KR100417528B1 - Liquid-phase admixture components of dual components based on fluosilicate salt for improving waterproofing and strength of concrete and its manufacturing method - Google Patents

Abstract

The present invention relates to a two-component silicate fluoride-based liquid additive composition and a method for manufacturing the same, in which zinc silicate and magnesium silicate are added to concrete in an aqueous state to improve waterproofness and increase compressive strength by 20% or more. Flame-based liquid additive is characterized in that the effective concentration of the silica fluoride salt is 5 to 30% (w / w), the zinc silica fluoride content is 50 to 90% by weight, magnesium magnesium fluoride content It is characterized by consisting of 10 to 50% by weight. When the two-component silicate-based liquid additive is added to the concrete at 1.0 to 3.0% by weight of the cement, it is possible to produce concrete with 10 to 30% increase in compressive strength according to age while improving waterproofness.

In addition, the addition of the two-component siliceous fluorinated salt-based liquid additive proposed in the present invention has the effect of reducing the heat of hydration of cement. Therefore, the mass of the concrete and the Seojung, which requires the suppression of the internal heat of hydration due to the large member cross-section, It can be applied to concrete.

Description

Liquid-phase admixture components of dual components based on fluosilicate salt for improving waterproofing and strength of concrete and its manufacturing method}

The present invention relates to a two-component gyubul flame-based liquid additive composition and a method of manufacturing consisting of a silicon fluoride, zinc having an increase of over 20% strength effect with improved water resistance of the concrete (ZnSiF ₆₎ and silicon fluoride, magnesium (MgSiF _6), Specifically, by adding 1.0 to 3.0% by weight of a two-component aqueous solution of silicate fluoride consisting of zinc fluoride and magnesium fluoride relative to the weight of cement, the concrete's waterproofness is improved and its compressive strength is increased by 10-30% depending on age. It relates to a two-component siliceous salt-based liquid additive composition and a method for producing the same.

Silica fluoride salts such as zinc fluoride and magnesium fluoride are dissociated into metal ions such as zinc and magnesium and fluoride ions (SiF ₆ ^2- ) by hydrolysis in an aqueous solution. The higher the dissociation characteristic increases. The dissociated silicate ions in the aqueous solution are hydrolyzed again to form amorphous silica and fluorine ions (F ⁻ ). Amorphous silica has the effect of promoting the pozzolanic reaction of soil and cement containing a large amount of Ca (OH) ₂ , and when the alkalinity of the aqueous solution is increased, fluorine ions dissociated from silicic ions and alkali metals such as Ca, Al and Na The reaction forms metal fluorides such as CaF ₂ , NaF, AlF _3, and the like. Due to the above characteristics, silicic salts have the function of controlling the condensation or curing rate of various hydraulic materials including soil and cement, and when combined properly, silicic salts are additives that can increase the strength of soil or cement. It can be utilized.

For example, in Korean Patent Application No. 1998-065526 [Composition of multifunctional high performance mortar], magnesium silicate, potassium silicate (K ₂ SiF ₆ ), sodium silicate (Na ₂ SiF ₆ ) to control the setting speed of high performance mortar The addition of 0.1 to 1.0% by weight of a silofluoride salt such as Magnesium fluoride was used in 1984-6714 [Soil coagulation hardener composition] and 1997-18924 [Soil coagulation hardener] as an additive for controlling the coagulation rate and hardening rate of soil. Lee et al. [Delayed Hydration Effect of Portland Cement by Magnesium Fluoride, Journal of the Korean Ceramic Society, Vol. 34, No. [2] published a study using magnesium silicate for the purpose of delaying the setting time of cement mortar.

On the other hand, Korean Patent Registration No. 0233778 discloses at least one of fluoride salts composed of magnesium fluoride, sodium fluoride, zinc fluoride, manganese fluoride (MnSiF ₆ ) and calcium fluoride (CaSiF ₆ ), type II anhydrous gypsum, 5 to 25% by weight was added to the mixed powder of coal ash and blast furnace slag to be used as an additive for increasing the strength of concrete.

In addition, the application of silica fluoride in order to impart waterproofness to cement or concrete. In Korea Patent Application No. 2001-63881 [method of improving the waterproofness of concrete or concrete using zinc fluoride aqueous solution] zinc fluoride in the silica fluoride By applying the aqueous solution alone, the waterproof effect was excellent, but the compressive strength enhancement effect of the concrete is weak, and in particular, the fluidity has a problem that the remarkably lowered.

