RU231891U1 - Arched reinforced concrete structure with prestressing without adhesion to concrete - Google Patents

Abstract

The utility model relates to construction, namely to prestressed arched reinforced concrete structures without adhesion to concrete, and can be used for crossing small water barriers in the form of streams and small rivers. An arched reinforced concrete structure with prestressing without adhesion to concrete, comprising a main body made of monolithic concrete, having a symmetrical T-shaped cross-section, working reinforcement made of individual radius bent rods of periodic profile, steel reinforcement cables - monostrands, covered with a continuous polymer shell with a layer of anti-corrosion composition, which are used as upper and lower reinforcement, and located in the longitudinal direction, auxiliary reinforcement made of individual bent rods of periodic profile, auxiliary reinforcement made of stirrups of periodic profile, support embedded parts installed in the base of the formwork, upper and lower end embedded parts located on steel reinforcement cables - monostrands, wherein the collets are located on the ends of the arched reinforced concrete structure, resting against the embedded parts. The technical result of using the claimed solution consists in increasing the durability of an arched reinforced concrete structure with preliminary stress without adhesion to concrete due to the possibility of additional tensioning of the cable reinforcement when a portion of the strength is lost during operation due to relaxation, as well as combining such products into a single element for use both for a pedestrian zone and for the passage of motor vehicles. 7 s.p. f-ly, 11 ill.

Description

The field of technology to which the utility model relates

The utility model relates to construction, namely to prestressed arched reinforced concrete structures without adhesion to concrete, and can be used for crossing small water barriers in the form of streams and small rivers.

State of the art

The first prestressed concrete bridge was built in 1938 according to Freyssin's plans in Oelde on the motorway from Dortmund to Hanover. The special feature of the prestressing system without adhesion to concrete is the absence of the injection process, since steel wire ropes in a sheath ("monostrand") with double anti-corrosion protection in the form of plastic grease and a plastic tube are used as prestressed reinforcement elements working without adhesion to concrete. The grease helps reduce friction forces when tensioning the rope, and the plastic tube allows tensioning the reinforcement rope after concreting and the concrete reaching its design strength. The rope in the sheath does not come into contact with the concrete during its entire service life.

In construction, the most commonly used arches are those with tension on supports and those with tension above supports, and variable cross-section arches. Prestressing without adhesion to concrete is most often used, which is performed immediately before the installation of the structure, since the arches are assembled or poured from a monolith at the construction site. The most difficult thing when working with arched structures is the placement of prestressed reinforcement along the arc, since the cable reinforcement must be placed strictly according to the moment diagram in the longitudinal direction. According to the static scheme, arched bridges are divided into:

1. Strut arch bridges;

2. Arched systems with ties (non-thrust).

A single-span metal beam bridge is known (the Flour Bridge in St. Petersburg). The span structure consists of two steel I-beams 0.8 m high at the locks. The distances in the axes of the main beams are 2.26 m. The upper and lower belts of the beams are outlined along circular curves of different radii, which increases the height of the beams at the supports to 1.26 m. The assembly joints of the main beams are welded and on high-strength bolts. The calculated span is 20.2 m. The abutments are monolithic reinforced concrete on a pile foundation made of bored piles. The length of the bridge (along the rear faces of the abutments) is 22.0 m, the width is 2.3 m. The bridge is intended for pedestrian traffic and laying heating pipes. The walkway is made of removable metal panels consisting of 12 mm thick metal sheets reinforced with longitudinal and transverse stiffeners. The covering of the walkway is a thin-layer polymer. The railing is welded metal, with a simple design. A metal cornice is arranged along the facades of the main beams.

The disadvantages of the known solution are that it is metal and during its operation the surface layer of the metal needs to be maintained, with the need for painting, etc.

A single-span arched bridge with a solid reinforced concrete hingeless vault is known (the Hermitage Bridge in St. Petersburg). The bridge abutments are made of rubble masonry on a pile foundation, faced with granite. The thickness of the reinforced concrete vault at the lock is 25 cm, at the heels - 45 cm; the dimensions of the elliptical vault in the clear are 9.73 m, with an arrow of rise of its internal outline of 3 m. The facades are faced with granite with rusticated stone in the lock. The length of the bridge is 12.2 m (24.8 m along the rear faces of the abutments), the width is 15.2 m (16.5 m along the cornices). The bridge is intended for the movement of vehicles and pedestrians. The roadway of the bridge includes two lanes for the movement of vehicles. The road surface is asphalt concrete, the sidewalks are covered with granite slabs. The sidewalks are separated from the roadway by a granite curb. Blind granite parapets are used as fences. The sidewalks of the bridge and embankments are connected by steps.

The disadvantages of the known solution are that the bridge cladding, as well as the roadway fencing, are made of granite, which results in a large mass.

