KR101962725B1 - Determination Method of composition ratio of multicomponent inorganic admixture of binder - Google Patents

Abstract

The present invention relates to various inorganic admixtures used in concrete or mortar, and it can be used for concrete type mortar or concrete suitable for the mixing condition of concrete and structure performance by deriving optimum mixing ratio based on the main chemical composition and particle size characteristics. And to a method of determining a composition ratio of a multi-component admixture.
In order to solve the above-mentioned problems, the present invention provides a method for determining a definite composition ratio of a mixed material to be used as a binder of mortar or concrete, comprising the steps of: (a) selecting an inorganic mineral admixture to be applied; (b) analyzing the chemical composition and particle size of the selected admixture material; (c) setting the particle size coefficient target value and the C / S ratio target value of the binder in consideration of the target fluidity and compressive strength of the final composition; (d) determining a mixing ratio of the admixture material in accordance with the C / S ratio target value; (e) mixing the mixture according to the mixing ratio to prepare a binder, and evaluating the chemical composition and the particle size coefficient of the binder; (f) evaluating the fluidity and aging compressive strength of the mortar or concrete to which the binder is applied, and (g) determining the mixing ratio of the step (d) as the definite composition ratio when the evaluation results satisfy the target fluidity and compressive strength ≪ / RTI > wherein the method comprises the steps of:

Description

Determination method of composition ratio of multicomponent inorganic admixture of binder

The present invention relates to various kinds of inorganic admixtures used in concrete or mortar, and it is a custom mortar or concrete binder suitable for the mixing conditions of concrete and the required performance of a structure by deriving optimum mixing ratio based on the main chemical composition and particle size characteristics The present invention relates to a method for determining an optimal composition ratio of a component material.

Cement is mainly used as mortar or concrete binder, but various kinds of mineral admixture materials (fly ash, blast furnace slag powder, swelling agent, silica fume, etc.) are used together with the purpose of cost reduction, workability improvement, strength and durability enhancement.

In this regard, KS F 4009 (Ready Mixed Concrete) states that "Since many types of concrete admixtures are used and their methods and effects are varied, they are carefully examined for their quality and usage records so that they do not adversely affect concrete or steel And the admixture materials determined by the KS standard are as follows. KS F 2562 (inflator), KS F 2563 (blast furnace slag fine powder), KS F 2567 (silica fume) and KS L 5405 (fly ash).

The current problems with the above-mentioned inorganic admixture materials are as follows.

[1] Unstable Supply and Demand Environment of Admixture for Concrete

In KS F 4009, the KS standard is limited to inorganic admixtures for concrete as inflators, blast furnace slag, silica fume, and fly ash. However, the recent concrete environment related to concretes (such as rising raw material costs, unstable supply conditions, And various performance requirements of the purchaser). However, there is a growing interest in the proper utilization of various inorganic admixtures which do not cause any significant problems in concrete performance.

"One of the blast furnace slag, pozzolan and fly ash" of KS L 5201, amended in 2016, may be mixed and pulverized within 5% of cement and limestone within 5% of cement. The demand for mineral admixtures increased. Despite the consumption of high quality blast furnace slag powder and fly ash from domestic cement makers in Korea, it is difficult to supply fly ash and it imports a large amount of fly ash from Japan and China.

Therefore, domestic remicon companies that demand more than 5 million tons of fly ash per year are looking for ways to utilize various mineral admixture materials which can be used at a level that does not cause any serious problems in concrete concrete performance, though it is somewhat lacking in KS standards .

[2] Current KS quality standards that do not take into account quality fluctuation characteristics of cement and various mineral admixtures

Even in the case of ordinary portland cement, which is considered to be the most stable quality level among the materials used for concrete, the quality fluctuation is very large as shown in [Reference Figure 1].

[Reference Figure 1]

Despite the above fluctuation in the quality of cement, only a single performance evaluation index as determined by KS is applied to fly ash and blast furnace slag fine powder which is used by replacing a part of cement in a weight ratio. Therefore, It is difficult to evaluate the quality performance of the composite material for concrete.