As described above, in the prior art in the field of the present invention, the composition of the silofluoride-based aqueous solution and the technique for adjusting the amount of addition to the weight of the cement are insufficient, thus excessively delaying the setting time of cement, and the strength and durability of mortar or concrete using cement. This degrading adverse effect can be caused.

Therefore, the present applicant has 50 to 90% by weight of zinc fluoride as a main component of the silica fluoride, and 10 to 50% by weight of magnesium silica fluoride as a secondary component in order to supplement the problems of the prior art in the application of the silica fluoride salt. The effective concentration of the silica fluoride salt in the two-component silica fluoride-based liquid additive was prepared in the range of 5-30% (w / w), and the liquid additive prepared by the present invention contained 1.0-3.0 wt. It can be seen that by adding%, the waterproofness of the concrete is excellently improved, the compressive strength is improved by 20% or more, it is very effective in improving the fluidity, and the heat of hydration of cement is effectively reduced.

An object of the present invention is to contain 50 to 90% by weight of zinc fluoride as the main component of the silica fluoride, in order to improve the conventional problems that can be generated by using the aqueous solution of silica fluoride as described above, magnesium silica fluoride 10 The water resistance of the concrete by adding 1.0 to 3.0% by weight of the cement in an aqueous solution having an effective concentration of 5 to 30% (w / w) in the two-component silicate-based liquid additive combined to contain -50% by weight. It is to provide a two-component silica fluoride-based liquid additive composition that can be improved and 20% or more strength can be improved and a method for producing the same.

1 is a process chart showing a method for preparing a two-component silicate fluoride-based liquid additive containing zinc silicate and magnesium silicate

Figure 2 is a schematic diagram of a reactor for exerting a waterproof and strength enhancing effect when adding a two-component silicate-based liquid additive to concrete

Figure 3 is a graph showing the results of the analysis of the hydration exothermic rate of calcium silicate (C ₃ S) according to the change in the amount of the two-component silica fluoride-based liquid additive

Figure 4 is a graph showing the measurement results for the fluidity change of the concrete according to the addition amount of the two-component silica fluoride-based liquid additive

In order to achieve the above object, the present invention reacts zinc and magnesium sources in various metal salt forms with hydrofluoric acid (H ₂ SiF ₆ ) to form zinc fluoride as a component of the silica fluoride. A composition of a two-component silicate fluoride-based liquid additive containing 10 to 50% by weight of magnesium silicate fluoride, and a method for producing the same are provided.

In addition, if necessary to dilute with water so that the effective concentration of the silica fluoride salt in the two-component fluorinated salt-based liquid additive prepared above is 5 to 30% (w / w), 1.0 to 3.0% by weight relative to the weight of the cement in the aqueous state By providing a composition of a two-component siliceous salt-based liquid additive that can enhance the waterproof and compressive strength of the concrete.

Hereinafter, the present invention will be described in detail.

The two-component silicate-fluoride-based liquid additive proposed in the present invention is one selected from zinc oxide (ZnO), zinc carbonate (ZnCO ₃ ), zinc sulfate (ZnSO ₄ ), and zinc hydroxide (Zn (OH) ₂ ) as a zinc source. Magnesium oxide (MgO), magnesium carbonate (MgCO ₃ ), magnesium sulfate (MgSO ₄ ) and magnesium hydroxide (Mg (OH) ₂ ) as a magnesium source is characterized in that it is prepared by reacting with hydrofluoric acid. At this time, the suitable concentration of hydrofluoric acid that can be used is 10 to 40% (w / w), by-products generated in the phosphoric acid manufacturing process and hydrofluoric acid manufacturing process and hydrofluoric acid produced by dissolving SiO ₂ in hydrofluoric acid (HF). Can be used.

Two components using zinc oxide (industrial, purity of 97%) as the zinc source, magnesium carbonate (industrial, purity of 96.5%) as the magnesium source, and 25% by weight of hydrofluoric acid produced during the production of phosphoric acid. Hereinafter, a method for preparing a silicic acid-based liquid additive is described in detail.

