RU2315840C2 - Construction extrusion-compensatory block, block production line and method for porous material production for block filling - Google Patents

Abstract

FIELD: construction, particularly building elements of block or other shape for the construction of parts of buildings.

SUBSTANCE: construction block comprises shell of solid sand concrete and core made of porous cement-based material. Block is produced by extrusion-compensatory method with shell cavity division into three sections by means of transversal stiffening diaphragms. The sections are shaped as triangular prisms. Solid sand concrete includes sand having gradation factor of at least 1.88. To provide cement-sand concrete plasticity during block forming tall oil pitch taken in amount of 0.3-1.5% of Portland cement mass is additionally used. Raw mix for porous material preparation includes (per 1m³ of ready mix) Portland cement - 159-300 kg, tall oil pitch - 0.9 l and aqueous protein solution with 0.75-0.9% concentration - 3.2-6.0 l. Shell and stiffening diaphragms of construction block have the same thicknesses. Shell production method and method for porous material production for shell filling are also disclosed.

EFFECT: increased quality and productivity.

3 cl, 2 tbl, 1 dwg

Description

The invention relates to the production of building materials and can be used in the manufacture of building blocks for fencing as load-bearing elements with heat-shielding properties, load-bearing elements of overlapping, coating on reinforced concrete beams of the T-profile.

Known wall building element, which is a concrete block with holes or recesses filled with foamed urea-formaldehyde resin before and after curing concrete (GB patent No. 1525238, CL E04C 1/06, publ. 09/20/1978).

The disadvantage of this unit is the complexity of its manufacture from different materials with the separation of operations, destruction of aggregate materials, over time - the loss of heat-shielding properties, the release of harmful substances into the environment during the operational period due to decomposition.

The closest in technical essence is a building element, comprising a dense shell and a core of porous material (patent RU No. 2030527, class Е04С 3/30, publ. 03/10/1995). One of the longitudinal walls of the shell along the upper plane is made with grooves for skipping connecting staples. The composition of the shell includes cement, sand and water, the core is made of cement, sand, water, foaming additives OP-3. Or "the shell is made of sand concrete, the core is made of porous sand concrete using an OP-3 foaming agent." In this invention, in order to avoid the formation of cold bridges, it is proposed to completely eliminate the installation of a “tying” element for wall dressing in the process of laying masonry (U-shaped staples from a reinforcing bar are used for dressing in two adjacent rows).

The disadvantage of this element when erecting the construction of enclosing load-bearing walls in a two-layer structure is the presence of a weak link in the ligation of the corner of the walls, since the uniform distribution of the arising stresses and forces from the overlying floors, coatings, etc.

Obviously, for the formation of the bearing part of the wall structure as a whole, it was advisable to use heavy concrete in the voids of the element and to install the reinforcing cage in corner joints. Due to the different intracenter loading during load transfer, the building element must have different thicknesses of the longitudinal and transverse walls. And this will lead to different thermal resistances in thermal protection.

In industry, wall blocks are produced mainly by volumetric vibropressing, pouring into molding and stripping forms (patent RU No. 2157875, class E04C 1/00, publ. 10/20/2000, AS No. 509429, class B28B 1/50 , publ. 04.05.1976. BI 13), the main disadvantage of which is insufficient plastic strength, vibration partially destroys the structure of crystalline hydrates of minerals of the binder.

It is known that in sandy concrete (in terms of compressive strength B7-B15), especially when using tough mixes, cement paste is always not enough to fill with an excess of fine-grained sand space. Such concretes belong to the category of large-pore (“lean”) concretes due to a decrease in the homogeneity of the material and their use as load-bearing structures is not recommended.

The formation of the shell of the block from rigid cement-sand mixtures is carried out only by volumetric vibropressing, while other methods of manufacturing building elements, in particular extrusion, cannot be used due to the abrasiveness of the material. After molding, the shell is subjected to immediate stripping and foam concrete with a bulk mass of at least 350 kg / m ³ prepared by traditional technology is poured into its core (patent RU No. 2030527, class Е04С 3/30, publ. 10.03.1995).

A method of preparing porous concrete includes dosing, mixing the components and their porization (patent RU No.2010021, class C04B 38/10, publ. 30.03.1994). Porization through gas formation during the preparation of the mixture creates the conditions for an uncontrolled reaction and the production of material with unpredictable properties.

A known line for the production of ultralight foam concrete. The starting components are mixed with foam in a batch screw mixer (Patent RU No. 2136490, class B28B 15/00, publ. 09/10/1999). Most of the artificially created bubbles are destroyed during mixing, the pores become open and, as a result, the foam concrete will have low porosity, poor air absorption and frost resistance.

