RU2214985C2 - Molding blend for manufacturing light-weight polystyrene foam/concrete products - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: water-based molding blend contains 67.7-69.2% Portland cement, 0.17-0.21% superplasticizer (S-3), 0.17-0.21% foaming agent, polystyrene filler, and additionally 0.055-0.10% sodium thiosulfate as hardening accelerator, said foaming agent being based on anionic surfactants of the PB-2000 type and said polystyrene filler being polystyrene foaming waste fraction no larger than 1 mm taken in amount 0.6-0.75 cu.m per 1 cu.m of molding blend or mixture of above-indicated fraction with foamed polystyrene fraction no larger than 5 mm used at ratio (4-5): 1. EFFECT: reduced density of polystyrene foam/concrete products. 3 cl, 1 tbl

Description

 The present invention relates to the construction materials industry, namely the production of polystyrene concrete.

 A known composition for the manufacture of polystyrene concrete products, including a mineral binder, polystyrene aggregate, fibrous material, an air-entraining additive and a plasticizer (see, for example, patent RU 2150446, class 04 04 38/08, 1998). As a polystyrene aggregate in the known mixture, predominantly fine fractions (from 0.04 to 1.63 mm) of foamed whole and torn polystyrene are used, which leads to an increase in the average density of the finished polystyrene concrete products and, as a result, to a noticeable deterioration in the thermal insulation properties of building envelopes. The introduction into the known mixture as an air-entraining additive of saponified wood resin, giving an insufficiently stable foam, only slightly reduces the density of the products.

Closest to the proposed technical essence and the achieved result is a molding mixture for the manufacture of lightweight polystyrene concrete products, including Portland cement, polystyrene aggregate, S-3 superplasticizer, as an air-entraining additive - viscous foam based on saponified wood and calcareous dough and quartz sand (see ., for example, patent RU 2033406, class C 04 B 38/08, 1990). The use of a known mixture of light granular polystyrene foam with a density of not more than 20 kg / m ³ significantly increases the efficiency of the building structure due to a significant improvement in its thermophysical properties while significantly reducing the weight of the structure. However, the high cost of expanded polystyrene significantly increases the cost of construction with its use. In addition, the introduction of quartz sand into the mixture, the content of which exceeds 20 wt.%, Leads to a significant increase in the average density of products in excess of 650 kg / m ³ , which affects the heat-shielding properties of the building structure.

 The purpose of the invention is to reduce the average density and cost of expanded polystyrene concrete products.

This goal is achieved by the fact that the molding mixture for the manufacture of lightweight polystyrene concrete products, including Portland cement, polystyrene aggregate, S-3 superplasticizer, air-entraining additive and water, additionally contains a hardening accelerator - sodium thiosulfate, as an air-entraining additive - a foaming agent based on anionic surface-active substances "PB-2000" in the following ratio of components of the solution part, wt.%:
- Portland cement - 67.7-69.2;
- superplasticizer C-3 - 0.17-0.21;
- sodium thiosulfate - 0.055-0.10;
- the foaming agent "PB-2000" - 0.17-0.21;
- water - the rest,
and as a polystyrene filler - waste polystyrene foaming fr. not more than 1 mm with a volume flow of 0.6-0.75 m ^{3 of} aggregate per 1 m ^{3 of} molding sand. Moreover, the superplasticizer C-3 and sodium thiosulfate the mixture contains in the form of the finished product - additives "Lignopan B-2", and as a polystyrene filler may also contain a mixture of foaming polystyrene foam. no more than 1 mm and granules of foamed polystyrene fr. no more than 5 mm, taken in the ratio (4-5): 1.

 The essence of the invention is as follows. The introduction into the molding mixture for the production of polystyrene concrete of the highly effective foam-forming agent PB-2000, the foam multiplicity of which, as production tests have shown, exceeds 14 units, can significantly reduce the average density of products containing finely dispersed polystyrene aggregates (fr. Less than 1 mm ) polystyrene foaming waste. At the same time, due to the high stability of the foam in the cement paste, which reaches several hours, as well as the additional introduction of a concrete mixture hardening accelerator into the mixture and, thus, a faster set of strength by the foam mass, it is possible to obtain lightweight polystyrene concrete products of a given density and required strength.

