RU2481946C2 - Method of making decorative reinforced concrete articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to construction, namely, to method of fabricating reinforced concrete articles. Method of fabricating prestressed concrete articles by off-form process at long stands comprises laying reinforcements, stretching them and locking at their ends, laying concrete mix of required grade over the stand length with simultaneous formation of bulk and positioning of reinforcements over bulk cross-section unless concrete transfer strength, release of stress and cutting obtained bulk into pieces. Said prestressed reinforcements are stretched at stand thrusts at 0.4-1.0 GPa and represent cable bundles made from continuous glass- and/or basalt-, and/or carbon fibers with tensile strength of 0.6-4.0 GPa. Fibroconrete mix is laid at articles of maximum stress over the stand length.

EFFECT: simplified process.

6 cl; 5 dwg

Description

The present invention relates to the field of construction, and more specifically to the manufacture of precast concrete combined reinforced products by formwork technology on long stands.

A known method of manufacturing prestressed reinforced concrete structures by continuous reinforcement by winding reinforcing wire or steel rope on the stops of the stand or on the product [1].

The disadvantage of this method is the narrow scope, the ability to use only small diameter wires and incompatibility with the formless molding method.

A known method of combined reinforcement of concrete products with prestressed wire, conventional reinforcement and metal fiber. In the manufacture by formless molding, the fiber is evenly distributed throughout the entire volume of the product, regardless of the stresses arising in it [2].

The disadvantage of this method is the increased consumption of reinforcement.

A known method of manufacturing prefabricated reinforced concrete prestressed products for formwork technology on long heated stands. The method consists of sequentially performing the following operations: the reinforcement is laid along the stand and passed through the holes of the fixing "comb", which ensures the design position (positioning) of the reinforcement in the cross section of the array during molding; they pull the wire or ropes with a given force and fix it on the contour stops, form the array in a sliding formwork with an extruder or a vibro-compactor, after the concrete has set strength, release the reinforcement tension from the stand stops and transfer the voltage to the concrete, then the molded mass is cut into a piece with a diamond disk [3].

The disadvantage of this method is the overspending of the reinforcement, difficulties in installing transverse reinforcement and positioning of the reinforcement during the molding of the concrete mass, low performance of products, which narrows the range of products.

The technical task of the invention is to simplify the method of manufacturing products using formwork technology due to the possibility of using non-metallic high-strength reinforcement for reinforcing, reducing material consumption through the use of combined reinforcing with various types of non-metallic reinforcement, expanding the technological capabilities and product range.

The problem is solved in such a way that in the method of manufacturing prefabricated prestressed concrete products using formless technology on long stands, including the layout of prestressed reinforcement, tensioning it with fixation on the stands of the stand, laying the concrete mix of the design grade along the length of the stand with the simultaneous molding of the array and positioning of the reinforcement along the cross section of the array, holding to a set of gearing strength of concrete, tension release and cutting of the array into products, according to the invention, as a longitudinal of the fitting reinforcement on the stops of the stand pull ropes of strands made of continuous glass and / or basalt and / or carbon fibers with a tensile strength of 0.6-4.0 GPa with a voltage of 0.4-1.0 GPa, and when forming along the length of the stand into zones occurrence in the products of the highest stresses lay fiber-reinforced concrete mixture. Moreover, in the transverse direction, composite rods or nets can be placed on the longitudinal prestressed reinforcement and fastened to longitudinal reinforced reinforcement, and the height positioning of the reinforcement is carried out using a rail during the molding process. In the transverse direction, first, composite rods or nets can be placed on the stand and positioned with clamps, and longitudinal tensioned reinforcement is laid on top and connected to the transverse one. In addition, the longitudinal tensioned reinforcement is laid in two layers, while the reinforcement of the lower layer is positioned using clamps, and the upper layer is in the process of forming the array using the rail. In the transverse direction, they can first place the working reinforcement on the stand by continuously winding and pulling the ropes on the pins located along the stand, lay longitudinal tensioned reinforcement on top, and perform height and width positioning by fastening with continuous reinforcement. As a concrete mix for forming an array, a claydite-concrete mixture can be fed to a stand.

