JPH1037458A - Construction temporary work steel tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability of temporary work by using raw material of high strength equal to or more than prescribed strength, and making a thin steel tube equal to or less than prescribed thickness a temporary steel tube. SOLUTION: High strength carbon steel material whose Mn content is about 1.5-2.5wt.% and tensile strength is about 900N/mm<2> or less is used as raw material for constituting a steel tube, and a thin steel tube of thickness of 1.5mm or less is made therefrom. The steel tube body 1 is formed as a rectangular square steel tube, and molten zinc galvanizing or Al-Mn alloy plating is performed on the inside and outside surface of the steel tube as corrosion prevention processing. Thus the steel tube has necessary strength as a temporarily set steel tube, and its weight is lightweight. Thereby working burden of temporary work workers is reduced, workability and safety are improved and material and transport costs can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an end material for formwork,
The present invention relates to a temporary steel pipe used for construction, such as a scaffold pipe, a support pipe, and a scaffold bracket pipe.

[0002]

2. Description of the Related Art Conventionally, with regard to this kind of temporary steel pipe for construction, in order to secure necessary strength and durability, a relatively thick steel plate is used to satisfy the performance conditions. I've been trying. For this reason, the product weight increases,
Workers handling this are remarkably tired, resulting in problems such as a reduction in work efficiency and a high risk of occupational accidents induced by fatigue. On the other hand, countermeasures have been demanded as a major environmental problem with respect to the effect of noise generated from metal temporary steel pipes used in large quantities at construction sites on the surroundings.

In recent years, as a means for solving the above-mentioned problems, aluminum alloy and resin products have been used to reduce the weight. However, both products are very expensive, so there is a major problem in terms of cost. Also, in terms of performance, aluminum alloy members have the disadvantage that it is very difficult to remove concrete when it adheres.Resin members have problems such as quality deterioration due to ultraviolet rays and waste disposal. There is a drawback that the problem remains.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical circumstances, and an object of the present invention is to provide a lightweight, sufficiently strong and durable Another object of the present invention is to provide a more practical steel pipe for temporary use, which is excellent in ease of use, is easy to use, and is effective in reducing costs, and aims to improve workability and reduce noise in temporary work.

[0005]

In order to solve the above-mentioned problems, the present invention has a Mn content of 1.5 to 2.5% by weight and a tensile strength of 1.5 to 2.5% by weight.
900 N / mm ² or more thickness 1.5m was formed from carbon steel
hot-dip galvanized or A
The one coated with l-Mn alloy or the one coated with a damping paint was adopted as a temporary steel pipe for construction. In the case where the former two plating methods are performed, a vibration damping paint may be further applied to at least the inner or outer plating layer of the steel pipe.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the temporary steel pipe, it is possible to select an appropriate cross-sectional shape such as a rectangle, a circle, a triangle, another polygon, or the like according to a use mode. Similarly, the thickness and length may be appropriately selected according to the use mode. Use a high-strength carbon steel material with a Mn content of 1.5 to 2.5% by weight and a tensile strength of 900 N / mm ² or more as the material constituting the steel pipe, and make it thin with a thickness of 1.5 mm or less. Accordingly, the steel pipe has the necessary strength as a temporary steel pipe and is lightened. As a result, the work load of the temporary worker is reduced, workability and safety are improved, and material costs and transport costs can be reduced. As chemical components other than Mn, it is desirable that the C content is 0.25% by weight or less, the Si content is 0.50% by weight or less, the P content is 0.035% by weight or less, and the S content is 0.035% by weight or less.

On the inner and outer surfaces of the steel pipe, as described above,
Hot-dip galvanizing or Al-Mn alloy plating is performed as rust prevention treatment. The galvanized, known galvanizing to form a galvanized layer on the surface was immersed in molten zinc which is conventional is applied, the coating weight is 300 g / m ² or more. In particular, in this hot-dip galvanizing, since the Mn content of the steel material is 1.5 to 2.5% by weight, which is larger than that of the conventional product, the adhesion of the plating is extremely good. Al-Mn alloy plating is a highly corrosion-resistant electroplating method that has recently been developed.
A plating layer made of a Mn alloy is formed (see Japanese Patent Publication No. 4-38837, Japanese Patent Publication No. 6-102839, and Japanese Patent Publication No. 7-65212).
Regarding the weight ratio between and Mn, various embodiments can be selected depending on the case.

The above-mentioned damping paint is a paint having a vibration damping action for damping vibration, and is, for example, a coloring material comprising one or more selected from the group consisting of asphalt, rubber, synthetic resin and cellulose derivatives. And a water-based coating composition in which a synthetic resin powder or a synthetic resin powder and an inorganic filler are mixed (see Japanese Patent Application Laid-Open No. 7-247446). Since many of these damping paints also have a rust-preventive effect, the damping paint may be used alone instead of the hot-dip galvanizing or Al-Mn alloy plating, or A damping paint may be additionally applied on the formed plating layer. By applying this damping paint, the vibration of the steel pipe itself caused by hitting the steel pipe at the time of work or collision or dropping between the steel pipes, that is, the sound generation energy is greatly attenuated, resulting in significant noise reduction. Since it is reduced, it is extremely effective as a noise countermeasure especially for temporary work at night.

