RU2426642C2 - Antirust tube and method of its production - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of construction materials, particularly, antirust reinforced concrete pipe. Proposed pipe comprises outer reinforced concrete envelopment glued to inner cast stone core. Said cast stone consists of several 1 m-long cylindrical inserts glued together. Note here that said outer envelopment is reinforced by single or dual unstrained spiral carcass while inner cast stone core is wound by wire gauze, wire diameter making 1-2.5 mm. Wire elements have their face surfaces glued together via antirust gaskets by polyurethane or other polymer adhesive. Proposed method comprises assembling inner core using glue, fitting it into die, reinforcing said die with said core and compacting concrete by vibration to produce multilayer pipe.

EFFECT: higher strength and rust resistance.

4 cl, 5 dwg

Description

The invention relates to the production of building materials and products, more specifically to the design of corrosion-resistant reinforced concrete pipes and the method of its manufacture.

In the practice of producing corrosion-resistant reinforced concrete pipes, as a rule, multilayer pipes, there are various structural varieties and methods of production. For example, pipes with an internal plastic coating are quite often manufactured and applied using compositions based on epoxy or polyester resins. They cover the inner surface of the pipes by coating or spraying. Such coatings are often reinforced with glass fiber, as a result a steloplastic layer is formed, enhancing the strength and abrasion of the inner surface of the product.

The occasional use of plastic coatings to impart corrosion resistance to pipes in sewer and storm networks is used in the Ural and Nizhny Novgorod regions, in the middle lane of the country, and others. There are information in prospectuses, advertisements for thematic exhibitions, etc. However, the above examples are difficult in technical design, the coatings are short-lived in time due to the difference in the pH of the concrete medium and the polymer composition (peeling of the coating).

More reliable is the method of internal insulation of pipes with a polymer sleeve or a cover having T-shaped protrusions along the perimeter of 15-18 mm in length. When concreting, the protrusions are anchored in the concrete of the pipe, and a continuous inner insulating layer of the pipe is formed, which resists aggression (Popov AN Concrete and reinforced concrete pipes. - M .: Stroyizdat, 1973). The cover, usually made of polyethylene, is tightly anchored in concrete and protects it from corrosion. In sewer pipes, where the weakest point is the upper section of the vertical diameter (husk), a polyethylene cover protects the concrete from gas corrosion, the most dangerous in sewage systems. The Belgian company Pedershaab (company prospectuses) solved this problem most successfully, according to which the equipment was purchased in Russia and working drawings of pipes and technical specifications were developed. Unfortunately, this design also has a drawback - instability to abrasive wear, especially in the lower zone of the pipe - the tray, where abrasive materials mainly move - sand, fine pebbles, gravel, etc. However, such pipes are used in sufficient volume in practice, especially with the microtunneling method, when pipes with a thickened wall, increased strength and corrosion resistance are required according to the laying conditions. In addition, the technology for manufacturing reinforced concrete pipes for microtunneling deserves attention from the point of view of its application in the proposed method for the manufacture of corrosion-resistant pipes.

Relatively close to the proposed pipe design, the solution includes pipes lined with mantel castings and manufactured by Pervouralsky Mining Equipment Plant OJSC (see the factory price list). Pipes are a multilayer structure consisting of an external metal cage, an inner liner - a cylindrical stone pipe, into the gap between which cement-sand concrete mixture is poured. The outer size of such a pipe determines the outer diameter of the metal pipe, the inner - the diameter of the stone-cast liner. Fine-grained concrete cements the outer pipe with an inner liner to form a single multilayer pipe, which is used in the hydrotransport of abrasive or chemically active materials. The description shows the complexity of manufacturing such pipes, as well as the need to connect them into the pipeline using a special bandage.

