SU975648A1 - Raw mix for making cellular concrete - Google Patents

Description

The invention relates to the composition of concrete mixtures for the manufacture of cellular concrete used in the construction of residential and industrial buildings.

A well-known concrete mixture comprising a mineral in the staying, asbestos filler, aluminum powder, additive and water. Cellular concrete of the above composition has a high flow rate and high humidity 1,

The closest in technical essence and the achieved result to the invention is a concrete mixture, including, wt.%; Portland cement 13.4-18.0 Lime13.4-18.0

Ground sand 65.0-70.0 Two-water gypsum 3.14-4.7 Aluminiev

powder 0.06-0.066

The disadvantages of this mixture are the high content of two-water gypsum, which significantly slows the swelling, the plastic strength of the cellular mass is high, the high post-autoclave moisture of the concrete, the low crack resistance of large-sized products, due to the high thermal stresses arising in the process of steaming.

The aim of the invention is to reduce. water demand, post-autoclave-. moisture and increase the plastic strength of concrete.

The goal is achieved by the fact that the raw mix for the manufacture of cellular concrete, including

10 Portland cement, lime, ground sand, two-water gypsum and aluminum powder, additionally contains a diabase fraction of 1.25-10 mm in the following ratio of components, wt.%:

15

1-12,7

Portland cement 26-26.2

Lime

Two-water

0.33-0.72

gypsum

Aluminum

20 0.07-0.08

powder

Diabazova

fractions 1,25134-24, 0

10 mm high

Ground sand

25

EXAMPLE The introduction of a heavy fraction of 1.25–10 mm of crushed materials, predominantly a blade-like, needle-shaped form instead of a part of sandy sand, significantly reduces water 30 the need of the mixture and reinforces its mortar part. With the simultaneous reduction of cement, dihydrate gypsum and a water-solid ratio, the bulking process and plastic strength set increase. It has been experimentally investigated that the 1.25-10 mm fraction is evenly distributed throughout the whole cell mass and does not settle for 30-120 minutes. This period is sufficient to prevent stratification of the mixture during the period of formation and the set of the structural strength of the mass. Lime, which has an activity of 70%, has a specific surface area of 6500 CMVT. Lime is crushed in a vine-mill with its preliminary hydration before grinding by 35%. Quartz sand is used. Unbound quartz content 60%. The content of clay, clay, dust particles in the sand is 7%. Sand grinding is carried out in a wet way in a ball mill. The specific surface of ground sand 3200 is at PSH-2. The grinding of two-water gypsum is carried out to a specific surface of 2000. The screening of diabase rubble is used as a heavy fraction. Fractional composition of filler sieve size. Frequent mm residues on the sieves,% 105.0 The content of flaccid, needle-like grains is 80%. The aerated concrete mixture is prepared in an SMS-40 mixer. The sequence of loading materials: water - sand slurry - cement - two-water gypsum - lime - aluminum slurry - diabase fraction 1.2510 mm, Mixing the mixture for 5 min. The dimensions of the product are 5980X36OL1200 mm. Cellular concrete mass swell without vibration. When the end of expansion is reached, the vibration is switched on for 5 seconds in order to eliminate discontinuities in the array between the reinforcement and the mixture to be expanded. The products are kept under autoclave treatment for 4 hours. The products are parked according to the 3 + 10 + 3 h mode with an isobaric holding of 9 kgf / cm. Products are cooled to stripping for 4 hours. Experimental moldings of a known composition are carried out to compare the results. During stripping and aging, the panels are visually inspected to complete cooling. Samples-cylinders are drilled from panels and tested according to GOST 128520-77, GOST 128526-77. The compositions of concrete mixes are given in table. 1, in table. 2 properties of the compositions. Table 1

12.7 26

47.5 13.4

0.33 0.07

one

26.2 48.0 24.0

0.72 0.08

Bulk weight kg / cm

Plastic strength after 1 hour,

G / CM

Claims (2)

Compressive strength, MPa The advantages of the proposed composition of a cellular concrete mixture over the known one are that the mold turnover cycle is reduced, cement consumption is reduced, concrete strength and product durability are improved. Formula of the invention sand, two-water gypsum and aluminum powder, which is tactile with the fact that, in order to reduce water demand, post-autoclave moisture and increase plastic strength, it additionally rzhit diabase frakTablitsa 700 720 700 thirty 120 100 4.5 6,6 6.4 1.25-10 mm with the following ratio of components, wt.%: Portland cement 1-12,7 Lime. 26-26.2 Two-water gypsum 0.33-0.72 Aluminum powder 0.07-0.08 Diabase fraction 1.2510 tviM13.4-24.0 Ground sand Other Sources of information that are taken into account during the examination 1. USSR author's certificate 87026 , cl. From 04 To 15/02, 1978. 2. Authors certificate of the USSR 53382, cl. From 04 To 21/02, 1973.