KR20050060409A - Mixed cement composition containing incinerator ash and pozzolan material as ingredients and mortar and concrete containing the same - Google Patents

Abstract

The present invention relates to a mixed cement composition comprising an incinerator and a pozzolan material as an additive, and to mortars and concrete prepared by using the same, and more particularly, to ashes and diatomaceous earth, fly ash, such as fly ash or floor ash, generated from municipal waste incineration plants. It relates to a mixed cement composition comprising a pozzolanic material such as an additive, and to mortar and concrete produced using the same. Mortar and concrete prepared using the mixed cement composition of the present invention shows an excellent compressive strength enhancement effect compared to the mortar and concrete using only ordinary cement, and also has an excellent fixing effect on various types of heavy metals contained in the incineration ash In addition, it can be usefully used as a recycling method for incineration ash, which contains a large amount of heavy metals harmful to the human body.

Description

Mixed cement composition containing incinerator ash and pozzolan material as ingredients and mortar and concrete containing the same}

The present invention relates to a mixed cement composition comprising an incinerator and a pozzolan material as an additive, and to a mortar and concrete prepared by using the same. More specifically, the incinerator and diatomaceous earth, fly ash, etc., generated from municipal waste incinerators, It relates to a mixed cement composition comprising as an additive, to mortars and concrete prepared using the same.

As the standard of living improves, the amount of construction and household waste also increases rapidly, causing social and environmental problems. The Ministry of Environment conducts a nationwide waste statistics survey every five years to understand the generation and treatment of waste, the amount of generation by type, regional distribution and trends of change. Recyclables increased by 21%, while waste generated by large wastes and national parks increased by 126% (Ministry of Environment, Environmental White Paper 2000). The waste generated in this way is mainly treated by incineration, and recently, it has been found that a large amount of environmental hormones such as dioxins are generated during incineration of waste, and the disposal of waste incineration and incineration is emerging as a new environmental problem. Incinerators are largely classified into fly ash (FA) and bottom ash (BA), and these incinerators contain a large amount of heavy metals that are harmful to humans as well as environmental hormones.

As of 2000, about 300,000 tons of incinerators are processed at designated landfills or the high seas in Korea's large domestic waste incineration facilities. Incineration ash generated from incineration facilities of more than 50 tons per day is estimated to be 14.7% to 19.5% (average 16.2%) of the total incineration, of which about 5 to 10% is fly ash and 90 to 95% is floor ash. The incineration ash contains harmful heavy metals such as Pb, Cu, Cr, Hg and trace amounts of dioxins, so it is usually added to the solidified material and general cement by about 10-30% of the weight of the incineration ash, and then landfilled. However, such chemical stabilization treatment is not an object of recycling incinerators but only a managed landfill, so it is urgent to develop an appropriate treatment method for these incineration ashes (Leesu-gu, urban waste incineration ash management and management plan, Seoul Metropolitan Forum, Seoul National University of Technology, 1999).

On the other hand, the present inventors have tried to develop a method for removing harmful heavy metals present in industrial wastes including waste, diatomaceous earth ground in a heavy metal solution obtained through a toxic filtration process after grinding steelmaking dust generated in an electric furnace After mixing, impregnating and drying, and then the diatomaceous earth was developed by mixing the ordinary portland cement, a concrete corrosion preventing cement mortar was developed and has been patented (Reg. No. 197795). However, the method can be very useful for removing harmful heavy metals present in industrial wastes, but it is far from the recycling method of the wastes itself, and also has to deal with wastes remaining after removing heavy metals. .

Therefore, the inventors of the present invention, as a result of preventing the harmful heavy metals present in the incineration ash to be discharged to the surrounding environment, and also to study how to use the incineration ash as a recycling resource that can be usefully used in industrial sites, incineration ash and pozzolanic material Mixed cement composition comprising an additive, and the mortar and concrete produced using the mixed cement composition shows an excellent compressive strength improvement effect compared to the mortar and concrete prepared using the general cement, and also included in the incineration ash The present invention has been completed by revealing that it has an excellent fixing effect against various kinds of harmful heavy metals.

The present invention is characterized in that the mixed cement composition comprising an incineration ash and pozzolanic material as an additive, and the mixed cement composition, excellent compressive strength enhancement effect and excellent fixing effect for various kinds of heavy metals contained in the incineration ash Its purpose is to provide mortar and concrete.

