SU1414830A1 - Concrete mix - Google Patents

Abstract

The invention relates to compositions of concrete mixtures and can be used for the production of concrete and reinforced concrete products operating under dynamic loads. The invention is directed to carrying concrete to shock loads. The concrete mixture has a composition, wt.%:.; cement 16.6-24.9i gravel 40.3-46.1 quartz sand 17.4-25.3; production waste of expanded vermiculite fraction less than 2.5 mm with a content of 55-80 wt.% weakly melted rock with a bulk density of 450 kg / m 0.9-2.5; vermiculite rock fraction 2.5 mm 0.9-2.5; water the rest. The resultant concrete is characterized by 50-143 reloading cycles before failure. 1 hp f-ly, 4 tab. with s

Description

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The invention relates to compositions of concrete mixtures and can be used in the manufacture of concrete and reinforced concrete products and structures under dynamic loads.

The purpose of the invention is to increase the endurance of concrete to shock loads.

Waste from the production of expanded vermiculite fraction less than 2.5 mm, used in the concrete mix, is formed when it is expanded and precipitated in Cyclones as a result of air-ejector separation.

The main characteristics of the aggregates - and additives used in the mixture are given in table 1,

As vermiculite additives, E concrete mixture is used natural and artificial mixtures of different fractions.

Concrete mixes are prepared and tested (table 2), vermiculite additives in which have a certain grain composition (Table 3).

To ensure that the concrete mixes with different content of additives are of the same workability, they are vibrated until they appear on the surface of cement milk samples.

Raw materials are loaded into a laboratory mixer in the following sequence; gravel, sand,: vermiculite additives, cement, water | Stirring time 4-5 min. Each concrete composition is molded into 9 concrete cubes with a 10 cm edge (3 for compressive testing, 6 for impact endurance) and 3 prisms with a size of 10 x HO40 cm to determine the flexural strength.

Samples are steamed in 4 + 3 + 6 + 3 mode at isothermal heating temperature,

The tests were carried out no earlier than 1 day after they were given in air at room temperature B to the test room.

The impact endurance of concrete is determined by testing to the destruction of 6 cube samples with a 10 cm edge on a vertical mechanical scraper with a free-fall weight of 12.5 kg. The results of the test images of steamed concrete are given in table 4.

Claims (2)

Invention Formula 1, Concrete mixture, including cement, coarse aggregate, quartz sand and expanded vermiculite, characterized in that, in order to increase the endurance of concrete to shock loads, it contains as an expanded vermiculite production waste of expanded vermiculite fraction less than 2.5 mm containing 55-80% by weight of weakly melted rock with a bulk volume mass of 450 kg / m and, additionally, vermiculite rock of a fraction of 2–5 mm in the following ratio of components, wt.%: Cement 16,6-24,9 Coarse aggregate 40.3-46.1 Quartz sand 17.4-25.3 Waste production5 properties of expanded vermiculite fractions less than 2.5 mm Vermiculite rock fraction less than 2.5 mm Water 0.9-2.5 0.9-2.5 Else 2. The mixture according to item 13 about the t of l and h ay - y and the fact that it contains vermiculite rock of the 42 M fraction of the following grain composition -1h ..%: five 1.25 - 2.5 mm 0.63 - 1.25 mm 0.315 - 0.63 mm O, 14 - 0.315 mm Kenei 0.14 mm 11-31 10.5 - 19.5 9.5 - 20.5 17.5 - 28.5 Rest Table 1 Large aggregate (river gravel), 5-20 mm Quartz sand, not less than 5 mm Vermiculite rock fraction, mm less than 2.5 less than 5 Expanded vermiculite, 0.315-0.63 mm Waste production of expanded vermiculite 160 350 Table3