[0009]

Embodiments of the present invention will be described below. FIGS. 1 and 2 show, as one embodiment of the present invention, a case where the present invention is applied to a rectangular steel pipe having a rectangular cross section used as, for example, a thick material. It is shown. FIG. 3 is a partially enlarged view of a portion A indicated in FIG. 1, and FIG. 4 is a partially enlarged view of a portion B indicated in FIG. In the figure, 1 is a steel pipe main body,
As shown in FIG. 2, it is formed as a square rectangular steel pipe having a Mn content of 1.5 to 2.5% by weight and a tensile strength of 900%.
Using high strength carbon steel material of N / mm ² or more, 1.5mm
It is formed with the following thin plate thickness. Thereby, the weight can be reduced by half as compared with the conventional product. Moreover, Mn
The content is, for example, STK400 or STK500 of a general structural carbon steel pipe (JIS G 3444) conventionally used or STK of a general structural square steel pipe (JIS G 3466).
Since a high-strength carbon steel material having a tensile strength of 900 N / mm ² or more is used, which is higher than that of R400 and STKR490, it has sufficient performance as a temporary steel pipe in terms of strength. Therefore, the work load of the temporary worker can be reduced by the above weight reduction, and the workability and safety can be improved. In addition, as a chemical component other than Mn, the C content is 0.
It is suitable that the content is 25% by weight or less, the Si content is 0.50% by weight or less, the P content is 0.035% by weight or less, and the S content is 0.035% by weight or less.

As shown in the partially enlarged view of FIG. 3, the above-mentioned hot-dip galvanizing or Al
-Plating layers 2 and 3 are formed by applying Mn alloy plating. In this case, as described above, since the Mn content of the steel material is large, the adhesion of plating is good. In the present embodiment, the above-described damping paint is further applied to the surface of the plating layer 2 on the inner surface side of the steel pipe main body 1 to form a damping paint layer 4. Due to these surface treatments, as described above, although the steel pipe main body 1 is formed of a material having a small thickness, a practical temporary steel pipe which is durable due to the rust prevention action of the former can be provided. By the latter damping action, it is possible to significantly reduce noise caused by the temporary work. As described above, by applying the damping paint directly to the inner and outer surfaces of the steel pipe main body 1 in some cases, the same effect can be obtained by the damping action and the rust preventing action.

As shown in FIG. 1, both ends of the steel pipe main body 1 are configured so that they can be easily attached by tapping the caps 5 and 6. In addition to the protection of the concrete, the noise is reduced by preventing intrusion of the ready-mixed concrete into the inside and confining the sound generated inside. The caps 5 and 6 are made of iron. As shown in FIGS. 2 and 4, a brim portion 7 is formed in the peripheral portion so that the cap 5 comes into contact with the end surface of the steel pipe main body 1 to protect the end surface. Is configured. The surfaces of the caps 5 and 6 are desirably subjected to an appropriate surface treatment using, for example, a special baking coating such as a dacrotized treatment to impart high corrosion resistance. Similarly,
It is desirable that the both end surfaces of the steel pipe main body 1 itself are also subjected to an appropriate rust prevention treatment such as hot-dip galvanization or application of a rust prevention paint.

[0012]

According to the steel pipe for temporary construction of the present invention, the following effects can be obtained. (1) Since the temporary steel pipe is formed using a high-strength thin steel material, the weight is significantly reduced as compared with a conventional product, and workability in temporary construction using the steel pipe can be greatly improved. Further, material and transportation costs can be reduced by reducing the thickness and weight. (2) In addition, since the inner and outer surfaces of the steel pipe are subjected to a surface treatment for rust prevention, a practical steel pipe with good durability and good durability can be provided despite the use of a thin steel material. (3) Since the Mn content of the steel material was increased compared to conventional products,
In particular, when the hot-dip galvanizing method is used as the surface treatment means, the adhesion of the plating is good, and a high-quality plating layer with a clean finished surface can be easily obtained. (4) Further, since the vibration damping paint is applied, noise generated from the steel pipe is reduced, and an easy-to-use temporary steel pipe can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a left side view of the embodiment.

FIG. 3 is an enlarged view of a portion A indicated in FIG. 1;

FIG. 4 is a partially enlarged view of a portion B indicated in FIG. 1;

[Explanation of symbols]

1: steel pipe body, 2, 3: plating layer, 4: damping paint layer,
5, 6 ... cap, 7 ... collar

Claims (4)

[Claims] 1. A thickness 1.5 formed from a carbon steel material having a Mn content of 1.5 to 2.5% by weight and a tensile strength of 900 N / mm ² or more.
A steel pipe for temporary construction, wherein inner and outer surfaces of a steel pipe having a diameter of less than 1 mm are subjected to hot-dip galvanizing. 2. A thickness 1.5 formed from a carbon steel material having a Mn content of 1.5 to 2.5% by weight and a tensile strength of 900 N / mm ² or more.
A steel pipe for temporary construction, wherein inner and outer surfaces of a steel pipe having a diameter of 1 mm or less are plated with an Al-Mn alloy. 3. A thickness 1.5 formed from a carbon steel material having a Mn content of 1.5 to 2.5% by weight and a tensile strength of 900 N / mm ² or more.
A steel pipe for temporary construction, characterized in that a damping paint is applied to inner and outer surfaces of a steel pipe having a diameter of not more than 1 mm. 4. The steel pipe for temporary construction according to claim 1, wherein a paint for damping is further applied to at least a surface of a plating layer inside or outside the steel pipe.