JPH0120986B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for coating the surfaces of steel pipes, coated steel pipes, and other various steel structures with polymer cement mortar. In particular, the present invention is applicable to various plant equipment, ships, piping parts such as buried pipes, supports such as bridges, legs, frames, and steel structures such as H steel and L steel, especially in the ocean, the coast, etc., sea water, salt wind, etc. The present invention relates to a method for forming an anticorrosive coating layer of polymer cement mortar with a thickness of about 1 to 10 mm on these steel structures in places where salt corrosion is severe or in water.

It is generally well known that polymer cements are useful as anticorrosive coatings, particularly as anticorrosive coatings against salt damage, and are in practical use. For this purpose,
It is customary to apply polymer cement mortar with a gun and a trowel.
Spraying construction on the following steel pipes results in significant losses.
Also, depending on the piping location, it may be difficult to install using a trowel, resulting in very poor work efficiency and high costs.

The object of the present invention is to provide a method for simply and efficiently forming a strong polymer cement mortar coating on the surface of such steel pipes and other steel structures that are difficult to apply by spraying, troweling, etc.

That is, according to the present invention, when coating the surfaces of steel pipes, coated steel pipes, and other various steel structures with polymer cement mortar, a laminated layer formed by adhering polymer cement mortar containing a synthetic fiber network (hereinafter referred to as a network) is used. Provided is a method for coating the surface of a steel structure with polymer cement mortar, the method comprising: wrapping a film base layer on the surface of the steel structure to obtain a mortar coating layer reinforced with a mesh body. be done.

This method is also provided as a method for coating the surface of a steel structure with polymer cement mortar in water or seawater.

The present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of a coating laminate applied to the surface of a steel structure according to the present invention, in which 1 is a synthetic resin film base layer, 2 is a synthetic resin film base layer, and 2 is a synthetic resin film base layer. The polymer cement mortar layers, 3 representing the network and 4 representing the polymer cement mortar layer, together constitute the covering laminate. Such a coating laminate is preformed, for example, on an apparatus as shown in FIG. 2, and the resulting laminate is applied to a steel structure (in the figure, a steel pipe) 12 with a polymer cement layer 4 as shown in FIG. The outer synthetic resin base layer 1 is then peeled off at an appropriate time to form a net. Obtain a polymer cement coating layer reinforced and hardened with the body. To explain the method for preforming a laminate on the apparatus illustrated in FIG. 2, rolls of the synthetic resin film 1 and the mesh body 3 are set as shown in the figure, and the ends of each are passed through the guide rolls 5 and 6 onto the conveyor. The synthetic resin film 1 is placed downwardly through the squeeze bars 7 and 8 set on the mesh 3.
Next, when the polymer cement coating agents 2 and 4 are put into the raw material hoppers 9 and 10 and the conveyor 11 is driven, the polymer cement coating agents are formed into a synthetic resin film with the thickness and the smoothness of the coated surface adjusted. 1 and the net-like body 3 to obtain the required coating laminate.

The synthetic resin film used as the base layer of the coating laminate is not particularly limited, but it is usually preferred to use a synthetic resin film without polar groups such as polyolefin, especially polyethylene or polypropylene. The film base layer also serves to prevent the moisture contained in the polymer cement mortar from rapidly escaping, thereby preventing the occurrence of cracks.

The mesh used as the intermediate layer is usually a mesh of about 1 to 10 mm, which is made of synthetic fibers such as nylon that are resistant to the alkali found in Portland cement. A preferred specific example is spun nylon thread (cotton count 10 to 40).
There is a mesh knit of approximately 4 mm square knitted with single or double yarns. The purpose of using a synthetic fiber network is to strengthen the impact and bending properties of the polymer cement mortar, and also to be able to bond well to the surface of the steel structure during construction, eliminating the need for tools such as trowels. It's for a reason.

The polymer cement mortar used as the anticorrosive coating layer in the present invention is generally any polymer cement mortar known to those skilled in the art, i.e., a powdered portion of cement such as Portland cement or blast furnace cement mixed with fine aggregate such as silica sand or river sand. (compound) mixed with an aqueous polymer emulsion may be used. The aqueous polymer emulsion can be aqueous emulsions based on various synthetic resins, including, for example, acrylics, vinyl acetate, epoxies, etc., natural or synthetic rubber latexes, or mixtures thereof. Synthetic resin-based aqueous emulsion alleviates the agglomeration effect of cement during hardening and prevents cracking. At the same time, it improves water permeability and water absorption resistance by filling the voids in cement mortar, and also improves adhesion to the surface of steel structures. It has the effect of increasing the contact force, bending and impact strength, and preventing the intrusion of adverse conditions from the outside air. Furthermore, it goes without saying that appropriate additives may be added to improve the impact resistance, bending workability, abrasion resistance, weather resistance, water resistance, seawater resistance, heat resistance, etc. of the polymer cement mortar. Furthermore, additives may be used as appropriate to prevent the polymer cement mortar from becoming cloudy in water or the sea.

Next, the present invention will be explained by examples.

Example Nylon thread (20 count x 3), polyethylene film (thickness 0.05 mm, width
450mm) and first apply polymer emulsion as a primer to the outside of a 100mm diameter steel pipe.
Mix and stir 25 parts of compound, 75 parts of compound, and 2 parts of fresh water, and use a brush or roller to mix 0.5 to 1.
Apply to mm thickness. After drying, polymer cement mortar (Melox Slurry ME-17) was applied to a thickness of 1 mm on the prepared polyethylene film as shown in Figure 2, and nylon net was layered on top of that, and then the same polymer cement mortar was applied. 3
It is coated to a thickness of mm to obtain a strip of laminate as shown in FIG. As shown in Fig. 3, the polymer cement mortar layer is placed on the inside, and the tube is wrapped around the outside of the steel pipe in a spiral manner, with good tension. In the case of sunny weather, the polyethylene film layer is peeled off and left to stand after 3 to 4 hours. If it is raining or is about to rain, leave it as it is for a day and night and then peel off the polyethylene film layer to prevent damage to the uncured parts during rain and obtain a complete anti-corrosion coating.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a coating laminate applied to the surface of a steel structure according to the present invention, FIG. 2 is a schematic diagram showing an example of an apparatus for preforming the laminate, and FIG.
The figure is an illustrative view showing a method of coating a steel pipe with a preformed laminate. 1... Synthetic resin film base layer, 2, 4... Polymer cement mortar layer, 3... Network layer,
5, 6... Guide roll, 7, 8... Squeeze bar, 9, 10... Polymer cement mortar hopper, 11... Conveyor, 12... Steel pipe.

Claims (1)

[Claims] 1. When coating the surface of steel pipes, coated steel pipes, and other various steel structures with polymer cement mortar,
A laminate consisting of a polymer cement mortar containing a synthetic fiber network attached to a synthetic resin film base layer is wrapped and coated on the surface of the steel structure with the film base layer as the outer surface, and the mortar is reinforced with the synthetic fiber network. A method of coating the surface of a steel structure with polymer cement mortar, characterized in that a coating layer is obtained.