SU1699770A1 - Method of manufacturing cellular concrete products - Google Patents

Abstract

The invention relates to the building materials industry, namely the manufacture of cellular concrete products. The purpose of the invention is to increase the homogeneity of concrete and reduce technological waste. In the manufacture of cellular concrete products, exothermic, heated to 35-40 ° C, the concrete mixture is placed in a mold, heated to a temperature exceeding the temperature of the mixture at C, covered with a lid and held at the temperature gradient across the section of the array 2 - 10 & ° C until a given plastic strength is reached, after which the mass is cut. 1 ill., 1 tab. with

Description

The invention relates to the building materials industry, namely to the manufacture of articles for cellular concrete.

The purpose of the invention is to increase the homogeneity of concrete and reduce technological waste.

In the manufacture of cellular concrete products, the exothermic heated concrete mixture is placed in a mold heated to a temperature exceeding the mixture temperature by 5–20 ° C, covered with a lid and held at a temperature gradient across the section of the array of 2–10 ° C. strength, followed by cutting the array.

The essence of the method is to create conditions that ensure the uniform process of swelling and hardening of the raw mix in the peripheral and internal zones of the array and, as a consequence, a simultaneous set of plastic strength with discrete movement of the form from the pouring station to its dismantling along a closed path. This provides an increase in the productivity of the line, and also eliminates defects in the structure of concrete due to thermal gradient gradients.

The drawing shows schematically a rotor molding apparatus for carrying out the proposed method.

The installation consists of a horizontal platform 1, on which the heat insulating radially located

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Forms on positions a, b, c, d, d,

The method is carried out as follows.

The raw material mixture with an initial temperature within the limits is discharged into a thermally insulated feed, the temperature of which is 5–20 ° C higher than the temperature of the mixture. The form is installed at position C (. The open surface of the form is insulated by a lid and it moves discretely along a circular path at position 6.6 and so on.

Thus, the position of the mixture and its structuring is carried out in a thermal envelope. Therefore, heat and moisture loss over the surface of the array is insignificant and the subsequent heating of the mixture occurs with a minimum thermal gradient from the periphery of the array to its center, no more than 2–10 ° C. This eliminates the formation of a stress gradient and ensures uniform solidification of the raw solid by volume, i.e. The values of plastic strength of bacon in the central part of the massif and on its surface are close. In 1.5–2 hours, the values are 0.025–0.030 MPa, and this allows cutting the array onto the product. After the form is dismantled (position g), it is at a temperature of 55 - 70 ° C (the final temperature of the raw concrete before stripping) arrives at the assembly post and then at the molding (position a).

Pr and measures. The form with thermally insulated sides is heated in a chamber to a temperature of 60 ° C, then filled with a raw mix with an initial temperature of 0 ° C and closed with a thermally insulated lid. A thermal chamber with its internal microclimate is formed, which significantly reduces heat loss to the environment. The heat released during hydration is consumed to heat the mixture and accelerate the process of gassing and hardening of the raw material. Thus, the primary heat treatment of the mixture occurs, and the temperature of the mixture reaches 70-90 C.

Due to the heat insulation of the form, the temperature gradient t between the central and peripheral zones of the raw does not exceed 2 - K) ° C, which creates conditions for the simultaneous intensive hardening of the raw throughout the whole volume

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The duration of the ripening of the raw before cutting it on the product is reduced, since there is no heat loss to the environment.

With a given plastic strength of 0.02-0.025 KPa, the ceisto-like raw material is fed to the cutting post, and the heat released form with a temperature of kO - 70 C is fed to re-molding, additional heat costs for heating the mold will not be required. The transfer of the warm form to the post forming is achieved by its successive movement on the rotary table-rotor on a closed path from the post forming to the demolding station.

For an experimental verification of the proposed method, a mixture consisting of cement 20–25%, lime-sand in a baking 20-25%, sand slime 50-60%, as well as water, a pore-forming agent and additives PLV was prepared.

The prepared mixture with the initial temperature is poured into a thermally insulated form, heated to a predetermined temperature. The form with the mixture is closed with a thermally insulated lid. In the process of holding the mixture (raw) control the growth of plastic strength over time, the temperature of the raw in the center and periphery.

According to the proposed method, due to the same conditions of expansion and setting of the mixture, the crust has a flat surface and a smaller height, the amount of waste decreases, and the uniformity of the concrete over the section of the mass rises.

Claims (1)

The test results are presented in the table. Invention Formula The method of manufacturing cellular concrete products by laying the exothermic concrete mixture into the mold, installing the lid and holding it until a given plastic strength is achieved, followed by cutting the array, characterized in that, in order to improve the uniformity of the concrete and reduce the process waste, the concrete mix is placed into the mold, heated to a temperature exceeding the temperature of the mixture by 5–20 ° C, and exposure is carried out at a temperature gradient over the cross section of an array of 2–10 HP. With a decrease in the consumption of the components of the mixture.