RU2474894C1 - Composition for protection against natural radiation background - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to production of concrete mixtures, plaster mortars, poured floors. The composition for protection against natural radiation background containing the following components, wt %: cement - 22.57, sand - 67.72, chitosan - 0.23.

EFFECT: invention makes it possible to provide for lower level of natural background radiation without reduction of strength characteristics of a material.

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Description

The invention relates to the construction materials industry, in particular the production of concrete mixtures, plaster mortars of bulk floors.

Modern building materials contain various fillers, such as sand, gravel, etc., which have a natural radiation background. To reduce the background radiation of fillers, special compositions are developed.

Closest to the proposed is a composition containing a binder - sulfur, finely ground filler, sand and crushed stone [1].

A disadvantage of the known composition is the insufficient reduction of the background radiation.

The objective of the invention is to create a radiation-protective composition having increased strength, radiation-protective and environmentally friendly indicators.

The problem is achieved by the fact that in the composition containing a binder - cement and filler - sand, an additional chitosan modifier is introduced in the following ratio of components, wt.%:

cement 22.57% sand 67.72% chitosan 0.23%

Chitosan is obtained by treating chitin in harsh conditions with an alkali solution. Chitin is the second (after cellulose) natural biopolymer, extracted from fully renewable natural raw materials, widely used in medicine, agriculture, crop production, food, cosmetic, paper, textile and other industries.

The use of chitosan allows you to get environmentally friendly and highly effective radiation-protective material.

The strength properties of the obtained material in comparison with the traditional are given in table 1

Table 1. Indicators Units rev. The content of additives,% 0 1,0 Average density kg / m ³ 2265 2305 Compressive strength MPa 33.6 33.9 Bending strength MPa 9.60 9.76 Water absorption by mass after 48 hours % 5.78 5.55 The coefficient of chemical resistance after 30 days. in solution: - Na ₂ SO ₄ (6% wt. Conc.); 1.03 ^∗ 1.01 ^∗ - H ₂ SO ₄ (2% wt. Conc.); 0.65 0.86 - NaOH (1% wt. Conc.); 0.98 0.92 - NaOH (6% wt. Conc.). 0.99 0.93 ^{∗ It} is understood that the strength of the samples increased after these tests.

The data presented indicate that the introduction of chitosan into the composition of the solution does not affect the strength characteristics of the building material.

The decrease in the natural background from radionuclides with the introduction of chitosan into the composition of the solution is given in table 2

table 2 Radionuclide The measurement results (A), Bq / kg Control sample without chitosan Chitosan Sample ⁴⁰ K 228.4 188.2 ²³² Th 9.2 5.3 ²²⁶ Ra 16.3 14.7 ¹³⁷ Cs - - Total effective sample activity 49.0 38.5

The use of the developed cement composition makes it possible to obtain environmentally friendly building materials of wide application with minimal natural radiation background.

Information sources

1. RF patent for the invention 2153714. Composition for protection against natural radiation background.

Claims (1)

Composition for protection against natural radiation background, containing a binder and filler, characterized in that cement is used as a binder, sand is used as a filler and additionally contains a chitosan modifier in the following ratio of components, wt.%:
Cement 22.57 Sand 67.72 Chitosan 0.23