SU1296555A1 - Method for preparing building mixture - Google Patents

Abstract

The invention relates to the industry of building materials, to the technology of preparing building and concrete mixtures. The invention aims to improve workability and increase the strength of concrete. To achieve the goal, the fine aggregate and the cement with a temperature of 100-140 ° C are mixed first, then the large aggregate is added during the mixing and the mixture is mixed with water in an amount of 2/3 of the total water volume and the remaining water with a plasticizing additive. 2 tab. about S (L to with 05 JV sd JV

Description

11296555

The invention relates to the building materials industry, in particular to the technology of preparing building and concrete mixtures.

. The purpose of the invention is to improve the ductility and improve concrete strength.

Example. Portland M-400 cement from the Voskresensky plant (cement temperature; 100-140 0), sand from Moscow quarries, 7, crushed granite fraction 5–20 mm, chemical-bank - SDB (sulphite-yeast brew) in the amount of 0.2% of masses of cement. Conduct a test of concrete with two compositions, 4, and 6.

The mixture is prepared in a forced action mixer. First I work 10

15

The test results are presented in Table. one.

The mobility of the concrete mix and the strength of concrete at the age of 28 days, depending on the preparation technology, are given in table. 2

With the known technology of preparation, the concrete mixture is difficult to set (sediment of a cone 1 cm). To achieve workability equal to 5-6 cm, it is necessary to increase its water content by 18%, which leads to a decrease in strength (to 33 MPa). To ensure a strength of 40 MPa, it is necessary to increase the consumption of cement by 18%.

The method according to the invention achieves the brand strength of the batch mixer, loading a small fractionon (40 MPa) with a given aggregate aggregate (sand) and hot (with a temperature of 100-140 ° C) cement, mixed, depending on the water-cement ratio 20-40 c, then coarse aggregate is injected, and after 10–20 s, 2/3 doses of water are poured and, after mixing, the remaining dose of water with plasticizing agent is poured with the total mixing time not exceeding 120 s.

After the mixture is prepared, its temperature is fixed, workability and molded on the vibrating plate with a standard vibration frequency control samples with a fin size of 10 cm. Samples are tested at the age of 28 days. Steaming mode at 2 + 3 + 6 + 2.

120

100

90

five

The test results are presented in Table. one.

The mobility of the concrete mixture and the strength of concrete at the age of 28 days, depending on the preparation technology, are given in table. 2

With the known technology of preparation, the concrete mixture is difficult to set (sediment of a cone 1 cm). To achieve workability equal to 5-6 cm, it is necessary to increase its water content by 18%, which leads to a decrease in strength (to 33 MPa). To ensure a strength of 40 MPa, it is necessary to increase the consumption of cement by 18%.

The method according to the invention ensures the achievement of the brand strength be5

0

five

bleedability of 6 cm without increasing cement consumption.

Claims (1)

Invention Formula A method for preparing a building mix, which includes mixing preheated cement, fine, coarse aggregate and water, is different in that, in order to improve workability and increase the strength of concrete, first mix the fine aggregate and cement with a temperature of 100-140 ° C, then successively without stopping the mixing, a large aggregate, 2/3 of water from the total volume of water, and the remaining water with a plasticizing agent are introduced. Table 1 40.3 26.1 40.2 26.0 38.7 24.7 Note. III III Compiler G. Rakcheeva Editor A. Ogar Tehred A. Kravchuk Proofreader N. Korol Order 714/27 Circulation 588Updated VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Continuation of table 1 table 2 simultaneous loading of all components of the concrete mixture into the mixer and their mixing, the same, is effective in mobility of the mixture, characterized by draft of a cone 5-6 cm. loading of components according to the invention.