off. Therefore, as shown in FIG. 8, the structure of the present invention is that, in the original invention, a support steel beam (for example, angle steel) 22 that supports the wood fiber cement board from below is placed above the upper end of the support steel beam in a direction parallel to the support steel beam. petrochemical insulation material (for example, foamed synthetic resin insulation material) 23
is covered in a plate shape with a certain width, and the right and left tips of the casing 25 are placed at positions slightly inside from the end surfaces of the adjacent wood fiber cement boards 24, 24, centering on the supporting steel beam 22 which faces back and adjoins. This invention is characterized in that the crotch frame is driven in a direction perpendicular to the supporting steel beam 22. Therefore, by carrying out the present invention, in addition to the excellent effects of the original invention such as dewatering, shortened construction period, and workability, it is also possible to completely eliminate dew condensation and rust in the supporting steel beams in the winter, as well as prevent accidental breakage. This invention has the effect of obtaining.

Additional relationship: The bottom surface of the wood fiber cement board reinforced with a reinforcing material is supported from below along the outer periphery, and concrete is laid on the upper surface of the wood fiber cement board reinforced with a reinforcing material, as described in the original patent application and patent no. No. 1543003 (Special Public Interest 1-
No. 25863), this invention is an invention in which this point is an essential part of the structure of the invention, and this invention has this point as a main part of the structure of the invention. This invention achieves the same object as the original invention in terms of the method of dewatering and strengthening horizontal slabs.

[Brief explanation of drawings]

FIGS. 1 to 5 are explanatory diagrams showing the experimental structure. FIG. 6 is a perspective view showing the state in which the spool according to the present invention is driven. FIG. 7 is a diagram showing a structure for a breakage experiment of the present invention. FIG. 8 is a longitudinal sectional view showing the present invention. 1... Concrete layer, 2... Wood fiber cement board, 3
... angle steel, 4 ... concrete layer, 5 ... wood fiber cement board, 6 ... angle steel, 7 ... foamable synthetic resin insulation material, 8 ... wood fiber cement board, 9 ... angle steel, 10 ... petrochemical insulation material, 11...Concrete layer, 12...Moisture, 13...Angle steel, 14...Concrete layer, 15...Moisture, 16...Angle steel, 1
7...Petrochemical insulation material, 18...Wood fiber cement board, 1
9...Holding steel beam, 20...Cassugai, 21...Reinforcement material, 22...Holding steel beam, 23...Petrochemical insulation material,
24...Wood fiber cement board, 25...Kasugai, A...Measurement position, B...Measurement position, C...Surface, D...Base, E
...Measurement position, F...Measurement position, G...Surface, H...Space, J...One side in the lateral direction, K...Orthogonal inner part.

Claims (1)

[Scope of Claims] 1. The bottom surface of a wood fiber cement board reinforced with a reinforcing material is supported from below by a holding steel beam along the outer periphery, and a holding steel beam is placed at an upper position of the holding steel beam. A petrochemical insulation material formed to a size equal to or greater than the sum of the lengths of the two horizontal sides of the holding steel beam is covered on the wood fiber cement board parallel to the wood fiber cement board, and the adjacent wood fiber cement board is Dewatering of a horizontal slab in a concrete building, characterized in that the above-mentioned supporting steel beams are straddled at the ends, a slat is driven in, and concrete is laid on the upper surface of a wood fiber cement board reinforced with a reinforcing material. Reinforcement method. 2. A method for dewatering and strengthening a horizontal slab in a concrete building according to claim 1, wherein the petrochemical insulation material is a foamable synthetic resin insulation material.