The closest technical solution is a multilayer pipe (AS 353834, 1973, B28B 21/60). This pipe is an outer concrete shell connected by cement glue to an inner stone core, consisting of several stone cylindrical elements, the length of which is 1 m, and the concrete shell is circumferentially reinforced with prestressed rods mounted on two end flanges located at the ends of the pipe, with which pipes are mounted between each other. On the centering device of the tubular base, fixed cantilever, stone elements (bushings) are installed and glued together. Flanges with reinforcing rods are worn on both sides of the glued core. The core assembled in this way is installed horizontally in the mold, flanges are attached to it, reinforcement is tensioned, and then concreting occurs with vibration compaction of the concrete and further formwork

From the above examples, for the prototype design we take a multilayer pipe according to as 353834.

A corrosion-resistant pipe is proposed, which is an external concrete reinforced shell connected by cement glue to an internal stone core, consisting of several stone-milled cylindrical elements (inserts) glued to each other, 1 m long, characterized in that the concrete outer shell is reinforced with an unstressed single or double spiral frame, depending on the diameter of the pipe and the thickness of its wall, determined by the strength of the pipe, and the inner stone core is wrapped around the perimeter with a mesh and 1-2.5 mm diameter wire, whose elements are bonded to each other through end faces of the corrosion-resistant liner resin adhesive, the latter being coated with an outer surface of the pipe in the weld zone and wrapped asbestos, mineral wool, tarpaulin fabric or nonwoven fabric on a polymer basis.

In geometric form, two types of pipes are offered: the first is used for closed trenchless pipe laying; the second - when laying pipes in an open, trench way.

The first type is a cylindrical pipe (Fig. 1), the bell of which is a steel shell 1, monolithic in the concrete body of the outer shell 2. The shell is reinforced with a single or double spiral reinforcing cage 4 and adhered by concrete to the inner core of stone elements 3, which is entwined with a mesh from a wire with a diameter of 1-2.5 mm or mesh netting 5 for better adhesion to the shell and stiffening the core along the length, especially for small diameters. This pipe is characterized by an increased thickness of the pipe wall, which is explained by the peculiarity of the technology of laying pipes into the pipeline in a closed way, in particular microtunneling. In more detail, the design of the pipe is presented in figure 2.

The assembled inner core (Fig. 3) consists of several (2-5, depending on the diameter) stone elements 3 fastened together by ends using a corrosion-resistant gasket 6 and polyurethane adhesive (possibly an epoxy, polyester adhesive bond). The seam of the glue joint is smeared around the perimeter with an adhesive strip, and then wrapped with a fine fiber cloth (7) (asbestos, glass, basalt, tarpaulin, from a nonwoven fabric on a polymer basis) 2-6 dm wide. The glued elements along the outer contour are wrapped with reinforcing mesh 5 from a wire with a diameter of 1-2.5 mm or a netting net. All core assembly operations are performed on a special centering device (figure 4).

The second type of pipe - with a bell made of concrete, which is a single whole pipe construction. The design (figure 5) consists of an outer reinforced concrete shell 2 reinforced with a frame 4, an inner stone core 3 entwined with a reinforcing mesh 5.

The length of the considered pipes, as a rule, is 3-5 m, but for pipes with a diameter of 800-1200 mm, it is advisable to reduce the length to 2-3 m.

Now we consider a method of manufacturing multilayer corrosion-resistant pipes, regardless of their type and method of laying in the pipeline. First, we say that the stone-cast element is a cylindrical liner 1 m long, made by high-temperature injection method of basalt or diabase and used as a corrosion-resistant and abrasion-resistant core located inside the pipe.