In order to achieve the above object, the present invention provides a mixed cement composition characterized in that it comprises an incineration ash and pozzolanic material as an additive.

The present invention also provides a mortar prepared using the mixed cement composition.

In addition, the present invention provides a concrete produced using the mixed cement composition.

Hereinafter, the present invention will be described in detail.

The present invention provides a mixed cement composition comprising an incinerator and a pozzolan material as an additive.

In the above description, "incineration ash" refers to materials remaining after incineration of household waste in a waste incineration facility. In the present invention, the ash ash is classified into a floor ash that sinks to a floor and fly ash floating in the air. In the mixed cement composition of the present invention, the incineration ash may be used alone or in combination with the bottom ash and fly ash, it is preferably included 1 to 30% by weight relative to the total mixed cement composition mass, 5 to 20% by weight It is more preferably included, most preferably 10% by weight.

In addition, the "pozzolanic material" is composed mainly of silica material, and the lime produced during the hydration of cement reacts slowly at room temperature to produce an insoluble compound, which is hardened to contribute to the enhancement of mortar and concrete. Collectively, natural pozzolanic materials include diatomaceous earth, volcanic ash, silicate clay, silicate earth, and the like, and artificial pozzolanic materials include heat treated clay, shale, fly ash, and the like. In the mixed cement composition of the present invention, such natural and / or artificial pozzolanic materials may be used without limitation, they may be used alone or in combination, and diatomaceous earth, fly ash or burnt clay is preferably used. It is more preferred that diatomaceous earth be used. In addition, the pozzolanic material is preferably included 1 to 30% by weight, more preferably 5 to 20% by weight, and most preferably 10% by weight based on the total mixed cement composition mass.

In addition, it is preferable to use ordinary Portland Cement selected from the group consisting of one common cement, two medium heat cements, three crude steel cements, four low heat cements, and five sulfate resistant cements. In some cases, special cements may be used selected from the group consisting of ultra-tough steel cement, cemented carbide cement, mesium, high strength cement, alumina cement, fireproof cement and slag cement.

In a preferred embodiment of the present invention, the plastic diatomaceous earth is activated by calcining (dialysis) the diatomaceous earth produced in Pohang district, the incineration ash is used four kinds of fly ash and three types of bottom ash collected from incinerators located in Seoul and Gyeonggi area. Using this, mixed cement compositions of various ratios were prepared (see Tables 1 to 3). As a result of analyzing the chemical components included in the incineration ash, the chemical composition of the incineration ash was similar to the chemical composition of general cement, but there was a slight difference in the composition ratio of the incineration ash. See Table 4). In addition, in the case of heavy metal content, the acceptance criteria were generally satisfied in the fly ash, but some of the heavy metal elements such as Pb and Cu exceeded the acceptance criteria, and in the case of flooring, the heavy metal content generally satisfied the acceptance criteria. In the case of Pb, there is a case where the limit is much exceeded (see Table 5). Therefore, it is urgently needed to take appropriate safety measures.

In addition, the present invention provides a mortar or concrete prepared using the mixed cement composition.

In the above description, "mortar" means cement and sand kneaded with water, and "concrete" means cement aggregate (cement paste) using a hydration reaction in which cement reacts with water to harden. It refers to the chopped by wrapping with water made of grass), usually means kneaded coarse aggregate (gravel), fine aggregate (sand) and cement with water. Mortar or concrete of the present invention is characterized in that it is prepared using the mixed cement composition, in the case of mortar 15 to 25% by weight of the mixed cement composition of the present invention, 40 to 55% by weight of sand and 25 to 40% by weight of water It is preferable to prepare by kneading each other, in the case of concrete 10 to 25% by weight of the mixed cement composition of the present invention, 25 to 35% by weight of sand, 25 to 35% by weight of gravel and 20 to 40% by weight of water to each other It is preferred to be prepared. In a preferred embodiment of the present invention, mortar and concrete were prepared using a mixed cement composition containing various content ratios of pozzolanic materials and incinerators (see Tables 2, 3 and 10).

