KR20040028313A - Admixture composition for cement or concrete comprising sludge from glass manufacturing process - Google Patents

Abstract

PURPOSE: A cement or concrete admixture containing glass abrasive sludge instead of conventional fly ash or blast furnace slag is provided. The admixture with fine size and high latent hydraulic property improves durability and physical properties in manufacture of cement mortar or concrete products. CONSTITUTION: The admixture contains glass abrasive sludge generated from glass processing, and optionally 0-8wt.% of gypsum as a hydration controller, preferably 0-80wt.% of fly ash, slag powder or their mixture. The glass abrasive sludge containing more than 70wt.% of total amount of SiO2, Al2O3 and CaO, has very fine size less than 50micrometer without the processes of grinding and separation.

Description

Admixture composition for cement or concrete comprising sludge from glass manufacturing process

The present invention relates to a blended material to be blended in the manufacture of cement or concrete, and more specifically, to a cement or concrete blended material containing abrasive sludge generated in glass manufacturing, processing, etc. It relates to cement compositions and concrete compositions.

Admixtures are materials used to impart desired properties by mixing them in the manufacture of cement or concrete for the purpose of improving the performance of cement or concrete by physical and chemical effects or for economical efficiency. Commonly used miscible materials include blast furnace slag powder and fly ash as Pozzolan substances having latent hydraulic properties. Such cement and concrete admixtures are not only economical by replacing relatively expensive cements, but also contribute to recycling of industrial by-products that are landfilled and disposed of, and develop long-term strength, increase chemical resistance, and mass. As a material having many advantages such as reduction of heat of hydration in concrete, its usage is gradually increasing.

However, in order to use blast furnace slag fine powder or fly ash as a mixed material of cement or concrete, a refinery process to finely grind blast furnace slag to have a powder level of 3,500 cm 2 or more, or to lower unburned carbon contained in fly ash below a certain content Since the latent hydraulic hardness of the admixture used in this way usually starts after 7 days, increasing the cement replacement amount of blast furnace slag or fly ash lowers the strength at the early age of 1 and 3 days, which shortens the air at the construction site. And there is a problem in that the curing time is increased in the production of cement secondary products decrease productivity.

In order to improve the above problems, it is necessary to increase the hydration activity or increase the reaction surface area. Conventionally, a method of using a chemical activator to increase the hydration activity or a fine grinding method to increase the reaction surface area has been attempted, but these methods cause problems such as durability degradation and cost increase.

On the other hand, glass polishing sludge is an industrial by-product generated in the glass manufacturing and processing process, which is mostly disposed of in landfills, and in order to recycle such polishing sludge, glass polishing sludge is mixed with waste glass, waste gypsum and lime, and 1000 ° C. There has been reported a method of manufacturing a building material such as bricks, lightweight foamed ceramics by firing at the above high temperature (Refer to Republic of Korea Patent Publication No. 2002-0015461, Republic of Korea Patent Publication No. 1998-068412)

The present invention is to solve the problems of the conventional cement and concrete admixtures and the problems that must be fired at a high temperature of 1000 ℃ or more in order to recycle glass polishing sludge, glass polishing sludge that is difficult to cause pollution and treatment as industrial by-products It can be used as a high-quality admixture without additional firing, pulverization, separation and screening process, and prevents the decrease of compressive strength at early age and prevents other cement and concrete admixture composition from deteriorating. The purpose is to provide.

According to the present invention to solve the above technical problem is provided a cement or concrete admixture composition characterized in that it contains a glass abrasive sludge.

Moreover, according to this invention, the cement composition which contains the said admixture composition is provided.

Moreover, according to this invention, the concrete composition characterized by containing the said admixture composition is provided.

Hereinafter, the present invention will be described in more detail.

Glass polishing sludge in the present invention is generated not only in the polishing sludge generated during the glass surface and edge processing, but also in all processes of manufacturing and processing glass such as glass raw material blending, melting, molding and processing, and occurring in various processes. It includes various types of mixed sludge from wastewater treatment process to treat wastewater.

The admixture composition of the present invention may contain 0 to 8% by weight of gypsum as a hydration control material in the glass polishing sludge, and an appropriate ratio of fly ash, fine slag powder or other admixture material, preferably 0 to 80% by weight, depending on the purpose of use. It may contain in ratio of. In order to improve the quality of concrete or increase the amount of admixture, the materials such as fly ash and fine slag powder can be used in parallel.