That is, when only one kind of mineral admixture (fly ash or blast furnace slag powder) is mixed with cement as a binder for concrete, the quality evaluation standard (KS standard) specified for each material is applied, It is an inadequate evaluation method that can not comprehensively evaluate the quality characteristics when the two materials are combined. Therefore, there is a need for a method for evaluating the integrated performance under the condition that the actual materials are combined.

[3] - A method for evaluating the performance of inorganic materials with various compositions

Due to the above-mentioned poor construction environment, some domestic remicon companies use various kinds of inorganic materials other than the KS range together with the existing KS range materials as concrete admixture materials. However, there is no way to evaluate the performance of various kinds of inorganic materials.

In the case of fly ash and blast furnace slag fine powders, which can be considered as typical concrete admixtures for concrete, the activity index (C1 / C2) of 28th and 91st days of fly ash as the final quality performance index, (CaO + MgO + Al ₂ O ₃ / SiO ₂ = 1.60 or more) together with the activity index (C 1 / C 2) of the day 7, day 28, day 91.

Therefore, when using a fly ash or blast furnace slag fine powder alone or in combination, it is difficult to evaluate the quality characteristics of the mixed material in which various kinds of inorganic materials other than the KS range are mixed.

1. Patent No. 10-1511767 entitled "Performance-Based Concrete Mixture Design Method Considering Environmental Load Assessment, and Recording Medium Recorded with Program for Executing the Method," Announcement 2015.04.17 2. Registration No. 10-1559698 "Method for predicting environmental load using performance evaluation of concrete ", Oct. 13, 2015 3. Registered patent 10-1399952 "Geopolymer formulation design method ", 2014.05.29. Announcement 4. Registration No. 10-1748119 entitled " Method for designing mixing and curing of fly ashio polymer mortar for secondary product production ", 2017.06.16. Announcement

1. Park, Won-joon, et al., "A Study on the Mixing Design of Concrete Using Recycled Aggregates", Proceedings of the Fall Conference, Vol. 11, No. 2, pp.

It is an object of the present invention to provide a method of determining the composition ratio of a multicomponent mineral admixture which can obtain a binder satisfying required physical properties by analyzing, evaluating and mixing various materials in addition to the inorganic materials disclosed in KS.

Thus, by improving the existing KS quality standard that does not consider the quality fluctuation characteristics of cement and various inorganic admixture materials, it is possible to utilize various inorganic materials for the purpose of comprehensive use, thereby coping with unstable supply and demand of blast furnace slag powder and fly ash There is another purpose.

In order to solve the above-mentioned problems, the present invention provides a method for determining a composition ratio of an admixture material applied as a binder of mortar or concrete, comprising the steps of: (a) selecting an inorganic admixture material to be applied; (b) analyzing the chemical composition and particle size of the selected admixture material; (c) setting the particle size coefficient target value and the C / S ratio target value of the binder in consideration of the target fluidity and compressive strength of the final composition; (d) determining a mixing ratio of the admixture material in accordance with the C / S ratio target value; (e) mixing the mixture according to the mixing ratio to prepare a binder, and evaluating the chemical composition and the particle size coefficient of the binder; (f) evaluating the fluidity and aging compressive strength of the mortar or concrete to which the binder is applied, and (g) determining the mixing ratio of the step (d) as the definite composition ratio when the evaluation results satisfy the target fluidity and compressive strength ≪ / RTI > wherein the method comprises the steps of:

In the step (b), a binder reference table having a particle size coefficient and a C / S ratio according to a binding material test sample prepared by adjusting a content ratio of the selected admixture material is prepared. In the step (c), each of the test examples is applied to mortar or concrete And a test result reference table in which the slump flow and age-specific compressive strength derived by applying the slump flow and the aging compressive strength are derived. From the binder reference table and the test result reference table, the granularity coefficient or C / S ratio, , The target fluidity and compressive strength of the final composition can be taken into consideration through the correlation graph.

If the liquidity in the result of the step (f) is out of the target liquidity range in the step (g), the mixing ratio of the step (d) is determined as the composition ratio, and the granularity target value is reset Repeat steps e) through f).

