RU2138465C1 - Method of manufacturing superlight cellular concrete and its composition - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: invention relates to pipe insulation field and building industry and can be used for insulating steel pipes for heating conduits with diameter from 57 to 1420 mm and for various building tasks. Method is characterized by that to sludge are added: ground quartz sand with specific surface at least 2900 sq/cm/g, special-type cement, and blowing agent, after which mortar is powered into molds preferably by the use of pumps. In particular, sludge is first dispensed at 15-30 C by means of periodical dispenser, agitated for 1-5 min, after which blowing agent is added and agitation is continued for further 3-8 min. Weight ratio of cement to sand varies from 0.6:1.4 to 1.4:0.6, and water to solids ratio is (0.4-0.8):1. EFFECT: Improved workability of concrete mortar and characteristics of concrete. 2 cl

Description

 The invention relates to the field of thermal insulation of pipes and the construction industry and can find application for thermal insulation of steel pipes for heat pipes with a diameter of 57 to 1420 mm, as well as in monolithic housing construction, roof insulation, pouring floors, attic floors, wall insulation, production of heat-insulating and building products .

 Known methods for the manufacture of lightweight foam in industry. Lightweight foam concrete is formed from a mixture of cement-sand mortar and small bubbles of foam obtained from the corresponding foaming agent as a result of mixing the cement-sand mortar (sludge) with foam in the mixer. The foam introduced increases the volume and thus reduces the density of the solution. Lightweight foam concrete is a fireproof material, has high sound and thermal insulation. It can be sawn, nailed and drilled. Having carefully selected the composition, they get a mass that flows freely, easily pumped out. In this case, the water-solid ratio B / C + P is of great importance, where B is the amount of water, l, C is the amount of cement, kg, P is the amount of sand, kg. Like ordinary cement mortar, lightweight foam concrete can be cast into any shape. The structure of its surface makes it a good sound absorbent and provides good mechanical adhesion to the surface of insulated pipes, plaster, brick, etc. due to the large number of closed pores (up to 91%) forming a multi-cellular structure, lightweight foam concrete has excellent thermal insulation properties.

The closest analogue to the proposed method of manufacturing ultralight foam concrete is a method of manufacturing ultralight foam concrete, which includes dosing the raw materials - sand slurry, cement and foaming agent, mixing them for at least 2 minutes and filling the mixture with the mixture. At the same time, sand with a specific surface area of 2700-3000 cm ² / m is used to obtain sand slurry.

 The closest analogue to the proposed composition of ultralight foam concrete is the composition of ultralight foam concrete containing sand slurry, including ground quartz sand, cement and a foaming agent, and the ratio of sand to cement is 0.75-1.25, the amount of foaming agent is determined by the type of binder, and the water-hard ratio appoint based on the requirements for fluidity and temperature of the mixture (see. Instructions for the manufacture of cellular concrete. CH 277-80, M, Stroyizdat, 1981, p.3-10).

 The objective of the invention is a method of manufacturing ultralight foam concrete and its composition - is to reduce the cost of the resulting products and save raw materials while ensuring strength and improving the quality of foam concrete, and the technical result is the reduction of heat losses during transportation through hot water pipes to residential buildings and energy conservation.

The problem is solved in that in a method of manufacturing ultralight foam concrete, comprising dosing the initial components - sand slurry containing ground quartz sand, cement and foaming agents, mixing them and filling molds, ground quartz sand is used with a specific surface area of at least 2900 cm ² / g, cement, mainly of the M500 brand, and mainly FOAMCEM as a foaming agent, the molds are filled mainly with the help of a pump, with the sludge being first dosed by means of periodical batchers action and mix for 1-5 minutes, and then add a foaming agent and mix for 3-8 minutes, and the dosage, mixing and filling of the forms is carried out at a temperature of 15-30 ^o C.

The task is also solved by the fact that in the composition of ultralight foam concrete, including sand slurry containing ground quartz sand, cement, foaming agent and water, ground quartz sand with a specific surface of 2900-4000 cm ² / g cement, mainly M500, chemically combined with a foaming agent, which is used mainly FOAMCEM with a cement: sand ratio of 0.6-1.4, 1.4-0.6 wt.h. and a water-solid ratio of 0.4-0.8.

 Examples of the method.