The author has set the task of obtaining a building extrusion-compensation block of sand concrete by extrusion by a continuous method with increased quality and productivity. The stated problem is solved in that the building extrusion-compensation block (ECB) contains a shell made of dense sandy concrete, divided by transverse stiffness diaphragms into three sections in the form of triangular prisms, which are filled with porous material - a highly porous structural composition (VSK), which serves as a thermal diaphragm. The shell of the block and the stiffness diaphragm have the same thickness. To eliminate the abrasiveness of the cement mixture and increase ductility, to protect against equipment failure to increase the uniformity of the “lean” sand concrete mixes from which the shell is formed (ECB), an air-entraining additive, pec tal, was used. The introduction of this additive makes it possible to convert randomly arranged macropores caused by a lack of cement paste into micropores uniformly distributed throughout the product. The consumption of the additive does not exceed 0.3-1.5% per cubic meter of sand concrete, based on the mass of cement. Along the way, the following activities were carried out:

- the concrete mixer with a vertical shaft was replaced with a mixer with horizontal shafts and mixing in oncoming flows; thereby compensating for the absence of coarse aggregate, which, when mixing the concrete mixture, involves adjacent layers, contributing to mixing in microvolumes;

- circular injection of water is used in the concrete mixer, which additionally increased the quality and reduced the mixing time.

Such a system of measures and a more thorough organization of work with aggregate sand ensured the required quality of sand concrete products.

The composition of sand concrete was selected for the production of the entire range of structures for possible use in low-rise construction.

Instead of the traditionally used fine sand (M _k = 1.4), a large line of wood was used in production (M _k = 1.88); this allowed practically no increase in cement consumption.

The basis of the extrusion-compensation block is a shell made of high-strength sand concrete, which immediately after molding is filled with a highly porous structural composition (VSK) based on cement, water with the addition of 0.9 l / m ³ pitch and an aqueous solution of protein with a concentration of 0.75-0, 9 wt.% In the amount of 3.2-6 l / m ³ . Volume weight VSC 150 kg / m ³ or higher. T.O. in a single technological process, a block is produced with a bearing capacity sufficient for multi-story construction, and corresponding to regional requirements for thermal protection in accordance with SNiP P-3-79 “Construction Heat Engineering”. ECB blocks can be made with colored, embossed, chipped and flute outer faces.

The construction equipment market has a wide range of both domestic and imported technologies for the production of sand concrete products.

The proposed device for the manufacture of electronic components

The proposed line for the production of an extrusion-compensation block (ECB) consists of a preliminary preparation of a cement-sand mixture in accordance with the available recipe, which includes: a sand bunker, a cement bunker, a water distribution tank, a mortar-mixing unit, a skip elevator, a weight doser of cement, sand, water. Next is the SMK-28 vacuum belt press (extruder) located in the technological sequence, a cutting unit, a stacker, a foam generator, a cycloid type mixer, a screw pump, and a metering device.

The content of the invention in the claimed technical solution is implemented as follows.

The proposed production line allows to increase the strength of the extrusion hollow beam (representing the supporting sand-concrete shell of the ECB block).

Due to the developing high pressure in the extruder head of the tape vacuum press SMK-28, the smooth surface of the nozzles in the production of hollow beams, due to the addition of sand to the cement-sand mixture, which forms a film on the entire surface of the product that protects the beam from dehydration during the consolidation of cement sand concrete, conditions are created for thermos holding products both in heat treatment chambers and during natural drying.

The pressure developed by the SMK-28 tape vacuum press (extruder) reaches 28-29 kg / cm ² during formation. Dust formation in the production process is completely eliminated, the border of the raw materials used in chemical and physical composition expands, construction and operating costs are reduced, and at the same time the cost of finished products.

The technical result achieved during the implementation of the invention consists in obtaining a set of thermally protected standardized products, a house-building system, mainly for low-rise construction and prefabricated-monolithic construction, using uniform extrusion-compensating unit sizes, for a wide range of climatic operating conditions, and improving quality due to accuracy assembly of products. At the same time, the complexity of masonry walls with fast-erected wall blocks (ECB) is 6-10 times lower compared to brickwork. Due to its high strength and frost resistance, there is no need for plastering or subsequent expensive cladding.

The thermal diaphragm is built in such a way that a significant part of its perimeter (up to 80%) extends and overlaps the interface seams in the plane, thereby providing thermal insulation for both the ECB itself and all interface joints along the entire perimeter, eliminating difficult heat losses (cold bridges) in spans enclosing structures above window and doorways.