In the present admixture composition, glass abrasive sludge, gypsum, fly ash, and fine slag powder may be simply mixed, mixed or pulverized independently of each other in order to obtain desired physical properties in the cement manufacturing process.

When the concrete is formed using the above-described admixture composition, it is preferable to contain about 10 to 40% of the weight of the cement.

The present invention can be used as a mixed material without the use of a separate grinding process or pre-treatment such as separation and screening by using the high potential hydroponicity and fine powder characteristics of the glass polishing sludge generated in the glass manufacturing and processing process, so that the conventional grinding and Compared to blast furnace slag powder or fly ash, which was used as admixture after separation and screening, the initial hydration is greatly improved while the price is greatly reduced, which prevents the initial strength from falling and enables the production of durable cement mortar and concrete products for a long time.

Glass abrasive sludge which is a mixed material used in the present invention has the following characteristics. Since the glass polishing sludge is mainly generated during the process of processing the glass surface, such as CRT, and when processing the edges of the plate glass, the polishing sludge mostly exists in the finely ground state of the glass and the abrasive.

Particularly preferred glass polishing sludge is a fine particle having an average particle diameter of 50 μm or less, and contains more than 50% of silicon dioxide (SiO ₂ ), which is an abrasive fine powder of amorphous glass, and thus has a high potential hydraulic property, and forms a silicon hydride mineral ( The total content of SiO ₂ ), alumina (Al ₂ O ₃ ), and calcium oxide (CaO) is 70% or more.

Representative chemical components of the glass polishing sludge are shown in Table 1.

SiO ₂ (%) Al ₂ O ₃ (%) Fe ₂ O ₃ (%) CaO (%) MgO (%) Na ₂ O (%) K ₂ O (%) Cl (%) Ignition loss (%) 61.0 11.5 9.5 2.1 1.5 2.8 2.5 0.03 7.2

Table 2 shows the typical Pozzolan activity of the glass abrasive sludge (K-L 5508 standard) and compares the results with the fly ash and blast furnace slag fine powders that have been used as conventional admixtures.

division Flow Compressive strength (㎏ / ㎠) 7 days 28 days Glass Grinding Sludge 67.0 120 152 Fly ash 65.2 42 88 Blast furnace slag powder 66.0 87 112

The action of the glass abrasive sludge of the present invention as a admixture is primarily promoted by the alkali components such as K ₂ O, Na ₂ O and CaO contained in cement and glass. The initial hydration activity is enhanced, and the basic action is that the fine abrasive injected during the glass polishing process plays a role of filling the particles and lubricating the particles, thereby improving flow characteristics.

The admixture composition of the present invention can also be applied to additives or concrete raw materials of cement secondary products such as bricks and roofing materials without undergoing a separate firing process.

Features and other advantages of the present invention as described above will become more apparent from the following examples. However, the present invention is not limited to the following examples.

[Examples and Comparative Examples]

The important point in using glass abrasive sludge as admixture is to replace glass abrasive sludge with a certain amount of cement and concrete, by proper combination of gypsum which is a hydration control material, or proper mixing of fly ash and blast furnace slag fine powder that have been used. It depends on whether the initial strength drop of cement mortar and concrete can be compensated for. As a result, numerous experiments have been carried out. As a result, it was confirmed that the initial strength of the cement mortar and concrete can be compensated for a certain value or more, and that the product can be manufactured without deterioration of other characteristics such as flow characteristics. Some of the experimental results are shown in Tables 3 to 4 below.

First, mortar specimens were prepared according to KS L 5105 standard by mixing the glass polishing sludge of the present invention with ordinary portland cement, and subjected to standard curing, and then the compressive strength of each elapsed day was measured. The results are shown in Table 3.

division Portland Cement (wt%) Admixture (wt%) Mortar Compressive Strength Ratio (%) Glass Grinding Sludge gypsum Fly ash Slag Powder 1 day 3 days 7 days 28 days Comparative Example 1 100 - - - - 100 100 100 100 Comparative Example 1-1 90 - - 10 - 65 79 85 92 Comparative Example 1-2 90 - - - 20 79 82 94 102 Example 1-1 90 9 One - - 102 103 106 105 Example 1-2 90 6 One 3 - 101 102 104 104 Example 1-3 90 5 One - 4 98 101 102 102 Example 1-4 70 26 4 - - 102 106 108 106 Example 1-5 70 16 4 10 - 100 104 104 103 Example 1-6 60 15 5 - 20 97 100 103 108