The proposed method differs from the known one in that, as a longitudinal tensile reinforcement, ropes made of bundles made of continuous glass and / or basalt and / or carbon fibers with a tensile strength of 0.6- 4.0 GPa, and when molding along the length of the stand, fiber-reinforced concrete mix is laid in the zones of occurrence in the products of the highest stresses. In addition, at the ends of the reinforcing element and along the length, anchor devices can be easily made or fastened both to fix the tension and to improve the adhesion of the reinforcing element to the concrete of the structure, since the selected reinforcing element has the properties of a flexible non-metallic tensile element, fire-resistant, with the possibility of increased adhesion to the concrete matrix, easily anchored and joined. These properties are inherent in basalt fiber, fiberglass and carbon fiber tape tows, consisting of "thin, thickened and coarse" in accordance with the textile classification of fibers with a thickness of 5-50 microns.

In the transverse direction, composite rods or nets can be laid on the longitudinal reinforcement as working reinforcement and fastened to the longitudinal reinforcement, and the height positioning of the reinforcement can be carried out using a rail during the molding process. Transverse reinforcement of the lower level can be laid on a stand, and longitudinal tensile reinforcement on top of it. In addition, the working tensioned reinforcement can be laid on the stand by continuous winding and tensioning of the reinforcement on the stops of the stand located along the stand, and on top of it lay the longitudinal tensioned reinforcement. As a concrete mix of the design grade for the formation of the array can be used, for example, expanded clay mixture.

The content of the proposed method is reduced to the use of different types of non-metallic reinforcement to obtain products that are optimally strong and rigid to the perception of various types of loads and impacts. The proposed scheme for reinforcing concrete products with composite reinforcement is reinforced concrete with composite reinforcement with strained (stretched) fiber and an unstressed concrete matrix. As a reinforcement, a high-tech flexible, non-metallic, tensile and bending reinforcing element with high performance characteristics (fire resistance, increased adhesion to a concrete matrix, tensile modulus of 80-200 GPa (easily joined and anchored)) was used. The reinforcing element is a rope, woven or twisted from basalt fiber, carbon fiber and / or glass fiber tape tows, consisting of "thin, thickened and coarse" in accordance with the textile classification of fibers with a thickness of 5-50 microns.

The technical result is the creation of an effective method for the manufacture of combined reinforced concrete products based on basalt or glass, or carbon fiber cement composite, rigid, flexible and dispersed reinforcement using formwork technology. At the same time, reinforcing can be performed both pre-stressed and post-stressed, continuous and discrete, internal and external, working and installation.

The method is illustrated in the drawing.

Figure 1 presents a diagram of the stand formless molding in the process of folding longitudinal reinforcement; figure 2 - plan of the stand in the process of continuous reinforcement; figure 3 is a cross section of a stand with a molded array; figure 4 - the same as in figure 3 (option reinforcement); 5 is a pile with an external composite reinforcement placed in the longitudinal and transverse directions.

An approximate list of prefabricated concrete structures reinforced with non-metallic materials manufactured by the proposed technology:

prefabricated concrete driven pile, power pole support, grape rack, tongue, foundation pit fence panel, retaining wall, railway sleepers, railway support panel, expanded clay concrete panel, fence panel, soundproofing panel, multi-hollow core slab, road slab, foundation pillow , foundation beam, wall lintel, communication tray, drainage tray, border.

Depending on the type of product: stand, plate or panel, a variant of the manufacturing method is selected.

The method is as follows.

