KR800000882B1 - Composition meterial of the cement aggregate - Google Patents

Abstract

The cement aggregates are prepd. from the sand formed by crushing the sour rocks of deep-weathered granite. The 6-mesh sized sand is mixed with 0.1-20% of the metal salt of lower fatty acid, such as sodium formate or calcium formate ot obtain the cement aggregates. The cement mortar contg. the aggregate, cement and water has the compressive strength higher than that contg. river sand.

Description

[Name of invention]

Composition of cement aggregate

Detailed description of the invention

The present invention relates to a composition of a cement aggregate obtained by mixing sodium salt or calcium salt of formic acid, which is a lower fatty acid, with sand (hereinafter referred to as acid sand) obtained by crushing acidic rock embedded in a layer near the surface due to deep weathering of granite. .

The used rock used in the present invention is deeply weathered in the strata due to the jointing and the Harley according to the characteristics of the structure and texture of the granite, which is the granite. Buried rock.

Therefore, in order to make it into sand, acidic rock should be collected and crushed into particles of 6 mesh or less, about 14% of which is 200 mesh or less.

Conventionally, there is an example in which an alkali metal salt of a higher fatty acid is added to an aggregate composition made of steel sand and cement, but in this case, waterproofness is improved but early strength or compressive strength cannot be improved.

The present inventors found that when sand mortar was mixed with cement to produce mortar, the compressive strength was superior to that of steel sand normally used for cement mortar. As a result of studying the method of using sand sand substitute for cement mortar, sand sand was found. When alkali metal salts or alkaline earth metals of lower fatty acids are added to the water, the water resistance is not significantly improved, unlike the alkali metal salts of higher fatty acids, but the early strength and the compressive strength are remarkably excellent.

This phenomenon is because the acid sand is crushed before it is exposed to the surface and subjected to chemical weathering, that is, it is buried in the ground and received only physical weathering. Therefore, its surface is not only rough but also has fine powder on the surface. Sodium salts or calcium salts are believed to occur by condensing fine powders on the surface of the particles and adhering to each other to fill the attack between the particles.

The metal salts of lower fatty acids used in the present invention are sodium salts and calcium salts of formic acid, which can be used in the range of 0.1% to 20% by weight of acid sand, but in particular in the range of 0.5% to 6.0% Excellent effect can be obtained.

When explaining an example of the composition according to the present invention in detail, the acid rock embedded in the strata near the ground surface is ground to have a particle size of 6 mesh or less, but the amount of 200 mesh passes is about 15-20%, and 0.1 to 0.1 It is prepared by combining 20% sodium formate or calcium formate.

The prepared composition is formulated with cement and usually in the ratio of steel sand and water is added to prepare mortar.

The composition according to the present invention has superior compressive strength than the case where acid sand is used alone, by using acid sand having a higher compressive strength than steel sand as a main component and combining sodium salt or calcium salt of formic acid, which is a metal salt of lower fatty acids. The fine powder on the particle surface is condensed with each other by the salt of formic acid, thereby binding the particles, the early strength is also excellent.

Example 1

The acidic rocks buried in the strata near the surface are collected and pulverized to 6 mesh or less, so that the amount of 200 mesh passes is 15% to 20% of the total and 23.88g of sodium formate is added to 1.990g of the produced sand. The resulting composition is blended with 900 g of cement, 540 kPa of water is added and kneaded to prepare mortar. After 3 and 7 days, the compressive strength is measured by KSF2514 and the results are shown in Table 1.

Using the same method, the same test was performed using only summon river sand and acid sand without the addition of sodium formate.

TABLE 1

Example 2

500 g of cement is mixed with 1 g of acid sand, 500 g of cement is mixed and kneaded using 250 kPa of water. After 7 and 14 days, compressive strength is measured by KSF2514.

For comparison, summed steel sand is mixed with cement to produce mortar and its compressive strength is measured.

The test results are shown in Table 2.

TABLE 2

According to the test report table of Table 1 and Table 2, there is a difference in compressive strength, but this shows a difference depending on the date of testing, the acidic odor area and the size of the sample.

However, it can be seen that when calcium formate is added to the acid sand, the compressive strength is improved compared to the steel sand or mortar using only acid sand.

Claims (1)

Granite is deeply weathered, and acidic rock which is buried near the surface of the earth is collected and mixed with 0.1 to 20% of formic acid sodium salt or calcium salt, which is a metal salt of lower fatty acid, in acid sand aggregates crushed to 6 mesh or less. Of cement cement aggregate.