RU199196U1 - MULTI-CAPACITY PRE-STRESSED CERAMZITE CONCRETE OVERLAPPING PLATE WITH INCREASED ANCHORING OF THE VALVES - Google Patents

Abstract

The utility model relates to the production of building structures, in particular to the production of hollow-core reinforced concrete floor slabs by the method of stand-off formwork. , and working reinforcement 6. The slab body is completely made of expanded clay concrete, in which high-strength expanded clay gravel of round shape, a mixture of fractions 0-20 mm, with low water absorption is used as a large aggregate, which creates a dense structure of a molded monolith along the entire length of the product, and As working reinforcement, steel reinforcing seven-wire, prestressed ropes 6, placed in the lower part of the slab body, were used. The technical result of using the proposed claydite-concrete floor slab is to improve the quality and reliability of the structure, as well as to eliminate the sealing of voids at the ends of the slabs, in the case when the value of stresses in the walls from the loads of the overlying floors should not exceed 2.4 MPa. Execution of the slab body from expanded clay concrete using high-strength expanded clay gravel of a round shape as an aggregate, in conjunction with steel seven-wire prestressed ropes, allows reliable anchoring of working reinforcement without the use of additional means. 2 ill.

Description

The utility model relates to the production of building structures, namely to the production of hollow-core reinforced concrete floor slabs by the method of stand-off formwork molding.

From the prior art, hollow-core slabs are known, made by the method of formless molding, for example, a hollow-core building product and a method for its manufacture according to RF patent No. 2204665, IPC V 28 V 3/20, 2003, according to which, laying on a stand of longitudinal reinforcement, installation in the front part of the stand enclosing the longitudinal reinforcement of a horizontally movable forming unit, laying in the process of its continuous movement along the longitudinal reinforcement of the concrete mixture on the stand pallet during the formation of a hollow-core massif of the body of a building product, cutting into separate products, holding the product for a set of stripping strength, formation in two stages in the longitudinal voids of the molded array of symmetric loop grips from installed in two levels and in contact with each other at the intersection points of crosswise arranged reinforcing bars, with the formation of a symmetrical loop grip, the sections of the upper surface of the concrete mass are collapsed siva over grips from reinforcing bars placed in its voids with the formation of through gripping nests. The described manufacturing technology refers mainly to the device of slinging elements in the product for the implementation of its demolding, movement by lifting mechanisms and installation on the construction site.

Known prefabricated hollow-core reinforced concrete slabs of lightweight concrete prestressed with rods made of steel of class A-IV according to the series II-04-4 "Reinforced concrete floor panels" issue 21. This structure includes a hollow-core slab made of lightweight concrete and prestressed rod or wire reinforcement tensioned on stops. This design has increased heat-engineering properties and reduced weight, but it has additional reinforcement in the form of nets and frames, which increases the price of the product.

It is also known that a technical solution for a patent for a useful model No. 115379 IPC E04B 5/02, publ. 27.04.2012 hollow-core prestressed lightweight aggregate concrete floor slab, manufactured by the method of stand-off formwork molding. The middle part of the slab's concrete body is made of expanded clay concrete. Inside the concrete body, there are voids oriented along the slab body. The support sections of the slab are made of heavy concrete and are anchors for reinforcement made of high-strength prestressed wire installed in the slab body. A hollow-core prestressed reinforced concrete floor slab is manufactured on a formwork stand. The pre-stressed high-strength wire is tensioned on the stops. The hollow-core floor slab is divided into sections: support and middle. The support sections are made of heavy concrete and increase the anchoring of the high-strength wire. The middle part of the slab is made of expanded clay concrete. A hollow-core slab is made in the following way: first, a high-strength reinforcing wire is pulled on stops installed at the ends of the stand, after which the hollow-core slab is concreted at a form-free stand. At the same time, heavy concrete is laid on the support sections of the slab, and expanded clay concrete is supplied in the middle sections. The support sections, made of heavy concrete, function as anchors for prestressed reinforcing wire and are subject to the known building codes used in the calculation of anchoring. The voids are made using standard core formers. Anchoring of high-strength wire is achieved by using heavy concrete in the support areas.

The disadvantage of the described hollow-core slab, according to the applicant, is the execution of the slab from a heterogeneous material, namely, the execution of sections of the slab from heavy concrete, which are anchors for reinforcement, and the middle part of the slab from lightweight concrete. But this technical solution is difficult to implement in the actual conditions of the production process in the mass production of products using the technology of stand-off formwork molding, since it is necessary to change the concrete mixture in the molding machine during the time of manufacture of each product on the molding stand.