A method of manufacturing prefabricated prestressed concrete products using formwork technology is carried out on long stands. Stand 1 for formless molding consists of a track 2, stops 3 and rail tracks 4. A method of manufacturing products 5 includes operations: the layout of the reinforcement using a technological trolley 6, equipped with a device 7 for the layout and tension of the ropes; tension of reinforcement with fixation on stops 3 of stand 1; laying of concrete mixture using paver 8 for molding concrete mass 9. Molding of the mass is carried out from concrete mix of design composition (fiber-reinforced concrete and expanded clay concrete or heavy), supplied separately to hopper 10 of concrete paver 8. When molding expanded clay or heavy concrete mixture 14 along the length of the stand occurrence in the products of the highest stresses lay fiber-reinforced concrete mixture 15. In the process of molding a concrete mass 9 produce the positioning of the longitudinal tensile reinforcement 11 using ra placed on the track 2 of the stand 1 pins 17, using working composite rods or nets 12, or using a rack 16 mounted on a paver 8 (figure 4). Then carry out the exposure to a set of concrete transmission strength, tempering and cutting the array on the product. As a longitudinal tensile reinforcement, ropes of strands made of continuous glass, and / or basalt, and / or carbon fibers with a tensile strength of 0.6-4.0 GPa are tensioned on the bench stops with a voltage of 0.4-1.0 GPa.

Example No. 1.

An example implementation of a method of manufacturing flat or ribbed slab products, such as a prefabricated floor slab, road slab, foundation pillow.

A feature of plate products is that there is no need for transverse vertical reinforcement; plates are reinforced in one or two directions in one or two levels in the horizontal plane.

On the prepared stand 1 with a length of 100-200 m for formless molding of concrete products, lay out the lower layer of the longitudinal tensile reinforcement 11 and fix its ends on the stops 3 (see figure 1). Then the reinforcement is tensioned to a value of 400-1000 MPa, then composite rods or nets 12 are laid and mounted on it in the transverse direction over the longitudinal tensile reinforcement 11. These rods provide for positioning the longitudinal reinforcement 11 along the width of the formed array 9. Then, the operation of positioning the longitudinal tensile reinforcement 11 in the top layer of the array. After that, embedded parts are installed and fastened to the reinforcement. Embedded parts can be equipped with foam rubber holders, which are removed after the manufacture of the product. Then the concrete mixture is laid with surface vibrating with a paver 8 equipped with two or three bins 10, and concreting is performed in accordance with the stress diagram in the product with a mixture of various compositions - heavy 14 and fiber-reinforced concrete 15, with the addition of non-metallic fiber. For positioning the longitudinal and transverse reinforcement 11 and 12 use inventory rails 16, ensuring the design position of the reinforcement along the height of the cross section of the molded array (see figure 3, 4).

After the concrete has gained strength, the array 9 is cut into products 5 in accordance with the layout of stand 1.

Considering the corrosion resistance of non-metallic reinforcement, the bottom layer of reinforcement can be laid on spacers 18 - latches of the protective layer, directly on track 2 of stand 1 simultaneously with embedded parts.

Example No. 2.

In this embodiment (see Fig. 2), the reinforcement is performed in a continuous way by winding flexible strands onto the pins 17. The device 7 (pin) is installed on the track 3 for winding and tensioning the continuous ropes. Along the molding track 2 of stand 1 along its entire length, pins 17 are mounted to fix continuous reinforcement 12. The rope is wound at different angles from 45 to 90 degrees relative to the axis of stand 1 with the design effort. When winding in two directions, a mesh of ropes can form.

Then, on top of the continuous reinforcement 12, the longitudinal reinforcement 11 is laid out and tensioned and fixed on the continuous reinforcement 12, ensuring its positioning during molding.

Then, the mass is formed by the concrete mixture, and in areas where it is required by the project, a fiber-concrete mixture 15 with polymer or basalt fiber is laid. After the concrete has gained strength, the array 9 is sawn into pieces of the design length and finished products 5 are obtained, which are removed from stand 1 and transported to the finished goods warehouse. Depending on the method of attaching the pins 17 to the stand track, they can be left in the sockets of the stand 1 or removed together with the product 5 with the subsequent extraction or cutting them flush with the surface of the product. To facilitate the removal of products from the stand 1 on the pins 17 can be worn on the lost sleeve of aluminum or plastic tubes.