In a preferred embodiment of the present invention, as a result of measuring the degree of heavy metal leakage and the compressive strength of the mortar and concrete specimen prepared using the mixed cement composition, in the mortar mixed with fly ash and a suitable amount of diatomaceous earth (10%) The amount of heavy metal ions eluted was somewhat different depending on the type of fly ashes mixed. However, the amount of toxic heavy metals was almost fixed (about 95% or more) and the amount of leaching met the national environmental standards. In addition, even mortar mixed with flooring and 10% diatomaceous earth was fixed with more than 99% of harmful heavy metals, and the amount of leaching satisfied the domestic environmental standards. In particular, Pb, which had a high content of 34 to 149 ppm in some floorings, was eluted only about 0.4 ppm, and ions such as Cu, Hg, and Cr were also immobilized in the hydrate of cement paste or transformed into a hydration product. While the elution amount was reduced (see Table 7).

In the case of the compressive strength of the mortar and concrete containing the mixed cement composition of the present invention, the 28-day compressive strength of the mortar prepared by replacing fly ash with cement was increased by about 14 to 15% compared to the mortar without the fly ash mixed, In the case of the 28-day compressive strength of mortar manufactured by replacing fly ash with fine aggregate, the compressive strength was increased by 39 to 54% compared to the mortar without mixing fly ash. It was confirmed that there was an enhancement effect (see Table 9). In addition, the compressive strength of concrete prepared from the mixed cement composition of the present invention including fly ash and diatomaceous earth was increased by 40 to 80% compared to concrete prepared using only portland cement (see Table 11).

Hereinafter, the embodiment of the present invention will be described in detail.

However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited by the following examples.

Example 1 Preparation of Mixed Cement Composition and Mortar

<1-1> Preparation of Activated Diatomite

Active diatomaceous earth was produced according to the process described in the patent (registration number 197795) registered by the present inventors. Diatomaceous earth is composed of diatoms, which are prone to degeneration and degradation of protoplasts and other organic substances due to the accumulation of diatoms, which grow at the boundary between fresh water and seawater.They are light and absorbent because they contain numerous micropores. There is a high nature. Diatomaceous earth is used as a pozzolanic material as a cement additive, and since various impurities are mixed in the present invention, the organic material is calcined and used after purification. In order to activate diatomaceous earth, calcination is usually performed at a low temperature, which is known to be optimal at 490-710 ° C (Nam. W. Lim, et al, "Effect of Sodium Hydoxide on the Shear Strength of Thermally Decomposed). Clays ", University of New South Wales, Kensington, NSW, Australia, UNICIV Report No. R-219, 1984; Nam. W. Lim and AW Manton-Hall," Pozzolanic Activity of Calcined Diatomite in Relation to Temperature and Time ", University of New South Wales, Kensington NSW Australia, UNICIV Report No. R-230, 1986. In the present invention, diatomaceous earth produced in Pohang district was calcined at 650 ° C. for 0.5 hour to activate, which was named as plastic diatomaceous earth “D ₆₅₀ ”.

<1-2> Manufacture of incineration ash

Incinerators collected four types of fly ash (FA) and three types of bottom ash (BA) at incinerators located in Seoul and Gyeonggi. The fly ash (FA) was classified into FA1, FA2, FA3 and FA4 according to the location of the collected incinerators, and they represent Yangcheon Incinerator, Daedeok Incinerator, Gangnam Incinerator, and Ilsan Incinerator, respectively. In addition, the flooring material (BA) is divided into BA1, BA2, BA3, respectively represents Yangcheon incinerator, Daedeok incinerator, Gangnam incinerator and Ilsan incinerator.

<1-3> Preparation of the mixed cement composition and mortar

The inventors have prepared a mixed cement composition containing cement and additive D ₆₅₀ and incineration ash. In this case, ordinary portland cement was used as the raw material cement. Mortar and / or was used to investigate the ratio of the appropriate D ₆₅₀ and the incineration ash used in concrete replacing the fly ash (FA) and bottom ash (BA), fine aggregate (sand) by 10%, respectively, based on the weight, D ₆₅₀ is a Portland cement The formulation was selected in the range of 0 to 20%, the ratio of cement to fine aggregates 1: 3, and the target flow 110 ± 10.

Tables 1 to 3 show mortar compounding ratios of various ratios used in the experiments.