In the step (g), when the compressive strength is less than the target compressive strength, the C / S ratio target value resetting and the steps (d) to (f) Is determined as the determined composition ratio.

According to the present invention, the following effects can be expected.

1. Various mineral admixture materials which are easy to supply and receive can be used as a raw material for mortar or concrete binder.

2. Mixing materials which are not specified in KS standards can be mixed to form a binder having physical properties in accordance with the C / S ratio and particle size factor.

3. It is possible to review the quality of binders in which cement with various quality fluctuations and various mineral admixtures are mixed with each other at the time of production.

1 is a flow chart of a method for determining a composition ratio of a multi-component admixture of a binder provided by the present invention.

The present invention relates to a method for determining a composition ratio of an inorganic admixture material applied as a binder of mortar or concrete, comprising the steps of: (a) selecting an inorganic admixture material to be applied; (b) analyzing the chemical composition and particle size of the selected mineral admixture material; (c) setting the particle size coefficient target value and the C / S ratio target value of the binder in consideration of the target fluidity and compressive strength of the final composition; (d) determining a mixing ratio of the inorganic admixture material to the C / S ratio target value; (e) mixing the mixture according to the mixing ratio to prepare a binder, evaluating the chemical composition and the particle size coefficient of the binder, and, when the particle size coefficient of the binder exceeds the target value of the particle size coefficient, ; (f) evaluating the flowability and aging compressive strength of the mortar or concrete to which the binder is applied, and (g) determining the mixing ratio of the step (d) as the determined composition ratio when the evaluation results satisfy the target fluidity and compressive strength , And when the liquidity out of the evaluation results is out of the target liquidity range, the granularity target value resetting and the steps (e) to (f) are repeated until the liquidity is within the target fluidity range, And a step of re-setting the C / S ratio target value and repeating the steps (d) to (f) when the ratio is less than the target compressive strength.

1 is a flow chart of a method for determining a composition ratio of a multi-component admixture of a binder provided by the present invention. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1. Step (a)

The step (a) is a step of selecting an inorganic admixture to be applied as a binder. Even if a material to be applied as a binder is arbitrarily selected from among the available inorganic admixture materials, a binder exhibiting a target physical property can be formed by each of the following steps.

2. Step (b)

Step (b) is a step of analyzing chemical composition and particle size of the selected admixture material.

X-ray fluorescence spectrometry (XRF) can be applied as a chemical analysis method. By analyzing the chemical composition, the content of SiO ₂ , CaO, Free CaO, etc. of the selected admixture can be grasped and the C / S ratio (weight ratio of CaO and SiO ₂ ) can be derived. The C / S ratio is an index used to evaluate the degree of formation of calcium silicate hydrate (CSH), which is the main hydrate of existing cement.

The particle size of the admixture can be analyzed through a Powder Fineness Modulus (PFM). The PFM is a factor closely related to the flow characteristics of mortar or concrete, and represents the particle size distribution of the powder as an integer. The calculation method is as follows.

PFM = cumulative amount (%) remaining in the 80 mu m sieve + cumulative amount (%) remaining in the 40 mu m sieve + cumulative amount (%) remaining in the 20 mu m sieve + cumulative amount ] / 100

As the PFM increases, the amount of fine aggregate and the unit quantity should be increased to secure the target fluidity, and the amount of AE agent and SP agent should be reduced.

In step (b), a binder reference table in which the particle size coefficient and the C / S ratio of each binder test sample are prepared by adjusting the content ratio of the selected admixture material is prepared. In the step (c) Value can be used to set the value.

[Table 1] is an example of the binder reference table, which is a summary of the results of calculating the PFM by analyzing the chemical composition and the C / S ratio of the OPC and the mineral admixture applied as the raw material of the binder. The values in parentheses in [Table 1] below show the content ratio of the admixture materials excluding OPC among the whole binders.

3. Step (c)

Step (c) is a step of setting a target value of the PFM and the C / S ratio of the binder material in which the admixture is mixed. That is, the PFM related to the fluidity and the early strength and the C / S ratio related to the compressive strength are first set, and the PFM and the C (S) ratio set as the target values based on the analysis result in the step (b) / S < / RTI > ratio.