The technical result in the claimed device is achieved by installing fillers in the mouthpiece of the SMK-28 extruder, opening up a wide possibility of obtaining various nomenclatures (ECB), since the extruder can be produced (along with hollow beams) full-bodied for front, ordinary, with a cut for door and window openings, longitudinal, front halves for sheltering concrete lintels and floor girders, transverse halves, providing mobility of the production itself. The thermal diaphragm in the ECB is made in the form of three hollow formations, which are filled with a highly porous structural composition (VSK) based on cement with a density of more than 150 kg / m ³ in a dry state. Filling is done after cutting a hollow extrusion bar into typical block sizes.

The laying of such elements is carried out in two rows. Dressing is carried out by installing a “tychkovy” block. To eliminate possible cold bridges, the masonry is carried out on cement glue and has a minimum thickness of 1.5-2 mm. The perception of loads in the wall envelope from its own weight and other loads in the block is carried out by the shell and stiffness diaphragms. Achieving high thermal protection properties of the block is ensured by a thermal diaphragm from a highly structural composition due to the large artificially developed porous structure formed by the introduction of additives: protein and tal so far into the cement slurry.

The barrier to the penetration and accumulation of condensate moisture during operation is the shell, which separates the stiffness diaphragms and the thermal diaphragm itself, completely eliminating air convection inside the unit.

The concrete brand of the ECB supporting concrete shell, depending on the technical conditions of the project, can be M15-M 400. Without changing the technology, it is possible to produce ordinary and facing blocks (colored, flute and chipped, under a natural stone). A wall material with these characteristics replaces a three-layer wall. It is suitable for the construction of houses up to five floors and, of course, for filling the interfloor gaps of frame houses as a building envelope and not requiring additional protection (plastering) and decorative finishing.

The main advantages of the wall of the proposed blocks: low cost, calibrated block sizes and the usual masonry technology that does not differ from the construction of ordinary brick walls. There are practically no cold bridges in the block, if the masonry is carried out on cement glue.

The wall, laid out from blocks with a thickness of 38-40 cm, has a reduced thermal resistance R ₀ = 3.0-3.6 m ² ° C / W. According to modern technological standards, this is enough for most Russian regions.

The technology for producing an extrusion-compensation block (ECB) is a wall stone according to GOST 6133-84.

The invention relates to a technology for the manufacture of electronic components from sand concrete with the required strength indicators, thermal resistance for various operating conditions, to the quality of prefabricated elements in the construction of building envelopes and load-bearing structures, to the use of uniform sizes, lower construction costs, reduced material consumption and laboriousness.

The proposed technical solution contains the introduction of a complex additive in a cement-sand mixture, with the corresponding water-cement ratio, while ensuring the plasticity of the cement dough, in the formation of a hollow beam made by an extruder; introducing highly porous compositions into the cement mixture as additives; adjusting the rheological properties of the mixture.

The molding material is prepared from a cement-sand mixture by the mechanochemical method in a concrete mixer and a belt vacuum press SMK-28 (extruder).

The mechanochemical method can be classified as new, in which the molding sand at the first stage acquires plasticity by introducing an air-entraining additive with stirring.

It has been established that with equal initial data, the ratios of cement, water, sand in the mixture, determining technological parameters that affect the process of plasticity, mobility of the mass, is the addition of taly pitch in accordance with GOST 29289 - a product of wood-chemical processing in accordance with GOST 28670-90. According to the classification of GOST 12.1.007-76, tack pitch belongs to class IV - low-hazard chemical products.

As a result of the complex of studies, the formulation and technological parameters for the production of sand concrete, which is the main structural shell (hollow beam) of extrusion-compensated ECB products (wall stones), are developed in Table 1.

Table 1 №№ pp Status, indicators Example 1 Example 2 Example 3 Example 4 (comparative) one 2 3 four 5 6 one Cement PTs 400, D-20, kg 350 350 350 350 2 Sand (M _to 1.88), kg 1400 1400 1400 1400 3 Water, l 325 325 325 325 four Talovy pitch, g 1050 5250 3500 - 5 Talovy pitch, 6% of the mass. cement 0.3 1,5 1,0 - 6 Density, kg / m ³ 1920 1750 1780 2136 7 Strength, kg / cm ² 75 fifty 70 120 8 Cone draft, cm 10 9 8 3,5

The appearance of the building block of the ECB is shown in the drawing.

The shell is made as follows. As the mineral binder cement is used as a silica component used sand with _a fineness modulus M of not less than 1.88. From the storage bins through the batchers, sand and cement enter a cycloid type mixer with two horizontal auger shafts rotating in oncoming flows. There, through the metering devices, tack pitch and water are supplied. In the mixer, all components are mixed. Then the prepared mixture is conveyed by conveyor to an aggregate belt vacuum press (extruder), for example, grade SMK-28, in which the extrusion hollow beam is formed with pre-installed hollow forming elements in the mouthpiece. Pressure developed by the vacuum belt press SMC 28, when forming timber reaches 28-29 kg / cm ^2. The formed bar with a size of 400 × 188 × 200 mm, having a shell thickness and a diaphragm of rigidity of 19 mm, enters a multi-string cutter, which cuts it simultaneously into 10 blocks. After separation, the blocks enter the filling unit with a highly porous structural composition (VSK). Laying of the finished blocks is carried out with a hydraulic manipulator in cassettes, which are then sent to the zone of natural or forced drying.