A single-span reinforced concrete arch bridge is known (the Baltic Bridge in St. Petersburg). The span structure is a double-hinged arch. In the cross section, two monolithic reinforced concrete arches of an L-shaped section are installed, with a distance in the axes of 3.8 m. Precast reinforced concrete slabs of the walkway are laid on top between the arches. In addition, along the length of the arches they are connected by transverse diaphragms, simultaneously serving to support two heat-conducting pipes with a diameter of 82 cm. The height of the arch in the lock is 1.04 m, in the heel - 3.20 m. The bridge abutments are monolithic reinforced concrete, on a pile wooden foundation. The facades of the arches and abutments are faced with pink granite. The calculated span is 21.5 m. The length of the bridge along the rear walls of the abutments is 22.80 m, along the axis of the embankment railings - 33.0 m, width - 4.5 m.

This bridge is intended for pedestrian traffic. The surface of the walkway is asphalt concrete.

Disclosure of a utility model

The technical result, when using the claimed solution, consists in increasing the durability of an arched reinforced concrete structure with preliminary stress without adhesion to concrete, due to the possibility of additional tensioning of the cable reinforcement when a portion of the strength is lost during operation due to relaxation, as well as combining such products into one element for use both for a pedestrian zone and for the passage of motor vehicles.

The technical result is achieved in that the prestressed arched reinforced concrete structure without adhesion to concrete contains a main body made of monolithic concrete, having a T-shaped symmetrical cross-section, working reinforcement made of individual radius bent rods of periodic profile, steel reinforcement cables - monostrands, covered with a continuous polymer shell with a layer of anti-corrosion composition, which are used as upper and lower reinforcement, and located in the longitudinal direction, auxiliary reinforcement made of individual bent rods of periodic profile, auxiliary reinforcement made of clamps of periodic profile, support embedded parts installed in the base of the formwork, upper and lower end embedded parts located on the steel reinforcement cables - monostrands, wherein the collets are located on the ends of the arched reinforced concrete structure, resting against the embedded parts. The prestressed structure without adhesion to concrete may additionally contain fences in the form of fiber-reinforced concrete hanging self-supporting panels, aluminum railings, or fences made of steel, galvanized, stainless steel or forged elements. The prestressed arched reinforced concrete structure without adhesion to concrete may additionally contain single reinforced concrete steps with an anti-slip coating, a wear-resistant composite coating containing dry rounded quartz sand, a preferred fraction of 0.8-1.2 mm, distributed on a one- or two-component polyurethane primer-enamel pre-applied to the base. The arched reinforced concrete structure may additionally contain single reinforced concrete steps with an anti-slip coating in the form of milled longitudinal grooves made in factory conditions. The arched reinforced concrete structure may additionally contain single reinforced concrete steps with an anti-slip polymer composition based on epoxy, polyurethane and methyl acrylate compounds. The arched reinforced concrete structure may additionally contain single reinforced concrete steps with anti-slip inserts made of ribbed polyurethane strips inlaid into the concrete at the molding stage. The arched reinforced concrete structure with prestressing without adhesion to concrete has the ability to combine at least two arched reinforced concrete structures into groups by width. In the arched reinforced concrete structure with prestressing without adhesion to concrete, the length of one structure is from 12,000 to 24,000 mm, and the width is from 1,500 to 3,000 mm. The arched reinforced concrete structure with prestressing without adhesion to concrete has the ability to combine three or more elements to enable the bridge to be used for both pedestrians and for the passage of motor vehicles in the forward and oncoming directions. Both single hollow and solid stair steps can be used as steps.

Brief description of the drawings

Fig. 1 shows the loading diagram of the arched reinforced concrete structure, Fig. 2-6 shows the longitudinal and transverse sections of the reinforcement cage of the arched reinforced concrete structure, Fig. 7 shows the end view of the arched reinforced concrete structure, Fig. 8 shows the visualization of the arched reinforced concrete structure after removal from the formwork, with stair steps and railings installed on it, through welding with embedded parts (embedded parts are not shown conditionally), Fig. 9 shows the visualization of arched reinforced concrete structures combined into a group, Fig. 10 shows the visualization of the arched reinforced concrete structure, Fig. 11 shows a photograph of loading tests of the arched reinforced concrete structure, where:

1 - the main body of the arched reinforced concrete structure,

2 - foundation building blocks, with the help of which the loading of the arched reinforced concrete structure is carried out,

3 - foundation building blocks installed on the sides of the arched reinforced concrete structure as insurance against overturning during loading tests,

4 - metal gussets,

5 - working reinforcement made of individual radius bent rods of periodic profile,

6-9 - working reinforcement made of high-strength steel reinforcement ropes - monostrands, covered with a continuous polymer sheath with an interlayer of anti-corrosion compound,

10 - auxiliary reinforcement made of individual bent rods of periodic profile,

11 - auxiliary reinforcement made of periodic profile clamps,

12 - supporting embedded parts,

13 - lower end embedded parts,

14 - upper end embedded parts,

15 - collets,

16 - reinforced concrete steps,

17 - fences,

18 - anti-slip coating.