Referring to Table 3 above, when the compressive strength of the mortar (Control 1) cured using Portland cement without adding admixture was 100%, mortar using 10% substitution of fine slag powder or fly ash with admixture (Comparative Example). It can be seen that the initial compressive strength of 1 day and 3 days of 1-1 and 1-2) is very low. On the other hand, in the case of mortar using glass abrasive sludge as a mixed material (Examples 1-1 to 1-6), the initial strength expression was greatly improved for 1 day and 3 days. In particular, when the glass abrasive sludge was used as a mixed material, even if 10% of the slag fine powder or fly ash was added, the initial compressive strength was not lowered, and the long-term strength of 7 days and 28 days was also significantly increased.

Using the mixture of the first Portland cement and the glass polishing sludge of the present invention, the mixture was prepared based on the compressive strength of 210 kg / cm 2 and slump of 12 cm, which is the standard concrete mixture, to prepare the specimens, and to perform standard curing. Compressive strength was measured for each age. The measurement results are shown in Table 4.

division Portland Cement (㎏ / ㎥) Admixture (㎏ / ㎥) water sand Pebble Admixture Concrete compressive strength ratio (%) Glass Grinding Sludge gypsum Fly ash Slag Powder 3 days 7 days 28 days Comparative Example 2 302 - - - - 184 735 1054 0.5 100 100 100 Comparative Example 2-1 272 - - 30 - 184 735 1054 0.5 81 88 94 Comparative Example 2-2 272 - - - 30 184 735 1054 0.5 84 95 100 Example 2-1 272 27 3 - - 184 735 1054 0.5 102 105 108 Example 2-2 272 15 3 - 12 184 735 1054 0.5 102 103 103 Example 2-3 212 48 12 30 - 184 735 1054 0.5 98 105 104 Example 2-4 182 45 15 - 60 184 735 1054 0.5 100 103 101

As can be seen from Table 4, concrete specimens using fly ash and slag as admixtures (comparative examples 2-1 and 2-) compared to the compressive strength of concrete specimens cured using 100 wt% of Portland cement (Comparative Example 2). The compressive strength at the early age of 2) decreased significantly. However, in the case of the concrete specimens (Examples 2-1 to 2-4) used by adding the glass abrasive sludge of the present invention, the compressive strength at the early and long-term age was greatly improved, and the amount of the blend was increased by 30% or more. Even if the concrete properties were not reduced.

As mentioned above, the use of the glass abrasive sludge of the present name as an admixture for cement and concrete can increase the development of compressive strength at the early age of 1 day and 3 days without any separate grinding, separation and screening process. When used in combination with the fine slag powder and fly ash, there is an advantage that can increase the overall admixture usage without deteriorating the quality of the concrete.

The present invention described above is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the technical spirit of the present invention.

As described above, the present invention utilizes the characteristics of industrial by-products generated in the glass manufacturing and processing process to the maximum, and can be used as a mixed material for cement and concrete without a separate grinding, sorting and separating process, thereby greatly reducing the cost. Overcoming the disadvantages of the previous fly ash and blast furnace slag fine powder in early age, it can increase the amount of admixtures in cement and concrete manufacturing, and prevent air delay due to the delay of initial hydration in construction sites. have.

In addition, it not only contributes to the prevention of mixed pollution and resource recycling due to the increase in the amount of industrial by-products, but also the environmental protection effect such as energy saving and harmful exhaust gas reduction by reducing the amount of cement used by increasing the amount of mixed admixture.

Claims (6)

A mixed material composition for cement or concrete, comprising glass abrasive sludge. The glass polishing sludge has an average particle diameter of 50 µm or less, and the total content of silicon dioxide (SiO ₂ ), alumina (Al ₂ O ₃ ), and calcium oxide (CaO) is 70% by weight or more. Admixture composition for cement or concrete. The admixture composition for cement or concrete according to claim 1, which contains 0 to 8% by weight of gypsum as a hydration regulator. The admixture composition for cement or concrete according to claim 1, which contains 0 to 80% by weight of fly ash, fine slag powder or a mixture thereof. 10 to 40% of the weight of cement is contained in the admixture composition according to claim 1, characterized in that the concrete. A cement secondary product containing the admixture composition of Claim 1.