The method of preparation (VSK) highly porous structural composition

Porous material (VSC) for filling the building block of the ECB is prepared as follows. In a sealed container under excess pressure and while mixing the cement of water and taly pitch, a cement-water suspension is prepared. Separately, in another closed container, liquid foam is prepared under overpressure while stirring with air and an aqueous protein solution. The resulting cement-water suspension under excess pressure is fed into the suction cavity of a centrifugal pump (ejector). Simultaneously with the cement slurry, a liquid foam in the composition of an aqueous solution of protein and air, which is a stabilizer and compressed air, is fed into the suction cavity of a centrifugal pump (ejector). When leaving the pump (ejector), the air bubbles “straighten” due to the reverse pressure drop. The finished porous mixture has closed pores, which significantly improves water absorption and frost resistance. The use of additives in VSC allows you to get a fairly stable semi-solidified mass for 5-10 minutes with evenly distributed air pores with a diameter of 0.1-1 mm, occupying 20-90% of the volume of the material. In this case, a reduction in technological humidity is achieved, not exceeding 10% by mass, and, which is especially important for porous material, a reduction of shrinkage by 1.5-2 times. According to the proposed technology, it is possible to obtain a VSK with any given density from 150 to 1050 kg / m ³ , changing the water-cement ratio (W / C) in the range of 0.6-0.9.

Table 2 provides information on the composition and properties of VSK.

table 2 №№ pp The composition of 1 m ³ indicators Example 1 Example 2 Example 3 one 2 3 four 5 one Cement PTs-100, D-20, kg 159 300 120 2 Water, l 190 212 80 3 Tall pitch, l / m ³ 0.9 0.9 0.9 four Protein, l / m ³ 3.2 3.0 6.0 5 The concentration of an aqueous solution of protein, wt.% 0.9 0.75 0.75 6 W / C 1,1 0.7 0.6 7 Density, kg / m ³ 850 1050 300

The word “compensation” defines the possibility, when using a building block in building and supporting building structures (walls, elements of typesetting and covering along T-beams), to compensate for the occurrence of stresses from perceived loads, the presence of thermal diaphragms in the block (due to the uniform structure of the block shell and diaphragms) VSK) allows you to compensate for the gradient vector (0 ° C isotherm) of alternating temperatures, to keep it practically (taking into account thermal resistance) at the edges the middle and middle parts of the building block, excluding completely frost-free delamination and peeling. In addition, at the stage of preparation of the cement-sand mixture, taking into account the added additive - pitch in the mixer with two horizontal auger shafts of the opposite rotation, the lack of cement paste is compensated for in hard mixes, eliminating the overspending of the main cement.

The word "cycloid horizontal mixer" defines the ability of the equipment to work in a cyclic mode, depending on the ductility of the mixture with different physical characteristics.

Claims (3)

1. A building block comprising a shell of dense sandy concrete and a core of porous cement-based material, characterized in that it is made by an extrusion-compensation method with a shell cavity divided by transverse stiffness diaphragms into three sections in the form of triangular prisms in a raw material mixture for to obtain dense sandy concrete, sand with a particle size modulus of at least 1.88 is used and to ensure the plasticity of cement-sand concrete during molding, tack pitch is additionally used in the amount of 0.3-1.5% by weight of Portland cement, and the raw material mixture for obtaining porous material contains, per 1 m ^{3 of the} mixture: Portland cement - 159-300 kg, tack pitch - 0.9 l and an aqueous solution of protein concentration 0, 75-0.9 wt.%, In the volume from 3.2 to 6.0 l, while this building block has the same thickness of the shell of the block and the diaphragm of rigidity. 2. A method of manufacturing a block casing (ECB) according to claim 1, characterized in that the mixing of the starting components is carried out in a cycloid type concrete mixer with two horizontal opposite rotor screw shafts in which circular injection of water is applied, and the block casing is molded by extrusion on a tape vacuum the press. 3. The method of preparing porous material for filling the shell of the block according to claim 1, characterized in that the cement slurry is mixed with the tar pitch and fed under overpressure to the suction cavity of a centrifugal pump (ejector) simultaneously with a mixture made up of overpressure consisting of air and an aqueous solution of protein.