SU1534041A1 - Method of producing concrete mix - Google Patents

Abstract

The invention relates to the building materials industry and can be used in the preparation of concrete mixtures. The aim of the invention is to increase the strength, water resistance and frost resistance of concrete, hardening at negative temperatures to (-15) ° C. An aqueous solution of a plasticizing additive is activated with an alkaline reagent — spent regeneration solution of anion-exchange filters up to PH 10.4–11.8 and treated with shock effects in a magnetic field with a strength of 100–150 kA / m at a frequency of 40–160 Hz. The resulting activated additive is introduced into a mixture of sand and cement and, after mixing, is subjected to shock at a frequency of 40-160 Hz in a magnetic field of 100-150 kA / m, then mixed with coarse aggregate until a homogeneous mass is obtained. The compressive strength of concrete hardening at a temperature of (-15) ° C is 23-25 MPa, water resistance 4-6, frost resistance 150-200. 1 tab.

Description

The invention relates to the industry of building materials, to methods for producing concrete mixes and can be used in monolithic construction.

The purpose of the invention is to increase the strength, water resistance and frost resistance of concrete hardening at negative temperatures of up to (-15) ° C.

Example. Dose cement in the sand in the amount of 290 and 670 kg / m. The mixture is stirred dry. An activated aqueous solution of a plasticizing additive (SDB) in an amount of 145 l / m3 is prepared by introducing into it an alkaline activator (spent regeneration anionic solution

Filters) to pH 11.0 and the required amount of water. Amount of the activated plasticizer

dry matter is 0.3%

from the mass of cement.

As an alkaline activator, a used regeneration solution of anion exchangers filters (waste of CHP and boiler production, wastewater and drinking water treatment) is used in the following ratio of chemical components, wt.%:

NaOH55-65

Na4SO, 20-26

Nag304.5-10

WaCl6-8

in

0

NaHCOjI-4

WaterEverything

Ratio (dry basis) RR: regeneration solution is 60:40 (wt.%). The resulting aqueous solution of plasticizer is subjected to shock at a frequency of 40 Hz in a magnetic field of 150 kA / m for 3 minutes,

The activated aqueous solution of the plasticizing agent is introduced into cement + sand and mixed to obtain a homogeneous suspension, which is also subjected to shock effects at a frequency of 40 Hz in a magnetic field of 150 kA / m. Then, coarse aggregate is metered into the mixer (crushed stone in the amount of 1340 kg / m3 and the treated cement-sand suspension is introduced. The mixture is stirred until a homogeneous mass is obtained.

The test results are presented in the table.

Changing the activation modes outside the proposed parameters leads to a decrease in the quality of the concrete mix.

Claims (1)

Invention Formula A method for preparing a concrete mix, which includes mixing cement, sand and coarse aggregate with an magnetised aqueous solution of a plasticizing agent, characterized in that, in order to increase the strength, water tightness and frost resistance of concrete hardening at negative temperatures to (-15) C, At first, the cement and sand are mixed with an aqueous solution of a plasticizing agent, activated with an alkaline reagent — a spent regeneration solution of anion-exchange filters up to pH 10.4–11.8 and previously treated with shock effects in a magnetic field of 100-150 kA / m at a frequency of 10-160 Hz, then the resulting cement-sand suspension is subjected to shock effects at a frequency of 40-160 Hz in a magnetic field of 100-150 kA / m intensity, after which mix with coarse aggregate until smooth. one