The closest technical solution (prototype) is a utility model under patent No. 133548, IPC E04B 5/02, publ. 20.10.2013, hollow pre-stressed expanded clay concrete floor slab with increased anchoring of reinforcement, containing a slab body in which internal voids are made oriented along it, and working reinforcement made of high-strength prestressed wire, in which the supporting sections of the slab body are made of expanded clay concrete with the addition of metal fiber or fiber from composite materials. The known technical solution involves the implementation of the slab body from a homogeneous material, in which, in order to increase the reliability of the anchoring, the support sections are made of expanded clay concrete with the addition of metal fiber or fiber from composite materials, which complicates the technology and increases the cost of the finished product. In addition, the technology of no-form molding implies a production process from rigid mixtures, and in rigid mixtures, as practice shows, the use of fiber is impractical due to its insufficient anchoring in expanded clay concrete stone. During the production process, the mixture becomes non-technological (not free-flowing), which makes it difficult for it to enter the working bodies of the forming machine.

The problem to be solved by the invention is to create a hollow-core floor slab, made using stand-off formwork technology, from expanded clay concrete mixture, which provides reliable anchoring of prestressed reinforcement without strengthening the support zone of the slab.

The problem is solved by using expanded clay concrete with a high class of compressive strength B30, where in the concrete mixture, as a coarse aggregate, high-strength expanded clay gravel of round shape, a mixture of fractions of 0-20 mm and low water absorption from 5% to 15%, in comparison with the requirements GOST 32496-2013 “Porous aggregates for lightweight concrete. Technical conditions ", as well as due to the additional use of steel reinforcing seven-wire stabilized ropes as working prestressed reinforcement.

The technical result of using the proposed hollow-core pre-stressed expanded clay concrete floor slab is to ensure high quality and reliability of the structure, as well as to exclude the sealing of voids at the ends of the slabs, in the case when the stress in the walls from the loads of the overlying floors should not exceed 2.4 MPa (FGBU series " TsNIIP of the Ministry of Construction of Russia "), at the same time it allows to ensure reliable anchoring of working reinforcement without the use of additional means.

The essence of the utility model is that in a hollow pre-stressed expanded clay concrete floor slab, with increased anchoring of reinforcement made by formless molding and containing a slab body in which internal voids are made, oriented along it, and working reinforcement made of high-strength pre-stressed reinforcement, the body slabs are completely made of expanded clay concrete with a high class of compressive strength, in which round-shaped expanded clay gravel is used as a coarse aggregate, a mixture of fractions of 0-20 mm, with low water absorption, allowing to provide a dense structure of a molded monolith along the entire length of the product, and as a working armature used steel reinforcing seven-wire, prestressed stabilized ropes.

The utility model is illustrated with graphic materials.

Figure 1 shows a general view of the proposed hollow pre-stressed expanded clay concrete floor slab at the time of production of the slab at the stand without formwork (before cutting).

Figure 2 is a hollow pre-stressed expanded clay concrete floor slab in section.

FIG. 1 shows stand 1, with an active end, 2 and a passive end 3. The stand is a slab 4. Hollow claydite concrete floor slab 4 (Fig. 1) contains a slab body (Fig. 1, 2) made of expanded clay concrete with a high strength class for compression, where in the concrete mixture, high-strength expanded clay gravel with a strength of 6 MPa according to GOST 9758-2012 is used as a coarse aggregate, a rounded mixture of fractions of 0-20 mm, which creates a dense structure of a molded monolith along the entire length of the product (see the explanatory photo) ... The prestressed structural wire 5 is located in the upper part of the slab, and the working reinforcement 6 is located in the lower part of the slab body 4. In the slab 4 body, voids 7 (Fig. 2) are made, oriented along the span of the slab body. Working reinforcement 6 is made in the form of steel reinforcing seven-wire prestressed ropes, stabilized in accordance with GOST R 53772-2010. The body of slab 4 is made of a homogeneous mass of expanded clay concrete of a high class in terms of compressive strength B30 with expanded clay gravel of a rounded shape as a large aggregate providing a dense structure of the molded monolith along the entire length of the product. Mounting loops 8 are made in the body of the slab 4. Longitudinal voids 7 have a special "skull-like" shape, which creates additional anchoring (compression) of the working reinforcement in the lower zone of the slab when the tension is released, due to the presence of side recesses 9 (Fig. 2). A metal comb 10 is fixed on the stand 1, and collet clamps 11 are installed (Fig. 1).

In Fig. 1, an arrow shows the direction of production.