Example No. 3.

An example of the implementation of a method of manufacturing products such as pile, rack support power lines and other types of bars. Such products (see figure 5) with a thickness of more than 20 cm are made as in example 1.

A feature of prefabricated concrete piles is the difference in the nature of work under the operational and installation loads of the product (when removed from the stand, transported by transport, lifted by a pile driver). Mounting loads require the use of a significant amount of longitudinal reinforcement 11, which is not used in further work under operational load. In this regard, some part of the reinforcement, in particular, mounting, can be made of material that is destroyed during the long-term operation of the product in an alkaline environment of concrete, for example glass fiber, as well as in the form of external reinforcement without a protective layer.

On the prepared stand 1, directly on the metal track 2, external lower-level reinforcement 19 is laid for the perception of tensile stresses in the places where the maximum bending moment acts (in the middle of the span of the product) and in places of maximum efforts (for example, when driving), in the head and heel of the pile. Then the longitudinal reinforcement 11 is laid out and strained and the massif 9 is concreted with concrete mixtures of various compositions.

Then, immersed parts of the external reinforcement 19 and embedded parts of the upper level are installed in the concrete mixture of the freshly formed products.

After the manufacture of the product 5, the reinforcement 19 protrudes outward and does not have a protective layer, since after immersion of the pile the functions of the external reinforcement 19 will be fulfilled.

Information sources

1. Recommendations for the manufacture of prestressed reinforced concrete structures by continuous reinforcement. NIIZHB Gosstoy of the USSR, M., 1986.

2. Recommendations for the design and construction of steel fiber concrete structures. SP 52-104-2006. NIIZHB them. A.A. Gvozdeva. M., 2009.

3. Dzhantimirov H.A., Yalaev P.P. Formwork-free technology for manufacturing prestressed piles without transverse reinforcement. Foundations, foundations and soil mechanics. No. 2, 2009 / prototype /.

Claims (6)

1. A method of manufacturing prefabricated prestressed concrete products using formwork technology on long stands, including the layout of prestressed reinforcement, tensioning it with fixation on the stand stops, laying the concrete mix of the design grade along the length of the stand with the simultaneous molding of the array and positioning of the reinforcement along the section of the array, exposure to a set of gearing strength of concrete, tension release and cutting of the massif into products, characterized in that, as longitudinal tensile reinforcement, the stands are pulled with with a voltage of 0.4-1.0 GPa, ropes made of bundles made of continuous glass, and / or basalt, and / or carbon fibers with a tensile strength of 0.6-4.0 GPa, and when forming along the length of the stand, fiber reinforced concrete is laid in the zones of the greatest stress mixture. 2. The method according to claim 1, characterized in that in the transverse direction on the longitudinal prestressed reinforcement, composite rods or nets are placed and fastened to the longitudinal prestressed reinforcement, and the longitudinal tensioned reinforcement is positioned in height by means of a rail during the molding process. 3. The method according to claim 1, characterized in that in the transverse direction, first, composite rods or nets are placed on the stand and positioned using clamps, and longitudinal tensioned reinforcement is laid on top and connected to the transverse one. 4. The method according to claim 3, characterized in that the longitudinal tensile reinforcement is laid in two levels, while the lower-level reinforcement is laid on a stand, and the upper level is positioned in the process of forming the array using a rail. 5. The method according to claim 1, characterized in that in the transverse direction, first, the working reinforcement is placed on the stand by continuous winding and tensioning of ropes on the pins located along the stand, and the longitudinal tensioned reinforcement is laid on top, and the latter is positioned in width by fasteners with continuous reinforcement. 6. The method according to claim 1, characterized in that as a concrete mixture for molding the array on the stand serves expanded clay mixture.

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