RU2042653C1 - Method for preparation of concrete mix - Google Patents

Abstract

FIELD: production of concrete mixes. SUBSTANCE: method involves preliminary processing of 3.45-46.15 wt.-% of cement jointly with superplasticizer introduced in the amount of 2.5-20% of the mass of cement, under a mechanical action of 30-120 W per kilogram of the treated mix within 20-3,6·10⁴ s followed by mixing with the remaining cement, fillers, and water. Power expenditures for treatment of 1 m³ of concrete mix are reduced, the plasticizer consumption diminishes by 53.85-96.55 wt.-% with unchanged strength of concrete and the total cement consumption. EFFECT: reduced consumption of superplasticizer and power expenditures while retaining the same strength of concrete and consumption of cement. 2 tbl

Description

 The invention relates to methods for the preparation of concrete mixtures containing superplasticizers, and can be used in the manufacture of products from monolithic and precast concrete.

 The purpose of the invention is to reduce the consumption of superplasticizer, reducing energy consumption while maintaining the strength of concrete and cement consumption.

The following materials were used: Portland cement M400, crushed granite washed fra. 5-10 mm, lake sand with M _cr. 2.2 cm, drinking water, superplasticizer (SP) S-3 based on the sodium salt of the condensation product of naphthalenesulfonic acid and formaldehyde.

 Cement processing with joint venture S-3 is carried out in the mill MBL-1. The processing parameters are as follows: steel balls weighing 50 kg, loading mixture 20 kg. The specific power of the mechanical impact was determined by dividing the power of the mill drive by the mass of the loaded mixture.

 Preparation of the concrete mixture is carried out in a concrete mixer SB-101, the mixing time is 2 minutes.

 The workability of the concrete mixture is determined on samples of cubes with an edge equal to 100 mm.

The composition of the concrete matrix is cement sand crushed stone 1: 2.2: 3.8, cement consumption 300 kg / m ³ , water-cement ratio 0.4.

 PRI me R 1 (control). 30 kg of initial cement, 66 kg of sand, 108 kg of crushed stone and 12 kg of water are mixed in a concrete mixer. The workability of the concrete mixture was 0 cm, the strength of concrete of normal hardening at the age of 24 hours was 7.9 MPa; 28 days 39.7 MPa.

PRI me R 2 (prototype). 30 kg of cement treated in a mill with 2.5% C-3 (0.75 kg) with a mechanical power of 30 W / kg for 3.6 ˙ 10 ⁴ s (energy consumption for processing 33.21 ˙ 10 ⁶ J) mix with 66 kg of sand, 108 kg of crushed stone and 12 kg of water in a concrete mixer. The workability of the concrete mixture was 4 cm, the strength of normal hardened concrete at the age of 24 hours was 28.0 MPa; 28 days 62.3 MPa.

PRI me R 3 (by the proposed method). In a concrete mixer, 1.035 kg of cement (3.45% of the total amount) treated in a mill with 2.5% C-3 (0.026 kg) is mixed with a mechanical power of 30 W / kg for 3.6 ˙ 10 ⁴ s (energy consumption for processing 11.46 ˙ 10 ⁵ J), 28.965 kg of initial cement, 66 kg of sand, 108 kg of crushed stone and 12 kg of water. The workability of the concrete mixture was 0.5 cm, the strength of concrete at the age of 24 hours was 28.4 MPa, at the age of 28 days, 62.6 MPa.

 PRI me R s 4, 5, 9-11, 13-15 (by the proposed method). The sequence of preparation of the concrete mixture as in example 3, specific ratios of the treated and the initial cement, processing parameters, test results are presented in tables 1 and 2.

 EXAMPLES 6 and 7 (outside the method).

 PRI me R s 8 and 12 (prototype). The sequence of preparation of the concrete mixture as in example 2, the values of all parameters in tables 1 and 2.

 As can be seen from the test results, the proposed (examples 3-5, 9-11, 13-15) method of preparing the concrete mixture allows to reduce the consumption of superplasticizer by 53.85-96.55% and the cost of electricity by 1.9-29 times compared with the prototype (examples 2, 8, 12), while maintaining the strength of concrete. Outside of the method (examples 6 and 7).

 Example 3 in relation to the treated and untreated cements corresponds to examples 5, 11, 15; Example 11 of the description of the invention corresponds to Examples 3, 9, 11; Example 6 corresponds to examples 4, 10, 14.

Claims (1)

METHOD FOR PREPARING A CONCRETE MIX, including preliminary processing of cement with superplasticizer in the amount of 2.5 to 20% of the mass of cement with mechanical action of 30-120 W per 1 kg of the treated mixture for 20-3.6 · 10 ⁴ s, followed by mixing with aggregates and water , characterized in that, in order to reduce the consumption of superplasticizer, reduce energy consumption while maintaining the strength of concrete and cement consumption, the process is subjected to 3.45 46.15 wt. cement of its total amount and the remaining amount of cement is introduced with stirring with the remaining components of the concrete mixture.

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