TABLE 1

Mortar formulation (%) by addition of D ₆₅₀

number OPC D ₆₅₀ sand all water One 29.0 - 71.0 100 41.0 2 27.55 1.45 71.0 100 41.0 3 26.10 2.90 71.0 100 42.0 4 23.20 5.80 71.0 100 46.0

TABLE 2

Mortar formulation (%) which mixed fly ash

number OPC D ₆₅₀ sand FA1 FA2 FA3 FA4 all water 5 27.55 1.45 61.0 10.0 - - - 100 50.0 6 26.10 2.90 61.0 10.0 - - - 100 50.0 7 23.20 5.80 61.0 10.0 - - - 100 48.0 8 27.55 1.45 61.0 - 10.0 - - 100 79.0 9 26.10 2.90 61.0 - 10.0 - - 100 40.0 10 23.20 5.80 61.0 - 10.0 - - 100 43.0 11 27.55 1.45 61.0 - - 10.0 - 100 58.0 12 26.10 2.90 61.0 - - 10.0 - 100 56.0 13 23.20 5.80 61.0 - - 10.0 - 100 58.0 14 27.55 1.45 61.0 - - - 10.0 100 56.0 15 26.10 2.90 61.0 - - - 10.0 100 57.0 16 23.20 5.80 61.0 - - - 10.0 100 48.0

TABLE 3

Mortar formulation (%) which mixed floor materials

number OPC D ₆₅₀ sand BA1 BA2 BA3 all water 3 26.10 2.90 71.0 - - - 100 42.0 17 26.10 2.90 61.0 10.0 - - 100 35.0 18 26.10 2.90 61.0 - 10.0 - 100 40.0 19 26.10 2.90 61.0 - - 10.0 100 39.0

In Tables 1 to 3 above, OPC represents normal Portland cement.

Experimental Example 1 Characterization of Samples

<1-1> Chemical Composition Analysis

The chemical components contained in the ash sample and the cement used by the inventors were analyzed, and the results are shown in Table 4.

TABLE 4

Sample Chemical Properties (wt%)

ingredient cement Fly ash Flooring FA1 FA2 FA3 FA4 BA1 BA2 BA3 SiO ₂ 18.8 5.31 33.30 38.10 27.50 6.88 11.10 7.11 Na ₂ O 1.07 6.02 3.41 4.51 3.58 8.24 7.06 5.82 MgO 3.68 3.06 1.20 2.05 2.02 2.51 4.47 1.96 K ₂ O 0.8 4.30 1.71 1.50 1.52 5.62 5.74 3.98 CaO 63.11 37.80 18.30 19.50 20.10 28.30 25.60 38.90 Fe ₂ O ₃ 3.63 0.64 3.86 5.95 9.77 0.63 0.72 0.79 MnO - 0.02 0.04 0.14 0.12 0.02 0.09 0.03 Al ₂ O ₃ 6.72 2.85 12.80 8.92 10.20 2.87 5.18 3.41 P ₂ O ₃ - 0.76 0.98 2.30 2.73 0.67 0.89 0.91 LOI 0.8 35.40 19.60 11.50 14.00 44.20 37.60 34.40

As can be seen from the above results, the chemical composition of the incineration ash was similar to the chemical composition of the cement as a whole, but there was a slight difference in the component ratio, and also it was confirmed that there is a difference in the chemical composition according to the type of incineration ash.

<1-2> Analysis of Heavy Metal Content in Incineration Ash

Heavy metals contained in incineration ash damage the natural environment and are harmful to the human body. Therefore, sufficient reviews and measures are required. In order to measure the elution degree of heavy metal ions contained in the incineration ash, distilled water was first put into a sample which passed through a 9.5 mm sieve and remained in a 2.5 mm sieve, and then adjusted to pH 4.9 ± 0.2 with 0.5 N acetic acid. The heavy metal was eluted by stirring at 200 rpm, and the content of the heavy metal contained in the sample was analyzed by using an atomic absorption analyzer. The results are shown in Table 5 below.