First, hydrofluoric acid is added to the reaction vessel, and then an appropriate amount of magnesium carbonate is slowly added while stirring (stirring speed: 100 rpm) with an agitator with an impeller. At this time, carbon dioxide gas may be generated from the stirring solution. After 10 minutes of adding all the magnesium carbonate, the appropriate amount of zinc oxide is gradually added to the reaction vessel under continuous stirring (first mixing). After diluting the mixed solution after stirring (secondary mixing) for about 1 hour with all of the zinc oxide in water, the two-component silicate fluorinated salt-based liquid additive containing zinc silicate and magnesium silicate fluoride proposed in the present invention at a desired concentration is prepared. It can manufacture. At this time, the amount of zinc oxide, magnesium carbonate and hydrofluoric acid can be adjusted to adjust the zinc silicate and magnesium silicate in the liquid additive to a desired concentration.

In the present invention, the amount of zinc fluoride in the silica fluoride salt contained in the two-component silica fluoride-based liquid additive is adjusted by appropriately adjusting the amounts of zinc oxide, magnesium carbonate and hydrofluoric acid, and the content of magnesium fluoride is 10 to 50% by weight. The two-component silicate salt composition prepared as described above may be prepared in a uniform liquid state, but considering the acidic state, the effective concentration of the silicate salt is 5 to 30% (w / w) so as not to cause neutralization when added to cement. It is preferable to dilute in an aqueous solution state of and use.

At this time, if the effective concentration of the manufactured fluoride salt is less than 5% (w / w), there is a problem in that an excessive amount of additive is added because the waterproofness and strength enhancing effect are insignificant. It is necessary to adjust the concentration of the two-component silicate fluoride-based liquid additive to 5-30% (w / w) because the acidity becomes so strong that it may inhibit the cement hydration reaction and cause concrete neutralization.

In addition, when the two-component silicate-based additive composition is prepared in the liquid phase as in the present invention, unlike the additive in a powder state, which is conventionally used for waterproofing and increasing strength, there is no introduction of an additional process for preparing a powder form and added to concrete. It is easy to mix uniformly with cement powder.

When the liquid additive is added to the cement-water system, which is a strong alkali having a pH of 12 or more, the zinc silicate and magnesium silicate contained in the additive can be easily converted into the metal ions and silicide ions (SiF ₆ ⁻ ) as shown in Schemes 1 and 2 below. Be dissociated

Scheme 1

_{ZnSiF 6 (. Aq) → Zn} 2+ + SiF 6 (aq.) - (aq.)

Scheme 2

_{MgSiF 6 (. Aq) → Mg} 2+ + SiF 6 (aq.) - (aq.)

At this time, dissociated silicic fluoride (SiF ₆ ⁻ ) is hydrolyzed as in FIG. 2 to generate amorphous silica, thereby fluorine ions are released in the aqueous solution. The fluorine ions released in this way react with alkali ions in cement to form poorly soluble metal fluorides (M'F) of submicron or less, resulting in compact structure due to the filling action against micropores and cracks of several to several tens of micrometers present in concrete. free), which ultimately increases the watertightness of the concrete, thereby contributing to the improvement of waterproofness. Amorphous silica, on the other hand, contributes to strength enhancement by the pozzolanic effect, which reacts with calcium hydroxide produced by the hydration of cement to promote the production of calcium silicate hydrogel (CSH gel), which dominates the ultimate strength of cement. .

Hereinafter, the present invention will be described in more detail based on the following examples. In the present embodiment, the content of zinc silicate and magnesium silicate contained in the two-component silicate-based liquid additive is 90% by weight and 10% by weight, respectively, and the effective concentration of the silicate salt in the liquid additive is 15% (w / w). The test specimens for concrete compressive strength and waterproofness were prepared by changing the amount of two-component silicate-based liquid additives added to the cement weight in the fixed state. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1

15% (w / w) bicomponent siliceous fluorinated liquid additive (hereinafter referred to as SWP) prepared using a 25 wt% aqueous hydrofluoric acid (H ₂ SiF ₆ ) solution and zinc oxide and magnesium carbonate, 1.0 wt% (SWP added: 0.219 kg / m ³ ) added to 21.96 kg / m ³ of cement, and 50.13 kg / m ³ and 54.53 kg / m ³ of sand (grain aggregate) and crushed stone (coarse aggregate) were added respectively. The post-mixed water was blended at 10.98 kg / m ³ (water cement ratio, W / C = 0.5). Cement used S type 1 ordinary portland cement (specific gravity: 3.14, Blaine: 3350 cm ² / g), sand 5 mm or less, and crushed stone 25 mm or less. After mixing the materials, the concrete was beamed using a forced pan-type mixer, and the cement and fine aggregates were first beamed for 30 seconds, and then water was added and rubbed again for 60 seconds. Finally, the high fluidizing agent (SP) and the two-component siliceous fluorinated liquid additive were added, and the mixture was bibeamed for 60 seconds, and the material was then beamed for a total of 3 minutes and 30 seconds.