 In the step (c), a test result reference table showing slump flow and age-specific compressive strength can be created by applying each test example of the binder reference table to mortar or concrete.

 By deriving a correlation graph between the particle size coefficient or C / S ratio and the slump flow or age-based compressive strength from the binder reference table and the test result reference table, the target fluidity and compressive strength of the final composition can be taken into consideration through the correlation graph have.

[Table 2] is a reference table of the test result, and shows the compressive strength of slump flow and age (3 days, 7 days) of mortar (or concrete) applied with each test example of Table 1 as a binder The results of the test are summarized.

[Table 2] shows the result of the compression strength test by slump flow and aging under the condition that the weight ratio of the binder to the sand was adjusted to 1: 3 by adjusting the water-binder ratio to 50% in all of the test examples. The water-binding ratio, the binder-sand ratio, and the like are preferably applied as the blending conditions corresponding to the final composition. In view of the above, the present invention is particularly effective when it is desired to find a suitable binder prepared by mixing various admixtures in a state in which other mixing conditions and required properties are determined.

The correlation between the PFM or C / S ratio of the binder and the slump flow or compressive strength is determined by the PFM and C / S ratios of the test examples given in [Table 1] and the test results of the slump flow and age- , And a correlation graph as shown in [Reference Figure 2] to [Reference Figure 5] below can be derived.

Therefore, it is possible to set a target value of the PFM and the C / S ratio of the binder in expectation of a slump flow, a compressive strength, etc. at a specific level based on the correlation graph.

For example, the PFM target value according to the target performance of the binder is shown in the graph of the relationship between the binder PFM and the fluidity shown in [Reference Fig. 2] and the relationship between the binder PFM and the early strength It can be set as shown in [Table 3] below by referring to the relationship graph.

[Reference figure 2] - Graph of the relationship between binder PFM and fluidity

[Reference figure 3] - Graph of relationship between binder PFM and early strength (age 3 days compressive strength)

Binding target performance PFM Goal Value The 1.0 or less Typical 1.0 to 1.25 Delayed type 1.25 or higher

In addition, the target value of C / S ratio according to the target performance of the binder is calculated by referring to the graph of the relationship between the binder C / S ratio and the compressive strength (7 days compressive strength at the age) shown in [References Fig. 4] and [Reference Fig. 5] Can be set as shown in Table 4.

[Reference figure 4] - A graph of the relationship between the C / S ratio and the compressive strength of the binder obtained with OPC included

[Reference figure 5] - A graph of the relationship between the C / S ratio and the compressive strength of the binder,

C / S ratio target value If the binder contains OPC If the binder does not contain OPC Chogang type 2.5 or more Crude steel type 0.8 or higher Standard Type 2.0 ~ 2.5 Typical 0.4 ~ 0.8 Delayed 2.0 or less Delayed type 0.4 or less

4. Step (d)

Step (d) is a step of determining the mixing ratio of the admixture material in accordance with the target value of the C / S ratio. Since the content of CaO, SiO _2, etc. of each component of the OPC and the admixture can be known through the step (b), the C / S ratio of the entire composition can be adjusted to the target value by adjusting the mixing ratio of each admixture.

Also, by referring to the binder reference table prepared in the step (b), the mixing ratio of the admixture material meeting the C / S ratio target value can be derived.

For example, when the C / S ratio target value is 1.8, it is found that Test Example 2 in which 75 wt% of OPC and 25 wt% of purified fly ash are mixed is 1.742 closest to 1.8 among the test examples shown in [Table 1] . However, since the C / S ratio target value is somewhat higher than the C / S ratio of Test Example 2, a binder having a C / S ratio of 1.742 is obtained by increasing the amount of OPC admixture and reducing the amount of refined fly ash having a high SiO2 content to less than 25 wt% .

On the contrary, if the C / S ratio target value is 1.7, a binder having a C / S ratio of 1.7 can be obtained by reducing the amount of OPC admixture having a relatively high CaO content in Test Example 2 and increasing the mixing amount of refined fly ash.