The production of hollow-core floor slabs using the bench technology of no-form molding is carried out as follows. On a heated metal stand 1, through a special system of rollers of a forming machine (not shown in the figure) and a metal comb 10 (Fig. 1), a prestressed wire 5 (Fig. 2) for the upper zone and reinforcing ropes 6 for the lower zone are fed to the stand. With the help of special collet clamps 11 (Fig. 1), the ends of the ropes 6 and wire 5 are fixed on the rear plate of the multifunctional trolley (not shown in the Fig.). The trolley is set in motion and moves the captured ends of the reinforcement towards the passive end 3 of the stand 1. When the passive end of the stand is reached, the collet clamps 11 are removed, and the ropes and wire are installed strictly in the indicated places (according to the reinforcement task) of the end stop plate and fixed with collet clamps 11 (Fig. 1). After installing the reinforcement and collet clamps, remove the formed reinforcing loop. Then, from the side of the active end of the stand, the rope 6 is trimmed so that the remaining edge of the rope, after passing through the second stop plate and installing the collet clamp, has a sufficient length to be able to be gripped (by hydraulic jack). Then the multifunctional trolley returns to the active end 2 of the stand and the reinforcement process is repeated. After that, with the help of a hydraulic jack, the process of mechanical tension of the reinforcement is carried out, first the working reinforcement of the lower zone, then the structural reinforcement of the upper zone.

Then follows the molding process, in which the expanded clay concrete mixture is fed into the molding machine layer by layer, first to the lower zone and after compaction to the upper zone, followed by compaction. Expanded clay concrete mixture with a high class of compressive strength B30, where in the concrete mixture, as a large aggregate, high-strength expanded clay gravel of rounded shape, a mixture of fractions 0-20 mm with a strength of 6 MPa according to GOST 9758-2012 and low water absorption is used.

The rounded shape of expanded clay gravel ensures uniform penetration of expanded clay concrete mixture into all forming bodies of the molding machine. To ensure the required category of the front ceiling surface A2 in accordance with GOST 9561-2016 “Reinforced concrete hollow-core floor slabs for buildings and structures. Technical conditions ”, a water mirror is supplied before the lower layer is fed. To ensure the stability of the expanded clay concrete mixture in terms of rigidity, an automated process of preparation and transportation to the place of molding is used.

Marking on plates of a given standard size is carried out using a marking machine. The slinging loops are installed in the freshly formed concrete canvas into the hollow channel 7. Next, the slinging loop 8 is installed, and it is cast with concrete. Then, the stand is covered with a reinforced waterproof cover to form a film on the concrete surface (not shown in the figure). After that, heat treatment of the product is carried out, which consists in transferring heat to the freshly formed product from the heated metal surface on which it was made. The duration of the heat treatment process is 16 hours. The heat treatment process begins at the moment of the end of molding and opening of the gate valve for supplying the heat carrier with the provision of the specified temperature at the inlet. When the concrete reaches its transfer strength, 70% of the brand strength, but not less than 21 MPa, stress is released from the reinforcement. The finished slabs are removed from the stand using special auto-grippers, or with rope slings by hooks on the slings for the formed mounting loops.

As plugs, when installing the mounting loops, concrete is used after the collapse of the upper flange of the slab, the purpose of which is to exclude the leakage of the grouting concrete from the installation zone of the sling loop and to ensure its thorough compaction with a concrete mixture of strength class at least B22.5, having a mobility of O.K. = 6 - 8 cm so that the concrete mix completely fills the space under the roof of the hollow channel.

Traditional equipment is used for the device of samples, notches and various technological holes.

The process of sawing the hardened monolith into slabs of a given standard size is carried out by a special automatic cutting machine equipped with a cutting disc with diamond-containing briquettes.

The use of the proposed hollow pre-stressed expanded clay concrete floor slab, completely made of expanded clay concrete with a high strength class, in which a round expanded clay gravel is used as a large aggregate, which ensures the creation of a dense structure of the molded monolith along the entire length of the product, ensures high quality and reliability of the structure, which, together with the use of steel reinforcing seven-wire prestressed ropes as a working armature, ensures reliable anchoring of the working armature without the use of additional means. The aforementioned characteristics of the slab are confirmed by the creation of a series of working albums with the calculation of the bearing capacity of floor slabs, developed by the Federal State Budgetary Institution TsNIIP of the Ministry of Construction of Russia for production at Zavod ZhBK-1, by actual testing of floor slabs by the loading method in accordance with GOST 8829-2018 "Reinforced concrete and concrete construction products prefabricated. Loading test methods. Rules for assessing strength, stiffness and crack resistance ", and are reflected in the test reports." In addition, it should be noted that at present the serial production of expanded clay concrete slabs has been prepared.

Thus, the problem facing the invention has been solved.

Claims (1)

A hollow pre-stressed expanded clay concrete floor slab containing a slab body in which internal voids oriented along it are made, and working reinforcement, characterized in that the slab body is completely made of expanded clay concrete, in which high-strength expanded clay gravel is used as a filler, a mixture of fractions no more 20 mm round shape, with low water absorption, which creates a dense structure of the molded monolith along the entire length of the product, and steel reinforcing seven-wire, prestressed ropes placed in the lower part of the slab body are used as working reinforcement.

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