Example 2

In Example 1, except that 2.0% by weight (SWP addition amount: 0.439 kg / m ³ ) of the SWP to the cement, respectively, was added to the cement, Example 2 was carried out in the same manner and conditions as in Example 1 Divided into.

Example 3

In Example 1, Example 3 was carried out in the same manner as in Example 1, except that 3.0% by weight (SWP addition amount: 0.658 kg / m ³ ) of the SWP to the cement, respectively, was added to the cement Divided into.

Curing of the compressive strength test specimen and the permeation test specimen for the evaluation of waterproofness in the present embodiment is fixed at room temperature (20 ° C.) in a humidity of 90% relative humidity and curing day. Each patient was cured.

Comparative example

Concrete mixture (co-mixing) without the addition of SWP was blended in the same conditions and the bibeam method as in Example 1 to make a comparative example, it was distinguished from the examples.

The results obtained by arranging the above Examples and Comparative Examples classified according to the amount of SWP added based on the material formulation are shown in the following table.

Table 1 Concrete material mix according to Examples 1 to 3 and Comparative Examples of the present invention

Test Example 1 Measurement of Compressive Strength

The compressive strength (kg _f / cm ² ) of the concrete specimens of Examples 1 to 3 and Comparative Examples, which were passed for 3, 7 and 28 days, respectively, were measured according to KS F 2405, and the measurement results are shown in Table 2 below. It was.

[Table 2] Compressive strength change of the concrete age according to Examples 1 to 3 and Comparative Examples of the present invention

As shown in the table, the addition of SWP increased the compressive strength from as little as 10% to as much as 30% regardless of age. However, it was confirmed that the compressive strength enhancement rate was higher for Example 2 added 2.0 wt% than Example 3 added 3.0 wt%. From this, in order to increase the compressive strength of concrete, the addition ratio of SWP may be presented as 1.0 to 3.0 wt%, but considering the increase in the compressive strength, it is preferable to add it within the range of 1.0 to 2.0 wt%.

Test Example 2 Measurement of Permeability

Permeability of the test specimens according to the Examples and Comparative Examples according to the KSF 2451 mortar permeability test method after 21 days or more after the curing of the mortar test compound formulated in the state of excluding the crushed stone in the above-described condition ( After measuring g) was calculated permeability (%) compared to the comparative example based on the measured value, which is shown in Table 3 below.

[Table 3] Permeability change of mortar test specimens according to Examples 1 to 3 and Comparative Examples of the present invention

From Table 3, when the SWP according to the present invention is added at 1.0 to 2.0% by weight, the water permeability of the concrete is significantly reduced to 0.2444 (%) and 0.1400 (%), respectively, compared to the case without addition, thereby greatly increasing the water resistance. Although it was confirmed that the addition of 3.0% by weight, the permeability was reduced to 0.3456 (%) than when not added, but the permeability was slightly increased compared to the case of adding 1.0 to 2.0% by weight of SWP.

Test Example 3 Measurement of Heat of Hydration

When the two-component silicate-based liquid additive proposed in the present invention is added to cement, the heat of hydration of cement, in particular, the amount of hydration calorific value of calcium silicate (3CaOSiO ₂ , C ₃ S), which is the main component mineral of cement, is suppressed. In order to confirm this, the hydration calorific value (cal / g) corresponding to the hydration of calcium silicate in the cement hydration pyrogen peak was analyzed, and the respective analysis results are shown in Table 4 below.

