SU706381A2 - Method of thermal treatment of concrete articles - Google Patents

Description

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This invention relates to the manufacture of

building products and structures, namely to their heat treatment.

According to the main author. St. No. 578290 is known a method of heat treatment of be- ton products in the environment of products of combustion of natural gas at normal pressure, including raising the temperature to 120-180 ° C with a decreasing rate in time. С / h: in the first 0.5 h of heating - 10О-120;

in the second Oh, 5 h - 10-2O; in the next 1–3 hours, isothermal aging and cooling are carried out.

The disadvantages of this method are low strength and low corrosion resistance of products.

The purpose of the invention is to increase the strength and corrosion resistance of products.

This is achieved by additionally changing the relative humidity of the environment,%; in the first 0.5 hours of heating - from 40-60 to 1O-2O, in the second O, 5 hours - up to 8-15

and in the next 1-3 hours - up to 3-8.

The method is carried out as follows.

Molded products are kept for 1-2 hours and placed in a heating chamber with natural gas combustion products. At the same time, the temperature is carried out simultaneously with a decrease in the humidity of the medium during the first 0.5 h. The temperature is raised at a rate of 1OO-120 С / h, while the humidity varies from 40-6% to 10-20%; in the second 6.5 hours, the temperature is raised at a rate of 30-300 C / h. and the humidity is changed to 8-15%; in the next 1–3 hours, the temperature will raise cf at a rate of 10–20 ° C / h, and the humidity will be reduced to 3–8%. Then, isothermal exposure of products is carried out for 6 hours and cooling for 3 hours. This mode can be carried out in chambers equipped with a recirculation system and suction of gases from the chamber by.

3 7063814

For example, adjusting the amount of heat treatment is carried out according to the gases that are directed from the chamber. one.

Example. Molded 3 batches ob-After temperature rise samples

The concrete mix from the concrete mix is held for 6 hours at a pressure of 2-6 cm, with a draft of a cone of 5-6 cm, with a condensing temperature of 150 ° C, then cooled by vibration. After two hours lazatsya for 3 hours.

The first preliminary exposure of the product is placed in a heat treatment chamber with natural gas combustion products.

Comparative characteristics of the samples for strength and frost resistance are given in Table. 2

Table 1

Humidity 11030 5, E pazhnost NO70. thirty

Claims (1)

15 less than the estimated limits 50-75155 more than the specified limits 503020152О - Table 5 7О63 The use of the proposed method allows to obtain in the construction industry plants products with high strength and durability while reducing cost by reducing the average gas flow. . The invention of the method of heat treatment of concrete U products by author. St. No. 578290, which is due to the fact that, in order to increase the strength and corrosion resistance of products, the relative humidity of the phase,%, is additionally changed according to the mode; In the first 0.5 hours of heating From 40-60 10-20 In the second 0.5 to 8-15 In the next 1-3 hours To 3-8 Sources of information taken into account during the examination 1. USSR author's certificate No. 578290, cl. C O4 B 41/30, 1976.