KR102011554B1 - Radiation shielding material comprising mortar or concrete containing borosilicate glass fine particle - Google Patents

Abstract

The present invention relates to a neutron shielding material comprising a mortar or concrete containing a borosilicate glass fine powder to increase the compressive strength of the concrete or mortar, lower the expansion ratio, and improve radiation shielding performance by including a borosilicate glass aggregate and a borosilicate glass fine powder. .

Description

Neutral shielding material comprising mortar or concrete containing borosilicate glass powder TECHNICAL FIELD

The present invention relates to a neutron shielding material comprising mortar or concrete containing borosilicate glass fine powder, and more particularly, to a borosilicate glass aggregate and a borosilicate glass fine powder, thereby increasing the compressive strength of the concrete or mortar, lowering the expansion ratio, and neutron shielding. A neutron shielding material comprising mortar or concrete containing borosilicate glass fine powder, which improves performance.

Many problems are caused by various industrial by-products and wastes such as the problem of environmental pollution or the high cost of disposal. Thus, several studies are underway to recycle industrial by-products and wastes. This trend is no exception in the construction industry, and in fact, various industrial by-products are used as cements and admixtures for concrete.

Concrete has been successfully used as a structural material to block radiation in various nuclear power projects and facilities. In general nuclear power plants, two layers of concrete are used, the inner and outer layers of which are designed to ensure stability by reducing the outflow of neutrons and gamma rays to the outside of the structural concrete. This is to prevent the outflow of gamma rays.

In the radiation shielding concrete as described above, it is well known that when the boron-containing material is blended, shielding performance is secured. In general, borosilicate glass aggregate is used as a mixed material of concrete to further improve radiation shielding performance. Sometimes. However, artificially injecting such borosilicate glass materials may cause an alkali aggregate reaction, causing swelling, delaying condensation and lowering of physical strength and other problems.

Korean Laid-Open Patent Publication No. 1997-0051470 discloses that a radioactive waste having a boron component is heated and melted to form a glass solid, which is used as a basic raw material of borosilicate glass, and is applied for the purpose of shielding thermal and slow neutrons. The patented technology also has problems such as expansion of the glass solids used as the reactive aggregates appear.

Korean Patent Publication No. 1997-0051470 Korean Patent Publication No. 2011-0037851

Accordingly, the present invention is to solve the conventional problems as described above, by including the borosilicate glass fine powder together with the borosilicate glass aggregate mortar or concrete to increase the compressive strength of the concrete or mortar, lower the expansion ratio, and improve the neutron shielding performance It is an object to provide a neutron shielding material comprising a.

Neutron shielding material according to the present invention for achieving the above object,

And mortars or concrete containing borosilicate glass aggregates and borosilicate glass fine powders.

The average particle diameter of the borosilicate glass aggregate may be 75 μm to 5 mm.

The average particle diameter of the borosilicate glass fine powder may be 20 μm or less.

The weight mixing ratio (cement: borosilicate glass fine powder) of the cement and the borosilicate glass fine powder in the neutron shielding material may be 85:15 to 70:30.

The weight mixing ratio of the borosilicate glass aggregate: borosilicate glass fine powder in the neutron shielding material may be 90:10 to 85:15.

The expansion ratio of the neutron shielding material according to the present invention may be 0.01% or less in w / c 0.40 and 0.009% or less in w / c 0.47 based on 28 days (4 weeks).

According to the neutron shielding material including mortar or concrete according to the present invention, in the case of containing the boron component by using a borosilicate glass provided with a mass production system in order to include the boron component which is not generally contained in concrete or mortar, As well as lowering the increase of the compressive strength of the concrete or mortar, and has the effect of improving the shielding ability of the low-speed neutron or thermal neutron.

1 is a photograph showing a borosilicate glass aggregate (a) and a borosilicate glass fine powder (b).

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

Hereinafter, the neutron shielding material according to the present invention will be described in detail.

In order to inject boron having neutron shielding ability into concrete or mortar, borosilicate glass, a material containing boron, is frequently used. When the borosilicate glass as described above is made of aggregate and included in concrete or mortar, it will react as a reactive aggregate, causing expansion.

The present inventors have found out that when borosilicate glass aggregate and borosilicate glass fine powder are added to mortar or concrete together, pozzolanic reaction can increase the compressive strength and reduce the expansion rate, thereby completing the present invention.

The neutron shielding material according to the present invention may include mortar or concrete containing borosilicate glass aggregate and borosilicate glass fine powder.

As used herein, the term “borosilicate glass aggregate” refers to an aggregate having an average particle diameter of 75 μm to 5 mm. Preferably, the particle size is less than 150 μm to 300 μm, 15 wt%, less than 300 μm to 600 μm, 25 weight% and 600. Borosilicate glass aggregates containing 25% by weight less than 1.18 mm, 25% by weight less than 1.18 mm to 2.36 mm, and 10% by weight 2.36 mm to 4.75 mm can be used.

In the present invention, the 'borosilicate glass fine powder' refers to a powder obtained by pulverizing the borosilicate glass aggregate with an average particle diameter of 20 μm or less, and when the average particle diameter of the borosilicate glass fine powder is 20 μm or less, it is advantageous for pozzolanic reaction of the borosilicate glass fine powder. desirable.

As for the average particle diameter of the said borosilicate glass fine powder, it is more preferable that it is 15 micrometers or less.

