SU1643150A1 - Method of manufacturing concrete products - Google Patents

Abstract

The invention relates to the manufacture of products from lightweight concrete on hot porous aggregates and can be used in building materials mills. The purpose of the invention is to increase the strength of concrete and reduce the time to manufacture the product. The essence of the invention is that coarse porous aggregate - expanded clay, having a temperature of 160-220 ° C, is placed in a mold to heat it, then the cement-sand mortar component of a concrete mix with a water-cement ratio is placed in the mold. , 6-0.7, vibration mixing and vibration compaction followed by isothermal exposure are carried out. The strength of concrete depending on the water-cement ratio | Sheni is 7.6-13.2 MPa „1 table„

Description

The invention relates to the manufacture of products from lightweight concrete on hot porous aggregates and can be used at building materials plants.

The purpose of the invention is to increase the strength of concrete and reduce the time of manufacture of products.

The essence of the invention is that coarse porous aggregate - expanded clay, having a temperature of 160–220 ° C, is placed in a mold to warm it up, then cement-sand mortar is placed in the mold, the concrete mix with water-cement ratio equal to 0.6-0.7, vibrating and vibrating followed by isothermal exposure are carried out.

The heat of hot dry claydite is used first to heat the mold. The effectiveness of this technique consists of several positive qualities. Firstly, due to the higher temperature of the expanded clay, the mold heats up faster. Secondly, it was possible to use higher temperatures of 160-220 ° C. For the prototype, this technique does not allow to obtain the same benefits: more than 30% would be required for water overrun, since most of the water would be spent on evaporation As a result of evaporation by the moment loading form the temperature of the mixture does not exceed 100CC. Therefore, in the prototype during the formation and initial hardening the temperature drops

oh

ate

15

20

31643150

another 30-40 ° C and reaches 40-50 ° C, which is lower than the isothermal holding temperature.

Mortar temperature due to vibratory mixing rises, and coarse aggregate decreases even by the time the temperature reaches a critical workability, the concrete mix is 90 - 95 ° C, which is practically unattainable with any technology at which the mixture is mixed prior to molding. The secondary energy savings of the proposed method results from the fact that there is no need to heat the molded products to an isothermal holding temperature. Accordingly, the process cycle is reduced by about 1/4.

The method is carried out as follows.

After firing, a large porous aggregate in the kiln is transported, sorted and metered by known means. As a result of these operations, cooled clay expanded clay is laid into molds and kept in it for 2–3 minutes. During this time, the mold warms up. A cement-sand mortar component is fed to the hot claydite with a water flow of 30% above the optimum, i.e., the water-cement ratio is 0.7, and vibro-mixing and vibro-compaction of the concrete mix is performed for 5 minutes. In the process of mixing, the water is heated to the boiling point. A portion of 30% of water evaporates. "Vaporization caused by heating the mixture by the hot surface of expanded clay increases the mortar porosity and also reduces the water absorption of the clay. As a result of vibratory re-formation of concrete, the internal stresses in the body of concrete that decrease during temperature rises and occur during observance of existing known technologies. In general, having in mind both a decrease in the water absorption of the aggregate and a reduction in internal stresses, the strength of concrete products increases.

When the claydite temperature is below 160 ° C, the form and the mixture cannot be heated to 90-95 ° C. At temperatures above 220 ° C, a decrease in the strength of the concrete due to under-compaction, non-uniform compaction, etc. is observed. (rapid evaporation of water from solution). The choice of a particular temperature depends on the mass of the mold, the volume of the mixture, the molding conditions, the ambient temperature, etc. The magnitude of the water / cement ratio is determined depending on the temperature of the claydite, since a certain amount of it goes to evaporation. By assigning a W / C below 0.6, evaporation occurs along with the excess water and water needed to hydrate the cement. As a result, strength is reduced. When assigning W / C more than 0.7, not all free water evaporates during vibration mixing, and some of it remains and increases the porosity of the cement-sand mortar, as a result, the strength also decreases.

The table provides comparative digital data on the strength of products manufactured by the known and proposed methods.

Claims (1)

40 claims A method of manufacturing concrete products, including mixing claydite with a temperature of 160-220 ° C with cement thirty 35 shivin and vibrocompaction the temperature of 45 with a sand solution, laying in the form of the concrete mixture is leveled by the im, vibro compaction and isothermal set within 90-95. Exposure different This creates an opportunity to direct concrete products directly into 50 In order to increase strength isothermal holding chambers, mine heating, which is carried out after molding products in accordance with known techniques. At the same time, not only is the production cycle for the manufacture of concrete products shortened. It is also important that conditions improve. 55 concrete and reduce the time of manufacture of products, first expanded clay is placed into the mold, then cement-sand mortar is fed and the mixture is agitated with vibro-compaction using cement-sand mortar with a water-cement ratio of 0.6-0.7. five 0 five structuring of concrete, as internal stresses in the body of concrete are reduced, which occur during temperature rises and occur while observing existing known technologies. In general, having in mind both a decrease in the water absorption of the aggregate and a reduction in internal stresses, the strength of concrete products increases. When the claydite temperature is below 160 ° C, the form and the mixture cannot be heated to 90-95 ° C. At temperatures above 220 ° C, a decrease in the strength of the concrete due to under-compaction, non-uniform compaction, etc. is observed. (rapid evaporation of water from the solution). The choice of a particular temperature depends on the mass of the mold, the volume of the mixture, the molding conditions, the ambient temperature, etc. The magnitude of the water / cement ratio is determined depending on the temperature of the claydite, since a certain amount of it goes to evaporation. By assigning a W / C below 0.6, evaporation occurs along with the excess water and water needed to hydrate the cement. As a result, strength is reduced. When assigning W / C more than 0.7, not all free water evaporates during vibration mixing, and some of it remains and increases the porosity of the cement-sand mortar, as a result, the strength also decreases. The table provides comparative digital data on the strength of products manufactured by the known and proposed methods. 0 five five 40 claims A method of manufacturing concrete products, including mixing claydite with a temperature of 160-220 ° C with cement In order to increase strength concrete and reduce the time of manufacture of products, first expanded clay is placed into the mold, then cement-sand mortar is fed and the mixture is agitated with vibro-compaction using cement-sand mortar with a water-cement ratio of 0.6-0.7. Composition 1: cement M 400 300 kg, expanded clay of fraction 10-20 with an average bulk density of 515 kg / m3 1 me / me, quartz sand 295 kg. Composition 2: cement M 400 200 kg; expanded clay of fraction 10-20 with an average bulk density of 515 kg / m3 1 m3 / m3, quartz sand 345 kg.