TABLE 5

Heavy metal content in incineration ash (mg / ℓ)

sample Pb Cu As Hg CD Cr ⁶⁺ FA1 33.2 0.142 0.035 0.0033 0.003 0.690 FA2 0.648 5.92 0.028 0.0017 0.002 0.689 FA3 2.84 2.87 0.016 0.0015 N.D. 0.023 FA4 0.127 1.20 0.014 0.0006 N.D. 0.039 BA1 149.0 0.703 0.027 0.0033 0.003 0.300 BA2 34.4 0.285 0.020 0.0022 0.002 0.686 BA3 1.49 0.47 0.02 0.0031 0.002 0.201 Tolerance 3.00 3.00 1.500 0.005 0.300 1.500

N.D. (No Detection): No Detection

As can be seen from the above results, in the case of fly ash, the heavy metal content generally satisfies the limit value, but in the case of Pb and Cu, there was a case where the limit value was exceeded. In addition, in the case of flooring materials, the heavy metal content generally satisfied the acceptance criteria, but in the case of Pb, the case of exceeding the acceptance criteria was found that the safety treatment measures are urgently needed.

<Experiment 2> Characterization of mortar containing incineration ash

<2-1> Flowability and compressive strength measurement

D ₆₅₀ and the liquid 7 and age compressive strength of 28, a mortar mixture by adjusting the optimal ratio and mixing ratio of bottom ash and D ₆₅₀ was measured. Specifically, 5 cm × 5 cm × 5 cm mortar specimens having the compositions of Tables 1 to 3 were prepared and cured in water at 20 ± 1 ° C., and then the mortar was compressed in accordance with KS L 5105 at 7 and 28 days. Intensity was measured.

The amount of unit for mortar to achieve the same fluidity varies depending on the type of sample. That is, since the incineration ash is fine powder, it is necessary to add a unit quantity in order to obtain a standard flow value, and the flowability of each type of incineration ash was evaluated by defining the measured flow value and water-cement ratio as a flow constant and calculating it as in Equation 1. It can be seen from the following equation that the larger the flow constant, the smaller the amount of the added water and the greater the fluidity.

[Equation 1]

In the above, FLc represents a flow constant, FL represents a flow value, and W / C represents a ratio of water and cement.

The flowability and compressive strength of the mortar were measured by the same method as described above, and the results are shown in Table 6.

TABLE 6

Measurement of flow and compressive strength of mortar samples

number Flow value (mm) Flow constant (mm /%) Compressive strength and compressive strength ratio 7 days 28 days Kgf / ㎠ % Kgf / ㎠ % One 114 2.78 348 100.00 357 100.00 2 112 2.74 341 97.99 429 120.17 3 113 2.70 367 105.46 458 128.29 4 112 2.44 307 88.22 404 113.17 5 109 2.18 154 44.25 232 64.99 6 114 2.28 151 43.39 239 66.95 7 115 2.40 140 40.23 210 58.82 8 112 2.87 205 58.91 316 88.52 9 113 2.83 215 61.78 364 101.96 10 115 2.68 209 60.06 373 104.48 11 n.f 0.00 268 77.01 290 81.23 12 n.f 0.00 256 73.56 320 89.64 13 n.f 0.00 251 72.13 310 86.83 14 n.f 0.00 195 56.03 325 91.04 15 n.f 0.00 199 57.18 287 81.04 16 n.f 0.00 203 58.33 252 70.59 17 106 3.10 315 90.52 350 98.04 18 115 2.90 331 95.11 414 115.97 19 110 2.85 337 96.84 397 111.20

As can be seen from the above results, as the mixing ratio of D ₆₅₀ increases, the fluidity was decreased (see samples 2 to 4), and at the same time, it was found that the flowability of mortar was somewhat different depending on the type of fly ash and flooring material. Flow values of FA3 and FA4 containing 1% or more of P ₂ O ₃ components could not be measured due to rapid freezing (see samples 11 to 16). In addition, the fluidity of the mortar mixed with the bottom ash was better than that of the reference mortar (see samples 17 to 19). This is presumably because the chemical component causing abnormal condensation of cement was stabilized by mixing D ₆₅₀ .