The weight mixing ratio of the fine borosilicate glass powder to the cement in the neutron shielding material is preferably 85:15 to 70:30, especially 80:20 to 75:25, but it is not preferable because the expansion phenomenon may appear outside the above range.

The weight mixing ratio of the borosilicate glass aggregate: borosilicate glass fine powder in the neutron shielding material is 90:10 to 85:15, preferably 94: 6 to 89:11, more preferably 93.75: 6.25 to 88.24: 11.76, most preferably 91.84: 8.16 to 90:10, but beyond this range, workability, in particular flow performance, deteriorates, which is undesirable.

The expansion ratio of the neutron shielding material according to the present invention may be 0.01% or less in w / c 0.40 and 0.009% or less in w / c 0.47 based on 28 days (4 weeks).

Hereinafter, the present invention will be described in detail through examples to demonstrate the superiority of the neutron shielding material of the present invention. However, the following examples are for illustrative purposes, and the present invention is not limited to the following examples.

Property Measurement Method

1) After 4 weeks from the compounding date, the expansion value was measured according to ASTM C 1260, and the expansion ratio formula for the measured value of the sample is as follows.

2) Compressive strength was measured in accordance with KS F 5105 after 4 weeks from the compounding date.

Example  1 and 2 and Comparative example  1 to 6

Cement (one ordinary portland cement, manufactured by Ssangyong Yangyang Co., Ltd.), borosilicate glass fine powder, glass fine powder, borosilicate glass powder, borosilicate glass aggregate and water were combined according to the composition of Table 1 to prepare a mortar paste.

                                                            (Unit: g) w / c weight
Mixing ratio cement
(A) Borosilicate
Glass
Fine powder ^{1 )} (B) Borosilicate
Glass powder ²⁾ (C) Glass
Fine powder ^{3 )}
(D) Borosilicate
Glass aggregate ⁴⁾ (E) Example 1 0.47 A ： B = 80: 10 352 88 - - 990 Example 2 0.47 A ： B = 71 ： 29 312.4 127.6 - - 990 Comparative Example 1 0.47 A ： B = 90: 10 396 44 - - 990 Comparative Example 2 0.47 A ： B = 65 ： 35 286 154 - - 990 Comparative Example 3 0.47 A ： D = 80 ： 20 352 - - 88 990 Comparative Example 4 0.47 A ： B = 30: 70 440 990 - - - Comparative Example 5 0.47 A ： B = 100 ： 0 440 - - - 990 Comparative Example 6 0.47 A ： C = 80 ： 20 352 - 88 - 990

Note 1) Average particle size 13㎛

    2) Average particle size 30㎛

    3) Average particle size 20㎛

    4) Average particle size 1mm

Experimental Example  1 ： Measurement of compressive strength

The mortar pastes prepared in Examples 1 to 2 and Comparative Examples 1 to 6 were used to prepare cube-shaped specimens of 50 × 50 × 50 mm according to the KS F 5105 standard, and the compressive strength thereof was measured. 2 is shown.

Experimental Example  2: Expansion  Measure

Table 2 shows the results of expansion by alkali silica reaction over time of the mortar pastes prepared in Examples 1 to 2 and Comparative Examples 1 to 6 above.

Experimental Example  3: neutron Shielding  Measure

Table 2 shows the results of the neutron shielding ability of the mortar pastes prepared in Examples 1 and 2 and Comparative Example 1.

Compressive strength (N / mm2) % Expansion Neutron shielding ability (s ^-1 ) ^* Example 1 49.87 0.0086 32.9 Example 2 48.75 0.0081 33.1 Comparative Example 1 34.78 0.2709 33.5 Comparative Example 2 41.21 0.0125 Unmeasured Comparative Example 3 47.24 0.0158 Unmeasured Comparative Example 4 30.51 0.1821 Unmeasured Comparative Example 5 31.61 0.2803 Unmeasured Comparative Example 6 45.72 0.0143 Unmeasured

Note) * Measured by Thermal Neutron Shielding Test of Korea Research Institute of Standards and Science.

As shown in Table 2, in Examples 1 and 2 of the present invention, it can be seen that the expansion ratio is very low, 0.009% or less, while maintaining excellent neutron shielding ability.

In Comparative Example 1, the neutron shielding ability was maintained, but the expansion ratio was very high, and the compressive strength was low. In Comparative Examples 2, 3, and 6, the compressive strength was maintained, but the expansion ratio was high, It can be seen that the compressive strength is low and the expansion ratio is high.

Claims (6)

A neutron shielding material comprising a mortar or concrete containing a borosilicate glass aggregate and a borosilicate glass fine powder having an average particle diameter of 20 μm or less,
The neutron shielding material is characterized in that the expansion ratio of the neutron shielding material is 0.01% or less at w / c 0.40 and 0.009% or less at w / c 0.47 on the basis of 28 days (4 weeks).
The method of claim 1,
The average particle diameter of the borosilicate glass aggregate is 75㎛ 5mm neutron shielding material.
delete The method of claim 1,
The neutron shielding material characterized by the weight mix ratio of the cement and borosilicate glass fine powder in the said shielding material being 85: 15-70: 30.
The method of claim 1,
The neutron shielding material of the neutron shielding material in which the weight mix ratio of the borosilicate glass aggregate and the borosilicate glass fine powder is 90: 10-10: 15.
delete

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