5. Step (e)

Step (e) is a step of mixing the mixture according to the mixing ratio to prepare a binder, and evaluating a chemical component (XRF) and a particle size coefficient (PFM) of the binder.

The C / S ratio (binder mixing ratio) can be determined according to the main chemical components of each admixture material to be used in the step (d). However, the particle size of the binder prepared by mixing each admixture material can not be satisfied simply by mixing the materials. Accordingly, in the step (e), when the PFM of the binder exceeds the PFM target value, a step of grinding the admixture material in accordance with the PFM target value is additionally performed.

For example, if the PFM measured by mixing various kinds of inorganic materials is 1.2, and the PFM target value is set to 0.9 to express toughness, the particle size may be adjusted by a pulverization process (ball mill, roller mill, etc.) will be.

That is, (1) when the target values of the PFM and the C / S ratio of the binder are determined, (2) the C / S ratio is firstly mixed with each admixture material, (3) , And (4) the final composition is prepared.

6. Step (f)

The step (f) is a step of evaluating the fluidity of the mortar or concrete to which the binder prepared in the step (e) is applied and the compressive strength of each concrete according to the age.

At this stage, we fabricated specimens simulating the mixing ratio of concrete or mortar to reflect the unit water content, water-binding ratio, coarse aggregate amount, fine aggregate amount, fine aggregate content, additive, etc. and measured the slump, slump flow, Can be evaluated.

7. Step (g)

The step (g) is a step of determining the mixing ratio of the step (d) as the definite composition ratio when it is in accordance with the target fluidity and the compressive strength.

When the inorganic admixture is to be used as a substitute for OPC, the target fluidity and compressive strength may be set based on the OPC 100% binder. For example, the target fluidity can be set to be equal to or higher than that of the 100% OPC binder, and the target compressive strength is 50% or more for 3 days at 100% OPC, 80% or more for 7 days and 110% or more for 28 days .

In this step, the mixing ratio of the step (d) is determined as the determined composition ratio, and when the liquidity is out of the target liquidity range in the step (f), the granularity target value is reset Repeat steps e) through f).

When the compressive strength is less than the target compressive strength among the evaluation results of the step (f), the C / S ratio target value resetting and the steps (d) to (f) Is determined as a fixed composition ratio.

As described above, the present invention has been explained by the limited test examples. However, the present invention is not limited thereto, and the technical idea of the present invention and those described below It is to be understood that various changes and modifications may be made without departing from the scope of the appended claims.

Not applicable

Claims (5)

A method for determining a composition ratio of an inorganic admixture material applied as a binder of mortar or concrete,
(a) selecting an inorganic mineral admixture to be applied;
(b) analyzing the chemical composition and particle size of the selected mineral admixture material;
(c) setting the particle size coefficient target value and the C / S ratio target value of the binder in consideration of the target fluidity and compressive strength of the final composition;
(d) determining a mixing ratio of the inorganic admixture material to the C / S ratio target value;
(e) mixing the mixture according to the mixing ratio to prepare a binder, evaluating the chemical composition and the particle size coefficient of the binder, and, when the particle size coefficient of the binder exceeds the target value of the particle size coefficient, ;
(f) evaluating the fluidity and age-specific compressive strength of the mortar or concrete to which the binder is applied, and
(g) determining the mixing ratio of the step (d) as the determined composition ratio when the evaluation results meet the target fluidity and compressive strength, and if the fluidity is outside the target fluidity range, (C) and (d) to (f) are repeated when the compression strength is less than the target compressive strength, and the step (e) And repeating the step of repeating the steps of:
delete delete delete The method of claim 1,
In the step (b), a binder reference table having a particle size coefficient and a C / S ratio according to a binding material test sample prepared by adjusting the content ratio of the selected inorganic admixture material is prepared,
In the step (c), a test result reference table showing slump flow and age-specific compressive strength derived by applying each of the test examples to mortar or concrete is prepared, and the binder reference table and the test result reference table A multicomponent mineral admixture material of a binder, comprising a correlation graph between a particle size coefficient or a C / S ratio and a slump flow or aging compressive strength, thereby taking into account the target fluidity and compressive strength of the final composition via said correlation graph Determination of composition ratio.

Images