A method of manufacturing corrosion-resistant pipes, including assembling the inner core from stone-cast elements (inserts) using glue, installing it in the mold, reinforcing the mold with the core, laying the concrete in the mold and compacting the concrete with vibration to form a multilayer pipe, characterized in that the assembly of the core carried out on an assembly mobile device, where the liners are centered, glued using gaskets and glue, turning the core, glue the butt joints with glue, wrap them with a fine fiber cloth ( glass, basalt), asbestos, tarpaulin, plastic non-woven fabric, then the core is wrapped with reinforcing mesh or netting made of wire with a diameter of 1-2.5 mm along the entire length and after it is removed from the shell of the mobile device and for a short time (1- 2 hours) the temperature treatment at 80-90 ° С of adhesive joints is vertically mounted on the inner mold, consisting of a metal cylinder with an outer rubber cover and located on the molding post, where the inner mold with the core is reinforced with a spiral frame, articulated with an external formwork having mounted vibrators with high-frequency characteristics of concrete compaction, and then vertically vibrate the pipe with concrete compaction in the high-frequency range (4500-5500 count / min), at the end of which an immediate pipe formwork is performed, for which the external is first removed the mold, then the freshly formed pipe is vertically removed, sending it to the concrete maturing post, and the internal mold with the rubber cover remains at the molding post for subsequent manufacture rub.

The rubber cover of the internal form serves as a shock absorber for stone-like elements during high-frequency vibroforming, therefore, in this case, the vibration core, often used in the technology for manufacturing reinforced concrete pressureless pipes, is not suitable.

High-frequency vibroforming and compaction of concrete must be applied due to the fact that, according to the conditions of installation and operation, concrete of class strength of at least B 35-40 is required, and with an increased thickness of the pipe wall.

According to this method, it is possible to use asbestos-cement, ceramic and other pipes for the inner lining, but mainly stone casting pipes, basalt and diabase pipes, which give the product a high chemical resistance and abrasion resistance.

Claims (4)

1. Corrosion-resistant pipe containing an outer concrete reinforced shell, connected by cement glue to an inner stone core, consisting of several stone-milled cylindrical elements glued together 1 m long (liners), characterized in that the concrete outer shell is reinforced with an unstressed single or double spiral frame, depending on the diameter of the pipe and its wall thickness, determined by the strength of the pipe, and the inner stone core is wrapped around the perimeter with a mesh of wire with a diameter of 1 -2.5 mm, the elements of which are fastened together by end surfaces through corrosion-resistant gaskets with polyurethane or other polymer glue. 2. Corrosion-resistant pipe according to claim 1, characterized in that the glue line between the liners is wrapped with a tape of fine-fibred material impregnated with this glue 2-6 dm wide. 3. Corrosion-resistant pipe according to claim 1, characterized in that in one case (option one) it consists of an inner stone core and an outer concrete reinforced shell with a thickened wall and a monolithic concrete steel cylindrical shell, which is a pipe bell, and in another In case (option two), the pipe consists of an inner stone core and an outer reinforced concrete shell and the same socket with the usual (standard) wall thickness of the shell. 4. A method of manufacturing a corrosion-resistant pipe, including assembling the inner core from stone-cast elements (inserts) using glue, installing it in a mold, reinforcing the mold with a core, laying concrete in the mold and compacting the concrete with vibration to form a multilayer pipe, characterized in that core assembly is carried out on a mobile assembly device, where the liner is centered, glued using gaskets and glue, turning the core, coated with glue and wrapped with butt fiber in the butt joint , wrap the core over the entire length with a reinforcing mesh of wire with a diameter of 1-2.5 mm, which, after removal of the adhesive joints from the assembly shell of the mobile device and short-term heat treatment at 80-90 ° C, is vertically mounted on an internal mold consisting of a metal cylinder with an external rubber cover and located at the molding station, where the inner form with the core is reinforced with a spiral frame, articulates with the outer formwork having mounted vibrators with high-frequency characteristics concrete densification, and then vertical vibroforming is performed with concrete compaction in the high-frequency range (4500-5500 count / min), at the end of which the pipe is immediately removed, for which the outer mold is first removed, then the freshly formed pipe is vertically removed, sending it to the concrete aging post and the inner form with a rubber cover remains at the molding post for the subsequent manufacture of pipes.

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