Implementation of a utility model

The claimed technical solution is as follows. The prestressed arched reinforced concrete structure without adhesion to concrete consists of the main body 1 made of monolithic concrete, preferably of class not lower than B40, frost resistance not lower than F ₂ 200, water resistance not lower than W8, has a T-shaped symmetrical cross-section, and prestressing is used, in which steel reinforcement ropes - monostrands 6-9, covered with a continuous polymer shell with an interlayer of anti-corrosion composition (according to the calculation) according to STO 71915393-TU100-2010 together with a set of collets 15, which are subdivided into passive and active collets, are used in the upper and lower parts of the structure as upper and lower working reinforcement. The layout of the steel reinforcement ropes - monostrands 6-9 is performed strictly according to the moment diagram in the longitudinal direction. The transfer of forces from the steel reinforcement ropes - monostrands 6-9 to the concrete is carried out through active and passive collets 15 installed on the ends of the structure, which rest against the embedded parts 13, 14, anchored in the end part of the structure. The passive collet 15 fixes the ends of the steel reinforcement ropes - monostrands 6-9 on the end of the structure and does not allow them to pull through when working with preliminary tension, and the active collet 15 secures the steel reinforcement ropes - monostrands 6-9 after tensioning. After tensioning in the hardened concrete, the steel reinforcement ropes - monostrands 6-9 remain in a polymer shell, which isolates the steel reinforcement ropes - monostrands 6-9 from the effects of the alkaline environment of the concrete during the operation of the arched reinforced concrete structure. The collets 15 are installed on both sides of the arched reinforced concrete structure and structurally they are located outside the main body 1 of the arched reinforced concrete structure, namely, outside, since they rest against the outer part of the embedded parts 13, 14 installed along the ends of the main body 1 of the arched reinforced concrete structure. The upper and lower end embedded parts 13, 14, against which the collets 15 rest, are put on steel reinforcement ropes - monostrands 6-9, wherein the steel reinforcement ropes - monostrands 6-9 are passed through through holes in the embedded parts 13, 14. The arched reinforced concrete structure can additionally contain fences 17 in the form of fiber-reinforced concrete hanging self-supporting panels, or aluminum railings, as well as fences made of forged elements. The arched reinforced concrete structure has the ability to combine at least two arched reinforced concrete structures into groups by width, for example: one structure with solid or hollow reinforced concrete steps 16 in a quantity corresponding to the project with an anti-slip coating 18.

Example 1. Three arched reinforced concrete structures are combined into a group by width to organize a pedestrian zone.

Example 2. Two arched reinforced concrete structures are combined into a group by width, with pedestrian traffic organized along one arched reinforced concrete structure, and traffic on individual mobility devices possible along the second arched reinforced concrete structure, both with fencing 17, for separating the flows, and without it.

Example 3. Four or more arched reinforced concrete structures are combined into a group by width, whereby on one arched reinforced concrete structure located on the sides it is possible to organize pedestrian traffic or traffic on individual mobility devices with the installation of barriers 17 for traffic safety, and on the remaining installed arched reinforced concrete structures it is possible to have one or multi-lane traffic of motor vehicles with the application of horizontal traffic markings within the lanes.

The length of the arched reinforced concrete structure is preferably from 8000 mm to 36,000 mm, and the width is from 1500 to 3000 mm.

The manufacturing method of the claimed technical solution consists in manufacturing separate individual elements of the future formwork form from sheet material, on a machine with Numerical Program Control (CNC) with their subsequent unification into the formwork form. Fig. 2-6 shows the reinforcement of an arched reinforced concrete structure, where in the process of manufacturing a volumetric reinforcement cage, auxiliary reinforcement made of separate bent rods 10, as well as from stirrups of a periodic profile 11, is sequentially distributed on a conductor stand, then the working reinforcement made of separate radius bent rods 5 of a periodic profile is tied. Next, the volumetric reinforcement cage is laid using crane equipment and a set of lifting devices in the prepared and lubricated formwork form, supporting embedded parts 12, end upper 14 and lower 13 embedded parts are placed in the base of the form, against which, after the concrete has gained the appropriate strength, the collets 15 will rest, holding in a taut state the pre-stressed steel reinforcement cables - monostrands 6-9 and loops necessary both for removing the main body 1 of the arched reinforced concrete structure from the formwork form and for transportation and installation. Next, the steel reinforcement cables 6-9, covered with a continuous polymer shell with an interlayer of anti-corrosion compound, are pulled into the design position through the end sides of the form with positioning in the volume of the product strictly according to the moment diagram in the longitudinal direction, according to the design requirements. Concreting of a monolithic arched reinforced concrete structure is carried out by placing concrete mixture into a prepared form with reinforcement accepted by technical services.

