SU1761727A1 - Stock mixture for production of lightweight concrete - Google Patents

Abstract

The invention relates to building materials, namely lightweight concrete for the manufacture of enclosing structures. Raw mix for making lightweight concrete, May. %: slag Portland cement 17.6-21.16, air-entraining additive 0.6-0.72, fine ground slag additive 38-4.69, slag-cement aggregate of the fraction 10-20 mm 24.58-26.79, lightweight porous aggregate from siliceous rocks of fraction 5-10 mm 7.45-10.32, 5 mm 18.39-23.25, water the rest. The technology for preparing a concrete mix is as follows: initially, a mixture of powders with finely ground additive is loaded into the concrete mixer and thoroughly mixed, then 1/2 of the water flow is introduced, mixing takes 0.5-1.0 minutes. Thereafter, slag Portland cement and the remaining mixing water with a heat entrainment additive are introduced. The mixture is stirred for another 2-3 minutes. The density of concrete is 1140-1440 kg / m3, strength is 3.5-15 MPa, the heat conductivity coefficient of concrete in the dry state, W / m & K is 0.22-0.34. 1 tab. sl C

Description

The invention relates to building materials, namely, light concrete mixes on lightweight aggregates, and can be used in the manufacture of enclosing structures of industrial, civil and residential buildings.

A concrete mix is known, consisting of the following components: slag Portland cement, slag pumice of 10-20 mm and 5-10 mm fractions, slag-and-land sand of 0-5 mm fraction, additive and water (1).

The disadvantages of the mixture include the rather high average density in the dry state - 1200-1800 kg / m and high

coefficient of thermal conductivity of concrete - 0.32-0.52 W / m ° K.

The purpose of the invention is to reduce the density and thermal conductivity of concrete.

Raw mix for the production of lightweight concrete contains the following components, wt.%:

Slag Portland cement17, 60-21,16

Wood resin

saponified 0.6-0.72

It is ground granulated slag additive4.38-4,69

Slagdark

chd o

Xi

3

aggregate fraction 16-20 mm21,58-26,79 Lightweight porous siliceous aggregate fraction:

5-10 mm7.45-10.32

5mm18.39-23.25

WaterEverything

In the proposed raw mix, slag pumice of a 5-10 and 5 mm fraction is replaced with a light porous aggregate of siliceous rocks of a 5-10 and 5 mm fraction, which leads to a decrease in the average density and thermal conductivity of concrete. This is due to the higher content of glass: (over 70%), low thermal conductivity coefficient (0.09-0.12 W / m ° K) and increased porosity of the aggregate of siliceous rocks compared to slag pumice.

The lightweight porous siliceous aggregate is a material obtained by burning at a temperature of 900 ° C of pellets formed from a raw material mixture. The raw material mixture includes siliceous opal cristobalite rock, alkali metal salts, a porous agent, and sodium fluoride.

The compositions of concrete and their physico-mechanical properties are shown in the table.

The concrete preparation technology is as follows: initially, a mix of aggregates with finely ground slag additive is loaded into the concrete mixer and thoroughly mixed, then 1/2 of the water flow is introduced, mixing takes 0.5-1.0 minutes. After that, the cement and the remaining mixing water are introduced and mixed for another 0.5-2.0 minutes, the air-entraining additive is introduced into the concrete mixer and the mixture is stirred for another 2-3 minutes. A DLS solution (wood saponified resin) with a density of 1.008 g / cm3 was used as GDT.

The mixture was placed in a mold, kept for 4 hours and steamed in a mode of 2 + 8

+ 3 h at a temperature of 90-95 ° C. The obtained samples of concrete were tested in accordance with GOST 12730.0-12730.2, 10180-78.

Using lightweight aggregate from siliceous rocks of 5-10 mm and 10-20 mm fractions together with slag pumice stone of 10-20 mm as a filler for light concrete allows you to get light concrete with an average density in the dry state of 950-1350 kg / m3, thermal conductivity coefficient of 0.22-0.34 W / m ° K, compressive strength 2.5-12.5 MPa.

The use of concrete on lightweight aggregate of siliceous rocks for the production of enclosing structures will reduce the thickness of the enclosing structures without compromising their thermal performance, as well as the cost of heating buildings without changing the thickness of the structures.

Claims (1)

Formula of the invention Raw mix for making lightweight concrete, including slag Portland cement, wood saponified resin, fine ground slag additive, slag-and-kemze aggregate of 10-20 mm fraction and water, so as to reduce the density and thermal conductivity of concrete, it contains an additional lightweight porous aggregate of siliceous rocks of fractions 5–10 and 5 m with the following ratio of components wt,%: Slac Portland cement17, 60-21,16; Wood saponified resin 0.6-0.72; The grind mill is 4,48-4,69; Slagdark aggregate fraction 10-20 mm24,58-26,79; Lightweight porous filler from the creamy rocks of the fractions: 5-10 mm7.45-10.32; 5mm18.39-23.25; Water Else. Table continuation