 Example 1

Cement of the M500 brand is weighed, the sludge is dosed, the mixture is mixed in the installation for 1.5 minutes, then the foam is dosed and the mixture is mixed for 4 minutes, the forms are filled. Preparation of the mixture, pouring and aging of the poured molds is carried out at a temperature of 18 ^o C. Next, the foam concrete is steamed in an autoclave at a pressure of 8 atm. within 14 hours

Foam former FOAMCEM contains proteins and a stabilizer (adhesive). Moreover, its consumption per 1 m ^{3 of} foam concrete with a volume of = 200 is 1.6 kg.

 Example 2

Cement of the M500 brand is weighed, the sludge is dosed, the mixture is mixed in the installation for 2 minutes, then the foam is dosed and the mixture is mixed for 5 minutes, the forms are filled. The preparation of the mixture, pouring and aging of the poured molds is carried out at a temperature of 20 ^o C. Then foam concrete is steamed in an autoclave at a pressure of 8 atm. within 14 hours

 Examples of the composition.

 Example 1

The specific grinding surface of quartz sand is 2900 cm ² / g. Cement grade M500, foaming agent - FOAMCEM, sand-cement ratio 1.1-0.9, water-solid ratio - 0.58. The obtained parameters γ = 200 kg / m ³ , compressive strength R _cr = 7.5 kg / cm ² , thermal conductivity λ = 0.05 W / m

 Example 2

In contrast to example 1, the specific grinding surface of quartz sand is 3000 cm ² / g, the sand-cement ratio is 0.8: 1.2, and the water-solid ratio is 0.6. Cement and foaming agent are the same. The obtained indicators: γ = 210 kg / m ³ , R _cr = 8 kg / cm ² , λ = 0.051 W / m ^o C.

 The described manufacturing method and composition of ultralight foam concrete are highly efficient energy-saving technologies. Foam concrete mass is manufactured at the enterprise, used for pipe insulation or delivered to the facility, including in the customer’s vehicle, for use in monolithic housing construction, roof insulation, pouring floors, attic ceilings, wall insulation. It is possible to produce foam concrete directly at the facility and supply it to the installation site.

Depending on the purpose, the density of the foam concrete can be set in the range from 200 to 1800 kg / m ³ , the compressive strength from 4 to 200 kg / cm ² , the thermal conductivity from 0.05 to 0.60 W / m ^o C, respectively.

 Excellent heat and sound insulation, strength, low water absorption, workability, ease of processing - all this opens up a wide range of applications for pouring ultralight foam concrete. Creamy in its consistency, it fills the slightest roughness and grooves, spreads excellently on the surface and is easily molded. Ecological cleanliness and absolute incombustibility open up the possibilities of using this material where there are restrictions on the use of traditional heat-insulating materials (polyurethane foam, polystyrene foam, mineral wool, etc.).

Compared to conventional foam concrete (γ = 400 kg / m ³ , λ = 0.11), the volumetric weight, thermal conductivity and the consumption of ultralight foam material (γ = 200 kg / m ³ , λ = 0.05) are halved at the same strength and a sharp increase in the quality of foam concrete. In addition, the material in question has frost and water resistance, low water absorption, durability, lower weight of thermal insulation, ultralight foam concrete is non-toxic in production.

Claims (2)

1. A method of manufacturing ultralight foam concrete, comprising dosing the initial components - sand slurry containing ground quartz sand, cement and a foaming agent, mixing them and filling the molds, characterized in that the ground quartz sand is used with a specific surface area of at least 2900 cm ² / g, cement predominantly of the M500 brand, and mainly FOAMCEM as a foaming agent, the molds are filled mainly with a pump, while the sludge is first dosed by means of batch feeders stirred for 1-5 minutes and then the foaming agent is added and stirred for 3-8 minutes and dosage forms of mixing and filling is performed at a temperature of 15-30 ^o C. 2. The composition of ultralight foam concrete, including sand slurry containing ground quartz sand, cement, foaming agent and water, characterized in that ground quartz sand with a specific surface area of 2900-4000 cm ² / g is used, cement mainly of the M500 grade, chemically compatible with the foaming agent, which is used predominantly FOAMCEM, with a cement: sand ratio of 0.6-1.4: 1.4-0.6 parts by weight, and a water-solid ratio of 0.4-0.8.