Optimum mixing ratio of D ₆₅₀ was shown with 10%, the D ₆₅₀ to a cement mortar mixture of incineration ash was about 35% of the compressive strength enhanced as compared to the reference mortar when mixed at a mixing ratio of 10% (to about 1 See compressive strength of sample 4). As a result of comparing the compressive strength of mortar mixed with fly ash and D ₆₅₀ , general mortar showed compressive strength of about 357 kgf / ㎠ on the 28th day of age, but D ₆₅₀ mixing ratio was included for fly ash FA1, FA3 and FA4. With this increase, the compressive strength decreased. However, the compressive strength of the mortar mixed with fly ash FA2 increased the compressive strength by 2% and 5%, respectively, when the D ₆₅₀ mixing ratio was 10% and 20% (compressive strength of samples 9 and 10, respectively). Reference). The compressive strength of mortar mixed with flooring material and D ₆₅₀ was slightly different depending on the type of flooring material. The compressive strength of the 28-day compressive strength was about 80% higher than that of the standard mortar. Was BA1 <BA3 <BA2.

<2-2> Heavy metal elution degree measurement

The heavy metal leaching amount of the mortar prepared by replacing the fly ash and the bottom ash by 10% with respect to the fine aggregate weight and mixing D ₆₅₀ with 10% of the cement weight was measured in the same manner as in Experimental Example <1-2>. Shown in

TABLE 7

Elution amount of heavy metal by incineration ash containing mortar (mg / ℓ)

number Pb Cu As Hg CD Cr ⁶⁺ 6 0.263 0.019 0.021 0.0009 0.0001 0.006 9 0.185 N.D. 0.020 0.0008 N.D. 0.004 12 0.102 0.003 0.023 0.0007 0.001 0.010 15 0.133 N.D. 0.021 0.0007 0.001 0.007 17 0.430 0.053 0.012 0.0005 N.D. 0.063 18 0.425 0.088 0.021 0.0005 N.D. 0.027 19 0.426 N.D. 0.012 0.0005 N.D. 0.032 Tolerance 3.00 3.00 1.500 0.005 0.300 1.500

N.D. : Not detected

As can be seen from the above results, the amount of leaching heavy metal ions of mortar mixed with fly ash and D ₆₅₀ was mixed according to the type of fly ash, but the harmful heavy metal was almost fixed (about 95% or more). Were satisfied (see samples 6 to 15). In addition, in the case of mortar mixed with the flooring material and 10% D ₆₅₀ , the harmful heavy metals were fixed more than 99%, which was below the domestic environmental standard (see samples 17 to 19). In particular, it was confirmed that only about 0.4 ppm of Pb having a high content of 149 and 34 ppm in BA1 and BA2 of flooring material was eluted to show a complete fixation rate. In addition, Cu, Hg, Cr ions, etc. were also immobilized in the hydrate of the cement particles or changed into a hydration product, the elution amount was greatly reduced.

Experimental Example 3 Incinerator Ash and D ₆₅₀ Simultaneous measurement of compressive strength of cement mortar and concrete

Cement was used as a mixture of ordinary Portland cement with a specific gravity of 3.15, a mixture of fly ash and Portland cement. In addition, fine aggregates used crushed sand having a specific gravity of 2.63, and coarse aggregates used crushed gravel having a maximum dimension of 25 mm and a specific gravity of 2.63.

<3-1> Compressive strength measurement of mortar

The characteristics of mortar and concrete were analyzed with respect to the method of replacing the fly ash with D ₆₅₀ mixed with 10% of the weight of cement and the loading of 10% of the weight of fine aggregate. At this time, as shown in Table 8, the mixing ratio was selected based on the ratio 1: 3 of the cement and fine aggregate and the target flow of 110 ± 10.

TABLE 8

Kinds Incinerator replacement cement(%) D ₆₅₀ (%) sand(%) Fly ash (%) CTM Standard mortar 29.0 0.0 71.0 0.0 FA1MR cement 23.5 2.9 71.0 2.6 FA2MR 23.5 2.9 71.0 2.6 FA3MR 23.5 2.9 71.0 2.6 FA4MR 23.5 2.9 71.0 2.6 FA1MA Fine aggregate 26.1 2.9 61.0 10.0 FA2MA 26.1 2.9 61.0 10.0 FA3MA 26.1 2.9 61.0 10.0 FA4MA 26.1 2.9 61.0 10.0

FAMR: mortar replacing cement with incineration ash,

FAMA: Mortar replacing fine aggregate with incineration ash

The compressive strength of mortar was measured in the same manner as in Experimental Example <2-1>, and the results are shown in Table 9.