After achieving the stripping strength and permission for removal, the main body 1 of the arched reinforced concrete structure is removed from the formwork. Then, collets 15 are installed on the ends of the arched reinforced concrete structure, after which, using equipment for single tensioning, prestressing is performed without adhesion to concrete with the transfer of the calculated compression force to the end parts of the product with embedded parts 13 and 14 located on them and fixed with collets 15. Collets 15 can be of any manufacturer and must allow working with prestressed reinforcement. Tensioning of steel reinforcement ropes - monostrands 6-9 is performed in a checkerboard pattern from the edges to the middle and from the upper row to the lower. In the declared arched reinforced concrete structure, the zone is stretched not only from below, but also from above.

An arched reinforced concrete structure is obtained with a length from 8000 mm to 36,000 mm, a width from 1500 to 3000 mm, a height from 1500 mm (at the lowest point of the arched reinforced concrete structure). The service life is at least 30 years. The bearing capacity of the arched reinforced concrete structure is 20 tons, which is confirmed by full-scale tests in Fig. 1, during which the arched reinforced concrete structure is installed using an overhead crane and a set of lifting devices on foundation blocks 3 for conducting loading tests, loaded with foundation blocks 2, with the help of which the arched reinforced concrete structure is loaded, wherein the outer foundation blocks 2 are supported using metal gussets 4, fixed on the upper end embedded parts 14.

Compared with known solutions, the claimed utility model allows:

1) reduce the overall weight,

2) increase seismic resistance,

3) increase strength,

4) reduce the consumption of concrete and non-stressed reinforcement,

5) reduce the deflections of the reinforced concrete structure during its service life,

6) to increase the durability and reliability of the prestressed reinforced concrete arch structure without adhesion to concrete, which can be combined into groups by width. The protective anti-corrosion coating of the seven-wire reinforcement rope allows to increase the durability of the structure due to the absence of corrosion.

Claims (8)

1. An arched reinforced concrete structure with prestressing without adhesion to concrete, comprising a main body (1) made of monolithic concrete, having a symmetrical T-shaped cross-section, working reinforcement made of individual radius bent rods of periodic profile (5), steel reinforcement cables - monostrands, covered with a continuous polymer shell with a layer of anti-corrosion composition, which are used as upper and lower reinforcement, and located in the longitudinal direction (6-9), auxiliary reinforcement made of individual bent rods of periodic profile (10), auxiliary reinforcement made of stirrups of periodic profile (11), support embedded parts (12), upper (14) and lower (13) end embedded parts located on steel reinforcement cables - monostrands (6-9), wherein collets (15) are located at the ends of the arched reinforced concrete structure, resting on embedded parts (13, 14). 2. An arched reinforced concrete structure with prestressing without adhesion to concrete according to paragraph 1, characterized in that it additionally contains fences (17) in the form of fiber-reinforced concrete self-supporting suspended panels, or aluminum railings, or fences made of steel, galvanized, stainless steel or forged elements. 3. An arched reinforced concrete structure with prestressing without adhesion to concrete according to claim 1, characterized in that it additionally contains single reinforced concrete steps (16) with an anti-slip wear-resistant composite coating (18) containing dry rounded quartz sand, with a preferred fraction of 0.8-1.2 mm, distributed over a one- or two-component polyurethane primer-enamel previously applied to the base. 4. An arched reinforced concrete structure with prestressing without adhesion to concrete according to paragraph 1, characterized in that it additionally contains single reinforced concrete steps (16) with an anti-slip coating (18) in the form of milled longitudinal grooves made in factory conditions. 5. An arched reinforced concrete structure with prestressing without adhesion to concrete according to paragraph 1, characterized in that it additionally contains single reinforced concrete steps with an anti-slip polymer composition based on epoxy, polyurethane and methyl acrylate compounds. 6. An arched reinforced concrete structure with prestressing without adhesion to concrete according to paragraph 1, characterized in that it additionally contains single reinforced concrete steps (16) with anti-slip inserts made of ribbed polyurethane strips inlaid into the concrete at the molding stage. 7. An arched reinforced concrete structure with prestressing without adhesion to concrete according to paragraph 1, characterized in that the length of one structure is from 12,000 to 24,000 mm, and the width is from 1,500 to 3,000 mm. 8. An arched reinforced concrete structure with prestressing without adhesion to concrete according to any of paragraphs 3-6, characterized in that both single hollow and solid stair steps are used as steps (16).