[Table 4] Hydration calorific value change of calcium silicate (C ₃ S) in cement according to Examples 1 to 3 and Comparative Examples of the present invention

In addition, the addition of SWP has the effect of delaying the hydration exothermic rate of the second peak corresponding to the hydration of the calcium silicate, which is the main constituent mineral of cement, as well as suppressing the cement hydration calorific value. In order to confirm this, the hydration exothermic rate of calcium silicate in the cement added with SWP was measured for 48 hours after cement kneading, and the measured results are shown in FIG. 3.

Test Example 4 Measurement of Fluidity

When the zinc silicate aqueous solution is added to concrete alone, the fluidity tends to be significantly lowered over time than the non-added concrete at the beginning of mixing. The drop in fluidity due to the addition of zinc alone is improved.

To confirm this, 1.0 to 3.0% by weight of zinc silicate aqueous solution having a concentration of 15% (w / w) alone was added (control) and uncontained concrete (comparative) and SWP having a concentration of 15% (w / w). The change in fluidity was measured after mixing for 90 minutes at 30 minute intervals for the added Examples 1 to 3, and the measured results are shown in FIG. 4. Compared to the case of adding 1.0 wt% of the zinc silicate aqueous solution alone to the weight of cement, the fluidity decrease of concrete with time was suppressed by about 50% when 1.0-2.0 wt% of SWP was added. Therefore, the addition of SWP in the state of containing magnesium silicate at an appropriate ratio in zinc silicate is more effective in suppressing the fluidity deterioration of concrete over time than zinc silicate alone.

As described above, according to the method of the present invention, when the two-component silica fluoride-based liquid additive containing 50 to 90% by weight of zinc silicate as a main component and 10 to 50% by weight of magnesium silicate as a secondary component is added, It is possible to produce concrete with improved and enhanced strength in the range of 10 to 30%. In addition to the above effects, the addition of a two-component silicate-based liquid additive suppresses the hydration calorific value and the hydration exothermic rate of calcium silicate in cement, and effectively suppresses the phenomenon that the fluidity of concrete decreases with time when zinc silicate is added alone. Has the effect.

In addition, hydrofluoric acid, which is the main raw material of the two-component silicate-based liquid additive proposed in the present invention, is a process by-product generated in Korea and can be supplied in a stable and inexpensive manner. It has an economic effect that can be very cheap.

Claims (6)

In a two-component hydrofluoric acid salt-based liquid additive using hydrofluoric acid and a metal salt containing zinc and magnesium, hydrofluoric acid is a process by-product generated in an aqueous solution of 10 to 40% by weight in hydrofluoric acid or phosphoric acid. Two-component silicate-based liquid additive composition, characterized in that The method of claim 1 Two-component silicate-based liquid additive composition, characterized in that the total effective concentration of zinc silicate and magnesium silicate in the two-component silicate-based liquid additive is 5-30% by weight. The method of claim 1, The metal salt containing zinc is one of zinc oxide (ZnO), zinc carbonate (ZnCO ₃ ), zinc sulfate (ZnSO ₄ ) or zinc hydroxide (Zn (OH) ₂ ), and the metal salt containing magnesium is magnesium oxide (MgO). ), Magnesium carbonate (MgCO ₃ ), magnesium sulfate (MgSO ₄ ) or magnesium hydroxide (Mg (OH) ₂ ), two-component siliceous fluorinated liquid additive composition The method of claim 2 Two component silicate fluoride salt-based liquid additive composition comprising 50 to 90% by weight of zinc silicate and 10 to 50% by weight of magnesium silicate in the total effective concentration of zinc silicate and magnesium silicate 5-30% by weight In two-component hydrofluoric acid salt-based liquid additives using hydrofluoric acid and metal salts containing zinc and magnesium, hydrofluoric acid is a process by-product generated in an aqueous solution of 10 to 40% by weight in hydrofluoric acid or phosphoric acid. , When the two-component silicate-based liquid additive having a total effective concentration of 5-30% by weight of zinc silicate and magnesium silicate constituting the silicate salt is added to the cement, it is added at 1.0-3.0% by weight relative to the weight of the cement. Two-component siliceous salt-based liquid additive composition In the preparation of a two-component hydrofluoric acid salt-based liquid additive using hydrofluoric acid and metal salts containing zinc and magnesium, hydrofluoric acid is generated in an aqueous solution of 10 to 40% by weight in hydrofluoric acid or phosphoric acid. Method for producing a two-component siliceous salt-based liquid additive, characterized in that the by-product is prepared as a raw material