TABLE 9

Kinds Incinerator replacement 7 days 28 days Kgf / ㎠ % Kgf / ㎠ % CM10 Standard mortar 261 100 273 100 FA1MR cement 303 116 311 114 FA3MR 310 119 314 115 FA4MR 255 98 267 98 FA1MA Fine aggregate 322 123 379 139 FA3MA 327 125 401 147 FA4MA 340 130 421 154

As can be seen from the above results, it was found that the compressive strength of the mortar prepared by replacing fly ash with cement and fine aggregate was significantly improved compared to the reference mortar without mixing fly ash. In addition, when the cement is replaced with the fine aggregate, the strength was found to be greater effect. Effective strength expression is considered to be due to the high content of CaO contained in fly ash and the active reaction of active diatomaceous earth, a pozzolanic material.

<3-2> Compressive strength measurement of concrete

The compressive strength of the concrete which replaced the crushed aggregate in the mixed cement was measured according to the mixing design criteria (compressive strength 240 ㎏ / ㎠ on 28 days curing). Specifically, a concrete specimen (ψ100 mm × L 200 mm) was produced using the formulation as shown in Table 10, wherein the air amount was adjusted to 4.5% ± 1.5%, and the slump was in the range of 12.0 cm ± 2.0 cm.

TABLE 10

Kinds G _max (mm) W / (C + FA) (%) s / a (%) Unit weight (㎏ / ㎥) Admixture (C ×%) Air volume (%) Slump (cm) W C S G FA AE SP CTMC 25 53.3 47.3 178 334 836 933 0 0.25 0.50 6.0 14.0 FA1C 25 53.3 47.3 178 301 836 933 33 0.25 0.50 6.0 13.5 FA3C 25 53.3 47.3 178 301 836 933 33 0.25 0.50 4.5 14.0 FA4C 25 53.3 47.3 178 301 836 933 33 0.25 0.50 3.5 11.5

W: water, C: cement, S: sand, G: gravel, FA: fly ash,

AE: air entrainment, SP: special pozzolia

The compressive strength of the concrete was measured in the same manner as in Experimental Example <2-1>, and the results are shown in Table 11.

TABLE 11

 Properties Plain concrete Concrete with fly ash and D ₆₅₀ FA1C FA3C FA4C Heavy metal elution NIL NIL NIL NIL Slump (cm) 14.0 13.5 14.0 11.5 Air volume 6.0 6.0 4.5 3.5 AE product (C × 0.5%) 1.67 1.67 1.67 1.67 Compressive strength (㎏f / ㎠) 7 days 152 195 226 235 28 days 194 273 338 350

As can be seen from the above results, the compressive strength of concrete mixed with fly ash and D ₆₅₀ is significantly increased compared to concrete using only Portland cement, and the 7-day and 28-day compressive strengths of FA1C, FA3C and FA4C are Compared to 28%, 49%, 55% and 41%, 74% and 80%, respectively.

As described above, the mortar and concrete prepared by using the mixed cement composition of the present invention shows an excellent compressive strength improvement effect compared to the mortar and concrete using only ordinary cement, and also for various types of heavy metals contained in the incineration ash. It has an excellent fixing effect. Therefore, the mixed cement composition of the present invention contains a large amount of heavy metals and environmental hormones harmful to the human body can be usefully used as a recycling method for incineration ash is prohibited.

Claims (7)

A mixed cement composition comprising an incinerator and a pozzolanic material as an additive. The mixed cement composition of claim 1, wherein the incineration ash is selected from the group consisting of bottom ash (BA), fly ash (FA) and mixtures thereof. The mixed cement composition according to claim 1, wherein the pozzolanic material is selected from the group consisting of diatomaceous earth, volcanic ash, clay silicate, silicate soil, fly ash, heat treated clay and shale. The method of claim 3 wherein the pozzolanic material is diatomaceous earth. The mixed cement composition according to claim 1, wherein the pozzolanic material is included in an amount of 5 to 20% by weight and the incineration material is included in an amount of 5 to 20% by weight based on the total weight of the mixed cement composition. A mortar, characterized in that the mixture is prepared by kneading 15 to 25% by weight, 40 to 55% by weight of sand and 25 to 40% by weight of water. 10 to 25% by weight of the mixed cement composition of claim 1, 25 to 35% by weight of sand, 25 to 35% by weight of gravel and 20 to 40% by weight of concrete, characterized in that the concrete is produced.