The following materials were used in the work: Portland cement grade 500 (GOST 10178); superplasticizer S-3 (TU 6-35-0204229-624-96); hardening accelerator - sodium thiosulfate; polystyrene aggregate - polystyrene fr. less than 1 mm; granular polystyrene foam (OST 301-05-202-92E); Foaming agent “PB-2000” manufactured by Ivkhimprom OJSC according to TU 2481-185-05744685-01 in the form of an aqueous solution of a mixture of anionic surfactants with a density of 1.0-1.2 g / cm ³ ; tap water (GOST 23732-79). Superplasticizer C-3 and sodium thiosulfate can be used in the form of a finished product - Lignopan B-2 additive manufactured by Biotech JSC in the form of a 30% aqueous solution or dry powder according to TU 2601-002-20127879-96.

 The molding mixture for the manufacture of lightweight expanded polystyrene concrete products is prepared by mixing the starting components in a concrete mixer, followed by foaming the resulting mass or mixing with the finished foam prepared using PB-2000 foaming agent, or by first introducing the foaming agent solution into the prepared molding mixture and then foaming it in the mixing process components to obtain foam mass of the required density.

 Examples of compositions of the proposed molding sand and the properties of polystyrene concrete products obtained from it are given in the table. Outside the compositions according to the invention, the goal is not achieved.

Analysis of the data given in the table shows that the inventive molding mixture containing finely dispersed porous aggregate provides lightweight (less than 450 kg / m ³ ) polystyrene foam concrete products, which significantly improves the heat-shielding properties of the building envelope. Moreover, in terms of their mechanical properties, the products comply with the requirements for such products by GOST R51263-99 for Polystyrene Concrete. The use of expanded polystyrene production as a porous filler of non-utilizable wastes (to be disposed of in a landfill with subsequent disposal) contributes not only to a significant reduction in the cost of heat-protecting structures, but also to the solution of environmental problems.

Claims (3)

1. Molding mixture for the manufacture of lightweight polystyrene foam concrete products, including Portland cement, polystyrene aggregate, C-3 superplasticizer, air-entraining additive and water, characterized in that it additionally contains a hardening accelerator - sodium thiosulfate, as an air-entraining additive - an anionic surfactant-based foaming agent active substances PB-2000 in the following ratio of components of the solution part, wt. %:
Portland cement - 67.7 - 69.2
Superplasticizer S-3 - 0.17 - 0.21
Sodium thiosulfate - 0.055 - 0.10
Frother "PB-2000" - 0.17 - 0.21
Water - Else
and as a polystyrene aggregate - foaming polystyrene fractions of not more than 1 mm at a volume flow of 0.6-0.75 m ^{3 of} aggregate per 1 m ^{3 of} molding sand.  2. The molding mixture according to claim 1, characterized in that it contains a C-3 superplasticizer and sodium thiosulfate in the form of a finished product - Lignopan B-2 additive. 3. Molding mixture for the manufacture of lightweight polystyrene foam concrete products, including Portland cement, polystyrene aggregate, C-3 superplasticizer, air-entraining additive and water, characterized in that it additionally contains a hardening accelerator - sodium thiosulfate, as an air-entraining additive - an anionic surfactant-based foaming agent active substances PB-2000 in the following ratio of components of the solution part, wt. %:
Portland cement - 67.7 - 69.2
Superplasticizer S-3 - 0.17 - 0.21
Sodium thiosulfate - 0.055 - 0.10
Frother "PB-2000" - 0.17 - 0.21
Water - Else
and as a polystyrene aggregate - a mixture of waste foaming polystyrene fractions of not more than 1 mm and granules of expanded polystyrene fractions of not more than 5 mm, taken in the ratio (4 ÷ 5): 1.

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