SU1668341A1 - Method for preparing expanded-clay lightweight concrete mix - Google Patents

Abstract

The invention relates to the field of building materials industry and can be used in the manufacture of keramsit concrete products. It allows you to increase the strength of claydite-concrete while reducing its bulk density. The method is carried out by mixing cement, fine aggregate, water and pre-cooled by irrigation with water claydite gravel at a temperature of 350 - 400 ° C, and water is taken in the amount of 25 - 30% by weight of the gravel and at a temperature of 90 - 95 ° C. 2 tab.

Description

The invention relates to the building materials industry and can be used in the manufacture of keramsit concrete products.

The aim of the invention is to increase the strength of the claydite-concrete while reducing its bulk density.

The claydite mixture is prepared by mixing cement, fine aggregate, water and hot claydite gravel coming from a kiln with a temperature of 900-1000 ° C, followed by step-by-step cooling to 120-150 ° C before mixing with the other components, cooling the expanded clay gravel from 350-400 to 120-150 ° C are led by irrigation with warm water. In this case, water is taken in the amount of 25-30 wt.% Of the mass of irrigated claydite gravel, which is then introduced into the previously prepared calculated mixture of cement, fine aggregate and cold water with a temperature of 15-30 ° C. Hot clay gravel

mixes with the cement-sand mortar, after which the clay-concrete mix with a temperature of 50-60 ° C is prepared, is laid in molds, compacted and matured without additional heating.

When irrigation of hot claydite gravel, having a temperature of 350-400 ° C, water with a temperature of 90-95 ° C, a thermal shock occurs caused by a large temperature difference between claydite and water, thus there is a partial destruction of the shells of expanded clay grains, the development of additional cracks, splits , which increases the open porosity of expanded clay grain and, as a consequence, its chemical activity.

Cooling expanded clay gravel water evaporates into the environment, and part of it in the form of saturated water vapor in an amount of 3-5 wt.% Migrates into the pores of expanded clay grains.

The amount of cooling hot clay water is 25-30% of its mass, since with a larger amount it can

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remain in the expanded clay gravel in the liquid state and change the water-cement ratio of the expanded clay mixture. With a smaller amount of water, expanded clay gravel has a higher temperature, which leads to the clumping of the stirred keramsit concrete mixture and its quick setting.

The degree of destruction of the expanded clay grain shell is necessary if the claydite temperature is 350-400 ° C, and the temperature of its cooling water is 90-95 ° C. At a lower clay temperature, its shell is not sufficiently destroyed. At a lower temperature of water or higher than that indicated, the temperature of keozmzite during thermal shock causes the destruction of not only the shell, but also the grain of expanded clay itself.

During the mixing of hot ceramsite grchvm, saturated with water vapor, with cement-g-eschznym solution having a temperature of 15-30 ° С, expanded clay grains are cooled to 50-60 ° С. The latter leads to condensation in the pores of expanded clay gravel, water vapor, the occurrence of negative pressure and suction as a result of cement paste into the grains of expanded clay, which is associated with the appearance of self-vacuum ceramsite gravel.

The penetration of the cement paste into the depth of the clay grains, lead / ton, to the hardening of the expanded clay grain and contributes to an increase in the width of the cnteck zone between the expanded clay grain and the cement-sand component of the concrete.

All this allows with a limited cement consumption not exceeding 300 kg / m11 of concrete, using low-grade expanded clay gravel with a strength of up to 2 MPa and a bulk weight of up to 450 kg / m3 of concrete to form a mixture, to obtain high-strength expanded clay cements grade 300-350 and a bulk weight of 1100 -1200.

Example. For the manufacture of the slab, it is covered with 300dr expanded clay concrete and a bulk weight of 1,100 kg / m3 takes 640 kg / m3 of expanded clay gravel having a strength of 1.8 MPa and a bulk weight of 430

kg / m with a temperature of 370 ° C. It is cooled with 140 kg of water with a temperature of 95 ° C to 130 ° C. After that, the hot claydite is fed to the concrete mixer, where it is mixed before

250 kg of cement grade 500, 180 kg of fine aggregate, for example, sand, 200 kg of water with a temperature of 20 ° C. The hot claydite is mixed with the cement-sand mortar for 2-3 minutes, after which

Lubricants having a temperature of 60 ° C are immediately placed in a mold, compacted and transferred to a thermos curing. Simultaneously with the manufacture of the product, reference samples are formed as

standard cubes with an edge size of 150 mm. According to the obtained ceramgite begon, the operational characteristics, which are represented by E geSl.1, are determined.

Table 2 summarizes the parameters characterizing the development of self-vacuuming processes in the proposed method in comparison with the known

The economic efficiency of the proposed method lies in the fact that increasing the strength of claydite-concrete allows to reduce the consumption of cement, to use low-strength claydite to obtain high-quality Konpono-joro claydite-carbon

bulk weight. The economy of cement reduces to 80-100 kg / m3. The reduction of self-cronMoci / i of the structure is due to the savings of cement and the use of low-strength claydite, up to 3-5 rubles / m, which

the whole can be up to 800-900 thousand rubles. h year.

Claims (1)

The invention The method of preparation of claydite-concrete mixture by mixing 0 fine aggregate cement, water and pre-cooled water sprinkled claydite gravel, characterized in that in order to increase the strength of the claydite concrete while 5, by reducing its bulk density, the irrigation of expanded clay gravel and water is carried out when it reaches a temperature of 350-400 ° C, then water having a temperature of 90-95 ° C, taken in an amount of 250–30% of the weight of expanded clay gravel, is used. Table 1 Note. The cement consumption in the known method is 350 kg / m, and in the proposed 250 kg / m3. table 2